<PAGE>
                                                                    EXHIBIT 10.6


PURCHASE AND LICENSE AGREEMENT                            [NORTEL NETWORKS LOGO]
================================================================================


This Purchase and License Agreement ("Purchase and License Agreement") is
between Nortel Networks Inc. ("Nortel Networks") and Dobson Communications
Corporation ("Dobson") and its Affiliates, as defined in Annex 2, (jointly or
individually, as the case may be ("Customer"), effective as of November 16,
2001, ("Effective Date") shall commence on the Effective Date and shall expire
December 31, 2004 ("Term"). Additional terms related to Customer's purchase or
license of Products or Services may be added by written agreements
("Supplements") referencing the Purchase and License Agreement, collectively
referred to as the "Agreement". The Services Supplement is attached hereto and
incorporated by reference.

1. DEFINITIONS

a) "Direct Competitor" includes all companies in the business of inventing,
manufacturing or selling switching products or products significantly or
functionally similar to those sold under this Agreement, as well as other
companies that are generally known in the industry as Nortel Networks' direct
competitors.

b) "Furnish-only" means Products that Customer installs.

c) "Hardware" means a Nortel Networks machine or components.

d) "Products" are any Hardware, Software or Third Party Vendor Items provided
under this Agreement.

e) "Services" means the activities to be undertaken by Nortel Networks pursuant
to an Order, including, but not limited to, engineering, maintenance and
installation, implementation, design, consulting, business planning, network
planning and analysis.

f) "Software" is owned or licensed by Nortel Networks, its parent or one of its
subsidiaries or affiliates, and is copyrighted and licensed, not sold. Software
consists of machine-readable instructions, its components, data, audio-visual
content (such as images, text, recordings or pictures) and related licensed
materials including all whole or partial copies.

g) "Switch" shall mean any one of the DMS-MTX family of switching components.

h) "Third Party Vendor Item" includes "Third Party Hardware" and "Third Party
Software" and means any non-Nortel Networks hardware and/or software supplied to
Customer under this Agreement.

i) "Turnover" shall mean the date upon which Nortel Networks completes
installation of Product(s) in accordance with Nortel Networks' standard
technical specifications for such Product(s).

2. ORDERS/COMMITMENTS

a) Customer may order Products or Services by issuing a written purchase order
signed by an authorized representative or, if Customer is enrolled in any then
current Nortel Networks' electronic commerce program, by submitting electronic
orders (collectively, "Orders"). All Orders shall reference this Agreement and
specify the quantity, price, Nortel Networks quotation number, shipping and
billing instructions, installation location, requested delivery dates, requested
commencement date for Services, any statement of work, and any other special
instructions. All Orders will be governed by and cannot alter the terms and
conditions of this Agreement. Customer and Nortel Networks hereby acknowledge
and agree that Orders numbered 50410-000 and 50413-000 shall be governed by the
terms and conditions of this Agreement. Nortel Networks' written or electronic
communication accepting the Order, shipment of Products or commencement of
Services will be Nortel Networks' acceptance of Customer's Order.

b) As provided for in this Agreement, Customer agrees during the Term of the
Agreement to purchase/license, pay for and accept delivery of Products pursuant
to this Agreement in a net amount (i.e., net price less any applicable
discounts, Product Credits, Purchase Credits or incentives, but exclusive of
taxes, shipping, insurance, and similar charges ("Net Price")) totaling not less
than * ("Volume Commitment"). In the event that Customer fails to achieve the
Volume Commitment prior to the expiration or termination of the Term of this
Agreement, Customer shall promptly pay Nortel Networks, as a liquidated damage
and not as a penalty, (i) an amount equal to * of that portion of the Volume
Commitment that remains unfulfilled, and (ii) any amounts of Training Bank
Dollars used by Customer prior to expiration or termination of this Agreement.
Such amount shall be due and payable within thirty (30) days of Nortel Networks'
invoice therefor. Upon execution of this Agreement, Customer's purchase
commitment pursuant to the DMS-MTX Cellular Supply Agreement dated on or about
December 6, 1995, as amended, is hereby considered fulfilled and Customer has no
further obligation thereto.

