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                                                                   Exhibit 10.56

                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT
                                     BETWEEN
                                 MOTOROLA, INC.
                                       AND
                                CLEARWIRE US LLC

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                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

This Wireless Broadband System Infrastructure Agreement ("Infrastructure
Agreement") is between Motorola, Inc., a Delaware corporation ("Motorola", which
term also means, where the context requires, Motorola subsidiaries involved in
providing services or materials for this Infrastructure Agreement) and Clearwire
US LLC, a Nevada limited liability company ("Clearwire, which term also means,
where the context requires, "Clearwire Affiliate(s)".

                                    RECITALS:

1.   Motorola and Clearwire share a vision of the opportunity for mobile
     broadband services both in the U.S. and Worldwide, progressing from
     Clearwire's current fixed/portable services to new and unique mobile
     broadband services. Clearwire currently has operations in the United States
     and select foreign countries.

2.   Motorola believes Clearwire is best positioned by virtue of sponsorship,
     management and spectrum assets to capitalize on this opportunity.

3.   This Infrastructure Agreement, as well as companion agreements concurrently
     executed regarding the purchase by Motorola of Clearwire's subsidiary
     NextNet Wireless, Inc. ("NextNet"), an investment by Motorola in Clearwire
     Corporation, and separate agreements for Motorola's supply of wireless
     broadband subscriber products and designated services to Clearwire, form
     the relevant commercial documentation of this collaborative engagement.

4.   Motorola desires to sell and Clearwire desires to purchase the
     Infrastructure for a wireless broadband System (as hereinafter defined) as
     set forth in this Infrastructure Agreement and in the attached Exhibits,
     all of which are incorporated herein.

                                   AGREEMENT:

The parties agree as follows:

1.   DEFINITIONS (capitalized terms used within a definition are defined in this
     Section in alphabetical order). Defined terms will be capitalized
     throughout this Infrastructure Agreement and will be read in the singular,
     plural or the tense as the context requires. Definitions are contained in
     Exhibit "E".

2.   SCOPE OF AGREEMENT: IMPLEMENTATION

     2.1  Motorola will furnish to Clearwire and Clearwire will purchase from
          Motorola the Infrastructure Products for the System. Affiliates of
          Clearwire will also have the right to purchase under this Agreement
          Clearwire Corporation will guarantee payment for any Infrastructure
          Products Motorola provides to Clearwire and Clearwire Affiliates.

          Clearwire will also have the right to purchase, and the definition of
          "Infrastructure Products" will be deemed to include any other products
          that are listed on Exhibit "A", and any Wireless Broadband
          Infrastructure Products that Motorola makes available to another
          wireless broadband service provider customer operating on licensed
          spectrum with channel widths of not less than 5 MHz, on terms and
          conditions, (including, but not limited to, financial terms and terms
          regarding the availability of such products) that are no less
          favorable to Clearwire than those agreed by another customer of
          Motorola, for similar purchase commitments.

          Motorola will make each Infrastructure Product available to Clearwire
          on the earlier of (a) the date specified in Exhibit "A", Schedule 2,
          or (b) the date on which Motorola makes that


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          Infrastructure Product available to any third party, provided that in
          the case where Wireless Broadband Infrastructure Products are uniquely
          developed for and funded by another customer, such Wireless Broadband
          Infrastructure Products will not be made available to Clearwire until
          such time as they are made commercially available to third parties
          other than the entity paying for development.

          If there is an insufficient supply of Infrastructure Product to
          satisfy unfulfilled purchase orders of Clearwire and other purchasers
          of the same Infrastructure Product, Motorola agrees not to
          disadvantage Clearwire compared to the other purchasers.

     2.2  This Infrastructure Agreement may be canceled only upon the terms and
          conditions contained herein.

     2.3  Except as provided elsewhere in this Section 2.3, Clearwire (and
          Clearwire Affiliates) agree to purchase 100% of their Wireless
          Broadband Infrastructure Products (excluding products purchased for
          non-commercial use, such as for purposes of internal testing)
          requirements from Motorola during the term of this Agreement.
          Exceptions to the foregoing purchase commitment:

          2.3.1 Starting on the 5th anniversary of the Effective Date, the
               Section 2.3 purchase commitment percentage drop's from 100% to
               51% of the Wireless Broadband Infrastructure Products.

          2.3.2 If any Infrastructure Product supplied by Motorola materially
               fails to meet the performance specifications and such material
               deficiencies are not remedied by Motorola within [***] days of
               written notice to Motorola, or if Motorola's production and
               delivery of any Infrastructure Product fails in any material
               respects to meet the requirements of this Agreement, which
               failures have not been cured in the 90 days after written notice
               to Motorola, then Clearwire will be released from its exclusive
               purchase commitment only for that specific Infrastructure Product
               Once Motorola cures the breach, the exclusive purchase
               requirement again covers that Infrastructure Product. For
               purposes of this Agreement, a material breach does not include
               the situation where Motorola, with Clearwire's consent,
               substitutes a substantially similar or comparable product at a
               similar price.

          2.3.3 If Clearwire identifies a Wireless Broadband Infrastructure
               Product need, and Motorola decides not to supply that product,
               Motorola will allow Clearwire to purchase that specific product
               from an agreed to ODM supplier (approval will not be unreasonably
               withheld), subject to a licensing agreement from Motorola to that
               ODM supplier on commercially reasonable terms. However, if such
               Wireless Broadband Infrastructure Product need is based on an
               industry-recognized public standard, and if Motorola decides not
               to supply that product, Motorola will have the right to OEM such
               product itself and sell it to Clearwire under the terms of this
               Agreement. If Motorola decides not to do so, Clearwire will be
               relieved of its exclusive purchase obligations under this Section
               2.3 with respect to such product only.

          2.3.4 Clearwire may terminate the exclusivity requirements under this
               Agreement if there are [***] uncured Infrastructure Product
               material breaches in any [***] month period.

     2.4  Except as contained in this Section 2.4, the aggregate price to
          Clearwire for Infrastructure Products purchased in any calendar year
          will be no less favorable than the aggregate price paid by other
          customers contemporaneously buying similar or lesser aggregate
          purchases of Infrastructure Products within the same country during
          such calendar year. The foregoing price level commitment 1) excludes
          unique Infrastructure Product sales

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          that are directly related to funded development programs, and any one
          time per customer initial promotional offer (not to exceed [***] units
          of Infrastructure Product), and 2) is given in consideration of the
          minimum purchase commitments by Clearwire (and Clearwire's Affiliates)
          in this Agreement. For avoidance of doubt, purchase Volumes of CDMA,
          GSM, UMTS and iDEN infrastructure and/or devices can not be considered
          for purposes of establishing MFN pricing comparisons between
          customers.

     2.5  Exhibit "B" sets forth Infrastructure Products and technical
          specifications therefor which Clearwire desires to purchase. Once
          mutually agreed upon by the parties, Exhibit "B" will be amended
          accordingly and Motorola will agree to deliver Infrastructure Products
          in accordance with the specifications and features described in such
          amended Exhibit "B". Motorola and Clearwire will use commercially
          reasonable efforts to achieve the objectives stated in Exhibit "B" by
          the dates specified in Exhibit "B" or elsewhere in this Agreement,
          including identifying those provisions of Exhibit "B", the breach of
          which will be mutually agreed upon to constitute a material breach for
          purposes of Section 2.3.4.

     2.6  In the two (2) years after the Effective Date, and in consideration of
          Motorola's obligations under this Agreement, Clearwire and its
          Affiliates will purchase no less than $150,000,000 in Infrastructure
          Products and Subscriber Products from Motorola.

     2.7  Infrastructure Products: Expedience

          2.7.1 Expedience Infrastructure Products. During the term of this
               Agreement, senior technical representatives of both Motorola and
               Clearwire shall meet quarterly to review system performance,
               coordinate on standards and technology evolution, and agree on
               the potential development and delivery of additional or modified
               features and functions that are not already specified in an
               Exhibit to this Agreement. If there is a technology improvement
               related to Expedience Infrastructure Products requested by and
               funded by Clearwire, Motorola will not sell any Expedience
               Infrastructure Product activating such improvement to other
               customers for a [***] period after such improvement is made
               commercially available to Clearwire, absent Clearwire's written
               consent. If there is a technology improvement related to
               Expedience Infrastructure Products conceptualized by Clearwire,
               but the implementation of the improvement is funded by Motorola,
               Motorola will not sell any Expedience Infrastructure Product
               activating such improvement to other customers for a [***] period
               after such improvement is made commercially available to
               Clearwire, absent Clearwire's written consent. If a particular
               technology improvement is described on the agreed upon product
               roadmap or such improvement is part of another standards-based
               technology, however, Clearwire is not entitled to exclusive
               availability of that improvement. Exhibit "B", Schedule 4
               (Expedience ICQ Requirements) outlines the Expedience interfaces
               and tools that must be maintained in order to allow the continued
               operation of the Clearwire network.

          2.7.2 Expedience Software. Motorola will offer an optional NSP Program
               as set forth in Exhibit "D". Should Clearwire elect to purchase
               NSP, Motorola will make available two Releases of Expedience
               Software each calendar year. The pricing for the NSP Program is
               set forth in Exhibit "A".

     2.8  WiMax Infrastructure Products

          2.8.1 Clearwire Network Transition Requirements. Motorola recognizes
               that Clearwire will, for some indefinite period of time, operate
               both Expedience-based networks and WiMax-based networks. Further,
               Clearwire may decide to initiate transition of Expedience
               Infrastructure to WiMAX Infrastructure in certain existing
               markets, while causing as little disruption to the existing
               Clearwire customer base as

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               possible; such Infrastructure Product modifications may require
               Custom Development. To this end:

               2.8.1.1 Motorola will, in as much as technically possible, work
                    closely with Clearwire to develop and modify WiMAX
                    Infrastructure equipment that will enable a seamless
                    transition of Expedience equipment to WiMAX equipment. The
                    transition equipment will include agreed to base station
                    configurations, power schemes, cabling assemblies, equipment
                    packaging, sizes and footprints.

               2.8.1.2 Clearwire has developed an architecture based on a
                    particular WiMax Forum ASN Profile which maps elements in
                    Expedience networks to elements in that profile as
                    illustrated in Exhibit "B", Schedule 1 "Clearwire
                    Expedience/WiMAX Architecture". Motorola will, in as much as
                    technically possible, supply Mobile WiMax Infrastructure
                    that is interoperable and compatible with Clearwire's
                    Exhibit "B", Schedule 1 specifications, based on
                    jointly-developed specifications that will be developed and
                    appended to this Agreement as Exhibit "B", Schedule 2
                    "Clearwire WiMAX ASN-GW Requirements". Motorola acknowledges
                    that, to some extent, Exhibit "B", Schedule 2 may deviate
                    from the WiMax Forum adopted profiles. Motorola will fully
                    cooperate with Clearwire, in joint agreement with Motorola,
                    to support adoption of the identified profile variant(s) to
                    the WiMax Forum.


               2.8.1.3 Motorola will cooperate with Clearwire to provide network
                    management interfaces on all supplied Network Infrastructure
                    that are compatible with Clearwire's deployed back office
                    (OSS), AAA and network management systems. Those existing
                    interfaces are specified in Exhibit "B", Schedule 3
                    "Clearwire WiMAX ICD Requirements".


               2.8.1.4 Motorola will, in as much as technically possible, equip
                    their WiMAX Infrastructure Products with the craft
                    interfaces and diagnostic providing metrics as jointly
                    defined in Exhibit "B", Schedule 3 and Schedule 5 "Clearwire
                    WiMAX Systems Validation Plan".

               2.8.1.5 All Infrastructure supplied by Motorola to Clearwire will
                    conform to the Mobile WiMax Certification Profiles
                    illustrated in Exhibit "B", Schedule 6 "WiMAX Certification
                    Profiles". Motorola acknowledges that, in some cases,
                    Exhibit "B", Schedule 6 may deviate from the 802.16e adopted
                    profiles and will fully cooperate with Clearwire and others
                    that Clearwire, in joint agreement with Motorola, may
                    identify to support adoption of the identified profile
                    variant(s) to the 802.16e profiles in the appropriate forum.

          2.8.2 WiMAX Infrastructure Products. In accordance with Exhibit "B",
               Motorola will supply base stations in various agreed
               configurations to Clearwire at the prices reflected in Exhibit
               "A". Features and functionality of each WMX configuration
               corresponding to the above Exhibits are detailed in Exhibit "B",
               Schedule 7 "Motorola WiMAX Infrastructure Product
               Specifications". WiMax base stations must meet performance
               requirements specified in Exhibit "B", Schedules 5, 8, 9 and 10.
               Motorola acknowledges that technology deployed by Clearwire is
               crucial to Clearwire's business success. During the term of this
               Agreement senior technical representatives of both Motorola and
               Clearwire shall meet quarterly to review System performance,
               coordinate on standards and technology evolution, and agree on
               development and delivery of new features and functions.


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          2.8.3 WiMAX Software. Motorola may supply and Clearwire may purchase
               from Motorola other optional software that is listed on Exhibit
               "A", as amended from time to time. Any such optional software
               purchased by Clearwire is an "Infrastructure Product". Motorola
               will offer an optional NSP Program as set forth in Exhibit "D".
               Should Clearwire elect to purchase NSP, Motorola will make
               available two Releases of WiMAX Software each calendar year. The
               pricing for the NSP Program is set forth in Exhibit "A".

          2.8.4 WiMAX Acceptance Tests. Motorola acknowledges that Clearwire
               intends to run acceptance tests for various WiMAX product
               versions and configurations as part of its lab, field trial, beta
               trial and wave 2 equipment tests. The agreed plan and schedule
               for testing these WiMAX products is contained in Exhibit "B",
               Schedule 5, Schedule 8 "Clearwire WiMAX Alpha Field Trial Test
               Plan", Schedule 9 "Clearwire WiMAX Beta Market Test Plan" and
               Schedule 10 "Clearwire WiMAX Wave 2 Test Plan".

          2.8.5 Clearwire Test Lab. For the term of this Agreement Motorola
               shall supply to Clearwire sufficient quantities of Infrastructure
               Products (at no charge) to support operation of a test
               environment similar to the test facilities maintained by NextNet
               up to a maximum value of $[***] per annum. This test lab must be
               capable of testing new Equipment and Software releases prior to
               field testing. Motorola will maintain a lab configuration such
               that lab-to-lab collaboration can utilize identical test
               scenarios.

     2.9  Network Elements. Motorola may supply and Clearwire may purchase from
          Motorola other Network Elements. Motorola will be Clearwire's
          Preferred Vendor on all Network Element wireless products (i.e.
          wireless backhaul, etc.). This provision does not imply that Clearwire
          will not seek to source Network Elements competitively.

     2.10 Wi-Max Acceptance Test and Timing. The agreed plan for testing Wi-Max
          Infrastructure Products is contained in Exhibit "B", Schedule 5, 8, 9
          and 10 to this Infrastructure Agreement.

     2.11 In consideration of the commitments made by Motorola in this
          Agreement, Clearwire will purchase no less than 25% of its WiMax
          subscriber handsets from Motorola so long as the capabilities and
          costs of the handsets (and the availability of such handsets) are
          equal for a given product in similar quantities or service offered by
          Motorola and another supplier or suppliers.


     2.12 Except as provided in this Section, and except for Clearwire's
          purchase commitments in Sections 2.3 and 2.11, this Infrastructure
          Agreement is non-exclusive and Motorola may sell Infrastructure
          Products, directly or indirectly, to any customer worldwide. Motorola
          hereby appoints Clearwire as Motorola's exclusive distributor of the
          Expedience Infrastructure Products in China only to a single operator
          for a period of [***] from the Effective Date of this Agreement.
          Should Clearwire not conclude a [***] agreement within the [***]
          period with the China operator (the [***], the exclusive distribution
          right will terminate. If the [***] agreement is executed within the
          [***] period, Clearwire will use its commercially reasonable efforts
          to bring an Expedience wireless broadband system into commercial
          service as soon as possible. Clearwire and Motorola agree to revisit
          the pricing for Expedience Infrastructure Products described above for
          units that ship during the 12 month period after the first shipment
          date should the total volume of such units exceed [***]
          Notwithstanding the foregoing, Motorola shall be free to market,
          distribute and sell Expedience products to any other China customer.


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          Motorola will sell all Expedience Infrastructure Products for delivery
          to the JV a [***] pricing until [***] after commercial service of the
          first System. From the [***] through the [***] after commercial
          service of the first System, Clearwire will pay to Motorola the agreed
          to Clearwire purchase price, plus an additional [***] of the
          difference between the Clearwire purchase price from Motorola and the
          Clearwire resell price to the [***]. After the [***] Clearwire will
          pay to Motorola [***] of the resale price to the [***] and will use
          its commercially reasonable efforts to cause the [***] to purchase
          Expedience Infrastructure Products directly from Motorola.

     2.13 If Clearwire informs Motorola that Clearwire desires to pursue Other
          Technology for Infrastructure Products, Motorola will use commercially
          reasonable efforts to supply Clearwire with an Other Technology
          solution under the terms of this Agreement.

3.   OBLIGATIONS OF CLEARWIRE

     Clearwire will:

     3.1  Bear the costs of its own legal fees, telephone and utility charges
          and other services and items being supplied by Clearwire under this
          Infrastructure Agreement.

     3.2  Make the payments according to the schedule set forth in Section 5 of
          this Infrastructure Agreement.

     3.3  Perform all other of its obligations set out in this Infrastructure
          Agreement and the Exhibits attached hereto.

4.   OBLIGATIONS AND REPRESENTATIONS OF MOTOROLA

     Motorola will:

     4.1  Adhere to the schedule for performance of the responsibilities set
          forth in the Exhibits and Schedules to this Agreement.

     4.2  Negotiate in good faith a Punchlist as part of the acceptance process,
          if Motorola performs installation.

     4.3  Supply replacement and expansion parts, subsequent Equipment revisions
          and Software upgrades to Clearwire on the terms and price as contained
          in this Infrastructure Agreement.

     4.4  Bear the costs of its own legal fees, telephone and utility charges
          and other services and items being supplied by Motorola under this
          Infrastructure Agreement.

     4.5  Perform all other of its obligations set out in this Infrastructure
          Agreement and the Exhibits attached hereto.

     4.6  At the time or times contemplated herein for the transfer of title to
          any equipment included in the System, Motorola will convey to
          Clearwire all right in and good title to such equipment by appropriate
          title documents. However, title to Software will not be conveyed to
          Clearwire at any time but will instead be licensed to Clearwire in
          accordance with the terms of Exhibit "C". Motorola will deliver the
          Infrastructure Products to Clearwire free and clear of all liens,
          security interests or encumbrances of any type.

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     FURTHER, Motorola represents to Clearwire that:

     4.7  Unless agreed to the contrary, all equipment sold to Clearwire
          hereunder is new and Motorola will provide any documents, which may be
          reasonably requested by Clearwire evidencing this fact.

5.   PAYMENT AND PRICING

     Clearwire will pay to Motorola the price of Infrastructure Products, as set
     forth in Exhibit "A", in U.S. dollars (except as specifically set forth
     below) and according to the following terms and payment schedules:

     5.1  General Payment Terms

          5.1.1 Payment for all Infrastructure Products will be net [***] from
               date of invoice, provided that Motorola will not invoice
               Clearwire prior to the date of shipment of Infrastructure
               Products to Clearwire.

          5.1.2 Clearwire will be responsible for the payment of all applicable
               sales, use, retailers occupation, excise, property, and other
               assessments in the nature of taxes however designated, on the
               Infrastructure Products and Services provided to Clearwire
               pursuant to this Agreement, exclusive however, of any taxes
               measured by Motorola's net income or based on Motorola's
               franchise. Personal property taxes assessable on the
               Infrastructure Products will be the responsibility of Clearwire.
               To the extent Motorola is required by law to collect such taxes
               (state or local), one hundred percent (100%) thereof will be
               added to invoices as separately stated charges and paid in full
               by Clearwire, unless Clearwire is exempt from such taxes and
               furnishes Motorola with a certificate of exemption in a form
               reasonably acceptable to Motorola. In the event Clearwire claims
               exemption from sales, use or other such taxes under this
               Agreement, Clearwire will hold Motorola harmless from any and all
               subsequent assessments levied by a proper taxing authority for
               such taxes, including interest, penalties and late charges.

          5.1.3 Clearwire will pay [***] costs from [***] and all applicable
               [***] and similar charges.

          5.1.4 Clearwire will use commercially reasonable efforts to notify
               Motorola of any disputed amounts under any invoice in writing
               prior to the invoice due date; but provided that Clearwire shall
               pay to Motorola the undisputed portion of any invoice within the
               time frame set forth in Section 5.1.1. Clearwire's failure to
               notify Motorola of any disputed amount prior to the invoice due
               date will not constitute a waiver by Clearwire of any dispute
               regarding any previously paid invoice; provided that, in no event
               shall Clearwire dispute any invoice submitted by Motorola
               hereunder more than [***] days after the date of such invoice.
               For any undisputed amount due hereunder which remains unpaid,
               Clearwire will pay Motorola a service fee at the rate of [***] of
               the amount due for each month or portion thereof that the amount
               remains unpaid.

     5.2  Infrastructure Product Purchases

          5.2.1 For Equipment and Software, Clearwire will be invoiced no
               earlier than the shipment date [***] of the total for the
               infrastructure products.

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6.   WARRANTIES

     The following warranties will be applicable to Infrastructure Products
     supplied under this Infrastructure Agreement.

     6.1  Equipment Warranty

          6.1.1 Motorola-manufactured or supplied Equipment will be warranted to
               be free from defects in material and workmanship for a period of
               [***] from the date of shipment. Parts will be replaced free of
               charge for the full warranty period. For Infrastructure Products
               manufactured by a third-party, Motorola will assign to Clearwire
               Equipment warranties received from such third-party manufacturers
               and will act in a commercially reasonable manner to pursue and
               coordinate warranty claims at Clearwire's request. For a fee,
               Motorola will provide warranty service for Expedience base
               stations deployed before the Effective Date.

          6.1.2 Clearwire will be responsible for the initial level of diagnosis
               (i.e. for identification and isolation of Equipment problems to
               the board level), for hardware, firmware and Software removal and
               replacement, and for sending the malfunctioning product, packed
               in a manner to prevent damage, to the designated Motorola repair
               depot. Motorola will provide Clearwire access to self test
               diagnostics, documentation detailing Motorola's factory equipment
               test software, and can supply unique, non-commercial interface
               elements. Subsequent sets of test tools are available for
               purchase, at the pricing summarized in Exhibit "A".

          6.1.3 Labor at the Motorola-designated repair depot to repair or
               replace defective Equipment will be provided without charge for
               the full warranty period.

          6.1.4 Postage, freight or other such transportation charges for
               shipping defective products to an authorized Motorola repair
               depot will be borne by Clearwire; when such products or their
               replacements are being returned to Clearwire, Motorola will bear
               such charges.

          6.1.5 In the event a defect occurs during the warranty period shown,
               Motorola, at its option, will either repair or replace the
               product. Any item so repaired or replaced will be warranted for
               the longer of [***] or balance of the warranty period. Any item
               retained by Motorola through replacement will become the property
               of Motorola. Except as specifically provided in this Agreement,
               such action on the part of Motorola will be the full extent of
               Motorola's liability and Clearwire's exclusive remedy hereunder.

          6.1.6 THIS EQUIPMENT WARRANTY DOES NOT COVER:

               Defects, damage or malfunctions resulting from:

               6.1.6.1 Use of the Equipment in other than their normal and
                    customary manner.

               6.1.6.2 Misuse, accident, neglect, improper storage or
                    environmental or Site conditions not conforming to the
                    specifications for the Infrastructure Product, to the extent
                    not caused by Motorola or its agents.

               6.1.6.3 Unauthorized alterations or repairs, use of unapproved
                    parts in the products or the combination or interfacing of
                    the products, in each case in a manner not approved by
                    Motorola.

               6.1.6.4 An event of Force Majeure.

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               6.1.6.5 Installation, optimization, movement or use of products
                    by anyone not authorized by Motorola and/or not in
                    accordance with commercially reasonable Motorola standards
                    and guidelines.

               6.1.6.6 Failure of antennas lines, or any part of the
                    Interconnection Facilities, unless such antennae are
                    internally integrated into the Infrastructure Product.

               6.1.6.7 Failure of Clearwire to maintain the Equipment
                    substantially in accordance with the Documentation.

               6.1.6.8 Damage which occurs during shipment of the product from
                    Clearwire to Motorola.

          6.1.7 This express warranty is extended by Motorola, Inc. to Clearwire
               only and is valid only in the country where the Equipment is
               first put into Commercial Service, except that Clearwire may
               assign this warranty in connection with any assignment of this
               Agreement that is permitted pursuant to Section 18.1.

     6.2  Software Warranty

          6.2.1 For the [***] following shipment after acceptance pursuant to
               the protocol set forth in Section 2.1, Motorola warrants that
               each Standard Software Release, as delivered, will perform
               substantially in accordance with Motorola's then-current user
               manual in all material respects: however, Motorola does not
               warrant that the Software will meet Clearwire's needs, be
               error-free, or operate without interruption.

          6.2.2 Motorola makes no warranties whatsoever regarding any software
               not supplied by Motorola. For software supplied by a third-party,
               Motorola will assign to Clearwire the warranties received from
               such third-party and will act in a commercially reasonable manner
               to pursue and coordinate warranty claims at Clearwire's request.

     6.3  THE WARRANTIES IN THIS AGREEMENT ARE GIVEN IN LIEU OF ALL OTHER
          WARRANTIES, EXPRESS OR IMPLIED, WHICH ARE SPECIFICALLY EXCLUDED,
          INCLUDING, WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY AND
          FITNESS FOR A PARTICULAR PURPOSE. FURTHERMORE, BECAUSE EACH WIRELESS
          BROADBAND SYSTEM IS UNIQUE, MOTOROLA DISCLAIMS LIABILITY FOR RANGE,
          COVERAGE, SUBSCRIBER CAPACITY, SERVICE LEVEL OR OPERATION OF THE
          SYSTEM, AS A WHOLE, EXCEPT AS SPECIFICALLY SET FORTH IN THE WARRANTIES
          CONTAINED IN THIS AGREEMENT.

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7.   PRODUCT DISCONTINUANCE

     Motorola may from time to time cease the supply of then existing versions
     of Infrastructure Product (the "Discontinued Product"), provided that a
     suitable replacement product is available. If Motorola does discontinue
     Product, it will notify Clearwire promptly in writing at least [***] before
     discontinuance ("Discontinuance Notice") and Clearwire, up to the date
     provided on the Discontinuance Notice, may place a final lifetime order for
     Discontinued Product. A shipping schedule for quantities ordered in any
     final lifetime order will be mutually agreed to between Clearwire and
     Motorola, but in any event will not exceed [***] from the date of the
     Discontinuance Notice. All final lifetime orders for Discontinued Product
     are non-cancelable.

8.   DISCLAIMER OF PATENT LICENSE

     Nothing contained in this Infrastructure Agreement will be deemed to grant,
     either directly or by implication, any license under any patents or patent
     applications of Motorola, except that Clearwire will have the normal
     non-exclusive (except as provided otherwise in this Agreement),
     royalty-free license to use that which is implied, or otherwise arises by
     operation of law, in the sale of an Infrastructure Product.

9.   PATENT AND COPYRIGHT INDEMNITY

     Excluding any intellectual property rights obtained through acquisition of
     NextNet, Motorola agrees to indemnify Clearwire against and to defend
     Clearwire, at Motorola's expense, for any claims, suits, arbitration or
     other disputes brought against Clearwire based upon a claim that any
     Infrastructure Product furnished hereunder by Motorola infringes a patent
     or copyright or misappropriates a trade secret in any country worldwide
     where Motorola sells such Infrastructure Product and to pay costs and
     damages awarded based upon such claim in any such suit, provided that
     Motorola is: (1) promptly notified by Clearwire in writing within [***] of
     the date on which Clearwire first received written notice of such claim;
     and (2) at Motorola's request and expense is given sole control of the suit
     and all reasonably requested assistance for defense of the claim. Motorola
     shall not be relieved of its indemnification obligation as a result of
     delays in notifying Motorola of the claim except to the extent the amount
     of the claim is increased as a result of such delay. Motorola will not be
     liable for any settlement made without its written consent If the use or
     sale of any Infrastructure Product furnished under this Agreement is
     enjoined as a result of such suit, Motorola at its option and at no expense
     to Clearwire, will: (1) obtain for Clearwire the right to use or sell such
     Infrastructure Products; (2) substitute a functionally equivalent product
     with the same or similar features reasonably acceptable to Clearwire and
     extend this indemnity to the substitute products, or; (3) accept the return
     of the Infrastructure Products and reimburse Clearwire the purchase price
     therefore, less a reasonable charge for prior use, if any, of the
     Infrastructure Products. If the claim is alleged prior to completion of
     delivery of the Infrastructure Products, Motorola has the right to decline
     to make further shipments without being in breach of contract

     This indemnity does not extend to any suit based upon any infringement or
     alleged infringement arising from Infrastructure Products furnished by
     Motorola that are: (1) altered in any way by Clearwire or any third party
     if the alleged infringement would not have occurred but for such
     alteration; (2) combined with any other products or elements not furnished
     or approved in writing by Motorola if the alleged infringement would not
     have occurred but for such combination; or (3) claims arising out of
     Clearwire's unique specifications or instructions, if the alleged
     infringement would not have occurred but for such unique specifications or
     instructions.

     The indemnity provided in this section is the sole, exclusive, and entire
     liability of Motorola and the remedies provided in this section are
     Clearwire's exclusive remedies against Motorola for patent, copyright
     infringement or trade secret misappropriation, whether direct or
     contributory and is provided in lieu of all warranties, express, implied or
     statutory in regard to these potential liabilities, including the warranty
     against infringement specified in the Uniform Commercial Code.

[*** Confidential Treatment Requested]


                                       10

<PAGE>


     Should any intellectual property right obtained through the acquisition of
     NextNet be subject to an infringement or other claim and, in order to
     continue to supply Infrastructure Products which contain those intellectual
     property rights, Motorola settles the claim, or is subject to a judgment,
     requiring the payment of any royalty, then Clearwire agrees Motorola may
     add that royalty fee, on a pass-through basis, to the Exhibit "A" price of
     the affected Infrastructure Products.

10.  CONFIDENTIALITY

     During the entire term of this Agreement, Section 1 of the Side Agreement
     between Clearwire and Motorola, dated June 28, 2006, applies to define
     Confidential Information, each party's use of the other's Confidential
     Information, and dissemination of information about this Agreement to third
     parties in any form.

11.  TRADEMARK AND PUBLICITY

     Nothing contained in this Infrastructure Agreement will be construed as
     conferring any right to use any name, trademark or other designation of
     either party hereto, including any contraction, abbreviation, or simulation
     of any of the foregoing, in advertising, publicity or marketing activities.

12.  FORECASTS, SHIPMENT, DELIVERY, OFF-LOADING AND WAREHOUSING

     12.1 Clearwire will provide to Motorola on a monthly basis a rolling [***]
          forecast of Clearwire's estimated Infrastructure Product purchases
          (the "Forecasts"). Each such Forecast will be delivered to Motorola
          not less than [***] days prior to the start of the next calendar
          month. All Forecasts are non-binding.

     12.2 All orders for Infrastructure Products by Clearwire will be submitted
          to Motorola in the form of electronic data interchange ("EDI") or
          other method as mutually agreed. Clearwire must provide firm,
          non-cancellable, purchase orders [***] prior to requested ship date.
          The only effect of any terms and conditions in Clearwire's purchase
          orders or any other documentation not signed by the parties shall be
          to request the time and place of delivery, and the number and models
          of Infrastructure Products to be delivered (provided that the time
          requested is not binding on Motorola unless the requested ship date is
          in accordance with this Section).

     12.3 New Motorola Infrastructure Products must be qualified and tested in
          Clearwire Alpha and Beta field tests, using processes and tests as
          outlined in Exhibit "B" Schedule 8 and Schedule 9 mutually agreed
          acceptance plans. Clearwire may choose to waive these tests on an
          individual case basis.

     12.4 No shipment of Infrastructure Products in the three weeks prior to the
          anticipated ship date will be considered early for purposes of
          invoicing.

     12.5 Motorola will ship Infrastructure Products directly to the Site where
          it will be permanently installed, or to such other location as
          Clearwire may specify.

     12.6 In the event that the Site is not available to receive the
          Infrastructure Products when shipped, Motorola, at its option, may
          ship said Infrastructure Products to a warehouse designated by
          Clearwire, and Clearwire will bear the costs of warehousing,
          reloading, transporting, off-loading and moving the Infrastructure
          Products into the warehouse.

13.  TITLE, RISK OF LOSS AND INDEMNITY

     13.1 Title to and risk of loss for all Equipment supplied hereunder will
          pass to Clearwire upon delivery to a carrier or to Clearwire at point
          of shipment. Motorola will deliver the

[*** Confidential Treatment Requested]


                                       11

<PAGE>

          Infrastructure Products to Clearwire free and clear of all liens,
          security interests or encumbrances of any type.

     13.2 The above notwithstanding, title to Software will not pass to
          Clearwire at any time.

     13.3 During the term of this Infrastructure Agreement, the parties will
          indemnify and hold harmless each other together with their officers,
          agents and employees from any and all loss, damage, expense, judgment,
          lien, suit, cause of action, demand or liability for personal injury,
          including death and tangible property damage, which may be imposed on
          or incurred by one party arising directly out of the negligent acts or
          omissions of the other, its agents, subcontractors, or employees
          during the performance of any work hereunder. The offending party
          will, at its sole expense, defend any suit based upon a claim or cause
          of action and satisfy any judgment that may be rendered against the
          other resulting therefrom, provided that the offending party will be
          given (i) prompt notice of any such claim or suit; and (ii) full
          opportunity to defend such suit. The offended party may, at its
          election, participate in the defense and will cooperate fully in
          defending any claim or suits. The offending party will pay all costs,
          expenses, and reasonable attorney's fees incurred by the offended
          party in connection with any such claim or suit or in enforcing this
          indemnity provision, provided a valid claim is presented.

14.  FORCE MAJEURE

     Except for payment due, neither party will be liable for any delay or
     failure to perform due to any cause beyond its reasonable control. Causes
     include strikes, acts of God and interruptions of transportation. The
     delivery schedule will be considered extended by a period of time equal to
     the time lost because of any excusable delay.

15.  TERMINATION

     15.1 The initial term of this Agreement will be for a period of eight(8)
          years following the Effective Date. Unless notice of termination is
          given by either party at least 120 days prior to the scheduled
          termination date, this Agreement will continue in effect beyond the
          initial term, in successive one-year terms. Notwithstanding any number
          of renewals, this Agreement is a fixed term agreement and not an
          agreement of indefinite term. Nothing contained in this Agreement
          creates any express or implied obligation on either party to renew or
          extend this Agreement or to create any right to continue this
          Agreement on the same terms and conditions.

     15.2 Either party may terminate this Agreement without liability by written
          notice to the other if the other makes a general assignment for the
          benefit of creditors, or if a petition in bankruptcy or under any
          insolvency law is filed by or against the other and such petition is
          not dismissed within sixty (60) days after it has been filed or the
          other commits a material breach of its obligations hereunder. However,
          in the case of any such breach which is capable of being cured,
          neither party will terminate this Agreement unless and until the other
          will have failed to make good such default within ninety (90) days
          after it will have been served with a written notice requiring that
          such default be made good and stating its intention to terminate the
          Agreement if compliance with the notice is not met; provided, however,
          that Infrastructure Product deficiencies described in Section 2.3.2
          will not give rise to the termination remedy in this Section 15.2. The
          termination of this Agreement will not affect or prejudice any
          provisions of this Agreement, which are expressly or by implication
          provided to continue in effect after such termination.

     15.3 Upon termination of this Agreement as a result of a material, uncured
          breach by Clearwire: (i) Motorola is relieved of any obligations to
          make any additional shipments and may cancel all of Clearwire's
          unshipped orders for Infrastructure Products, regardless of previous
          acceptance by Motorola of those orders, and Motorola has no obligation
          or


                                       12

<PAGE>

          liability to Clearwire or any other party in connection with such
          cancellations; (ii) all outstanding invoices to Clearwire and other
          amounts due to Motorola from Clearwire become immediately due and
          payable, and each invoice not yet submitted to Clearwire for
          Infrastructure Products shipped prior to termination will be due and
          payable immediately upon submission of the invoice to Clearwire; (iii)
          Clearwire will immediately discontinue any further use of all Motorola
          names and trademarks in association with the Infrastructure Products,
          as well as any other combination of words, designs, trademarks or
          trade names that would indicate that Clearwire is or was an authorized
          distributor of the Infrastructure Products; and (iv) within 30 working
          days after termination, Clearwire will deliver to a location Motorola
          will specify all Motorola property, including all equipment, customer
          data, software items, catalogs, drawings, designs, engineering
          photographs, samples, literature, sales aids and any confidential
          business information and trade secrets of Motorola in Clearwire's
          possession, along with all copies of these items. Motorola's
          acceptance of any order by Clearwire for Infrastructure Products after
          the termination of this Agreement will not be construed as a renewal
          or extension of this Agreement, nor as a waiver of termination of this
          Agreement.

     15.4 The terms, provisions, representations and warranties contained in
          this Agreement that by their sense and context are intended to survive
          the performance by either or both parties will so survive the
          completion of performances and termination of this Agreement,
          including the making of any and all payments due under this Agreement.

     15.5 On or after January 1, 2009, Motorola may terminate this Agreement
          upon one year's prior written notice to Clearwire with continued
          supply of Infrastructure Products to Clearwire for a two year period
          commencing on the termination notice date under the terms of this
          Agreement.

     15.6 Motorola will place the source code for current versions of the
          Expedience Infrastructure Product software owned by Motorola, as well
          as a copy of the software itself, in escrow, at Clearwire's cost,
          under terms and conditions that are mutually agreeable to the Parties.
          The parties agree to promptly enter into good faith, commercially
          reasonable negotiations in an effort to conclude a software escrow
          agreement within forty-five (45) days after the Effective Date.

16.  [RESERVED]

17.  LIMITATION OF LIABILITY

     EXCEPT FOR THE INDEMNITY OBLIGATIONS IN SECTIONS 9 AND 13, AND BREACHES OF
     CONFIDENTIALITY, NEITHER PARTY, WHETHER AS A RESULT OF BREACH OF CONTRACT.
     WARRANTY, TORT (INCLUDING NEGLIGENCE), PATENT INFRINGEMENT, COPYRIGHT
     INFRINGEMENT OR OTHERWISE, WILL HAVE ANY LIABILITY FOR INCIDENTAL OR
     CONSEQUENTIAL DAMAGES, INCLUDING, BUT NOT LIMITED TO, LOSS OF PROFIT OR
     REVENUES, LOSS OF USE OF THE INFRASTRUCTURE PRODUCTS OR ANY ASSOCIATED
     EQUIPMENT, COST OF CAPITAL, COST OF SUBSTITUTE INFRASTRUCTURE PRODUCTS,
     FACILITIES OR SERVICE, OR DOWNTIME COSTS. EXCEPT FOR THE INDEMNITY
     OBLIGATIONS IN SECTIONS 9 AND 13, AND FOR PAYMENTS DUE, AND BREACHES OF
     CONFIDENTIALITY OBLIGATIONS, A PARTY'S TOTAL LIABILITY TO THE OTHER FOR ANY
     BREACH OF THIS INFRASTRUCTURE AGREEMENT WILL IN NO EVENT EXCEED THE TOTAL
     VALUE OF SERVICES INVOICED BY MOTOROLA TO CLEARWIRE IN THE PRIOR [***]
     PROVIDED, HOWEVER, THAT DURING THE FIRST [***] OF THE TERM OF THIS
     AGREEMENT, THE CAP ON LIABILITY WILL BE THE GREATER OF [***] OR THE
     AGGREGATE AMOUNT PAID BY CLEARWlRE TO MOTOROLA UNDER THIS AGREEMENT IN THE
     PRIOR [***]

[*** Confidential Treatment Requested]


                                       13

<PAGE>

18.  ASSIGNMENT AND EQUIPMENT RESALE

     18.1 The Infrastructure Agreement will accrue to the benefit of and be
          binding upon the parties hereto and any successor entity into which
          either party will have been merged or consolidated or to which either
          party will have sold or transferred all or substantially ail its
          assets, but it will not be otherwise assigned by either party (other
          than for security purposes to a bona fide lender to the assigning
          party) without the prior written consent of the other party. It is the
          intention of the parties that the exclusive and preferred supplier
          commitments survive any change of control of Clearwire. The parties
          agree that any consent to a requested assignment will not be
          unreasonably withheld or delayed.

     18.2 Notwithstanding any other provision of this Infrastructure Agreement,
          the Software license granted to Clearwire in the form of Exhibit "C",
          may not be sublicensed, assigned or otherwise transferred by
          Clearwire, except when Clearwire transfers Infrastructure Products for
          inventory balancing purposes with its Affiliates. In the event
          Clearwire subsequently elects to sell to a third party the equipment
          purchased by Clearwire hereunder, Motorola agrees to relicense the
          Software to such third party in accordance with the then current terms
          of Motorola's Relicensing Policy.

19.  GOVERNING LAW

     The laws of the State of New York, USA, will govern the validity,
     performance, and all matters relating to the effect of this Infrastructure
     Agreement and any amendment hereto.

20.  EXPORT CONTROLS

     20.1 If, at the time or times of Motorola's performance hereunder, a
          validated export license is required for Motorola, or its
          subcontractor, to lawfully export the goods or technical data from the
          United States of America, or the such other country of origin, then
          the issuance of such license to Motorola, or its subcontractor in
          accordance with the rules and regulations of the applicable
          country(ies), will constitute a condition precedent to Motorola's
          performance of its obligations hereunder. Motorola will apply for the
          export license for the products supplied hereunder based upon
          information timely supplied by Clearwire. Clearwire is responsible for
          any applicable import license requirements. Clearwire acknowledges
          that it may be required to obtain additional approvals to implement
          certain features of the System, including without limitation,
          encryption or authentication algorithms. Clearwire and Motorola
          acknowledge and agree that any delay in the grant of such licenses
          and/or approvals may impact the schedule of performance.

     20.2 If, at time or times of Motorola's performance hereunder, approval by
          a regulatory body is required under applicable law, then such approval
          will constitute a condition precedent to Motorola's performance of its
          obligations hereunder (but only to the extent Motorola would be in
          violation of applicable law without such approval) and Motorola will
          use commercially reasonable efforts to obtain such approval.

     20.3 Clearwire and Motorola agree to comply with all applicable export laws
          and regulations of the United States of America or such other country
          of origin. Specifically, but without limitation, Clearwire agrees that
          it will not resell or re-export Motorola Infrastructure Products or
          technical data in any form Without obtaining appropriate export or
          re-export licenses from the respective governmental authority of the
          United States of America or other country of origin.

21.  ORDER OF PRECEDENCE

     In the event of an inconsistency in this Infrastructure Agreement, the
     inconsistency will be resolved by giving precedence in the following order:


                                       14

<PAGE>

     21.1 Exhibit "A" and all duly executed amendments to Exhibit "A";

     21.2 All other Exhibits and all duly executed amendments to said Exhibits;
          and

     21.3 This Infrastructure Agreement and duly executed amendments to this
          Infrastructure Agreement, with the latest amendment taking precedence
          over earlier amendments.

22.  LANGUAGE OF AGREEMENT

     In the event that this Infrastructure Agreement is translated into any
     other language, the English language version hereof will take precedence
     and govern.

23.  NOTICE

     23.1 Notices required to be given by one party to another will be in the
          English language unless expressly agreed otherwise, and will be deemed
          properly given if reduced to writing and personally delivered or
          transmitted by registered or certified post to the address below,
          postage prepaid, and will be effective upon receipt.

          23.1.1 Motorola will send notices as follows:

                    Clearwire US LLC
                    5808 Lake Washington Blvd. NE, Suite 300
                    Kirkland, WA 98033
                    Attention: Chief Executive Officer
                    And with a copy to Legal Department

                    With a copy to:

                    Davis Wright Tremaine LLP
                    2600 Century Square
                    1501 Fourth Avenue
                    Seattle, WA 98101
                    Attention: Julie Weston

          23.1.2 Clearwire will send notices as follows:

                    Motorola, Inc.
                    1501 W. Shure Drive
                    Arlington Heights, II 60004
                    Fax 847-632-2683
                    Attention: Clearwire Program Management

                    CC: Senior Commercial Counsel, Law Department

     23.2 Either party may change the addresses for giving notice from time to
          time by written instructions to the other of such change of address.

24.  SURVIVAL OF PROVISIONS

     The parties agree that where the context of any provision indicates an
     intent that it will survive the term of this Infrastructure Agreement then
     it will survive.


                                       15

<PAGE>

25.  WAIVER

     Failure or delay on the part of Motorola or Clearwire to exercise any
     right, power or privilege hereunder will not operate as a waiver thereof.

26.  SEVERABILITY

     In the event any one or more of the provisions of this Infrastructure
     Agreement is held to be unenforceable under applicable law, (a) such
     unenforceability will not affect any other provision of this Infrastructure
     Agreement; (b) this Infrastructure Agreement will be construed as if said
     unenforceable provision had not been contained therein; and (c) the parties
     will negotiate in good faith to replace the unenforceable provision by such
     as has the effect nearest to that of the provision being replaced.

27.  AUTHORITY

     Each party hereto represents and warrants that (i) it has obtained all
     necessary approvals, consents and authorizations of third parties and
     governmental authorities to enter into this Infrastructure Agreement and to
     perform and carry out its obligations hereunder; (ii) the persons executing
     this agreement on its behalf have express authority to do so, and, in so
     doing, to bind the party thereto; (iii) the execution, delivery, and
     performance of this Infrastructure Agreement does not violate any provision
     of any bylaw, charter, regulation, or any other governing authority of the
     party; and (iv) the execution, delivery and performance of this
     Infrastructure Agreement has been duly authorized by all necessary
     partnership or corporate action and this Infrastructure Agreement is a
     valid and binding obligation of such party, enforceable in accordance with
     its terms.

28.  TERM

     The initial term of this Infrastructure Agreement will be for eight (8)
     years from the Effective Date. This Infrastructure Agreement will be
     automatically renewed for consecutive one (1) year terms unless either
     party notifies the other party in writing of its intent to terminate the
     Infrastructure Agreement at least one hundred and twenty (120) days prior
     to the expiration of the initial term or any renewal thereof.

29.  UNITED STATES OF AMERICA ("U.S.") - GOVERNMENT COMPLIANCE

     This Agreement is a commercial contract and is governed by the terms and
     conditions negotiated by the parties. Clearwire represents and warrants
     that: (i) it is not a governmental entity; (ii) it is not owned in whole or
     in part, directly or indirectly, by any governmental entity; (iii) the
     purchases contemplated under this Agreement will not be financed using any
     funds obtained from any government entity (including, without limitation,
     OPIC, Eximbank or other similar agencies); and (iv) there is no other basis
     on which any regulations, decrees or laws applicable to sales to a
     governmental entity could be deemed applicable to this Agreement. The term
     "governmental entity," as used herein, will include agencies and
     instrumentalities of U.S. federal, state and local governments as well as
     of governments outside of the U.S.