c) Customer agrees during the fourth quarter of 2001 (i.e., Effective Date
through December 31, 2001) to purchase/license and accept delivery of Products
in a Net Price totaling not less than * ("Fourth Quarter Commitment"). Upon
fulfillment of the Fourth Quarter Commitment, Nortel Networks shall provide
Customer with * of product credits ("Product Credits"). Such Product Credits may
only be used by Customer to pay for Annex 1 Products purchased hereunder,
excluding Third Party Vendor Items. Any Product Credits provided to Customer
pursuant to this Section 2 shall not reduce the total price of any Order by more
than * . Product Credits must be used during calendar year 2002, after which
such Product Credits will be forfeited, and shall have no cash value. Purchases
made pursuant to the Fourth Quarter Commitment shall count toward fulfillment of
Customer's Volume Commitment. In the event Customer fails to achieve the Fourth
Quarter Commitment, Customer shall receive no Product Credits hereunder.

3. ELECTRONIC COMMERCE PROGRAMS

By enrolling in any Nortel Networks' electronic commerce program including, but
not limited to, the electronic data interchange, Customer agrees to comply with
the terms of such program. Customer agrees that all electronic Orders issued are
equivalent to a written Order, are governed by the terms and conditions of this
Agreement and that in the event of any conflict between this Agreement and the
information contained in Customer's or Nortel Networks' electronic commerce
website, this Agreement governs. Customer is responsible for the use and
protection of all electronic commerce passcodes provided by Nortel Networks and
agrees that all Orders submitted using such passcodes are valid and binding
Orders authorized by Customer. Nortel Networks shall have no liability to
Customer due to Customer's failure to access

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* Confidential information has been omitted and filed separately with the
  Securities and Exchange Commission.





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PURCHASE AND LICENSE AGREEMENT                            [NORTEL NETWORKS LOGO]
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Customer's or Nortel Networks' electronic commerce website or errors or failures
relating to its operation.

4. LICENSED USE OF SOFTWARE

Nortel Networks grants Customer a nonexclusive license to use a copy of the
Software to the extent of the activation or authorized usage level. To the
extent Software is furnished for use with designated Products or Customer
furnished equipment ("CFE"), Customer is granted a nonexclusive license to use
Software only on such Products or CFE, as applicable. Software contains trade
secrets and Customer agrees to treat Software as Information. Customer will
ensure that anyone who uses the Software does so only in compliance with the
terms of this Agreement. Customer shall not a) use, copy, modify, transfer or
distribute the Software except as expressly authorized; b) reverse assemble,
reverse compile, reverse engineer or otherwise translate the Software; c) create
derivative works or modifications unless expressly authorized; or d) sublicense,
rent or lease the Software. Licensors of intellectual property to Nortel
Networks are beneficiaries of this provision. Upon termination or breach of the
license by Customer or in the event designated Product or CFE is no longer in
use, Customer will promptly return the Software to Nortel Networks or certify
its destruction. Nortel Networks may audit by remote polling or other reasonable
means to determine Customer's Software activation or usage levels. With respect
to Third Party Software, Customer agrees to abide by the terms provided by
Nortel Networks with respect to any such software. Customer further agrees that
the terms contained in any Nortel Networks or third party "shrink wrap" or
"click" licenses shall govern the use of such software.