     In the event that Clearwire elects to sell the products to a governmental
     entity, Motorola makes no representations with respect to the ability of
     its goods, services, or prices to satisfy any statues, regulations or
     provisions relating to such governmental sales.

30.  ENTIRE AGREEMENT

     This Infrastructure Agreement and the Exhibits hereto, together with
     Section 1 of the Side Agreement referred to in Section 10, constitute the
     entire understanding between the parties concerning Infrastructure Products
     and supersede all prior discussions, agreements and


                                       16

<PAGE>

     representations, whether oral or written and whether or not executed by
     Motorola and Clearwire with respect to the subject matter of this
     Agreement. No modification, amendment or other change may be made to this
     Infrastructure Agreement or any part thereof unless reduced to writing and
     executed by authorized representatives of both parties.

     The terms and conditions of this Infrastructure Agreement will prevail
     notwithstanding any variance with the terms and conditions of any order
     submitted by Clearwire following execution of this Infrastructure
     Agreement. In no event will the preprinted terms and conditions found on
     any Clearwire purchase order, acknowledgment or other form, or on any
     Motorola invoice, be considered an amendment or modification of this
     Infrastructure Agreement, even if such documents are signed by
     representatives of both parties; such preprinted terms and conditions will
     be null and void and of no force and effect.

31.  COUNTERPARTS

     This Infrastructure Agreement may be executed in multiple counterparts,
     each of which will be deemed an original and all of which taken together
     will constitute one and the same instrument. Facsimile or digital
     signatures will be treated as originals.

                            [Signature page follows]


                                       17

<PAGE>

Executed as of this 29th day of August, 2006 ("Effective Date").

MOTOROLA, INC.                          CLEARWIRE US LLC


/s/ C. F. WRIGHT                        /s/ Benjamin G. Wolff
-------------------------------------   ----------------------------------------
Signature                               Signature

C. F. WRIGHT                            Benjamin G. Wolff
Printed/Typed Name                      Printed/Typed Name

SENIOR VICE-PRESIDENT                   Co-President & Co-CEO
Title                                   Title

8/29/06                                 8/29/06
Date                                    Date

Clearwire Corporation guarantees payment of the purchase price for any
Infrastructure Products or services purchased by Clearwire or any Clearwire
Affiliate under this Wireless Broadband System Infrastructure Agreement, subject
to the exercise of any rights of Clearwire or such Clearwire Affiliate with
respect to such payment. Motorola need not exhaust remedies against Clearwire
and Clearwire Affiliates(other than to demand payment and to allow for the
passage of the applicable cure period) prior to pursuing this guarantee of
Clearwire Corporation.

CLEARWIRE CORPORATION


/s/ Benjamin G. Wolff
-------------------------------------
Signature

Benjamin G. Wolff
Printed/Typed Name

Co-President & Co-CEO
Title

8/29/06
Date

<PAGE>

                                   EXHIBIT "A"

                                   SCHEDULE 1

                                     TO THE
                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

            EXPEDIENCE AND WI-MAX INFRASTRUCTURE PRODUCTS AND PRICING

The pricing stated in this Exhibit A, Schedule 1 is the [***] pricing to be
charged by Motorola under this Agreement. Throughout the term of this Agreement,
Motorola will use commercially reasonable efforts to [***] for the
Infrastructure Products specifically listed in this Exhibit A, Schedule 1;
provided, however that all Expedience Infrastructure Product pricing shall [***]
by [***] on [***].

                                  SEE ATTACHED

[*** Confidential Treatment Requested]


                                       A-1

<PAGE>

2006 EXPEDIENCE INFRASTRUCTURE EQUIPMENT

<TABLE>
<CAPTION>
                                                                     TOTAL   (I)NFRA/
     ITEM                           DESCRIPTION                      PRICE     (C)PE
     ----                           -----------                      -----   --------
<S>             <C>                                                  <C>     <C>
123-0350-1002   ANTENNA BRACKET INEGRAL BASE ASSEM.                  [***]       I
123-0350-1010   INTEGRAL BASE POLE MOUNTING KIT                      [***]       I
250-0100-0010   GPS SYSTEM 10 FT                                     [***]       I
250-0100-0025   GPS SYSTEM 25 FT                                     [***]       I
250-0100-0050   GPS SYSTEM 50 FT                                     [***]       I
250-0100-0100   GPS SYSTEM 100 FT                                    [***]       I
250-0100-0132   BTS OUTDOOR MOUNTING KIT                             [***]       I
250-0100-0200   GPS SYSTEM 200 FT                                    [***]       I
250-0150-0001   DEUTSCH TOOL KIT                                     [***]       I
250-0150-0010   GPS RECEIVER KIT (INCL 10' CABLE, BRACKETS, TERM)    [***]       I
250-0150-0025   GPS RECEIVER KIT (INCL 25' CABLE, BRACKETS, TERM)    [***]       I
250-0150-0050   GPS RECEIVER KIT (INCL 5' CABLE, BRACKETS, TERM)     [***]       I
250-0150-0100   GPS RECEIVER KIT (INCL 100' CABLE, BRACKETS, TERM)   [***]       I
250-0150-0101   GPS SYSTEM 100 FT(AMOD) SPECIFIC TO CLEARWIRE        [***]       I
250-0150-0200   GPS RECEIVER KIT (INCL 200' CABLE, BRACKETS, TERM)   [***]       I
250-0150-0202   GPS SYSTEM 200 FT(AMOD) SPECIFIC TO CLEARWIRE        [***]       I
301-0015-0001   COMMAND ADHESIVE STRIPS                              [***]       I
350-0100-0002   BTS WALLMOUNT BRACKETS                               [***]       I
350-0100-0025   5 ALUMINUM CABLE MOUNT FOR 7' RACK                   [***]       I
350-0100-0101   BTS 1U 19 RACK MTG BRACKET (2 REQD/BTS)              [***]       I
350-0200-0001   PIVOT BRACKET                                        [***]       I
350-0200-0002   SWING BRACKET                                        [***]       I
350-0200-0003   BRACKET HINGE PIECE TOP                              [***]       I
350-0200-0004   BRACKET HINGE PIECE BOTTOM                           [***]       I
350-0200-0005   WALL MOUNTING BRACKET INTEGRAL BASE                  [***]       I
350-0200-0016   SHORT TOOTH BRACKET WITH BOLT LIP                    [***]       I
350-0200-0017   SMALL TOOTH BRACKET NO BOLT LIP                      [***]       I
350-0200-0101   BRACKET FOR STANDARD RACK                            [***]       I
370-0200-0001   DE-MATING TOOL FOR CPP SERIES, SIZE 02 DEUTSCH CON   [***]       I
420-0060-0010   16.9 WATT WALL MOUNT ADAPTER                         [***]       I
420-0060-0020   16.9 WATT WALL MOUNT ADAPTER (UK)                    [***]       I
420-0060-0030   16.9 WATT WALL MOUNT ADAPTER (EU)                    [***]       I
420-0060-0040   16.9 WATT WALL MOUNT ADAPTER (AUS)                   [***]       I
440-0101-0060   INTERFACE CONNECTOR BD ASSM. A-MOD                   [***]       I
440-0200-0060   INTERFACE CONNECTOR BOARD ASSM.                      [***]       I
450-0010-2000   GPS, TRIMBLE ACUTIME 2000 (P/N 39091-00)             [***]       I
450-0010-2001   Trimble Acutime 2000 Lightning Protector             [***]       I
450-0010-2002   ACCUTIME 2000 SYNCHRONIZATION KIT (WITH 100" CABLE   [***]       I
501-0350-1011   STELLA DORADUS ANTENNA MOUNTING KIT                  [***]       I
501-1002-2701   DIRECTIONAL ANTENNA 2.6 V, 15dBi 120 X 7 DEG, NF     [***]       I
501-1002-3401   STELLA DORADUS 3.3-3.6 GHZ V POL 120 X 7 ANTENNA     [***]       I
501-1002-3701   ANTENNA 3.7 V. 15DBI 120X7 DEG NF(LESS MTG BKT)      [***]       I
501-1006-2701   DIRECTIONAL ANTENNA 2.6 V, 15dBi 60 X 7 DEG, NF      [***]       I
501-1006-3401   ANTENNA, 3.4 V 18DBI, 60 X 7 DEG,NF                  [***]       I
501-1009-2301   ANTENNA 2.3-2.5V 16dBi 90X7 DEG NF                   [***]       I
501-1009-2701   ANTENNA, 2.6 V, 16dBi, 90x7 DEG, NF                  [***]       I
501-1009-2791   ANTENNA, 2.6V 16DBI, 90X9 DEG 1EDT                   [***]       I
</TABLE>

[*** Confidential Treatment Requested]


                                       A-2

<PAGE>

<TABLE>
<CAPTION>
                                                                     TOTAL   (I)NFRA/
     ITEM                           DESCRIPTION                      PRICE     (C)PE
     ----                           -----------                      -----   --------
<S>             <C>                                                  <C>     <C>
501-1009-2792   ANTENNA, 2.6V 16DBI, 90X7 DEG 2EDT                   [***]       I
501-1009-2793   ANTENNA, 2.6V 16DBI, 90X9 DEG 3EDT                   [***]       I
501-1009-2794   ANTENNA, 2.6V 16DBI, 90X8DEG 4EDT                    [***]       I
501-1009-2795   ANTENNA, 2.6V 15DBI, 90X9 DEG 5EDT                   [***]       I
501-1009-3401   ANTENNA 3.4, V, 16DBI, 90X7 DEG, NF                  [***]       I
501-1009-3701   ANTENNA 3.7 V. 16DBI 90X7 DEG NF(LESS MTG BKT)       [***]       I
501-3002-2601   ANTENNA =, 2.6V. 13DBI, 360 X 7 DEG                  [***]       I
501-3004-2601   ANTENNA, 2.6V. 10DBI, 360 X 10 DEGREE                [***]       I
501-3004-3301   ANTENNA 3.3 V. 13DBI 360 X 5 DEG                     [***]       I
501-3004-3601   OMNI-DIRECTIONAL ANTNNA 360 3.4-3.6GHZ               [***]       I
501-3004-3701   ANTENNA 3.7 V. 13BDI 360 X5 DEG                      [***]       I
515-1005-0002   2 POS, HIGH CURRENT, SCREW TERM CONN. FOR TVS        [***]       I
515-1012-0202   DC PWR JACK W/SWT                                    [***]       I
515-2015-0004   4-PIN TERMINAL BLOCK 5.08 MM PITCH                   [***]       I
515-2016-0004   4 PIN CONN TERMINAL BLOCK 3.81 MM PITCH              [***]       I
515-6005-0002   BASE STATION ii IMPEDANCE TERMINATOR PLUG 100 OHM    [***]       I
597-0160-0002   INDB CABLE HARNESS                                   [***]       I
597-0160-0005   INDOOR BASE PWR EXTENDED CABLE                       [***]       I
597-1162-0500   500' ROLL 16/2 DC POWER CABLE                        [***]       I
597-5001-0100   BASE FILTER CABLE ASSEMBLY, MCX (JCI 416-8813-001)   [***]       I
597-5001-0105   BASE FILTER CABLE ASSEMBLY, MCX 4"                   [***]       I
597-5001-0110   3.3/3.5 GHZ LIGHTNING PROTECTOR CABLE ASSM.          [***]       I
597-5001-0403   RF JUMPER CABLE, TYPE N ST/90 DEG, 3FT               [***]       I
597-5001-0404   RF JUMPER CABLE, TYPE N ST/90 DEG, 4FT               [***]       I
597-5001-0406   RF JUMPER CABLE, TYPE N ST/90 DEG, 6FT               [***]       I
597-5001-0408   RF JUMPER CABLE, TYPE N ST/90 DEG, 8FT               [***]       I
597-5001-0410   RF JUMPER CABLE, TYPE N ST/90 DEG, 10FT              [***]       I
597-5001-0412   RF JUMPER CABLE, TYPE N ST/90 DEG, 12FT              [***]       I
597-5120-0207   BRITISH NON-DETACHABLE                               [***]       I
597-5120-0507   7' THREE- WIRE POWER CORD (CHINA/ AUSTRALIA)         [***]       I
597-5212-0004   4 FT JUMPER                                          [***]       I
597-5212-0006   6 FT TOP JUMPER CABLE                                [***]       I
597-5212-0008   8 FT 1/2" HELIAX CABLE ASSEMBLY                      [***]       I
597-5212-0012   12 FT 1/2" HELIAX CABLE ASSEMBLY                     [***]       I
597-6011-0010   BASE STATION TO GPS CABLE, 10 FT                     [***]       I
597-6011-0025   BASE STATION TO GPS CABLE, 25 FT                     [***]       I
597-6011-0050   BASE STATION TO GPS CABLE, 50 FT                     [***]       I
597-6011-0100   BASE STATION TO GPS CABLE, 100 FT                    [***]       I
597-6011-0200   BASE STATION TO GPS CABLE 200 FT                     [***]       I
597-6012-0003   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 3 FT        [***]       I
597-6012-0004   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 4 FT        [***]       I
597-6012-0010   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 10 FT       [***]       I
597-6012-0025   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 25 FT       [***]       I
597-6012-0050   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 50 FT       [***]       I
597-6012-0100   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 100 FT      [***]       I
597-6012-0200   BASE TO BASE DAISY CHAIN CABLE-GPS CABLE 200 FT      [***]       I
597-6013-0001   BASE STATION TO TVS POWER/ETHERNET CABLE, 1 FT       [***]       I
597-6013-0002   BASE STATION TO TVS POWER/ETHERNET CABLE, 2 FT       [***]       I
597-6013-0004   BASE STATION TO TVS POWER/ETHERNET CABLE, 4 FT       [***]       I
</TABLE>

[*** Confidential Treatment Requested]


                                       A-3

<PAGE>

<TABLE>
<CAPTION>
                                                                     TOTAL   (I)NFRA/
     ITEM                           DESCRIPTION                      PRICE     (C)PE
     ----                           -----------                      -----   --------
<S>             <C>                                                  <C>     <C>
597-6013-0006   BASE STATION TO TVS POWER/ETHERNET CABLE, 6 FT       [***]       I
597-6013-0010   BASE STATION TO TVS POWER/ETHERNET CABLE, 10 FT      [***]       I
597-6013-0025   BASE STATION TO TVS POWER/ETHERNET CABLE, 25 FT      [***]       I
597-6013-0050   BASE STATION TO TVS POWER/ETHERNET CABLE, 50 FT      [***]       I
597-6013-0100   BASE STATION TO TVS POWER/ETHERNET CABLE, 100 FT     [***]       I
597-6013-0200   BASE STATION TO TVS POWER/ETHERNET CABLE, 200 FT     [***]       I
597-6013-0300   BASE STATION TO TVS POWER/ETHERNET CABLE, 300 FT     [***]       I
597-6014-0010   BASE STATION PROGRAMMING CABLE, 10 FT                [***]       I
597-6025-0010   CABLE GPS-TO-BTS 10' DEUTSCH CONN                    [***]       I
597-6025-0025   CABLE GPS-TO-BTS 25' DEUTSCH CONN                    [***]       I
597-6025-0050   CABLE GPS-TO-BTS 50' DEUTSCH CONN                    [***]       I
597-6025-0100   CABLE GPS-TO-BTS 100' DEUTSCH CONN                   [***]       I
597-6025-0200   CABLE GPS-TO-BTS 200' DEUTSCH CONN                   [***]       I
597-6025-0300   NEXTNET EXPEDIENCE BASE STATION II TO GPS 300FT      [***]       I
597-6026-0004   STATION II RS442/1 PPS DAISY CHAIN ASSY (4FT)        [***]       I
597-6026-0010   BASE STATION II RS442/1 PPS DAISY CHAIN ASSY (10)    [***]       I
597-6026-0025   RS442/1 PPS DAISY CHAIN ASSY                         [***]       I
597-6026-0050   STATION II RS442/1 PPS DAISY CHAIN ASSY (50FT)       [***]       I
597-6026-0100   BASE STATION II RS442/1 PPS DAISY CHAIN ASSY (100)   [***]       I
597-6026-0200   BASE STATION II RS442/1 PPS DAISY CHAIN ASSY (200)   [***]       I
597-6027-0002   BASE STATION II TO TVS MODULE CABLE 2 FT             [***]       I
597-6027-0004   BASE STATION II TO TVS MODULE CABLE 4 FT             [***]       I
597-6027-0006   BASE STATION II TO TVS MODULE CABLE 6 FT             [***]       I
597-6027-0010   BASE STATION II TO TVS MODULE CABLE 10 FT            [***]       I
597-6027-0025   BASE STATION II TO TVS MODULE CABLE 25 FT            [***]       I
597-6027-0050   BASE STATION II TO TVS MODULE CABLE 50 FT            [***]       I
597-6027-0100   BASE STATION II TO TVS MODULE CABLE 100 FT           [***]       I
597-6027-0200   BASE STATION II TO TVS MODULE CABLE 200 FT           [***]       I
597-6027-0300   BASE STATION II TO TVS MODULE CABLE 300 FT           [***]       I
597-6028-0010   BASE STATION RS232 PROGRAMMING CABLE                 [***]       I
597-6125-0010   CABLE GPS-TO-BTS 10' DEUTSCH CONN INTENSE WEATHER    [***]       I
597-6125-0025   CABLE GPS-TO-BTS 25' DEUTSCH CONN INTENSE WEATHER    [***]       I
597-6125-0050   CABLE GPS-TO-BTS 50' DEUTSCH CONN INTENSE WEATHER    [***]       I
597-6125-0100   CABLE GPS-TO-BTS 100' DEUTSCH CONN INTENSE WEATHER   [***]       I
597-6125-0200   CABLE GPS-TO-BTS 200' DEUTSCH CONN INTENSE WEATHER   [***]       I
597-6125-0300   CABLE GPS-TO-BTS 300' DEUTSCH CONN INTENSE WEATHER   [***]       I
597-6126-0004   BASE RS442/1 PPS DAISY CHAIN ASSY 4' INT WEATHER     [***]       I
597-6126-0010   BASE RS442/1 PPS DAISY CHAIN ASSY 10' INT WEATHER    [***]       I
597-6126-0025   BASE RS442/1 PPS DAISY CHAIN ASSY 25' INT WEATHER    [***]       I
597-6126-0050   BASE RS442/1 PPS DAISY CHAIN ASSY 50' INT WEATHER    [***]       I
597-6126-0100   BASE RS442/1 PPS DAISY CHAIN ASM 100' INT WEATHER    [***]       I
597-6126-0200   BASE RS442/1 PPS DAISY CHAIN ASM 200' INT WEATHER    [***]       I
597-6127-0002   BASE STATION II TO TVS MOD CABLE 2 FT INT WEATHER    [***]       I
597-6127-0004   BASE STATION II TO TVS MOD CABLE 4 FT INT WEATHER    [***]       I
597-6127-0006   BASE STATION II TO TVS MOD CABLE 6 FT INT WEATHER    [***]       I
597-6127-0010   BASE STATION II TO TVS MOD CABLE 10FT INT WEATHER    [***]       I
597-6127-0025   CABLE GPS-TO-BTS 25' DEUTSCH CONN INTENSE WEATHER    [***]       I
</TABLE>

[*** Confidential Treatment Requested]


                                       A-4

<PAGE>

<TABLE>
<CAPTION>
     ITEM                           DESCRIPTION                       TOTAL PRICE   (I)NFRA/(C)PE
     ----                           -----------                       -----------   -------------
<S>             <C>                                                   <C>           <C>
597-6127-0050   CABLE GPS-TO-BTS 50' DEUTSCH CONN INTENSE WEATHER     [***]               I
597-6127-0100   CABLE GPS-TO-BTS 100' DEUTSCH CONN INTENSE WEATHER    [***]               I
597-6127-0200   CABLE GPS-TO-BTS 200' DEUTSCH CONN INTENSE WEATHER    [***]               I
597-6127-0300   CABLE GPS-TO-BTS 300' DEUTSCH CONN INTENSE WEATHER    [***]               I
598-0002-0002   2FT X 3/4" OD MOUNTING PIPE                           [***]               I
598-0002-0004   4FT X 3/4" OD MOUNTING PIPE                           [***]               I
598-0002-0100   COPPER SET SCREW LUG, STRAIGHT TONGUE, 14-4 AWG,      [***]               I
598-0160-0001   GUIDE PINS BASE UNIT                                  [***]               I
598-0160-0040   STRAP STR RELIEF FOR DIP 40 CONN                      [***]               I
598-1000-0001   HINGE, LIFT-OFF / WITH PIN                            [***]               I
598-1000-0002   HINGE, LIFT-OFF / WITHOUT PIN                         [***]               I
598-1000-0010   U-TYPE FASTENER                                       [***]               I
700-0150-0001   DMC CRIMP TOOL, MH860                                 [***]               I
700-0150-0002   DMC CRIMP TOOL, AF-8                                  [***]               I
700-0150-0003   DMC POSITIONER TOOL, # 86-7                           [***]               I
700-0150-0004   DMC POSITIONER TOOL, # TH163                          [***]               I
700-1100-2001   GREEN / WHITE INSERTION / EXTRACTION TOOL             [***]               I
700-1100-2201   RED / ORANGE INSERTION / EXTRACTION TOOL              [***]               I
900-0009-0055   NETWORK INTERFACE MODULE KIT                          [***]               I
900-0100-0125   TVS MODULE BOX                                        [***]               I
900-0323-1000   BTS-2300-A, ISPOOO, CHP DIECAST                       [***]               I
900-0337-1000   BTS-3700-C. DIECAST ISPOOO. CHPL-3-7030               [***]               I
900-0337-9100   3.7 ROHS NON-ENHANCED BTS-3700-C ISPOOO CHPL-3-7010   [***]               I
900-0350-1000   BTS-2500-C ISPOOO, CHPL -2-6010 DIECAST               [***]               I
900-0350-9100   2.6 ROHS NON-ENHANCED BTS-2500-C ISPOOO CHPL-2-6010   [***]               I
900-0352-1000   BTS-3300-C, ISPOOO, CHPL-3-3010 DIECAST               [***]               I
900-0354-1000   BTS-3500-C, ISPOOO, CHPL-3-5030 DIECAST               [***]               I
900-0354-9100   3.5 ROHS NON-ENHANCED BTS-3500-C ISPOOO CHPL-3-5030   [***]               I
900-0360-1000   BTS-2500-E, ISPOOO, CHPL-2-6010                       [***]               I
</TABLE>

[*** Confidential Treatment Requested]


                                       A-5

<PAGE>

WIMAX- CLEARWIRE PRICING

PRODUCT/DESCRIPTION

Diversity Access Point-2006 (non-Redundant) 4 Sector integrated base site.
Includes antennas, 2.5 GHz RF modules, GPS, modem, fiber optic and power cables,
power supplies and mounting brackets. Includes any necessary hardware upgrades,
if any, from Wave 1 to Wave 2 if originally purchased as Wave
1. Channelization is 5 and 10 MHz.

     Tiers Measured on CUMULATIVE Lifetime purchases of both 4 Sector and 3
     Sector products for the DAP 2006 products

Available [***]

<TABLE>
<CAPTION>
        [***]    2008    2009    2010    2011
        -----   -----   -----   -----   -----
<S>     <C>     <C>     <C>     <C>     <C>
[***]   [***]   [***]   [***]   [***]   [***]
[***]   [***]   [***]   [***]   [***]   [***]
[***]   [***]   [***]   [***]   [***]   [***]
</TABLE>

Diversity Access Point - 2006 (non-Redundant) 3 Sector integrated base site.
Includes antennas, 2.5 GHz RF modules, GPS, modem, fiber optic and power cables,
power supplies and mounting brackets. Includes any necessary hardware upgrades,
if any, from Wave 1 to Wave 2 if originally purchased as Wave
1. Channelization is 5 and 10 MHz.

     Tiers Measured on CUMULATIVE Lifetime purchases of both 4 Sector and 3
     Sector products for the DAP 2006 products

Available [***]

<TABLE>
<CAPTION>
         2007    2008    2009    2010    2011
        -----   -----   -----   -----   -----
<S>     <C>     <C>     <C>     <C>     <C>
[***]   [***]   [***]   [***]   [***]   [***]
[***]   [***]   [***]   [***]   [***]   [***]
[***]   [***]   [***]   [***]   [***]   [***]
</TABLE>

WIMAX Network Support (Including Software Maintenance)

     WIMAX NSP per Sector & per CAP Controller per year. Starts January 1st in
     the year after shipment. Does not include Extended Hardware Maintenance

[***] per Sector per year [***] per CAP controller per year.

- capped at the lesser of 1) [***] per year or 2 [***] per Subscriber per year.

CAP Controller - 1000 Site Configuration

     Hardware includes redundant ATA shelf and access point controller cards for
     up to 1,000 sites and 1,000,000 users. One(1) is required per access point
     network.

[***] Available [***]

Portal Element Management System

     Central Server Software per workstation. Excludes PC Hardware License Keys,
     one required per DAP

[***] Available [***]
[***] Available [***]

Notes - all pricing quoted is for the 2.5 Ghz products in US Dollars - Taxes,
        Insurance & Freight will be added as applicable 3.5 Ghz DAP products (5
        and 7 mhz chnl only) are offered at [***] price as above 3.5 Ghz CPE/PC
        Cards (5 and 7 mhz chnl only) are offered at [***] to prices shown above

Expedience - Clearwire Pricing

<TABLE>
<CAPTION>
                         2007    2008    2009    2010
                        -----   -----   -----   -----
<S>                     <C>     <C>     <C>     <C>
Expendience Network     [***]   [***]   [***]   [***]
Support (Including
Software Maintenance)
</TABLE>

Experience NSP per sector per year. Starts January 1st in the year after
shipment. Does not include Extended Hardware Maintenance

- capped at the lesser of 1) [***] per year or [***] per Subscriber per year

[*** Confidential Treatment Requested]


                                       A-6

<PAGE>

                                   EXHIBIT "A"

                                   SCHEDULE 2

                                     TO THE
                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

                      TARGETED EQUIPMENT AVAILABILITY DATES

<TABLE>
<CAPTION>
MILESTONE #    DATE   2.5 GHZ NETWORK MILESTONES
-----------   -----   --------------------------
<S>           <C>     <C>
     N1       [***]              [***]
     N2       [***]              [***]
     N3       [***]              [***]
     N4       [***]              [***]
     N5       [***]              [***]
     N6       [***]              [***]
     N7       [***]              [***]
</TABLE>

This Schedule sets forth Infrastructure Products and target availability dates
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the target availability dates
described in such amended Schedule. Motorola and Clearwire will use commercially
reasonable efforts to achieve the objectives stated in this Schedule by the
dates specified above or elsewhere in this Agreement, including identifying
those provisions of this Schedule the breach of which will be mutually agreed
upon to constitute a material breach for purposes of Section 2.3.4 of this
Agreement.

[*** Confidential Treatment Requested]


                                       A-7

<PAGE>

                                   EXHIBIT "B"

                                     TO THE
                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

                            TECHNICAL SPECIFICATIONS

<TABLE>
<CAPTION>
                                                           TARGETED DISCUSSION
                                                          DURATION PERIOD FROM
                  EXHIBIT B SCHEDULE                     PERMITTED START DATES*
                  ------------------                     ----------------------
<S>                                                      <C>
Exhibit B-Schedule 1 - Clearwire Expedience WiMAX                  N/A
Ntw.doc

Exhibit B-Schedule 2 - ASN requirements vO.5.doc                    60

Exhibit B-Schedule 3 - WiMAX ICD requirements vO.3.doc              60

Exhibit B-Schedule 4 - Expedience ICD requirements                 120
vG.3.doc

Exhibit B-Schedule 5 - System validation plan_vO.2.doc              60

Exhibit B-Schedule 6 - Wimax cert profiles vO.2.doc                120

Exhibit B-Schedule 7 - DAP CAP Product                             120
Description1.2a.pdf

Exhibit B-Schedule 8 - Alpha field testplan vO.2.doc                60

Exhibit B-Schedule 9 - Beta market testplan vO.3.doc               180

Exhibit B-Schedule 10 - Wave2 testplan vO.3.doc                    180

*TO the extent the discussions involve third parties
other than Motorola and Clearwire, start date will not
begin prior to closing.
</TABLE>

                           SEE SCHEDULES 1-10 ATTACHED

THIS EXHIBIT "B" SETS FORTH INFRASTRUCTURE PRODUCTS AND TECHNICAL SPECIFICATIONS
THEREFOR WHICH CLEARWIRE DESIRES TO PURCHASE. ONCE MUTUALLY AGREED UPON BY THE
PARTIES, THIS EXHIBIT "B" WILL BE AMENDED ACCORDINGLY AND MOTOROLA WILL AGREE TO
DELIVER INFRASTRUCTURE PRODUCTS IN ACCORDANCE WITH THE SPECIFICATIONS AND
FEATURES DESCRIBED IN SUCH AMENDED EXHIBIT "B". MOTOROLA AND CLEARWIRE WILL USE
COMMERCIALLY REASONABLE EFFORTS TO ACHIEVE THE OBJECTIVES STATED IN THIS EXHIBIT
"B" BY THE DATES SPECIFIED ABOVE OR ELSEWHERE IN THIS AGREEMENT, INCLUDING
IDENTIFYING THOSE PROVISIONS OF THIS EXHIBIT "B" THE BREACH OF WHICH WILL BE
MUTUALLY AGREED UPON TO CONSTITUTE A MATERIAL BREACH FOR PURPOSES OF SECTION
2.3.4 OF THIS AGREEMENT.

[*** Confidential Treatment Requested]


                                       B-1

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 1

Clearwire Expedience/WiMAX Network Architecture

-    THIS DIAGRAM OUTLINES A STANDARD WIMAX ARCHITECTURE AS PROPOSED IN NWG
     STAGE 2 DESIGN.

-    [***]

-    [***]

-    THE COLORED BOXES ILLUSTRATE THE NETWORK FUNCTIONS THAT NEED TO EXIST IN
     THE FUNCTIONAL NETWORK ELEMENTS

[***]

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.

[*** Confidential Treatment Requested]

<PAGE>

CLEARWIRE WIMAX NETWORK

[***]

[*** Confidential Treatment Requested]


                                        2

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 2

                            WIMAX ASN-GW REQUIREMENTS

                             DOCUMENT NUMBER: CLROOX
                                  RELEASE: 0.5
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER        DATE                AUTHOR                  DESCRIPTION
------   -------------   ------------------------   ----------------------
<S>      <C>             <C>                        <C>
0.4      June 14, 2006   Mark Winter/Pete Gelbman   Initial version
..05      June 21, 2006   Pete Gelbman               Joint CW/MOT edits for
                                                    clarification
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                            <C>
1. ASN PROFILE REQUIREMENTS ................................................   5
   1.1. PMIP ...............................................................   5
   1.2. R6 Tunnel ..........................................................   5
   1.3. RRM and R8 Interface ...............................................   5

2. PLATFORM ARCHITECTURE ...................................................   5
   2.1. High Availability ..................................................   5
   2.2. Scalability ........................................................   6
   2.3. Access Control .....................................................   6
   2.4. Interface Support ..................................................   6
   2.5. Protocols ..........................................................   6
   2.6. Latency Performance ................................................   6
   2.7. Server support .....................................................   6

3. ASN BILLING .............................................................   6

4. QOS .....................................................................   7

5. MANAGEMENT ..............................................................   7
   5.1. Security ...........................................................   7
   5.2. Command Line Interface (CLI) .......................................   7
   5.3. Network communications (remote) ....................................   7
   5.4. Serial Communications (local console port) .........................   7
   5.5. Debugging ..........................................................   7
   5.6. Dedicated Management Port ..........................................   7
   5.7. Reporting ..........................................................   8
   5.8. Configuration Management ...........................................   8
   5.9. Storage ............................................................   8
</TABLE>


                                                                               3

<PAGE>

1.   ASN PROFILE REQUIREMENTS

ASN PROFILE C is required, including all functional entities, protocols, and
interfaces as defined by the WiMAX Forum Network Working Group (NWG) in current
and future versions of WiMAX End-to-End Network System Architecture, Stage 2 and
Stage 3 reference documentation, dated 2006.04.17. At the time these
requirements are being written, NWG Stage 3 (Detailed protocols and procedures)
are still under development. The following sections clarify specific functional
requirements in certain areas where necessary.

     1.1. PMIP

ASN must support Proxy Mobile IP.

     1.2. R6 TUNNEL

R6 must support GRE tunneling protocol between BTS and ASN-GW.

     1.3. RRM AND R8 INTERFACE

Within ASN profile C, RRM (including RRA and RRC) and related mobility HO
functions are defined to reside in the BS. Separation of BS and ASN-GW functions
in this manner is generally in line with Clearwire ASN requirements. However,
having all RRM functions reside only in BS may preclude or make it difficult to
implement optimized soft handover or network managed mobility handovers. This
issue has been recognized within the WiMAX NWG and proposals for using R8
interface (inter-BS communications) to resolve this issue. To date, these
strategies have not been defined within NWG stage 2 or 3 documentation. Even
within the context of an R8 solution there may be significant implementation
challenges, that may requires proprietary BS RRM solutions, or necessitate
revisiting the split of RRM functions between BS/ASN within profile C.

Since this issue is currently under investigation in NWG, there is no specific
requirement that Clearwire can articulate other than to require that both ASN
and BS vendors recognize that this issue exists and commit to the joint
development of a comprehensive solution that meets Clearwire mobility
requirements.

2.   PLATFORM ARCHITECTURE

     2.1. HIGH AVAILABILITY

The ASN-GW should have the following HA features:

     -    System should be designed to provide carrier class with 99.999%
          availability

     -    No Single Point of failure.

     -    Hitless software upgrades.

     -    Hitless failover for non-stop forwarding.

     -    ASN-GW should have messaging if a connection limit has been reached to
          communicate to the BS to contact another ASN-GW.


                                                                               4

<PAGE>

     2.2. SCALABILITY

     -    ASN-GW platform should be scalable enough to support cost effective,
          flexible hardware deployments of both large and small markets, while
          maintaining common software functionality & configuration.

     [***]

     2.3. ACCESS CONTROL

ASN-GW should support Access Control Lists

     2.4. INTERFACE SUPPORT

The system must support the following standard network interfaces:

     [***]

     2.5. PROTOCOLS

ASN-GW must support the following protocols:

     [***]

     2.6. LATENCY PERFORMANCE

System should introduce minimal latency as traffic flows through it.

     2.7. SERVER SUPPORT

Any server based application must run on major open source Linux distribution
such as CentOS, RedHat Enterprise Linux, etc.

3.   ASN BILLING

ASN platform must provide billing function to CRM. It's expected that this will
occur via industry standard AAA/RADIUS interface from ASN elements; however
WiMAX has not fully defined these requirements.

Issues to be jointly worked out:

     -    Per current WiMAX stage 2/3 docs, AAA lives in CSN. Its recognized
          that having AAA/Proxy live within ASN may be a good thing.

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                                                                               5

<PAGE>

     -    Another complexity is that CW USA is actually a ASN & CSN so these
          boundaries do not currently directly align with overall sys-arch.

4.   QOS

ASN-GW should support [***] techniques. These should facilitate QoS policy
definition, classification, and enforcement.

5.   MANAGEMENT

ASN-GW Management details shall be specified in detail under general Clearwire
OAM&P requirements. The following sections provide specific additional
requirement.

     5.1. SECURITY

ASN-GW operator security authentication should be capable of supporting RADIUS
AAA. NOTE: this is not WIMAX SS authentication - this is management login
authentication.

     5.2. COMMAND LINE INTERFACE (CLI)

ASN must provide a terminal CLI access to operating system commands. UNIX shell
characteristics with hierarchical menu structure with the common function [arg1]
[arg2] format, context help, and tab-completion is preferred. The shell CLI
should be common to various access methods such as network, or serial. The
well-known Cisco router IOS provides a good example of an engineering-friendly
CLI.

     5.3. NETWORK COMMUNICATIONS (REMOTE)

A method for logging into a remote target and for executing commands over a
TCP/IP network is required. Industry standard tools such as Telnet and SSH are
preferred. For file transfer, SCP, TFTP, and FTP are preferred. These protocols
have client programs available on all popular operating systems and API's are
available in many programming languages.

     5.4. SERIAL COMMUNICATIONS (LOCAL CONSOLE PORT)

A dedicated local RS-232 interface is required for initial configuration and
reliable access to the target shell when the network may not be functional.

     5.5. DEBUGGING

ASN software should provide module/function level debug and data logging
capabilities. Since such functions significantly impact MIPS and system
performance, each module should provide its own ability to enable/disable
debug/logging and discreet levels of verbosity.

     5.6. DEDICATED MANAGEMENT PORT

A dedicated management Ethernet port is required for out of band management of
the system.

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<PAGE>

     5.7. REPORTING

System should support the following event, fault, and troubleshooting features
at a minimum:

     [***]

     -    All these functions should be designed with performance impact
          considerations.

     5.8. CONFIGURATION MANAGEMENT

     -    ASN devices must provide following functionality:

     [***]

     -    ASN-GW software configuration shall be provided via a single text file
          than can be edited and saved locally or remotely and transferred to
          and from the device via TFTP/SCP network protocols.

     5.9. STORAGE

The platform should have flash based storage where backup code images and files
can be stored.

Todo:

-    Need to add Acronym def

     [***]

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<PAGE>

     [***]

-    It's recognized that there are many approaches to these issues with various
     complex pros/cons that need to be addressed jointly.

     [***]

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<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 3

                             WIMAX ICD REQUIREMENTS

                            DOCUMENT NUMBER: CLR00X
                                  RELEASE: 0.3
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER        DATE          AUTHOR                  DESCRIPTION
------   -------------   ------------   -----------------------------------
<S>      <C>             <C>            <C>
0.1      June 13, 2006   Scott Jacka    Initial version
0.3      June 21, 2006   Pete Gelbman   Join CW/MOT edits for clarification
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                           <C>
1.   INTRODUCTION..........................................................    4
2.   INTERFACE DESCRIPTIONS................................................    5
     2.1. AAA to ASN Interface.............................................    5
          2.1.1. Network Connectivity......................................    5
     2.2. EMS to BS Interface..............................................    5
          2.2.1. Network Connectivity......................................    5
          2.2.2. Management and Monitoring.................................    5
     2.3. EMS to ASN Interface.............................................    5
          2.3.1. Network Communications....................................    5
          2.3.2. Management and Monitoring.................................    5
     2.4. EMS to SS/MS Interface...........................................    6
     2.5. EMS to NMS/CRM Interface.........................................    6
3.   EMS REQUIREMENTS......................................................    7
     3.1. General EMS Requirements.........................................    7
     3.2. Tiered Access and Logging........................................    8
     3.3. Command Line Interface...........................................    8
4.   CENTRAL SOFTWARE, INVENTORY, AND CONFIGURATION REPOSITORY.............   10
5.   SS TROUBLESHOOTING API................................................   12
6.   NETWORK SUPPORT TOOLS.................................................   13
     6.1. Drive test application software..................................   13
     6.2. SS/MS Test Tool..................................................   13
</TABLE>


                                                                               3

<PAGE>

1.   INTRODUCTION

This ICD provides the framework for the interfaces to be supported within the
WiMAX network. These functions can be classified into the following categories:
Operations, Maintenance and Provisioning and will be vital to the Clearwire
network deployment. The high level interfaces to be included in this appendix
are shown in Figure A.2.1 -ICD High Level Diagram. The blue shaded blocks in the
diagram are vendor provided elements while the green shaded items are
implemented and provided by Clearwire.

                                      [***]

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<PAGE>

2.   INTERFACE DESCRIPTIONS

     2.1. AAA TO ASN INTERFACE

          2.1.1. NETWORK CONNECTIVITY

The interface between the ASN and the AAA server should support RADIUS, or
DIAMETER via a TCP/IP network connection.

     2.2. EMS TO BS INTERFACE

          2.2.1. NETWORK CONNECTIVITY

It is required that the BS be reachable via a [***]

          2.2.2. MANAGEMENT AND MONITORING

The management and monitoring of the ASN by the EMS should be completed through
widely accepted industry standard interfaces. Specifically the ASN to EMS
interface should support [***]

     2.3. EMS TO ASN INTERFACE

The EMS to ASN interface must support the management of the ASN. The functions
associated with this management are specified in this section of the appendix.

          2.3.1. NETWORK COMMUNICATIONS

It is required that the ASN be reachable via a [***]

          2.3.2. MANAGEMENT AND MONITORING

The management and monitoring of the ASN by the EMS should be completed through
widely accepted industry standard interfaces. Specifically the ASN to EMS

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                                                                               5

<PAGE>

interface should support [***]

     2.4. EMS TO SS/MS INTERFACE

The EMS to SS interface is unique in the network [***]

The services relative to the EMS to SS interface are specified in section 3.0
EMS Requirements section of the appendix. A summary of these functions to be
supported via the EMS to SS interface are as follows:

     [***]

Any information exchanged between the SS/MS and the network should be done in a
safe manner and minimizing risks networking security. For example the BS and
associated management network should not be directly accessible through the air
interface of the SS.

     2.5. EMS TO NMS/CRM INTERFACE

EMS must support industry standard interfaces to 3rd party NMS and CRM
platforms. The definition of industry standard may vary, currently its felt that
[***]

Specific capabilities of the EMS which may impact the information exchanged on
this interface are further outlined in the 3.0 EMS Requirements section of this
document and ASN requirements doc.

An API should be provided on the EMS using industry standard interfaces to
facilitate the integration between CRM and the EMS. This connection is required
to facilitate management and troubleshooting of subscriber issues.

Specific capabilities related to the EMS to CRM Interface are further outlined
in section 3.0 EMS

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<PAGE>

3.   EMS REQUIREMENTS

The EMS is a key focal point of the WiMAX network which allows for the
operation, maintenance, and provisioning of the network. The WiMAX SPWG team is
still in the process of developing requirements of the EMS as of Release 1.5 of
the document "Recommendations and Requirements for Networks based on WiMAX Forum
Certified Products".

     3.1. GENERAL EMS REQUIREMENTS

Many specific requirements of the EMS will require [***]. However, capabilities
[***] follows:

     [***]

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<PAGE>

     3.2. TIERED ACCESS AND LOGGING

Applications within the EMS should support tiered access levels. The
tiered-access levels should be configurable by Clearwire on a per-user basis.
The included capability should also allow for the viewing of capability to be
removed from users where access permissions are not allowed.

All login attempts (failed and successful), executed user commands, and command
results should be logged in a human readable log file. Entries should include
the user performing each action as well as the date and timestamp the action was
performed.

The management of user passwords should either be stand alone within the
application or via the use of RADIUS.

     3.3. COMMAND LINE INTERFACE

Clearwire views CLI as [***] and would like to submit the following as initial
input towards a MOI MRD:

The WiMAX system should contain a Command Line Interface (CLI) for each device
where appropriate (examples: ASN, BS, SS/MS). This Interface will be used for
executing operating system commands from direct or remote locations. The
following requirements are placed on the CLI:

[***]

The CLI should allow for basic and advanced troubleshooting of the network
element. Key functionality which should be available via the CLI are as follows:

[***]

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                                                                               8

<PAGE>

[***]

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                                                                               9

<PAGE>

4.   CENTRAL SOFTWARE, INVENTORY, AND CONFIGURATION REPOSITORY

The WiMAX system must offer a central, or regionally, located service which
performs software management and element configuration. The preliminary list of
requirements generic to each tool are as follows:

     -    This core functionality should be part of a delivered EMS package.

     -    The application should allow for authenticated and tiered access as
          described elsewhere in this document.

     -    All login attempts (failed and successful), executed user commands,
          and command results should be logged in a human readable log file.
          Entries should include the user performing each action as well as the
          date and timestamp the action was performed.

The preliminary list of requirements for the software upgrade aspect of the tool
are as follows:

     -    Upgrades of the BS or SS/MS can be performed on a scheduled, ad-hoc,
          or automatic basis for the BS and SS/MS software updates.

     -    Delivery of the software should be performed in a reliable and
          efficient manner, particularly with respect to the SS/MS.

     -    Application software should be delivered to an inactive software
          partition on the BS and SS/MS in order to minimize the chance of
          having a defective unit as the result of the upgrade process.

          [***]

     -    The software update application should provide detailed reports on the
          SS upgrade process (ie units successfully upgraded, units that failed,
          units that were last known on each software revision).

The preliminary list of requirements for the inventory configuration management
tool are as follows:

[***]

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                                                                              10

<PAGE>

[***]

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                                                                              11

<PAGE>

5.   SS TROUBLESHOOTING API

The EMS interface should contain the capability to support subscriber
diagnostics. This API should allow for remote diagnostics to be performed on a
specified SS/MS in order to support the customer care process.

At a minimum, the information provided by this interface should contain the
following types of information:

     -    Device status (enabled, disabled)

     -    Device state (registered - provide BTS information, not registered -
          provide last registration time and location)

     -    Running software version

     -    CPE type and model information

     [***]

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                                                                              12

<PAGE>

6.   NETWORK SUPPORT TOOLS

There are additional network support tools required to be provided by the
equipment vendor. These tools will have specific interfaces to the hardware
being provided.

     6.1. DRIVE TEST APPLICATION SOFTWARE

A drive test application will required in order to capture the performance of
the [***]

     6.2. SS/MS TEST TOOL

Clearwire is requesting that a tool be provided to test field returns in order
to quantify if a device is defective, or if the issue for return could be
related to user error. This tool should exercise as much of the SS/MS as is
practical without requiring disassembly of the device.

The exact specifications of this tool should be defined as a part of further
technical discussions with the vendor with an intention to provide a tool for
use prior to a general-availability release of the WiMAX network. The
expectation is that discussions would lead to an MRD resulting in an available
tool.

NOTES:

In reference to section 2.1 (AAA interface), its jointly recognized that RADIUS
solution is fine. Ref to Diameter is supplied due to WiMAX ref document
compliance.

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                                                                              13

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 4

                           EXPEDIENCE ICD REQUIREMENTS

                             DOCUMENT NUMBER: CLROOX
                                  RELEASE: 0.1
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER        DATE          AUTHOR       DESCRIPTION
------   -------------   -----------   ---------------
<S>      <C>             <C>           <C>
0.1      June 13, 2006   Scott Jacka   Initial version
0.2      June 16, 2006   JS
0.3      June 21, 2006   Scott Jacka
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                            <C>
1. NEXTNET EXPEDIENCE OPERATIONS AND SYSTEM MAINTENANCE ....................    4
   1.1. NextNet Provided Applications -ISP/AP/PLADMIN ......................    4
   1.2. Clearwire Cheetah Application ......................................    4
   1.3. NextNet Expedience Syslog ..........................................    4
   1.4. NextNet Command Line Interface .....................................    5
   1.5. NextNet SNMP MIB ...................................................    5
   1.6. NextNet BTS Software Upgrade Tool ..................................    5
   1.7. NextNet Expedience Field Test ......................................    6
   1.8. NextNet Expedience Load Master .....................................    6
   1.9. NextNet Link Monitor ...............................................    6

2. NEXTNET EXPEDIENCE SUBSCRIBER PROVISIONING ..............................    6
   2.1. Clearwire BOSS to NextNet Expedience Interface......................    6
   2.2. Support for clustering .............................................    6
   2.3. Roaming Requirements ...............................................    6
</TABLE>


                                                                               3

<PAGE>

1.   NEXTNET EXPEDIENCE OPERATIONS AND SYSTEM MAINTENANCE

The existing NextNet Expedience interfaces and tools must be maintained in order
to allow the continued operation of the Clearwire network. These applicable
interfaces and tools are described in this appendix of the document.