5. CHARGES AND PAYMENT

a) Amounts, less any amounts disputed in accordance with Section 19 ("Dispute
Resolution"), are due upon receipt of invoice and shall be paid by Customer
within 30 days. Any disputed amounts that are determined to be validly billed
are due for payment based upon the original invoice date and all other disputed
amounts, if any, shall be due upon resolution of the dispute. In the event of
non-payment not disputed in accordance with Section 19 ("Dispute Resolution"),
Nortel Networks may suspend performance, product shipments or otherwise
terminate this Agreement. Customer shall pay interest on any late payments at
the rate of 18% per annum (1 1/2 % per month). Nortel Networks will inform
Customer in advance whenever additional charges apply. Additional charges shall
apply for shipping, insurance and special handling. Switch Products shall be
shipped to the installation site(s). Cell site Products shall be shipped to
Customer's designated initial delivery location. Customer shall be responsible
for the coordination of all cell site delivery arrangements required to comply
with project schedule dates and for freight and handling charges from Customer's
initial delivery location to the installation sites. Charges for Software may be
based on extent of use authorized as specified in a Supplement or invoice.
Customer agrees to pay the charges applicable for any activation or usage beyond
the authorized level. If any authority imposes a tax, duty, levy or fee,
excluding those based on Nortel Networks' net income, upon a Product or Service
supplied by Nortel Networks under this Agreement, Customer agrees to pay that
amount as specified in the invoice, or supply exemption documentation. Customer
is responsible for personal property taxes for each Product from the date of
shipment by Nortel Networks. Customer consents without qualification to the sale
of receivables, in whole or in part, including all or any part of any associated
rights, remedies, and obligations, by Nortel Networks without further notice and
authorizes the disclosure of this Purchase and License Agreement and Supplements
as necessary to facilitate such sale.

b) With respect to Orders for Products that include Nortel Networks'
installation Services therefor, Nortel Networks shall invoice Customer and
Customer shall pay in accordance with the following schedule: (i) 80% of the
Order shall be invoiced upon shipment of the Products; and (ii) the remaining
20% of such Order will be invoiced upon the earlier of: (a) Customer's
acceptance of such Products, such acceptance not to be unreasonably withheld,
provided that, Customer shall notify Nortel Networks of its acceptance or of the
specific non-conformance within three (3) Business Days of Turnover and any
failure of Customer to provide such notice will result in deemed acceptance; or
(b) the date Customer places Products into commercial operation, exclusive of
operation for purposes of determining compliance with this Agreement or beta
testing, whether or not revenue is actually being generated; or (c) thirty (30)
days from Turnover; provided that, the occurrence of either (b) or (c) above
shall not relieve Nortel Networks of its obligations under this Agreement.

c) With respect to Orders for Products that do not include Nortel Networks'
installation services therefor, Nortel Networks shall invoice Customer for 100%
of the Order upon shipment thereof.

6. WARRANTY

a) Nortel Networks warrants that Hardware i) is free from defects in materials
and workmanship and ii) substantially conforms to Nortel Networks' published
specifications. If Hardware does not function as warranted during the warranty
period, Nortel Networks will determine to either i) make it do so, or ii)
replace it with equivalent Hardware.

b) Nortel Networks warrants that when Software is used in the specified
operating environment it will substantially conform to its published
specifications. If Software does not function as warranted during the warranty
period, Nortel Networks will provide a suitable fix or workaround or will
replace the Software; provided Software is within one software release level of
the then-current software.

c) Services will be performed in a professional and workmanlike manner. If
Services are not performed as warranted and Nortel Networks is notified in
writing by Customer within 30 days, Nortel Networks will re-perform the
non-conforming Services.

d) The warranty period for Hardware and Software shall be the warranty period
identified in the Nortel Networks warranty matrix in effect at the time of
Customer's Order. In the event Nortel Networks determines that repair or
replacement as set forth in this Section 6 cannot be made using commercially
reasonable efforts, Nortel Networks will refund to Customer the price paid for
the Product, less applicable depreciation.

e) No warranty is provided for i) supply items normally consumed during Product
operation; ii) failures caused by non-Nortel Networks products; iii) failures
caused by a Product's inability to operate in conjunction with other Customer
hardware or software; or iv) performance failures resulting from services not
performed by Nortel Networks or Customer's


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PURCHASE AND LICENSE AGREEMENT                            [NORTEL NETWORKS LOGO]
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failure to purchase all necessary Products under this Agreement. Warranty will
be voided by misuse, accident, damage or modification, failure to maintain
proper physical or operating environment or improper Customer maintenance.
Software is not warranted to operate uninterrupted or error free. THESE
WARRANTIES AND LIMITATIONS ARE CUSTOMER'S EXCLUSIVE WARRANTIES AND SOLE REMEDIES
AND REPLACE ALL OTHER WARRANTIES OR CONDITIONS, EXPRESS OR IMPLIED, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE.

f) Nortel Networks provides Third Party Vendor Items on an "AS IS" BASIS WITHOUT
WARRANTIES OF ANY KIND, unless Nortel Networks specifies otherwise. However,
such Third Party Vendor Items may carry their own warranties and Nortel Networks
shall pass through to Customer any such warranties to the extent authorized.

7. WARRANTY SERVICE

Nortel Networks provides certain types of warranty repair and exchange service,
without charge. Nortel Networks will inform Customer of the types of warranty
services available to Customer consistent with Nortel Networks standard
practices and response times. Nortel Networks Technical Assistance Services
("TAS") are available for warranty repair during the warranty period at no
charge only for specified Products. When Customer is required to return Hardware
to Nortel Networks for warranty service, Customer agrees to ship it prepaid and
suitably packaged to a location Nortel Networks designates. Nortel Networks will
return the Hardware to Customer at Nortel Networks' expense. Nortel Networks is
responsible for loss of, or damage to, Customer Hardware while it is a) in
Nortel Networks' possession or b) in transit back to Customer. Any returned
Hardware becomes Nortel Networks' property and, subject to Nortel Networks'
receipt of the exchanged Hardware, its replacement becomes the Customer's
property. The replacement Hardware may not be new but will be in working order
and equivalent to the item exchanged. The warranty period for the Hardware shall
be the greater of ninety (90) days from the date of repair or replacement or the
remaining Hardware warranty period. Customer agrees to ensure that exchanged
Hardware is free of any legal obligations or restrictions that prevent its
exchange and represents that all returned items are genuine and unaltered. Where
applicable, before Nortel Networks provides warranty services, Customer agrees
to a) follow the problem determination, problem analysis, and warranty services
request procedures that Nortel Networks provides; b) secure all programs and
data contained in Hardware; and c) inform Nortel Networks of changes in the
Hardware's location. Post warranty services may be available at Nortel Networks'
then-current prices.

8. TITLE AND RISK OF LOSS

Title and risk of loss for ordered hardware shall pass from Nortel Networks to
Customer upon delivery to the carrier. Until receipt of the applicable amounts
due from Customer hereunder, Customer grants to Nortel Networks a continuing
purchase money security interest in the Products sold and/or licensed under this
Agreement and agrees to support Nortel Networks in the perfection of such
interest. Customer authorizes Nortel Networks to file financing or continuation
statements, including amendments thereto, relating to the Products without the
signature of Customer where permitted by law. A copy of this Agreement shall be
sufficient as a financing statement and may be filed as a financing statement.

9. IMPLEMENTATION AND INSTALLATION SERVICES

a) Customer agrees to provide sufficient, free and safe access to Customer's
facilities and a suitable physical environment meeting Nortel Networks'
specified requirements to permit the timely installation of Products and/or
performance of Services. Nortel Networks will perform its responsibilities in
accordance with the standard Nortel Networks statement of work where applicable.
Nortel Networks will successfully complete its standard installation and
commissioning procedures before it considers Products installed. Nortel
Networks, at its expense, may make alterations to any Product and Service as
necessary to comply with specifications, changed safety standards or
governmental regulations, to make a Product non-infringing with respect to any
patent, copyright or other proprietary interest, or to otherwise improve a
Product or Service. Except as provided for in the Agreement, Customer is
responsible for i) the results obtained from the use of Products and Services;
ii) integration and interconnection with Customer's hardware and/or third party
hardware and/or systems; and iii) installation of Furnish-only Products.

b) Nortel Networks shall have no liability as a result of non-performance,
failures or poor performance of the Products caused by, resulting from or
attributable to Customer-provided designs, specifications or product
configuration requirements or Customer's portion thereof. Nortel Networks may
rely upon and utilize any Customer-provided designs, studies, specifications or
requirements, including but not limited to microwave path studies, RF
propagation studies and tower location and loading requirements, without
liability therefore. Nortel Networks shall not be responsible for any failures
or inadequacies of performance resulting from equipment or facilities or
services not supplied and/or installed by Nortel Networks or its subcontractors
pursuant to the Agreement, or for interference or disruption of service caused
by operation of other radio systems, lightning, motor ignition or other similar
interference.