Actual deliverable dates and commitments associated with changes or new
requirements will be involved in a 3-way discussion between Clearwire, NextNet,
and Motorola. Deliverables are also dependent upon adequate project funding.

     1.1. NEXTNET PROVIDED APPLICATIONS -ISP/AP/PLADMIN

The NextNet Expedience system must maintain the existing web page functionality
for the ISP server, AP server, and pladmin applications which exist today.
Future application enhancements and tool capability are anticipated with the
expectation that these changes do not remove existing functionality and all
modifications should be fully documented.

[***]

The existing NextNet Expedience architecture requires [***]

     1.2. CLEARWIRE CHEETAH APPLICATION

The Clearwire Cheetah application is an internal Clearwire tool used by customer
care, the NOC, and engineering to investigate the current status of a CPE on the
Clearwire network. This CPE diagnostics tool leverages [***] to enhance the
Cheetah support as required.

     1.3. NEXTNET EXPEDIENCE SYSLOG

The NextNet Expedience BTS generates a number of [***]

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<PAGE>

[***]

     1.4. NEXTNET COMMAND LINE INTERFACE

The NextNet Operating System (NNOS) command line is the [***]

     1.5. NEXTNET SNMP MIB

The NextNet Expedience system offers a variety of [***]

     1.6. NEXTNET BTS SOFTWARE UPGRADE TOOL

NextNet must maintain a BTS upgrade tool with as much, or more, capability then
the existing tool. Full documentation from NextNet should be produced at the
time the any new software is released to Clearwire in a Beta stage.

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<PAGE>

     1.7. NEXTNET EXPEDIENCE FIELD TEST

NextNet must maintain a Field Test application with as much, or more, capability
then the existing tool. Full documentation from NextNet should be produced at
the time the any new software is released to Clearwire in a Beta stage.

     1.8. NEXTNET EXPEDIENCE LOAD MASTER

NextNet must maintain a LoadMaster application with as much, or more, capability
then the existing tool. Full documentation from NextNet should be produced at
the time the any new software is released to Clearwire in a Beta stage.

     1.9. NEXTNET LINK MONITOR


NextNet must maintain a Link Monitor application with as much, or more,
capability then the existing [***] application. Full documentation from NextNet
should be produced at the time the any new software is released to Clearwire in
a Beta stage.


2.   NEXTNET EXPEDIENCE SUBSCRIBER PROVISIONING

     2.1. CLEARWIRE BOSS TO NEXTNET EXPEDIENCE INTERFACE

The inserted document [***]

     2.2. SUPPORT FOR CLUSTERING

Clearwire has a need to create a [***]

     2.3. ROAMING REQUIREMENTS


There is an operational requirement that [***]


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                                                                               6

<PAGE>

[***]

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                                                                               7

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 5

                          WIMAX SYSTEMS VALIDATION PLAN

                             DOCUMENT NUMBER: CLR00X
                                  RELEASE: 0.2
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER        DATE          AUTHOR       DESCRIPTION
------   -------------   -----------   ---------------
<S>      <C>             <C>           <C>
0.1      June 15, 2006   Scott         Initial version
                         Jacka/Pete
                         Gelbman
0.2      June 21, 2006   Scott Jacka   Joint updates
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                           <C>
1. INTRODUCTION ...........................................................    5

2. VALIDATION TEST PLATFORM REQUIREMENTS ..................................    5
   2.1. Test Platform Configurations ......................................    5
   2.2. Network Configuration .............................................    6
   2.3. Network Test Tools - Chariot ......................................    6

3. SOFTWARE VERIFICATION INTERFACE REQUIREMENTS ...........................    6
   3.1. RF performance metrics (BS/SS) ....................................    6
   3.2. Frame counters and modulation class statistics (BS/SS) ............    6
   3.3. System and session status/reports (BS) ............................    7
   3.4. Radio Resource Control (BS) .......................................    7
   3.5. Radio/Antenna hardware control (BS) ...............................    7
   3.6. Power Control and Link Adaptation (BS) ............................    7
   3.7. Test data (BS/SS) .................................................    7
   3.8. Data logging (BS) .................................................    7
   3.9. Processor and Memory Status (BS/SS) ...............................    8
   3.10. Test Client Requirement ..........................................    8
4. CWG AND SPWG 802.16E PROTOCOL AND PROFILE REQUIREMENTS .................    8

5. ASN TESTING ............................................................    8
   5.1. ASN-GW failover ...................................................    9
   5.2. ASN-GW under load .................................................    9
   5.3. General Testing ...................................................    9

6. SECURITY VALIDATION ....................................................    9

7. NETWORK IP VALIDATION ..................................................    9

8. PHY/RF TESTS ...........................................................    9
   8.1. RF Testing Overview ...............................................    9
   8.2. Hardware RF Performance ...........................................   10
      8.2.1. Transmitter ..................................................   10
      8.2.2. Receiver .....................................................   10
   8.3. Mobility/Fading Tests .............................................   10
   8.4. WiMAX Wave 2 PHY Validation .......................................   10
      8.4.1. Calibration Tests ............................................   10
      8.4.2. Maximum Ratio Combining ......................................   10
      8.4.3. MIMO Processing/Multiplexing .................................   11
      8.4.4. AAS Spatial Processing .......................................   11
   8.5. Additional RF Requirements ........................................   11
      8.5.1. Interference Rejection .......................................   11
9. MAC VALIDATION (LAB TESTING, CABLED RF) ................................   11
   9.1. Resource Allocation/QoS ...........................................   11
   9.2. Oversubscription ..................................................   11
   9.3. Transmission Latency ..............................................   11
10. MANAGEMENT VERIFICATION ...............................................   12
   10.1. Command Line Interface ...........................................   12
   10.2. SNMP MIB .........................................................   12
</TABLE>


                                                                               3

<PAGE>

<TABLE>
<S>                                                                           <C>
   10.3. Alarm Traps ......................................................   12
   10.4. Exception Testing ................................................   12
</TABLE>


                                                                               4

<PAGE>

1.   INTRODUCTION

System Validation testing will be conducted in a controlled lab environment
prior to, and in parallel with, the radiated field testing. The testing in the
laboratory environment is intended to occur over a conducted airlink. Laboratory
testing will be used to establish that the system meets minimum performance
criteria before the commencement of more complex and involved radiated field
testing. The laboratory environment can also be used for problem replication of
field issues where applicable.

The system validation stage is also intended to allow for Clearwire to become
familiar with the hardware, software, and operational requirements of the WiMAX
platform. As new hardware and software releases are introduced the laboratory
environment this allows for a controlled exercise of the network and its
elements. Major issues encountered during the laboratory validation should be
resolved prior to the introduction of the software into the radiated Alpha field
trial system.

Many of the test scenarios in this document are capable of being executed in the
Motorola or Clearwire test labs and network. More detailed work to complete the
scope and requirements of the testing and where it is appropriate to complete
the test program. Any, or all, of the test cases outline may be satisfied
through the existing Motorola test program subject to review by Clearwire.
Clearwire believes that it is critical that the performance metrics outlined in
Section 3 of this document be supported in the platform, [***]

2.   VALIDATION TEST PLATFORM REQUIREMENTS

A large scale laboratory test bed will be created that will constantly exercise
the ASN, BS, and SS capabilities in controlled environment. This testing will
include a mix of data traffic types, VoIP traffic, airlink conditions, and
management traffic.

These test beds shall be available for the purposes of the test cases called out
in the remainder of the document.

     2.1. TEST PLATFORM CONFIGURATIONS

[***] test beds are being requested at this time in order to support the
project.

They are described as follows:

[***]

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                                                                               5

<PAGE>

Each test bed should contain a mixture of SS variants that will be deployed into
the Clearwire network. The exact type of SS for each test bed will be determined
at a later date. Five SS and one BTS sector worth of spare parts should also be
provided.

     2.2. NETWORK CONFIGURATION

(TBD) Basically all basic network infrastructure required; switches, routers,
      etc

     2.3. NETWORK TEST TOOLS - CHARIOT


In order to concentrate on the RF system performance alone, a test tool called
[***] that allows a tester to emulate and model a wide variety or end-to-end
application layer traffic across the radio network while avoiding the logistical
nightmares associated with executing such large scale tests with real
client/server network infrastructure.


[***]

3.   SOFTWARE VERIFICATION INTERFACE REQUIREMENTS

System integration and validation testing requires significant software support
for test interfaces, functions and reporting. The following sections describe
the software test requirements for both BS and SS.

     3.1. RF PERFORMANCE METRICS (BS/SS)

The following radio measurements are required for both [***]

[***]

     3.2. FRAME COUNTERS AND MODULATION CLASS STATISTICS (BS/SS)

[***]

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                                                                               6

<PAGE>

[***]

     3.3. SYSTEM AND SESSION STATUS/REPORTS (BS)

[***]

     3.4. RADIO RESOURCE CONTROL (BS)

[***]

     3.5. RADIO/ANTENNA HARDWARE CONTROL (BS)

[***]

     3.6. POWER CONTROL AND LINK ADAPTATION (BS)

[***]

     3.7. TEST DATA (BS/SS)

The BS/SS should have some method of generating continuous test data in a
fashion representative of end-user data sessions.[***]

     3.8. DATA LOGGING (BS)

During development and debug and later validation phases it is [***]

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                                                                               7

<PAGE>

     3.9. PROCESSOR AND MEMORY STATUS (BS/SS)

The processor utilization, at a per task level, and memory consumption for each
processor task should be [***]

     3.10. CAPC TEST TOOL REQUIREMENT

It is required that a software test tool be included in the test program which,
at a minimum, has the following capabilities:

[***]

     This tool will be maintained by Motorola and the testing program will be
     subject to review by Clearwire.

4.   CWG AND SPWG 802.16E PROTOCOL AND PROFILE REQUIREMENTS

The work of the WiMAX Certification Working Group (CWG) is considered within the
scope of the lab phase of qualification testing. The work of the CWG is still in
draft form and the applicable document is the "Test Suite Structure and test
Purposes (TSS&TP) for testing the Interoperability between WiMAX devices in
WiMAX Forum Plugfest #3". The work of the CWG team will continue to be monitored
and it is expected that the provided WiMAX platform will be able to successfully
pass all applicable tests.

The WiMAX Service Providers Working Group (SPWG) is creating a set of
requirements for certified WiMAX products. The output of this work will provide
additional guidance into the required performance of the delivered WiMAX
solution. The work of the SPWG is captured in the "Recommendations and
Requirements for Network based on WiMAX Forum Certified Products". This document
is still in draft form at this time.

5.   ASN TESTING

All interfaces and functionality of ASN-GW and BS interoperation must be
validated in accordance with the requirements of their individual WiMAX and
vendor specifications.

The following are performance tests that will be exercised in controlled lab
environment.

It should be noted that the ASN testing requirements were drafted without
considering the existing Motorola CAPC architecture. Therefore the specific test
cases in this section will be modified, but the generic failover scenarios will
apply. Actual test cases to be updated pending further discussions between
Motorola and Clearwire. Please reference the ASN notes section in the ASN
appendix document.

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<PAGE>

     5.1. ASN-GW FAILOVER

Verify the following when an ASN-GW fails (for instance loss of power):

[***]

     5.2. ASN-GW UNDER LOAD

Generate load on the ASN. Ideally get it [***] an 'Internet' mix of packet
sizes.

[***]

     5.3. GENERAL TESTING

[***]

6.   SECURITY VALIDATION

Validate complete WiMAX end-2-end IP assignment flow [***]

7.   NETWORK IP VALIDATION

Validate complete WiMAX end-2-end IP assignment flow [***]

8.   PHY/RF TESTS

     8.1. RF TESTING, OVERVIEW

RF testing is accomplished in [***] phases:

     [***] This typically means testing the radio channels in a cabled lab
     environment with [***]

     [***] This is the next level of RF testing, where channel conditions such
     [***] as they are in a real world wireless environment. This exercises the
     radio system's full functionality and [***]

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<PAGE>

     [***]

     8.2. HARDWARE RF PERFORMANCE

Prior to radiated testing the BS/SS hardware must meet established RF
performance specifications. Detailed specs will be derived from WiMAX Mobility
and Certification Profiles, as well as vendor specifications. The following
items are representative of the basic radio hardware performance criteria areas
that will be tested:

          8.2.1. TRANSMITTER

     [***]

          8.2.2 RECEIVER

     [***]

     8.3  SYSTEM

     [***]

     8.4. WIMAX WAVE 2 PHY VALIDATION

The following sections outline lab tests to be performed in a conducted cabled
RF environment to validate the [***]

          8.4.1. CALIBRATION TESTS

     [***]

          8.4.2. MAXIMUM RATIO COMBINING

     [***]

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<PAGE>

          8.4.3. MIMO PROCESSING/MULTIPLEXING

     (TBD)

          8.4.4. AAS SPATIAL PROCESSING

     [***]

     8.5. ADDITIONAL RF REQUIREMENTS

          8.5.1. INTERFERENCE REJECTION

     [***]

9.   MAC VALIDATION (LAB TESTING, CABLED RF)

The performance of the MAC is [***] to the overall success of the deployed WiMAX
solution. It is important to stress the MAC is [***] The testing related to the
MAC is specified in this section.

     9.1. RESOURCE ALLOCATION/QOS

Measure performance with multiple SS utilizing the same channel resources for
data transmission. At maximum load, users should [***]

[***]

     9.2. OVERSUBSCRIPTION

Measure performance with multiple SS utilizing the same channel resources for
data transmission [***]

     9.3. TRANSMISSION LATENCY

Verify performance of uplink and downlink transmission latency for various
packet sizes under [***]

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<PAGE>

10.  MANAGEMENT VERIFICATION

     10.1. COMMAND LINE INTERFACE

Verify that the command line functions within provided guidelines and that the
level of debugging and troubleshooting interfaces is sufficient.

     10.2. SNMP MIB

Verify that the SNMP MIB can compile and that the MIB is functional and provides
sufficient information to operate and maintain the network.

     10.3. ALARM TRAPS

Verify that the equipment generates alarms and SNMP traps in accordance with the
manufacturer specifications.

     10.4. EXCEPTION TESTING

Verify that when interface cables are removed that the system performs as
anticipated. Verify that given the failure of one sector that the remaining
sectors continue to process traffic normally.


                                                                              12

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 6

                          WIMAX CERTIFICATION PROFILES

                             DOCUMENT NUMBER: CLR00X
                                  RELEASE: 0.2
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER        DATE          AUTHOR                    DESCRIPTION
------   -------------   ------------   --------------------------------------
<S>      <C>             <C>            <C>
0.1      June 14, 2006   David Holmes   Initial version
0.2      June 21, 2006   Scott Jacka    Updates from the joint review session.
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                            <C>
1. FREQUENCY BANDS & CHANNEL SPACING .......................................   4

2. OTHER PHYSICAL LAYER PARAMETERS .........................................   4

3. CERTIFICATION PROFILE REQUIREMENTS ......................................   4

   3.1. Certification profile features .....................................   4
   3.2. Exceptions .........................................................   4
</TABLE>


                                                                               3

<PAGE>

1.   FREQUENCY BANDS & CHANNEL SPACING

WIMAX BANDCLASS: [***]
FREQUENCY COVERAGE: 2496-2680MHz
CHANNEL RASTER: [***]

CHANNEL BANDWIDTHS:
- 5MHz (512 FFT, 5.6MHz sample rate),
-  10MHz (1024 FFT, 11.2MHz sample rate).

Note: This does not include requirements for international roaming (e.g.
Clearwire US to Clearwire Europe).

2.   OTHER PHYSICAL LAYER PARAMETERS

[***]

3.   CERTIFICATION PROFILE REQUIREMENTS

Due to the developmental nature of the WiMAX Mobile Certification profiles at
this time (June 2006), these are included by reference in this appendix.
Specific versions to be used for certification of products covered by this
contract will be agreed between Clearwire & XYZCo as they are approved by the
WiMAX Forum. Exceptions to the agreed WiMAX profiles are (or will be) as noted
below.

     3.1. CERTIFICATION PROFILE FEATURES

Refer to "WiMAX Forum6:41:59 PM(TM) Mobile Certification Waves System Profile
Features" v1.0.0. 04/06 as applicable (i.e. to base stations). This may be found
at http://www.wimaxforum.org/apps/org/workgroup/211ghz/download.php/7281
/WiMAX%20Forum%20System%20Profile%20Certification%20Wave%20Recommendation%20XX
%20xxx%20xxx%2Ov1.0.0.pdf.

     3.2. EXCEPTIONS

No exceptions are noted at this time.

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<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 7

                                     MOTOWI4
                                   WMX1.0/2.0
                       DIVERSITY ACCESS POINT (DAP)/ CAPC

                         PRELIMINARY PRODUCT DESCRIPTION
INFORMATION CONTAINED WITHIN THIS PRELIMINARY PRODUCT DESCRIPTION IS SUBJECT TO
                                     CHANGE

[ ]  Initial Draft                      Version: 1.2

[ ]  Working Draft                      Date: 2006-06-2

[ ]  Pilot

[ ]  Released

[X]  Revision to Released

THIS SCHEDULE SETS FORTH INFRASTRUCTURE PRODUCTS AND TECHNICAL SPECIFICATIONS
THEREFOR WHICH CLEARWIRE DESIRES TO PURCHASE. ONCE MUTUALLY AGREED UPON BY THE
PARTIES, THIS SCHEDULE WILL BE AMENDED ACCORDINGLY AND MOTOROLA WILL AGREE TO
DELIVER INFRASTRUCTURE PRODUCTS IN ACCORDANCE WITH THE SPECIFICATIONS AND
FEATURES DESCRIBED IN SUCH AMENDED SCHEDULE. MOTOROLA AND CLEARWIRE WILL USE
COMMERCIALLY REASONABLE EFFORTS TO ACHIEVE THE OBJECTIVES STATED IN THIS
SCHEDULE BY THE DATES SPECIFIED IN EXHIBIT "B" OR ELSEWHERE IN THIS AGREEMENT,
INCLUDING IDENTIFYING THOSE PROVISIONS OF THIS SCHEDULE THE BREACH OF WHICH WILL
BE MUTUALLY AGREED UPON TO CONSTITUTE A MATERIAL BREACH FOR PURPOSES OF SECTION
2.3.4 OF THIS AGREEMENT.

                        Motorola Confidential Proprietary
                    Preliminary DAP/CAPC Product Description
                          Document is subject to change

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<S>                                                                           <C>
1. Introduction ...........................................................    4
   1.1 Broadband Wireless Access ..........................................    4
   1.2 MotoWi4 based on 802.16e ...........................................    4

2. Diversity Access Point (DAP) ...........................................    6
   2.1 Base Control Unit (BCU) ............................................    7
      2.1.1 Site Controller ...............................................    7
      2.1.2 Modem .........................................................    7
      2.1.3 Alarm/IO ......................................................    8
      2.1.4 Medium Stability Oscillator ...................................    8
      2.1.5 Power Supply ..................................................    8
      2.1.6 Fans ..........................................................    8
      2.1.7 Backplane .....................................................    8
      2.1.8 Surge Protector ...............................................    9
   2.2 Diversity RF Module ................................................    9
   2.3 DAP Redundancy .....................................................   10
   2.4 DAP Capacity .......................................................   11
   2.5 Interfaces .........................................................   12
      2.5.1 Physical Interfaces ...........................................   12
      2.5.2 Logical Interfaces ............................................   12
   2.6 Summary Spec Sheet .................................................   12

3 DAP in a Distributed Network Architecture ...............................   14

4 Network Implementation ..................................................   15
   4.1 Wimax Forum Defined Architecture ...................................   15
   4.2 Mapping of Motorola Architecture to the Wimax Reference
       Architecture .......................................................   18
   4.3 CAPC Details .......................................................   19
      4.3.1 CAPC platform .................................................   20
      4.3.2 CAPC Redundancy ...............................................   21
      4.3.3 CAPC Capacity .................................................   21
      4.3.4 CAPC Interfaces ...............................................   21
   4.4 QoS ................................................................   22
   4.5 Security ...........................................................   22

5 Feature Set .............................................................   23
   5.1 IMS based features and services ....................................   24

6 Backhaul ................................................................   25

7 Standards Compliance ....................................................   26

Appendix A - Abbreviations ................................................   28
</TABLE>

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<PAGE>

                                TABLE OF FIGURES

<TABLE>
<S>                                                                           <C>
Figure 1: DAP view ........................................................    7
Figure 2: BCU Layout ......................................................    8
Figure 3: DAP RF Integrated Module ........................................    9
Figure 4: Diversity Access Point Architecture .............................   10
Figure 5: Wimax Distributed Architecture ..................................   14
Figure 6: Wimax Forum Network Reference Architecture ......................   16
Figure 7: Motorola's implementation of the Wimax Architecture .............   17
Figure 8: ASN Decomposition ...............................................   19
Figure 9: CAPC Platform ...................................................   21
</TABLE>

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1    INTRODUCTION

1.1  Broadband Wireless Access

Networks including wireless and wireline are converging towards mobile broadband
allowing for greater mobility providing user experience similar to what a user
would have in an office LAN environment. The technology that offers both
mobility and broadband wireless access is the 802.16e based Wimax technology
offering significant benefits over other technologies.

Wimax networks are geared to support deployments that range from fixed to
nomadic to fully mobile solutions. Motorola provides an end to end solution
combining it's Wimax products with commercial off the shelf equipment for either
a fixed or mobile solution.

1.2  MotoWi4 based on 802.16e

Motorola is already a leader in Broadband Wireless Access through the Canopy(TM)
product line, a low cost solution primarily used for unlicensed fixed
applications. Governments (municipalities) and enterprises use Canopy for voice,
video and data backhaul, while many carriers use Canopy for Wireless Internet
service, primarily in rural and developing areas. Canopy's excellent RF
interference rejection characteristics make it an ideal solution for unlicensed
bands at 900MHz, 2.4GHz, and 5.2 to 5.7GHz. Motorola's first Wimax product Ultra
Light Access Point leverages heavily on the success of the canopy product line
and offers a Wimax 802.16e based solution for early fixed deployments.

Motorola decided to adopt the 802.16e specification after carefully weighing the
benefits of 802.16e over 802.16d. There are significant benefits in using
802.16e over 802.16d even for fixed deployments. These benefits are listed
below.

[***]

The "MotoWi4" is an umbrella marketing term encompassing Motorola Wimax products
addressing the broadband wireless access including both fixed and mobile
segments. The following segments are the target markets for MotoWi4 solutions.

[***]

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[***]

The product line includes the Ultra Light Access Point (ULAP), Diversity Access
Point (DAP), a range of Subscriber Devices - portable and mobile handset
solutions, and multi-mode terminals to support other 2G/3G cellular technologies
simultaneously, and other supporting network elements such as the CAPC. This
document focuses on the DAP in light of "Mobile" broadband wireless access.

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                                                                               6


2    DIVERSITY ACCESS POINT (DAP)

Diversity Access Point provides an operator the capability to provide fully
mobile broadband wireless access coverage similar to coverage provided by 2G and
3G low speed cellular data networks. This document covers in detail the DAP
product itself in addition to providing some high level details on network
implementation utilizing DAPs to provide service to end users.

Fully compliant to the IEEE 802.16e specification the DAP solution has the
following features

[***]

Figure 1 shows the layout of the DAP. As shown the DAP consists of two major
subsystems: the base control unit (BCU) and the RF sections or heads (one per
sector). The BCU cabinet resides at the bottom of the antenna tower containing
hot-pluggable slots for up to two site controllers and up to four modem boards.
It also contains an Alarm/IO board, fans, and the power distribution system for
the entire site. The Diversity Access Point has a 2-antenna RF section that is a
single self-contained field replaceable unit (FRU).

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                              (FIGURE 1: DAP VIEW)

The DAP major subsystems are further broken down into specific modules.

2.1  Base Control Unit (BCU)

The following modules are part of the BCU as illustrated in Figure 2:

2.1.1 SITE CONTROLLER

[***]

2.1.2 MODEM

[***]

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                             (FIGURE 2: BCU LAYOUT)

2.1.3 ALARM/IO

[***]

2.1.4 MEDIUM STABILITY OSCILLATOR

[***]

2.1.5 POWER SUPPLY

[***]

2.1.6 FANS

[***]

2.1.7 BACKPLANE

[***]

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2.1.8 SURGE PROTECTOR

[***]

2.2  Diversity RF Module

[***]

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[***]

2.3  DAP Redundancy

Motorola's M0T0Wi4 products are designed to achieve high availability and can be
configured to support redundancy options.

[***]

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[***]

2.4  DAP Capacity

The DAP RF capacity will vary significantly based on the terrain where the DAP
is deployed and the subscriber density. The table below shows some sample values
for throughput and range for the DAP based on the following assumptions.

     -    Capacity Driven Scenario

[***]

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                                      [***]

                              Table 1: DAP Capacity

The DAP is designed to support up to [***] users (combination of active, idle,
and sleeping users) with up to [***] active users per sector.

2.5  Interfaces

2.5.1 Physical Interfaces

The over the air interface between the DAP and the subscriber device (CPE, MSS,
PCMCIA, etc.) is per the 802.16e specification. The air interface covers both
the physical and the MAC layers. The DAP provides an RJ-45 port for connectivity
to the network allowing for the base stations to connect to a layer 2 backbone
enabling faster handoff times.

2.5.2 Logical Interfaces

The DAP base stations form a part of the [***] (please refer to Section 4 for
details). As shown in Figure 6, the interfaces that are considered to be
external to the [***] are the [***] and [***] interfaces as defined by the Wimax
forum. Per Wimax forum stage 2 definition, the [***] interface is defined to
consist of the set of control plane protocols between the [***] and the [***] to
support [***]policy enforcement and mobility management capabilities. It also
encompasses the bearer plane methods (e.g., tunneling) to transfer user data
between the [***] and the [***]. The [***] interface consists of the set of
control and bearer plane protocols originating/terminating in various functional
entities of an [***] that coordinate [***] mobility between [***] and [***]

2.6  Summary Spec Sheet

Table 2 summarizes the preliminary set of specifications of the Diversity Access
Point.

Air Interface

[***]

Duplex Mode

[***]

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[***]

                           Table 2: DAP Specifications

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                                                                              14


3    DAP IN A DISTRIBUTED NETWORK ARCHITECTURE

[***]

                    Figure 5: Wimax Distributed Architecture

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                                                                              15


4 NETWORK IMPLEMENTATION

4.1  Wimax Forum Defined Architecture

The Wimax forum (http://www.wimaxforum.org) defines the reference architecture
for solutions utilizing Wimax products providing full mobility similar to
today's cellular network deployments. The reference architecture also defines
the interface between the different logical entities [***]

Figure 6 below shows the definition of the Wimax forum defined reference
architecture followed by Figure 7 showing a representation of Motorola
embodiment of the reference architecture.

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             (FIGURE 6: WIMAX FORUM NETWORK REFERENCE ARCHITECTURE)

[***]

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         (FIGURE 7: MOTOROLA'S IMPLEMENTATION OF THE WIMAX ARCHITECTURE)


[***]


          Figure 7: Motorola's implementation of the Wimax Architecture

A brief description of the various entities is provided below.

[***]

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[***]

4.2  Mapping of Motorola Architecture to the Wimax Reference Architecture

[***]

The [***] and [***] interfaces as shown in Figure 8 below are considered to be
Motorola internal interfaces with only the [***] and [***] interface exposed for
interoperability with other vendor equipment. Connectivity to the [***] as well
as [***] domains is done over the [***] interfaces.

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                                                                              19


[***]

4.3  CAPC Details

The [***] as shown in Figure 8 contains [***] divided into two parts called the
[***] shown below.

[***]

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4.3.1 CAPC PLATFORM

[***]

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                            (FIGURE 9: CAPC PLATFORM)

4.3.2 CAPC REDUNDANCY

[***]

4.3.3 CAPC CAPACITY

[***]

4.3.4 CAPC INTERFACES

[***]

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[***]

4.4  QOS

The 802.16e specification defines a set of scheduling classes at the MAC level
that making a range of services possible. The five classes that are spelled out
in the 802.16e specification and supported by Motorola are UGS, rtPS, ertPS,
nrtPS, and BE enabling realtime as well as non-realtime services. 802.16e
definition, however, is not enough to satisfy the end to end QoS implementation.
Motorola's solution provides an end to end capable QoS framework.

Each user is provisioned with a set of service flows which map to different
services that are offered. For example, VoIP and best effort data services may
be defined as two distinct service flows for a user with each service flow being
associated with QoS related parameters including the 802.16e defined scheduling
class, DiffServ CodePoint (DSCP), minimum and maximum data rates, etc. These
parameters are utilized at different points in the network providing proper
handling of the service flow.

4.5  SECURITY

[***]

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5    FEATURE SET

The following is a list of high level features that are supported as part of the
Motorola Wi4 architecture

[***]

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[***]

5.1  IMS based features and services

The Motorola Wimax when combined with the Motorola IMS solution can provide a
compelling array of features and services. These services may include, but are
not limited to the following.

     -    VoIP

     -    Seamless Mobility (WiFi/Cellular)

     -    Seamless Mobility (Common Service Profile)

     -    Presence

     -    Common Address Book

     -    Location

     -    Video Call Video Streaming (Advertising, TV, VOD, etc.)

     -    Audio Streaming (Advertising, Radio, MOD, etc.)

     -    Audio/Video File Download

     -    Machine to Machine Solutions (e.g., Vending Machines)

     -    Prepaid Push To X (Talk, View, Video)

     -    Instant Messaging (Picture or Video Component)

     -    Instant Voice Message

     -    Unified Messaging

     -    Text Messaging (Alerts, Notifications)

     -    Conferencing (Audio/Video)

     -    Find Me/Follow Me

     -    Multi-Player Gaming

     -    IVR

     -    Ring Back Tones

     -    Splatt

The standard interface between the IMS domain and the Wimax network is being
defined within the Wimax Forum and Motorola will comply with the specification
when it becomes available. The connectivity is possible already using standard
IP connectivity.

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                                                                              25


6    BACKHAUL

Motorola's DAP and CAPC can be connected to an operator's existing network
through L2 as connectivity from the DAP and the CAPC can be provided using
Ethernet. Motorola's Wimax products are being tested against multiple vendors'
L2 and L3 equipment to ensure interoperability. Motorola can work with
greenfield operators in case they need help setting up an end to end network.

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                                                                              26


7    STANDARDS COMPLIANCE

Motorola's proposal is based on the IEEE 802.16e (2005) specification; thus
conformant to an international standard. In addition, the Wimax Forum has
defined an architecture based on the 802.16e specification that allows for
standardized interfaces between different network elements which Motorola
complies with. Motorola is a principal member of the Wimax forum actively
participating in working groups defining profiles that vendors must support for
compliance.

Interoperability with third party infrastructure and CPE will be assured through
Wimax certification and interoperability testing. Motorola will go through the
certification process and will ensure that its products meet the
interoperability criteria set forth by the Wimax forum. Prior to Wimax
certification Motorola has plans to conduct thorough product testing for all its
Wimax products for interoperability with each other. Some of this verification
will also be done as part of our forthcoming customer trials.

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APPENDIX A - ABBREVIATIONS

<TABLE>
<S>      <C>
2G       2nd Generation
3G       3rd Generation
AAA      Authorization, Authentication, Accounting.
AEMS     Advanced EMS
A-GPS    Assisted GPS
AP       Access Point
ASN      Access Service Network
ASN-GW   ASN-gateway
BCU      Base Control Unit
BEMS     Basic EMS
BTS      Base Transceiver Station
CAPC     Carrier Access Point Controller
CGL      Carrier Grade Linux
CPE      Customer Premise Equipment
CPRI     Common Public Radio Interface
CSN      Core Service Network
DAP      Diversity Access Point
DC       Direct Current
DL       Downlink
DSCP     Diffserv Code Point
DSP      Digital Signal Processor
EAP      Extensible Authentication Protocol
EIRP     Effective Isotropic Radiated Power
EMS      Element Management System
FRU      Field Replaceable Unit
GHz      Gigahertz
GPS      Global Positioning System
I/O      Input/output
IDS      Intrusion Detection System
IMS      Internet Multimedia System
IP       Internet Protocol
IPSec    IP Security
IPv6     IP Version 6
IVR      Interactive Voice Response
LAN      Local Area Network
MAC      Media Access Control
MBS      Multicast Broadcast Service
MHz      Megahertz
MIMO     Multiple Input Multiple Output
MIP      Mobile IP
MOD      Music On Demand
MSO      Medium Stability Oscillator
MSS      Mobile Subscriber Station
OFDMA    Orthogonal Frequency Division Multiple Access
PHS      Payload Header Suppression
PHY      Physical
PTT      Push to Talk
PUSC     Partial Usage Subchannelization
QAM      Quadrature Amplitude Modulation
QoS      Quality of Service
QPSK     Quadrature Phase Shift Keying
</TABLE>

                        Motorola Confidential Proprietary
                    Preliminary DAP/CAPC Product Description
                          Document is subject to change

<PAGE>

                                                                              29


<TABLE>
<S>      <C>
RF       Radio Frequency
RoHC     Robust Header Compression
SNMP     Simple Network Management Protocol
TDD      Time Division Duplex
TLS      Transport Layer Security
TRX      Transceiver
UL       Uplink
ULAP     Ultra Light Access Point
VAC      Volts Alternating Current
VDC      Volts Direct Current
VOD      Video On Demand
VoIP     Voice Over Ip.
VPN      Virtual Private Network
WiFi     Wireless Fidelity
WIMAX    Worldwide Interoperability for Microwave Access
</TABLE>

                        Motorola Confidential Proprietary
                    Preliminary DAP/CAPC Product Description
                          Document is subject to change

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 8

                           WIMAX ALPHA FIELD TEST PLAN

                             DOCUMENT NUMBER: CLR00X
                                  RELEASE: 0.2
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1


<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER        DATE            AUTHOR              DESCRIPTION
------   -------------   ----------------   ----------------------
<S>      <C>             <C>                <C>
0.1      June 15, 2006   Scott Jacka/Pete   Initial version
                         Gelbman
0.2      June 21, 2006   Pete Gelbman       Joint CW/MOT edits for
                                            clarification
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                           <C>
1.    INTRODUCTION.........................................................    4
2.    CELL SITE REQUIREMENTS...............................................    4
   2.1.    Cell Site Preparation...........................................    5
3.    PRELIMINARY EQUIPMENT REQUIREMENTS...................................    5
4.    SERVICE PROVIDERS WORKING GROUP (SPWG)...............................    5
5.    RF CONFIGURATION.....................................................    5
6.    EQUIPMENT INSTALLATION...............................................    5
7.    NETWORK TRAFFIC GENERATION/MEASURERMENT..............................    5
8.    RF COVERAGE VERIFICATION.............................................    6
9.    WIFI CO-EXISTENCE TEST...............................................    6
10.   MOBILITY/HANDOVER....................................................    6
   10.1.   Performance at Mobile rates.....................................    6
   10.2.   OFDMA Uplink SER/ICI under load, under motion...................    6
   10.3.   Handover........................................................    7
11.   VOIP.................................................................    8
12.   THROUGHPUT TEST......................................................    8
13.   NEXTNET EXPEDIENCE CO-EXISTENCE......................................    9
14.   DETAILED SYSTEM PERFORMANCE TESTS....................................    9
   14.1.   Throughput/Capacity Tests.......................................    9
      14,1.1.   Maximum User Data Rate.....................................    9
      14.1.2.   Sector Data Rate...........................................    9
      14.1.3.   Sector Edge Boundary Data Rate.............................    9
   14.2.   MAC Performance.................................................   10
   14.3.   Coverage Tests..................................................   10
   14.4.   Mobility/Handover...............................................   10
</TABLE>


                                                                               3

<PAGE>

1.   INTRODUCTION

This document describes a basic field network configuration required to perform
field test measurements and validation of a WiMAX system. This document does not
provide test procedures or detailed software/hardware configuration parameters -
it is meant to provide only a high-level overview of basic network
configuration issues and test methodology, sufficient to guide and initiate
future detailed planning phases.

The initial radiated trial systems will consist of [***]. The four sites
selected should be located in close geographic/coverage proximity in order to
allow for the simulation of various real-world deployment scenarios. WiMAX
system performance will be characterized through a variety of throughput,
range, mobility, and capacity oriented tests, across a range of noise and
interference limited scenarios to simulate commercial deployment conditions.

Formal criteria for the testing in this plan are under development. A formal
go/no-go meeting should be scheduled between the vendor at Clearwire at the end
of the testing process to review any outstanding issues and ensure that an
appropriate action plan is in place to address documented problems.

NOTE: It is understood that performance requirements specified in this document
are can only be met under the overall requirements provided by Wavel/Wave2
802.16e/WiMAX specs.

NOTE: Clearwire has requirements for WiMAX system to support both 5 and 10 MHz
RF channel BW, For early prototype equipment Motorola BS support [***].

NOTE: Due to NOTE above, this means in order to facilitate Expedience vs.
Motorola WiMAX comparisons, obviously both systems needs to support [***] in
field trial timeframe.

NOTE: Both Clearwire & Motorola need to jointly agree on resource requirements
(staff, equipment, etc) in order to execute this test plan.

2.   CELL SITE REQUIREMENTS

[***]

[*** Confidential Treatment Requested]


                                                                               4

<PAGE>

     2.1  CELL SITE PREPARATION

     -    RF Spectrum survey to ensure the spectrum used by BS/CPE equipment is
          free and clear of external interference.

     -    Identification and verification of SS/CPE locations and drive routes

3.   PRELIMINARY EQUIPMENT REQUIREMENTS

The preliminary list of equipment required for the four radiated site is
described as follows:

     [***]

     [***] and based upon equipment availability; In addition to the above
     equipment, one full BS site and 10 spare SS/MS should be provided.

4.   SERVICE PROVIDERS WORKING GROUP (SPWG)

The WiMAX Service Providers Working Group (SPWG) is creating a set of
requirements for certified WiMAX products. The output of this work will provide
additional guidance into the required performance of the delivered WiMAX
solution. The work of the SPWG is captured in the "Recommendations and
Requirements for Network based on WiMAX Forum Certified Products". This document
is still in draft form at this time.

5.   RF CONFIGURATION

As a part of the trial the WiMAX solution will be evaluated using the [***]

6.   EQUIPMENT INSTALLATION

It is important that the delivered WiMAX solution does not require an overly
complex and burdensome installation procedure. It will be verified that the
system is easy to install in accordance with the manufacturer specified
recommendations.

7.   NETWORK TRAFFIC GENERATION/MEASUREMENT

All testing will be end-to-end TCP/IP network traffic using [***]

[*** Confidential Treatment Requested]


                                                                               5

<PAGE>

8.   RF COVERAGE VERIFICATION


RF Coverage drive testing will be performed using the provided RF drive test
tools. This purpose of this testing is to directly compare the coverage of the
[***] to ensure that an appropriate network planning infrastructure is in place.
[ref drive test tool notes from WiMAX ICD doc].


9.   WIFI CO-EXISTENCE TEST

Each of an [***] Both the test units and the aceess points will be on a standard
height desktop.

WiFi access points will be placed [***] from the access point.

This test will then be repeated with an [***]

Note: Antenna configuration options and specifications will need to be
re-visited and validated prior to the implementation of this test. There are
recognized equipment variances that should be considered in order to make this
an apples-to-apples comparison.

10.  MOBILITY/HANDOVER

     10.1. PERFORMANCE AT MOBILE RATES

Measure performance degradation at various mobility rates in various system
configurations.

     10.2. OFDMA UPLINK SER/ICI UNDER LOAD, UNDER MOTION

[***]

[*** Confidential Treatment Requested]


                                                                               6

<PAGE>

     10.3. HANDOVER

Perform drive testing using a single SS and verify that the units will handover
in accordance with the published specifications of the SPWG forum in the
"Recommendations and Requirements for Networks based on WiMAX Forum Certified
Products".

[***]

[*** Confidential Treatment Requested]


                                                                               7

<PAGE>

11.  VOIP

System must support [***] decrease of total aggregate BS capacity. The [***] for
all call scenarios.

12.  THROUGHPUT TEST

Throughput testing will be performed in a number of scenarios and traffic types
to ensure system integrity is maintained in a dynamic real world environment.

In general the performance of the WiMAX solution is expected to be at least
equivalent and hopefully better in "user bits" throughput, as measured in Mbps
for both the uplink and downlink channels.

The first test scenario is as follows:

     [***]

The second test scenario is as follows:

     [***]

The third test scenario is as follows:

     [***]

[*** Confidential Treatment Requested]


                                                                               8

<PAGE>

     [***]

The remaining testing scenarios repeat the scenarios listed above, but with a
[***]

13.  NEXTNET EXPEDIENCE CO-EXISTENCE

It is anticipated that the NextNet Expedience and the provided WiMAX solution
will be [***]. Any impairment detected will need to be mitigated in order to
successfully transition Clearwire markets.

14.  DETAILED SYSTEM PERFORMANCE TESTS


The following sections provide a preliminary list of tests that will be further
developed. All tests will be performed under various BTS and channel
configurations as supported by the Motorola platform. Example of this would be
[***] required for the Clearwire network.


     14.1. THROUGHPUT/CAPACITY TESTS

          14.1.1. MAXIMUM USER DATA RATE

[***]

          14.1.2. SECTOR DATA RATE

[***]

          14.1.3. SECTOR EDGE BOUNDARY DATA RATE

[***]


[*** Confidential Treatment Requested]

                                                                               9

<PAGE>

     14.2. MAC PERFORMANCE

[***]

     14.3. COVERAGE TESTS

[***]

     14.4. MOBILITY/HANDOVER

[***]

[*** Confidential Treatment Requested]


                                                                              10

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 9

                           WIMAX BETA MARKET TEST PLAN

                             DOCUMENT NUMBER: CLR00X
                                  RELEASE: 0.3
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described In such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER   DATE            AUTHOR         DESCRIPTION
------   ----            ------         -----------
<S>      <C>             <C>            <C>
0.1      June 15, 2006   Scott Jacka    Initial version
0.2      June 16, 2006   JS
0.3      June 21, 2006   Pete Gelbman   Joint CS/MOT edits for clarification
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                          <C>
1.   INTRODUCTION.........................................................    4
   1.1   Preliminary [***] Site Equipment Requirements....................    4
   1.2   Service Providers Working Group (SPWG)...........................    5
   1.3   Beta Test Process and Exit Criteria..............................    5
   1.4   RF Configuration.................................................    5
   1.5   RF Coverage Verification.........................................    6
   1.6   Handover Performance.............................................    6
   1.7   Throughput Test..................................................    6
</TABLE>

[*** Confidential Treatment Requested]


                                                                               3

<PAGE>

1.   INTRODUCTION

The WiMAX beta system will consist of [***] sites. The [***] sites selected
should be located in close geographic/coverage proximity and allow for
verification in diverse RF conditions.

Formal criteria for the testing in this plan are under development. The purpose
of this system is to allow clearwire to work out deployment issues of a WiMAX
network in a [***] and to perform some benchmark testing of the WiMAX network
under reasonable subscriber loads.

A formal go/no-go meeting should be scheduled between the vendor and Clearwire
at the end of the testing process to review outstanding issues and ensure that
an appropriate action plan is in place to address documented problems.

NOTE: It is understood that performance requirements specified in this document
are can only be met under the overall requirements provided by Wavel/Wave2
802.16e/WiMAX specs.

NOTE: Clearwire has requirements for WiMAX system to support both 5 and 10 MHz
RF channel BW. For early prototype equipment Motorola BS support [***]

NOTE: Due to NOTE above, this means in order to facilitate Expedience vs.
Motorola WiMAX comparisons, obviously both systems needs to support [***]

NOTE: Both Clearwire & Motorola need to jointly agree on resource requirements
(staff, equipment, etc) in order to execute this test plan.

     1.1 PRELIMINARY [***] SITE EQUIPMENT REQUIREMENTS

The preliminary list of equipment required for the radiated sites is described
as follows:

     -    [***] fully populated 3 and 4 sector BS sites and associated hardware.

     -    Minimum [***] SS/MS SISO units to kickstart NRT/ORT tests

This should include a mixture of MS/SS variants once it has been determined what
equipment types will be deployed into the Clearwire network and based upon
equipment availability. In addition to the above equipment, two full BS site and
fifty spare SS/MS should be provided.

The Beta test will start using [***]

[*** Confidential Treatment Requested]


                                                                               4

<PAGE>

     1.2 SERVICE PROVIDERS WORKING GROUP (SPWG)

The WiMAX Service Providers Working Group (SPWG) is creating a set of
requirements for certified WiMAX products. The output of this work will provide
additional guidance into the required performance of the delivered WiMAX
solution. The work of the SPWG is captured in the "Recommendations and
Requirements for Network based on WiMAX Forum Certified Products". This document
is still in draft form at this time.

     1.3 BETA TEST PROCESS AND EXIT CRITERIA

In order for the Beta test to be considered successful the final measured
performance results should be within 10% of the mutually defined and agreed upon
test plan and criteria. The test criteria will be jointly defined between
Clearwire and the WiMAX vendor. The detail test plan will be agreed upon between
parties involved in this agreement with the purpose of establishing that the
WiMAX network is ready for commercial deployment.

Areas to be considered as a part of the Beta exit criteria are as follows:

[***]

Clearwire will jointly conduct the tests, along with the WiMAX equipment vendor.
Unacceptable test results will be repeated until performance objectives are met.
Remediation of test failures is the responsibility of the infrastructure vendor.

All tests performed should collect a statistically relevant number of samples
and under similar test conditions as prior stages of testing.

Latency for the purposes of this test plan is defined as the round trip time
from the subscriber unit to a single defined point in the Clearwire network.
This will be measured in all cases and should not be greater that the NextNet
expedience platform.

Tests have been defined at stages prior to this set of tests such that system
performance issues may be detected and remediated as early as possible in the
schedule.

     1.4 RF CONFIGURATION

As an early stage of the trial process the WiMAX network will be evaluated using
various [***] scenarios.

[*** Confidential Treatment Requested]


                                                                               5

<PAGE>

     1.5 RF COVERAGE VERIFICATION

RF Coverage drive testing will be performed using the vendor provided RF drive
test tools with minimum capabilities as specified in the ICD. This purpose of
this testing is to directly compare the coverage of the WiMAX system against the
predicted model to ensure that an appropriate network planning infrastructure is
in place.

The RF coverage validation should be performed for both the [***] ons after the
bulk of the system has been built our in order to measure the coverage and
Interference of the WiMAX network.

     1.6 HANDOVER PERFORMANCE

Perform drive testing using a single MS and verify that the units will handover
within the [***] site coverage area in accordance with the published
specifications of the SPWG forum in the "Recommendations and Requirements for
Networks based on WiMAX Forum Certified Products".

     1.7 THROUGHPUT TEST

Throughput testing will be performed in a number of scenarios and traffic types
to ensure system integrity is maintained in a dynamic real world environment.

The performance of the Wave 1 mobile WiMAX solution is expected to perform equal
to or better in "user bits" throughput as measured in Mbps for both the uplink
and downlink channels.

The first test scenario is as follows:

[***]

The second test scenario is as follows:

[***]

[*** Confidential Treatment Requested]


                                                                               6

<PAGE>


The third test scenario is as follows:

[***]

The fourth test scenario is as follows:

[***]

The fifth test scenario is as follows:

[***]

The sixth test scenario is as follows:

[***]

The seventh test scenario is as follows:

[*** Confidential Treatment Requested]


                                                                               7

<PAGE>

[***]

The eighth test scenario is as follows:

[***]

The ninth test scenario is as follows:

[***]

[*** Confidential Treatment Requested]


                                                                               8

<PAGE>

                            INFRASTRUCTURE AGREEMENT

                                    EXHIBIT B

                                   SCHEDULE 10

                             WIMAX WAVE-2 TEST PLAN

                             DOCUMENT NUMBER: CLR00X
                                  RELEASE: 0.3
                                   JUNE, 2006

This Schedule sets forth Infrastructure Products and technical specifications
therefor which Clearwire desires to purchase. Once mutually agreed upon by the
parties, this Schedule will be amended accordingly and Motorola will agree to
deliver Infrastructure Products in accordance with the specifications and
features described in such amended Schedule. Motorola and Clearwire will use
commercially reasonable efforts to achieve the objectives stated in this
Schedule by the dates specified in Exhibit "B" or elsewhere in this Agreement,
including identifying those provisions of this Schedule the breach of which will
be mutually agreed upon to constitute a material breach for purposes of Section
2.3.4 of this Agreement.


                                                                               1

<PAGE>

DOCUMENT HISTORY

<TABLE>
<CAPTION>
NUMBER   DATE            AUTHOR         DESCRIPTION
------   ----            ------         -----------
<S>      <C>             <C>            <C>
0.1      June 15, 2006   Scott Jacka    Initial version
0.2      Jun 17          JS
0.3      June 21, 2006   Pete Gelbman   Joint CW/MOT edits for clarification.
</TABLE>


                                                                               2

<PAGE>

CONTENTS

<TABLE>
<S>                                                                          <C>
1.    INTRODUCTION........................................................    4
   1.0   Preliminary [***] Site Equipment Requirements....................    4
   1.1   Service Providers Working Group (SPWG)...........................    4
   1.2   Wave-2 Test Process and Exit Criteria............................    5
   1.3   RF Configuration.................................................    5
   1.4   RF Coverage Verification.........................................    6
   1.5   Handover Performance.............................................    6
   1.6   Throughput Test..................................................    6
   1.7   Beta Network Tests & Expected Performance Over Time..............    8
</TABLE>

[*** Confidential Treatment Requested]


                                                                               3

<PAGE>

1. INTRODUCTION

The WiMAX Wave 2 system will consist of [***] sites. The [***] sites selected
should be located in close geographic/coverage proximity and allow for
verification in diverse RF conditions.

Formal criteria for the testing in this plan are under development. The purpose
of this system is to allow the vendor and Clearwire to find tune the WiMAX
system and optimize the network in preparation for larger system qualification
testing.

A formal go/no-go meeting should be scheduled between the vendor and Clearwire
at the end of the testing process to review outstanding issues and ensure that
an appropriate action plan is in place to address documented problems.

NOTE: It is understood that performance requirements specified in this document
are can only be met under the overall requirements provided by Wave1/Wave2
802.16e/WiMAX specs.

NOTE: Clearwire has requirements for WiMAX system to support both 5 and 10 MHz
RF channel BW. For early prototype equipment Motorola BS support [***]

NOTE: Due to NOTE above, this means in order to facilitate Expedience vs.
Motorola WiMAX comparisons, obviously both systems needs to support [***] in
field trial time frame.

NOTE: Both Clearwire & Motorola need to jointly agree on resource requirements
(staff, equipment, etc) in order to execute this test plan.

     1.0 PRELIMINARY [***] SITE EQUIPMENT REQUIREMENTS

The preliminary list of equipment required for the four radiated site is
described as follows:

     -    [***] fully populated three or four sector BS sites and associated
          Wave 2 hardware.

     -    Minimum [***] SS/MS SISO Wave 2 units

This should include a mixture of MS/SS variants once it has been determined what
equipment types will be deployed into the Clearwire network and based upon
equipment availability. In addition to the above equipment, two full BS site and
fifty spare SS/MS should be provided.

The provided system should be Wave 2 capable/compliant (TBD).

     1.1 SERVICE PROVIDERS WORKING GROUP (SPWG)

The WiMAX Service Providers Working Group (SPWG) is creating a set of
requirements for certified WiMAX products. The output of this work will provide

[*** Confidential Treatment Requested]


                                                                               4

<PAGE>

additional guidance into the required performance of the delivered WiMAX
solution. The work of the SPWG is captured in the "Recommendations and
Requirements for Network based on WiMAX Forum Certified Products". This document
is still in draft form at this time.

     1.2 WAVE-2 TEST PROCESS AND EXIT CRITERIA

In order for the Wave-2 test to be considered successful the final measured
performance results should be within 10% of the mutually defined and agreed upon
test plan and criteria. The test criteria will be jointly defined between
Clearwire and the WiMAX vendor. The detail test plan will be agreed upon between
parties involved in this agreement with the purpose of establishing that the
WiMAX network is ready for commercial deployment.

Areas to be considered as a part of the Wave-2 exit criteria are as follows:

[***]

Clearwire will jointly conduct the tests, along with the WiMAX equipment vendor.
Unacceptable test results will be repeated until performance objectives are met.
Remediation of test failures is the responsibility of the infrastructure vendor.

All tests performed should collect a statistically relevant number of samples
and under similar test conditions as prior stages of testing.

Latency for the purposes of this test plan is defined as the round trip time
from the subscriber unit to a single defined point in the Clearwire network.
This will be measured in all cases and should not be greater that the NextNet
expedience platform.

Tests have been defined at stages prior to this set of tests such that system
performance issues may be detected and remediated as early as possible in the
schedule.

     1.3 RF CONFIGURATION

As an early stage of the trial process the WiMAX network will be evaluated using
various [***] scenarios.

[*** Confidential Treatment Requested]


                                                                               5

<PAGE>

     1.4 RF COVERAGE VERIFICATION

RF Coverage drive testing will be performed using the vendor provided RF drive
test tools with minimum capabilities as specified in the ICD. This purpose of
this testing is to directly compare the coverage of the WiMAX system against the
predicted model to ensure that an appropriate network planning infrastructure is
in place.

The Wave-2 testing will also [***]

The RF coverage validation should be performed for both the [***] options after
the bulk of the system has been built out in order to measure the coverage and
interference of the WiMAX network.

     1.5 HANDOVER PERFORMANCE

Perform drive testing using a single MS and verify that the units will handover
within the [***] site coverage area in accordance with the published
specifications of the SPWG forum in the "Recommendations and Requirements for
Networks based on WiMAX Forum Certified Products".

     1.6 THROUGHPUT TEST

Throughput testing will be performed in a number of scenarios and traffic types
to ensure system integrity is maintained in a dynamic real world environment.

The performance of the Wave 2 mobile WiMAX solution is expected to perform as
described below both the uplink and downlink channels.

The first test scenario is as follows:

[***]

The second test scenario is as follows:

[***]

The third test scenario is as follows:

[*** Confidential Treatment Requested]


                                                                               6

<PAGE>

                                      [***]

The fourth test scenario is as follows:

                                      [***]

The fifth test scenario is as follows:

                                      [***]

The sixth test scenario is as follows:

                                      [***]

[*** Confidential Treatment Requested]


                                                                               7

<PAGE>

                                      [***]

The seventh test scenario is as follows:

                                      [***]

The eighth test scenario is as follows:

                                     [***]

The ninth test scenario is as follows:

     1.7 BETA NETWORK TESTS & EXPECTED PERFORMANCE OVER TIME

No later than [***] after successful completion of the first Wave 2 tests as
defined above, we will [***] the above mentioned tests. It is expected that with

[*** Confidential Treatment Requested]


                                                                               8

<PAGE>

additional time for network optimization and equipment fixes, the overall
spectral efficiency of the beta network will deliver [***] given a mix of
traffic, devices and services on a loaded network when compared to an [***]

[*** Confidential Treatment Requested]


                                                                               9

<PAGE>

                                   EXHIBIT "C"

                        TO THE WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

                            SOFTWARE LICENSE AND FEES

For purposes of uniformity and brevity, references to Agreement or to an Exhibit
shall refer to the Infrastructure Agreement to which this document is Exhibit
"C" and to the other Exhibits to that Agreement, except as otherwise stated
herein. All definitions set forth in the Agreement shall apply hereto except as
otherwise expressly defined herein.

1.   DEFINITIONS

Annual Software License (ASL). The Annual Software License contains the
right-to-use the Operating System Software (O/SS) and all Standard Features for
the applicable period purchased. This license also contains the right to receive
all Software-Release Upgrades available during the applicable period.

Annual Software License Fee. This license fee is charged [***] and is renewable
[***] the initial purchase of the ASL requires Clearwire to make a [***]
commitment. This license fee does not cover the use of any Optional Features.
This license fee does cover the use of Software on expansion equipment
associated with specific Network Elements for the relevant period.

Features. Features include Optional Features and Standard Features.

Initial Program Load (IPL). The Initial Program Load contains the Operating
System Software (O/SS) and the Standard Features of the current Software Release
at the time the initial System Configuration is provided to Clearwire.

Initial License Fee (ILF). The Initial License Fee is the License Fee for
perpetual use of the O/SS, and all Standard Features included in the IPL
received. This fee does not cover the use of any Optional Features. This fee
also does not cover the use of Software on expansion equipment associated with
Network Elements. For expansion equipment associated with Network Elements,
additional Initial License Fees are due in order to license the use of Software
on that expansion equipment.

License Fee. License Fee means the fee paid by Clearwire for the right to use
Software in accordance with the terms of this Exhibit.

Network Elements. Network Elements refer to the network Infrastructure
components. Network Elements may be either manufactured or supplied by Motorola
or by third parties.

Network Features. Network Features allow specialized communication between any
Network Elements.

Operating System Software (O/SS). The O/SS brings the hardware platform to a
state of readiness that allows Standard and Optional Features to run.

Operational Features. Operational Features improve the overall non-call
performance of the network. Non-call performance includes increased call
quality, increased availability and decreased cost of ownership. Examples of
Operational Features include Billing Features, CAMP Terminal Expansions,
Interference Cancellation, and Multiple Alarm Expansions.

Optional Features. Optional Features provide incremental functionality beyond
the Standard Features and require the purchase of individual feature licenses.
Optional Feature categories include Subscriber Features, Network Features and
Operational Features.

[*** Confidential Treatment Requested]


                                       C-1

<PAGE>

Software. Software is any computer program in object code form, including the
O/SS, the Features and any other computer program, whole or partial copies of a
computer program, adaptations, derivative works, modifications, translations,
updates or enhancements of all or part of a computer program, documentation
associated with a computer program, and the techniques and ideas embodied and
expressed in a computer program (including but not limited to the structure,
sequence and organization of a computer program.) A computer program comprising
Software under this Agreement is in any medium (including but not limited to all
types of permanent or semi-permanent memory or storage devices, in hardwired
logic instructions, or in any electronic medium), that is furnished directly or
indirectly by Motorola to Clearwire, or, to the extent permitted under this
Agreement is a Clearwire's copy, adaptation, derivative work, modification,
translation, update or enhancement of a computer program furnished directly or
indirectly by Motorola to Clearwire. The computer programs comprising Software
may be used solely in conjunction with the System Configuration. NOTWITHSTANDING
THE FOREGOING, THE TERM SOFTWARE SHALL NOT INCLUDE THIRD PARTY COMPUTER PROGRAMS
PROVIDED UNDER SEPARATE LICENSE AGREEMENTS SUCH AS SHRINK-WRAP LICENSE
AGREEMENTS, OR THIRD PARTY COMPUTER PROGRAMS NOT LICENSABLE UNDER THE TERMS OF
THIS AGREEMENT, SUCH AS THIRD PARTY COMPUTER PROGRAMS PROVIDED UNDER THE FREE
SOFTWARE FOUNDATION'S GENERAL PUBLIC LICENSE. Any reference herein to Software
being "sold" or "purchased" shall in fact be deemed to be a reference to
Software being "licensed."

Software Release. A Software Release is a new version of Software that contains
new Standard Features, O/SS upgrades, and those Optional Features that have been
licensed separately and individually by Clearwire.

Standard Features. Standard Features are included in the current Software
Release at no additional charge. Included in the Standard Features is the Call
Processing functionality that allows the Network Elements to operate as a
wireless communications system.

Subscriber Features. Subscriber Features are those that can either be offered on
a per-subscriber or per-traffic channel basis and/or which are apparent as
features to the subscriber. Examples of Subscriber Features include Caller
Preview Service, Message Waiting Notification and Authentication.

System Configuration. System Configuration means the combination of Software and
Network Elements installed in the System for which the most recent License Fees
due under the terms of this Agreement have been paid by Clearwire. (For the
purposes of this definition, a Network Element does not include that expansion
equipment associated with such Network Elements if such expansion equipment has
not yet been installed.)

2.   LICENSE GRANT

2.1 Concurrent with the execution of the Infrastructure Agreement and payment of
applicable License Fees hereunder, Motorola grants to Clearwire a non-exclusive
license under applicable copyrights and trade secret rights to use Software in
connection with the System Configuration. This license, if perpetual (based on
payment of the ILF), shall be revocable by Motorola only pursuant to the
provisions of Section 6.2 of this Agreement. This license is non-transferable
and non-sublicenseable, except as expressly permitted by this Agreement. The
term "use" means to load, execute, store or display the Software as part of the
System Configuration, for the purpose of operating or maintaining the System.
The term "maintain" means performing diagnostic and testing functions necessary
to fulfill its obligation to provide first eschelon diagnosis under the Software
warranty, and to sustain the operation of the System following termination or
expiration of this Agreement.

2.2 The following License Fees for the use of Software on the initial System
Configuration are set forth in Exhibit "A" of the Agreement (i) ILF or ASL; and
(ii) License Fees for specified Optional Features.


                                       C-2

<PAGE>

2.3 Changes to System Configuration and/or additional use of existing Software
(by Network Elements or subscribers) may require payment of additional License
Fees. Examples of changes to System Configuration and/or additional Software
uses include, but are not limited to, the following:

     (i)  use of additional Optional Features;

     (ii) increased capacity of Optional Features;

     (iii) increased call processing capacity;

     (iv) expansion of Network Elements (e.g. increase in the number of trunk
          shelves);

     (v)  addition of Network Elements.

3.   LIMITATIONS ON USE OF SOFTWARE

3.1 The Software may contain Confidential Information of Motorola or its
licensors. Clearwire agrees to keep confidential, in accordance with the terms
of the Agreement, and not use, provide or otherwise make available in any form
any Software or its contents, or any portion thereof, to any third party, except
as an integrated component of Infrastructure Products that are delivered to
System subscribers.

3.2 Clearwire shall not translate, modify, merge, adapt, de-compile,
disassemble, or reverse engineer the Software or any portion thereof.

3.3 In the event of subsequent sale of Network Elements by Clearwire, Clearwire
shall not transfer the Software for such Network Elements. Any purchaser of the
Network Elements must obtain a Software license from Motorola. Motorola's
granting of such license shall be within the sole discretion of Motorola and its
licensors, who shall not unreasonably withhold consent to entering into such
license. In the event that Clearwire wishes to sell Network Elements, (i)
Clearwire shall notify Motorola in writing prior to any such sale of the
identity of the purchaser and the Network Elements to be sold, (ii) Clearwire
shall notify the purchaser in writing that a license agreement with Motorola is
required for the use of the Software on such Network Elements, and (iii) the
purchaser shall enter into a license agreement with Motorola for such Software
prior to delivery of the Network Elements to the purchaser by Clearwire.

4.   RIGHT TO COPY, PROTECTION AND SECURITY

4.1 Software provided hereunder may be copied (for back-up purposes only) in
whole or in part, in machine-readable form for Clearwire's internal use only,
provided, however, that no more than two (2) printed copies and two (2)
machine-readable copies will be in existence at any one time without the prior
written consent of Motorola, other than copies resident in the System
Configuration.

4.2 With reference to any copyright notice of Motorola associated with Software,
Clearwire agrees to include the same on all copies it makes in whole or in part.
Motorola's copyright notice may appear in any of several forms, including
machine-readable form. Use of a copyright notice on the Software does not imply
that such has been published or otherwise made generally available to the
public.

4.3 Software and any copy of Software is the sole and exclusive property of
Motorola or its licensors and no title or ownership rights to the Software or
any of its parts is transferred to Clearwire.

5.   REMEDIES

Clearwire acknowledges that violation of the terms of this Exhibit or the
Agreement may cause Motorola irreparable harm for which monetary damages may be
inadequate, and Clearwire agrees that Motorola may seek temporary or permanent
injunctive relief without the need to prove actual harm in order to protect
Motorola's interests.


                                       C-3

<PAGE>

6.   TERMINATION

6.1 Any license granted hereunder may be terminated by Clearwire upon one (1)
month's prior written notice.

6.2 Motorola may revoke any license granted hereunder if Clearwire is in
material default of Section 3 of this Agreement, and such revocation shall be
effective if Clearwire fails to correct such default within ninety (90) days
after written notice thereof by Motorola.

6.3 Within one (1) month after termination or revocation of any license,
Clearwire shall furnish to Motorola a document certifying, through its best
efforts and to the best of its knowledge, the original and all copies in whole
or in part of all Software, in any form, including any copy in an updated work,
have been returned to Motorola or destroyed.

7.   LICENSEE RIGHTS

7.1 Nothing contained herein shall be deemed to grant either directly or by
implication, estoppel, or otherwise, any license under any patents or patent
applications of Motorola or Motorola's licensors, except where an license may
arise by operation of law, and only to the extent that such license is necessary
to operate the System.

7.2 Clearwire acknowledges that the provisions of this Exhibit are intended to
inure to the benefit of Motorola and its licensors. Clearwire acknowledges that
Motorola or its licensors have the right to enforce these provisions against
Clearwire, whether in Motorola's or its licensor's name.

7.3 Motorola MAY PROVIDE TO Clearwire UNDER THE ORIGINAL LICENSOR'S LICENSE
CERTAIN THIRD PARTY COMPUTER PROGRAMS NOT LICENSABLE UNDER THE TERMS OF THIS
AGREEMENT, SUCH AS THIRD PARTY COMPUTER PROGRAMS PROVIDED AS OPEN SOURCE
SOFTWARE PROGRAMS SUBJECT TO PUBLIC LICENSES (GENERALLY ALLOWING FREE
DISTRIBUTION AND ACCESS TO SOURCE CODE) DISTRIBUTED ON A FREE BASIS BY A NUMBER
OF SOFTWARE ORGANIZATIONS SUCH AS, BUT NOT LIMITED TO, CERTAIN UNIVERSITIES,
NOT-FOR-PROFIT COMPANIES, CORPORATIONS, FOUNDATIONS, INDIVIDUALS, THE OPEN
SOURCE INITIATIVE AND THE FREE SOFTWARE FOUNDATION ("FREEWARE PROGRAMS'). THE
FREEWARE PROGRAMS ARE SUBJECT TO THE TERMS AND CONDITIONS OF THE ORIGINAL
LICENSOR'S LICENSE AND THE AGREEMENT. THEY ARE ONLY LICENSED UNDER AND TO THE
EXTENT ALLOWED BY THE ORIGINAL LICENSOR'S LICENSE, BUT ARE NOT SUBJECT TO THE
TERMS AND CONDITIONS OF THIS EXHIBIT.

IF REQUESTED BY Clearwire, (i) SUCH FREEWARE PROGRAMS SHALL BE IDENTIFIED BY
Motorola, USING COMMERCIALLY REASONABLE EFFORTS AND (ii) FOR A PERIOD OF THREE
YEARS AFTER RECEIPT OF SUCH FREEWARE PROGRAMS, A COPY OF THE ORIGINAL LICENSOR'S
PUBLIC LICENSE AND A FREE COPY OF THE SOURCE CODE OF SUCH FREEWARE PROGRAMS IN
MACHINE-READABLE FORM SHALL BE PROVIDED BY Motorola (ALTHOUGH DISTRIBUTION FEES
MAY BE APPLICABLE).

8.   SOFTWARE FEES AND CHARGES

8.1 Charges for the ILF or ASL are billed when the equipment (including
expansion equipment) on which the Software resides is invoiced, with payment due
30 days from the invoice date.

8.2 Charges for Optional Features are invoiced upon installation of the Optional
Features, with payment due 30 days from the invoice date.


                                       C-4

<PAGE>

9.   ENTIRE UNDERSTANDING

Notwithstanding anything to the contrary in other agreements, purchase orders or
order acknowledgments, the Infrastructure Agreement and this Exhibit set forth
the entire understanding and obligations regarding use of Software, implied or
expressed.


                                       C-5

<PAGE>

                                   EXHIBIT "D"

                                     TO THE
                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

                             NETWORK SUPPORT PROGRAM

For purposes of uniformity and brevity, references to Agreement or to an Exhibit
shall refer to that Services Agreement to which this document is Exhibit - and
to the other Exhibits to that Agreement, except as otherwise stated herein. This
Agreement covers technical support and software maintenance programs.

1.0  DEFINITIONS. All definitions set forth in the Services Agreement shall
     apply hereto, except as otherwise expressly defined herein, and all such
     defined terms will be capitalized throughout this Exhibit and shall be read
     in the singular, plural or the tense as the context requires.

<TABLE>
<S>                  <C>
CLEARWIRE NETWORK    means Motorola's Clearwire support centre which shall serve
RESOLUTION CENTRE    Clearwire from a location notified by Motorola to
("CNRC")             Clearwire.

CLEARWIRE SERVICE    means the telephone support operation in place to enable
Desk                 Clearwire to solicit help with technical issues.

FIELD REPLACEABLE    means a distinctly separate component that has been
UNIT("FRU")          designed so that it may be exchanged at its site of use for
                     the purpose of maintenance or service adjustment. An
                     example of an FRU is a plug-in circuit board. In some
                     instances, a field replaceable unit may contain other field
                     replaceable units, for example, a circuit board or power
                     supply.

FIX AVAILABLE        Applies to Service Requests with associated Product Change
                     Requests. The release containing the fix to the problem
                     documented in the Product Change Request is available for
                     Clearwire to order.

FIX DEFERRED         Used where Clearwire does not want Motorola to provide a
                     patch or tape but would prefer that the repair be released
                     in a future release. In such cases Clearwire is to provide
                     Motorola with a waiver not to claim Motorola's support for
                     new events caused due to the lack of the patch or fix.

MANAGEMENT REPORTS   means the reports to be prepared and presented by Motorola
                     in accordance with the NSP Specification.

NON PRODUCT CHANGE   A system problem or query that can be resolved without the
                     need for a change to the product to effect a final solution
                     E.g. changes to parameter settings or configurations,
                     general technical questions, questions regarding documented
                     procedures.

PRODUCT CHANGE       A system problem that can only be resolved with a change to
                     the product E.g. software fixes or documentation errors.

NSP PROGRAM          means the Network Support Program, which includes 7x24
                     technical support and software maintenance.

NSP SPECIFICATION    Shall mean the detailed description of the Support Services
                     described and set forth in Appendix A to this Exhibit
</TABLE>


                                       D-1

<PAGE>

<TABLE>
<S>                  <C>
PREMISES             means each of the locations comprising the Network,
                     including the location that houses the System.

GRADE OF Service     With respect to the delivery of the Support Services in any
(GOS)                Year, GoS means the standard of performance actually
                     achieved by Motorola in providing the NSP Specification in
                     that Year (calculated and expressed as a ratio and set out
                     in the NSP Specification).

RECOVERY             means the implementation of a temporary solution to
                     immediately restore the System to a default condition.

RECOVERY TIME        means the elapsed time between receiving first escalation
                     call from Clearwire and achieving Recovery.

RESOLVED             A resolution for the problem has been presented to
                     Clearwire and the CNRC is awaiting confirmation that the
                     resolution was successful.

RESOLUTION TIME      means the elapsed time between being granted access to the
                     network (either remotely or, where required by Motorola, on
                     arrival on-site) and making available to Clearwire a patch
                     or software release that resolves the problem. Resolution
                     time for Product Change is measured to "fix available",
                     "resolved not fixed" or "fix deferred". Resolution time for
                     Non-Product Change is measured to "Resolution" status.

RESPONSE TIME        means the elapsed time between the Clearwire Service Desk
                     acknowledges receipt of a Clearwire request for assistance
                     and the time work is commenced on the request, during
                     Clearwire's coverage hours, as described in the NSP
                     Specification.

SUPPORT FEES         means the total net sum for the Support Services, net of
                     all purchase tax, Value Added Tax and all other similar
                     governmental charges which shall be additional thereto.

SUPPORT SERVICES     means those Motorola functions as set forth in this Exhibit
                     "D", including, but not limited to, ongoing support,
                     technical advice, resolution of identified problems,
                     provision of technical bulletins, and software updates to
                     provide consolidated bug fixes and such other functions as
                     may be more fully described in this Exhibit "D". Support
                     Services exclude post warranty hardware repairs.

WORKAROUND           means short term temporary fix or recommended action
                     provided in order to prevent the reoccurrence of a
                     Clearwire issue.

YEAR                 means any successive period of 12 calendar months measured
                     from the Effective Date.
</TABLE>

2.0  SCOPE

     2.1  This Exhibit is for the purpose of defining the Network Support
          Program and the conditions applicable to the provision of the Support
          Services to be provided by Motorola and/or its authorised affiliates
          and subcontractors, which has the objective of supporting the
          performance of the System.

     2.2  The NSP covers equipment manufactured or supplied through Motorola and
          software supplied by Motorola, both integrated into the Network and
          accepted into live service by Clearwire.

     2.3  The Warranty coverage will be provided during the warranty period as
          defined in the Agreement. This NSP or similar program commences when
          warraty coverage ends.


                                       D-2

<PAGE>

3.0  SERVICE LEVELS

     Where any Support Service is stated in the NSP Specification to be subject
     to a specific Service Level, Motorola shall provide that Support Service in
     such a manner as to ensure that the Grade of Service with respect to that
     Service is equal to or higher than such specific Service Level, as follows:

     3.1  First Line maintenance - First Line Maintenance is defined as the day
          to day monitoring and maintenance of the communications system using
          procedures outlined in the Documentation and available under one of
          the Motorola provided technical training courses. This would include,
          but not be limited to (i) accurate diagnosis, identification and
          isolation of FNE malfunctions to the FRU level, (ii) removal and
          replacement of faulty FRU's, (iii) carrying out preventative
          maintenance activities, and (iv) sending the malfunctioning product,
          packed in a manner to prevent damage, to the Motorola designated
          repair depot.

     3.2  Second Line Maintenance - Second Line Maintenance is defined as the
          investigation of system level faults that cannot be resolved under
          First Line Maintenance. Resolution for system level problems/issues is
          falls under Second Line Maintenance where a change of the Software is
          not required. Where a change in the Software is required (a product
          change), Second Line Maintenance is limited to investigation, data
          gathering and fault analysis.

     3.3  Third Line Maintenance - Third Line Maintenance is defined as the
          techniques and procedures used to resolve issues/problems which cannot
          be resolved using First Line Maintenance or Second Line Maintenance
          techniques, and includes the provision of Hardware repair or
          replacement services. These problems typically require a product
          change to resolve. Hardware repair also comes under third line
          support.

4.0  SOFTWARE MAINTENANCE AND TECHNICAL SUPPORT

     4.1  Motorola will offer optional Software Maintenance Program, providing
          CNRC support and bug fixes for the current and immediately preceding
          Software Release.

     4.2  Prices for new Software releases with no increase in features or
          functionality are included in this program; new feature releases and
          increased Software capabilities are separately offered and charged.
          The price for Software Maintenance Program is contained in Exhibit
          "A".

5.0  GENERAL

     5.1  Services will be provided strictly in accordance with the NSP
          Specification. Any amendment, modification or expansion of the
          responsibilities set forth in the Specification will be subject to the
          written agreement of the parties.

     5.2  Motorola reserves the right to subcontract, in whole or in part,
          Support Services. The subcontractors must be certified by Motorola.

     5.3  All Motorola personnel providing onsite services as part of this
          Exhibit will be under the direct control of Motorola and at all time
          are considered Motorola employees. Motorola will be liable for any
          damages caused by Motorola personnel or subcontractors operating on a
          Clearwire Network or within a Clearwire facility.


                                       D-3

<PAGE>

6.0  OBLIGATIONS OF MOTOROLA

     6.1  Motorola will:

          6.1.1 Deliver the Support Services to Clearwire in accordance with the
               obligations, Service Levels and conditions of the NSP
               Specification or other Service provided, such as Software
               Maintenance Services or extended Hardware Maintenance Services,
               but subject to the provisions of this Exhibit;

          6.1.2 Ensure that its employees, agents and sub-contractors comply
               with all of Clearwire's reasonable requests, directions or
               regulations made known to Motorola or its employees, agents or
               sub-contractors in relation to the safety and security of
               Clearwire's Premises, property or personnel; and

          6.1.3 Monitor hardware failures and identify any fault trends
               indicating a potential hardware design fault. Motorola shall
               deliver to Clearwire electronically a monthly report in an agreed
               format that summarizes all field returns, root cause analyses and
               paretos of all fault trends identified.

          6.1.4 If Motorola is unable to resolve an issue through immediate
               telephone assistance, Motorola will provide Clearwire with a
               Response Time and Resolution Time in accordance with the detailed
               criteria and Service Levels set forth in the NSP Specification.

7.0  CLEARWIRE RESPONSIBILITIES

     7.1  Subject to any provision of the NSP Specification to the contrary, and
          depending on the Service taken, Clearwire will:

          7.1.1 Be responsible for the first level of maintenance, including but
               not limited to diagnosis and (i) identification and isolation of
               Equipment malfunctions to the FRU level and reproducible software
               malfunctions; (ii) hardware, firmware and software, removal and
               replacement, (iii) isolation of reproducible Software
               malfunctions, and (iv) sending the malfunctioning product, packed
               in a manner to prevent damage, to the Motorola designated repair
               depot, provided, however, that such first level of maintenance
               shall be required only to the extent Clearwire can reasonably be
               expected to perform given its Documentation and the training
               available to Clearwire's personnel. Motorola will provide
               Clearwire with any reasonably requested aid in performing such
               diagnosis, provided Motorola may charge for such aid if it
               constitutes first echelon diagnosis that is Clearwire's
               responsibility. In the event of Software malfunction, Clearwire
               will notify Motorola promptly of the failure through the
               Clearwire Service Desk, followed by written confirmation of such
               notice. Motorola will acknowledge receipt of notice of verified
               Software malfunctions.

          7.1.2 All escalations and communications with the Motorola CNRC will
               be conducted through the Clearwire Network Operations Center
               (NOC) and/or Clearwire Engineering.

          7.1.3 Supply the requested data in a timely manner as required by
               Motorola. The time during which data is not available, for any
               reason whatsoever that is not within Motorola's sole control,
               will not be included in any calculation of timescales or service
               levels set out in this Exhibit.

          7.1.4 If, having no internal closure policy, agree with Motorola the
               following policy regarding the closure of Service Requests: If no
               response has been received


                                       D-4

<PAGE>

               after seventy two (72) hours following a request from Motorola,
               then Motorola shall contact Clearwire and request closure of the
               relevant Service Request. If no response is received after a
               further seventy two (72) hours, Motorola shall be entitled to
               close the relevant Service Request.

          7.1.5 Bear the costs of its own telephone and utility charges and
               other services and items being supplied by Clearwire under this
               Exhibit.

          7.1.6 Make the payments according to the schedule set forth in Clause
               10 of this Exhibit.

          7.1.7 Perform all other of its obligations set out in this Exhibit and
               Appendices attached hereto.

          7.1.8 Appoint a System Manager for the System and supply Motorola with
               the name, address and telephone number of the System Manager. The
               System Manager is responsible for coordination with Motorola
               personnel and will, at the option of the Clearwire System
               Manager, make available a Clearwire Representative during
               Motorola performance of Support Services.

          7.1.9 [RESERVED]

          7.1.10 Provide reasonable facilities including, but not limited to,
               secure storage space, a designated workspace with adequate
               temperature control and light, and use of all System and
               communications facilities, including access to a telephone line.

          7.1.11 Supervise and perform all normal day-to-day System operational
               activities.

          7.1.12 Perform System restarts or other maintenance or
               trouble-shooting activity as directed by the Documentation prior
               to initiating a service call for any System problem, unless
               previously instructed otherwise by a Motorola representative.

          7.1.13 Assist and cooperate with Motorola in the diagnosis of
               reproducible Software malfunctions and provide such information
               as may be reasonably requested by remote and local personnel as
               they provide technical supervision and support to Clearwire's
               maintenance technicians.

          7.1.14 Furnish, maintain and repair equipment, products and services
               supplied by:

               7.1.14.1 Vendors other than Motorola; and

               7.1.14.2 Vendors of mobile and/or other portable subscriber
                    units.

          7.1.15 Supervise, manage and control its use of the Software,
               including, but not limited to:

               7.1.15.1 Assuring proper machine configuration, program
                    installation, audit controls and operating methods;

               7.1.15.2 Implementing adequate backup plans, based on alternate
                    procedures to diagnose, patch and repair Software defects in
                    the event of a Software malfunction; and

               7.1.15.3 Implementing sufficient procedures and checkpoints to
                    satisfy Clearwire's requirements for security and accuracy
                    of input and


                                       D-5

<PAGE>

                    output. Such procedures and checkpoints will be provided to
                    and followed by Motorola.

          7.1.16 Perform and comply with all available Motorola maintenance
               procedures covering all routine system administration and
               maintenance tasks which Clearwire will be required to perform on
               a regular basis in order to ensure the integrity of operation of
               the System. To the extent that such procedures need to be
               developed, they shall be mutually agreed to by Clearwire and
               Motorola.

          7.1.17 Clearwire will allow persons duly authorised by Motorola such
               access to the Premises as is reasonably required for the purpose
               of providing the Support Services. Authorisation procedures will
               be agreed upon by Clearwire and Motorola from time to time.
               Motorola will use such rights of access for the purpose of
               providing the Support Services only. Motorola's right of access
               will end upon termination of this Exhibit

          7.1.18 Any delays associated with the performance of any of
               Clearwire's obligations shall serve to extend any time periods
               within which Motorola is obliged to carry out its
               responsibilities and obligations hereunder.

          7.1.19 For Priority 1 cases, Clearwire must support Motorola with
               appropriate on-site resources to support system Recovery.

8.0  PRIORITY CLASSIFICATION FOR SUPPORT DELIVERY

     8.1  In order to classify the urgency to be attributed to a problem
          Motorola will classify the each Service Request as a priority P-1
          through to P-4 according to the following guidelines:

     8.2  Motorola Service Request Designators and Definitions:

          8.2.1 PRIORITY 1 (P1) Critical (Target Recovery Time: 24 hours from
               time of escalation)-This is the maximum level of urgency assigned
               to Service Requests based on one or more of the following
               conditions:

               -    More than 10% of the call or data processing capability of a
                    major Network Element is affected. Eg. Site controller

               -    Significant ongoing loss of critical functionality of a
                    revenue-generating feature.

               -    inability of the network management product(s) to provide
                    critical operations and maintenance (O&M) functionality.

               -    Billing is out of service, or there is a significant ongoing
                    loss of billing information, if provided by Motorola.

               -    Clearwire has declared an emergency with the concurrence of
                    Clearwire and Motorola management.

               -    Any conditions that may affect safety.

               -    Problems with a planned activity on previously operational
                    equipment (such as a software upgrade roll-out) that
                    requires the installation of the previous software load.

               -    inability to process emergency calls.


                                       D-6

<PAGE>

          8.2.2 PRIORITY 2 (P2) Major (Target Recovery Time: 48 hours from time
               of escalation) - This is normally the urgency assigned to Service
               Requests based on one or more of the following conditions:

               -    Major impact on the functionality of the Network but it does
                    not prevent the System from meeting its primary requirements

               -    Failures in operational and system performance information
                    that require additional dedicated resources in order to
                    maintain core System operations

               -    Failures in the ability to add, delete or reconfigure any
                    in-service Network Element

               -    Failure in the ability to provision subscribers

               -    Errors in procedures where service risks are involved

               -    Less than 10% of the call or data processing capability of a
                    major Network Element is affected. E.g. Site controller

               -    A revenue-generating feature is out of service.

               -    Total outage of a Network Element that is determined to be a
                    high profile site by Clearwire and Motorola.

               -    Clearwire-declared major issue with the concurrence
                    Motorola.

               -    A redundant device on a major Network Element is lost.

               -    Failure of any portion of a duplex operation for periods of
                    excess of 30 seconds.

          8.2.3 PRIORITY 3 (P3) Minor (Target Recovery Time: 5 days from time of
               escalation) - Minor problems are classified based on one or more
               of the following conditions:

               -    Loss of administrative capabilities (not classified as
                    Priority 1 or Priority 2)

               -    Loss of feature functionality (not classified as Priority 1
                    or Priority 2)

               -    Configuration discrepancies or questions related to error
                    messages or alarms that are being generated on the system.

               -    Other equipment or software issues that are not service
                    affecting.

               -    Follow-up cases for Priority 1 or Priority 2 cases.

          8.2.4 PRIORITY 4 (P4) Low Impact (Target Recovery Time: ICB or next
               software release)- Priority assigned to a case type of
               information. This is normally the urgency assigned to Service
               Requests with low impact and is based on one or more of the
               following conditions:

               -    Basic questions

               -    Cosmetic problems

               -    Documentation errors

               -    Remote support of software load (scheduled maintenance)

               -    System probe requests for upcoming installations, upgrades
                    etc.

               -    Other


                                       D-7

<PAGE>

9.0  RISK OF LOSS

     Risk of Loss for equipment shipped by Clearwire to Motorola under this
     Exhibit shall pass to Motorola upon receipt at a designated Motorola repair
     facility. Risk of Loss for equipment shipped by Motorola to Clearwire under
     this Exhibit shall pass to Clearwire upon receipt by Clearwire.

10.0 WARRANTY RELATED TO REPAIRS OR REPLACEMENTS

     Repairs performed under this Exhibit are warranted under the same terms and
     conditions as the Agreement, with the exception of the Warranty term, which
     shall be for (i) a period of ninety (90) days from the date of Motorola's
     return shipment to Clearwire; or (ii) the balance of the remaining Warranty
     term under the Agreement, whichever is longer. Typical warranty repairs are
     thirty (30) days from receipt to dispatch.

11.0 PAYMENT

     11.1 Clearwire will be invoiced annually, in advance, for the Support Fee.
          Payment shall be made within thirty (30) days from the invoice date
          and otherwise in accordance with the payment terms set forth below.

     11.2 The Support Fee covers all travel, accommodation, time and other
          expenses incurred by Motorola or any of its employees, agents or
          sub-contractors in providing the Support Services (with the exception
          of such expenses and taxes described in Clauses 11.4 and 11.5 below)
          other than where such costs have been incurred as a result of errors
          or misuse attributable to Clearwire.

     11.3 In the event that any payment is delayed by Clearwire, an interest
          charge shall be payable equivalent to two (2) percent above the
          Barclays Bank base rate prevailing at the time that payment should
          have been made.

     11.4 Postage, freight or other such transportation charges for shipping
          defective products to an authorized Motorola Repair Depot will be
          borne in accordance with the NSP Specification; when such products or
          their replacements are being returned to Clearwire, Motorola shall
          bear such charges.

     11.5 Clearwire is responsible for the payment of all applicable import,
          sales. Value Added Tax, use, retailers occupation, excise, property
          and other duties and assessments in the nature of taxes, however
          designated, on the Support Services provided to Clearwire pursuant to
          this Exhibit, exclusive however, of any taxes measured by Motorola's
          net income or based on Motorola's franchise. To the extent Motorola is
          required by law to collect such taxes, one hundred percent (100%) of
          such taxes, etc. shall be added to invoices as separately stated
          charges and paid in full by Clearwire, unless Clearwire is exempt from
          such taxes and furnishes Motorola with a certificate of exemption in a
          form reasonably acceptable to Motorola. In the event Clearwire claims
          exemption from sales, use or other such taxes under this Exhibit,
          Clearwire shall hold Motorola harmless from any and all subsequent
          assessments levied by a proper taxing authority for such taxes,
          including interest, penalties and late charges.

12.0 EXCLUSIONS

     12.1 The Software support provisions set forth in this Exhibit apply only
          to the Software as supplied or modified by Motorola. Modifications,
          attempted modifications or additions to the Software by Clearwire or
          by any party other than Motorola is a breach of the Software License
          and will void all obligations of Motorola included herein.


                                       D-8

<PAGE>

     12.2 This Exhibit shall not apply to any specific item of Equipment that
          has attained the fifth anniversary of the date that Motorola (or
          authorized Motorola third-party manufacturers) ceases manufacture of
          such specific items. To the extent that Clearwire expects it will
          require support beyond such five-year period, extended end-of-life
          support may be purchased from Motorola, but only at the time of
          entering into this Exhibit and prior to the date of cessation of
          manufacture.

     12.3 Support Services do not include the repair of any transmission line,
          antenna, tower, tower lighting, racks, cabinets, defective or
          phosphor-burned cathode ray tubes (CRTs), consumables, including but
          not limited to, cables, connectors, batteries, duplexers, circulators,
          printers, keyboards and frames, and their installation.

     12.4 The NSP Specification will apply to all software released by Motorola
          to Clearwire.

     12.5 The Support Services to be provided by Motorola will exclude all work
          necessary to restore or rebuild lost or destroyed data or any part
          thereof consequent upon corruption by Equipment failure, incorrect use
          of the System or any upgrade to the Equipment Systems not approved by
          Motorola. If undertaken, such work will be charged at Motorola's
          normal daily fee rate for the time being in force, in addition to
          travel and accommodation costs.

     12.6 Service does not include installation of System hardware expansions
          requested by Clearwire.

     12.7 Service does not include normal system operating responsibilities, the
          provision of operating supplies or replacement of consumable supplies,
          electrical work external to the System or any other functions not
          required under this Exhibit.

     12.8 Service does not include maintenance or repair of any equipment and
          software not provided by Motorola.

     12.9 Movement of equipment and reinstallation by anyone not authorized by
          Motorola may void any obligation or warranty by Motorola. Such
          authorization by Motorola will not be unreasonably withheld. Motorola
          will publish commercially reasonable documents and standards on how it
          authorizes third parties.

     12.10 Clearwire will not modify, remove or obliterate the bar code, serial
          number or any other identifying mark(s) on System components. Any
          System component so altered and in need of repair will be repaired at
          the sole discretion of Motorola.

     12.11 Motorola has no obligation to repair or replace items when such
          repair or replacement is caused by the following:

          12.11.1 An event of Force Majeure. However, Motorola agrees, upon
               Clearwire's request, to participate with Clearwire and make an
               assessment with respect to any damage as a result of such event
               and to provide a quotation with respect to the repair and/or
               replacement of the items damaged.

          12.11.2 Acts of vandalism

          12.11.3 Attempts by other than personnel authorized by Motorola to
               repair, maintain, install or modify the System, or if the System
               is used in other than its normal and customary manner

          12.11.4 Clearwire's failure to maintain prescribed environmental
               conditions or external electrical tolerances


                                       D-9

<PAGE>

          12.11.5 Damage that occurs during shipment from Clearwire to Motorola

          12.11.6 Damage due to misuse

          12.11.7 Replacement or malfunction of consumable items such as
               printing ribbons

          12.11.8 Failure of any part of the Interconnected Carrier equipment

     12.12 Motorola will provide Clearwire with any reasonably requested aid in
          performing Clearwire's responsibly hereunder, provided Motorola may
          charge for such aid if it constitutes activities that are within
          Clearwire's responsibility. Clearwire's Travel expenses related to
          site visits, which are expressly excluded from coverage.

13.0 RE-CERTIFICATION

     Except for the Clearwire network as of the Effective Date of this
     Agreement, if the System or a part of the System is not covered by Warranty
     or a previous Motorola Network Support Program, or similar Motorola support
     agreement, Motorola is entitled to inspect the System to determine its
     qualification for Support Services. The inspection and any repairs,
     adjustments or upgrades deemed necessary by as a precondition for Support
     Services shall be made by Motorola and paid for by Clearwire at Motorola's
     time and material rates then in effect and will be made prior to
     commencement of Support Services for the relevant part of the System.


                                      D-10

<PAGE>

                                   EXHIBIT "E"

                                     TO THE
                            WIRELESS BROADBAND SYSTEM
                            INFRASTRUCTURE AGREEMENT

                                   DEFINITIONS

ACCEPTANCE TEST PLAN

The testing described and administered as set forth in Exhibit "C".

CLEARWIRE AFFILIATES

Entities which are controlled with greater than 50% ownership by Clearwire
Corporation.

CUSTOM DEVELOPMENT

Features, functions or capabilities in Equipment or Software for which Clearwire
funds Motorola's development activity.

DOCUMENTATION

The documentation described in Exhibit "B" or which is included with the
Infrastructure Products.

DUAL MODE PRODUCTS

The base station/access point unit with the capability to operate (but not
seamlessly between) the Expedience and 802.16e technologies.

EQUIPMENT

The Motorola-supplied hardware for the System, but excluding Subscriber
Products.

EXPEDIENCE INFRASTRUCTURE PRODUCTS

The access point/base stations using Expedience technology.

INFRASTRUCTURE AGREEMENT

This Infrastructure Agreement and the accompanying Exhibits.

INFRASTRUCTURE PRODUCTS

All Equipment and Software purchased for use in the System which are listed on
Exhibit "A".

OTHER TECHNOLOGY

Any other standards-based, alternative wireless broadband Infrastructure
technology deployed by Clearwire.


                                       E-1

<PAGE>

NETWORK ELEMENTS

Infrastructure equipment and related software for the System other than
Equipment, Software and Subscriber Product. Examples include wireless backhaul
equipment, ethernet switches, IP routers, etc.

PREFERRED VENDOR

A status that means Clearwire will, when capabilities, costs and availability
are equal for a given product or service offered by Motorola and another
supplier or suppliers, purchase the product or service from Motorola in
preference to the other supplier or suppliers.

SERVICES

Those Motorola functions included in the concurrently signed Services Agreement.

SITE

Each of the site locations comprising the System, including the location that
houses the core.

SOFTWARE

See Exhibit "C".

SUBSCRIBER

A person who uses the System and, thereby, entitling Clearwire to revenue.

SUBSCRIBER PRODUCT

Any device or portable radiotelephone equipment intended for System use, whether
or not in actual use.

SYSTEM

The wireless radiotelephone system comprised of the Infrastructure Products and
other Clearwire-supplied products.

WI-MAX INFRASTRUCTURE PRODUCTS

The access point/base station or equivalent using 802.16e technology.

WIRELESS BROADBAND INFRASTRUCTURE PRODUCTS

Wireless broadband base station/access point infrastructure products operating
on licensed spectrum, including Other Technology infrastructure products.


                                       E-2