c) Customer may intend to interconnect the Products to equipment and facilities,
which may not have been purchased pursuant to this Agreement, and Customer
hereby agrees that the making and maintaining of all necessary arrangements
(whether commercial, legal or otherwise) with the supplier of such equipment,
including not only arrangements necessary to permit the timely performance by
Nortel Networks of its responsibilities under this Agreement (e.g., physical and
remote dial-up access for installation and services purposes), but also any
arrangements necessary for the ongoing operation of the equipment in conjunction
with Products, shall be solely the responsibility of Customer, and failure by
Customer to timely make or maintain any necessary arrangements shall not excuse
Customer from its obligations under this Agreement.

d) Not later than thirty (30) days prior to the earliest ship date relating to
any Products covered by the applicable Order, Customer may notify Nortel
Networks that Customer i) does not wish to receive shipment of any Products on
the date set forth in such Order or applicable work order, or ii) that
Customer's facilities are not prepared in accordance with this


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PURCHASE AND LICENSE AGREEMENT                            [NORTEL NETWORKS LOGO]
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Agreement in sufficient time for Nortel Networks to make delivery pursuant to
the date set forth in the applicable Order or work order. In such case, Nortel
Networks shall invoice Customer for a holding fee equal to ten percent (10%) of
the Order or portion thereof and Nortel Networks shall, also, have the right to
place such Products in storage and Customer shall be liable for all additional
transportation, demurrage, loading, storage, and associated costs thereby
incurred by Nortel Networks. The shipment of Products to a storage location as
provided in this Section 9(c) shall be deemed to constitute shipment of the
Products for purposes of invoicing, passage of title and risk of loss, and
commencement of the warranty period.

10. CONFIDENTIAL INFORMATION

a) Confidential information ("Information") means i) Software and Third Party
Software; and ii) all business, technical, marketing and financial information
and data that is clearly marked with a restrictive legend of the disclosing
party ("Discloser").

b) The party receiving Information ("Recipient") will use the same care and
discretion, but not less than reasonable care, to avoid disclosure, publication
or dissemination of Information as it uses with its own similar information that
it does not wish to disclose, publish or disseminate. The Recipient may disclose
Information only to i) its employees and employees of its parent, subsidiary or
affiliated companies who have a need to know for purposes of carrying out this
Agreement; and ii) any other party with the Discloser's prior written consent.
Before disclosure to any of the above parties, the Recipient will have a written
agreement with such party sufficient to require that party to treat Information
in accordance with this Agreement.

c) The Recipient may disclose Information to the extent required by law.
However, the Recipient must give the Discloser prompt notice and make a
reasonable effort to obtain a protective order.

d) No obligation of confidentiality applies to any Information that the
Recipient i) already possesses without obligation of confidentiality; ii)
develops independently; or iii) rightfully receives without obligations of
confidentiality from a third party. No obligation of confidentiality applies to
any Information that is, or becomes, publicly available without breach of this
Agreement.

e) The release of any advertising or other publicity relating to this Agreement
requires the prior approval of both parties. f.) The provisions of this Section
10 shall terminate five (5) years following the expiration or termination of
this Agreement.

11. PATENTS AND COPYRIGHTS

If a third party claims that Nortel Networks Hardware or Software provided to
Customer under this Agreement infringes that party's patent or copyright, Nortel
Networks will defend Customer against that claim at Nortel Networks' expense and
pay all costs and damages that a court finally awards or are agreed in
settlement, provided that Customer a) promptly notifies Nortel Networks in
writing of the claim and b) allows Nortel Networks to control, and cooperates
with Nortel Networks in, the defense and any related settlement negotiations. If
such a claim is made or appears likely to be made, Nortel Networks agrees to
secure the right for Customer to continue to use the Hardware or Software, or to
modify it, or to replace it with one that is equivalent. If Nortel Networks
determines that none of these alternatives is reasonably available, Customer
agrees to return the Hardware or Software to Nortel Networks on Nortel Networks'
written request. Nortel Networks will then give Customer a credit equal to
Customer's net book value for the Hardware or Software provided Customer has
followed generally-accepted accounting principles. Any such claims against the
Customer or liability for infringement arising from use of the Hardware or
Software following a request for return by Nortel Networks are the sole
responsibility of Customer. This represents Nortel Networks' entire obligation
to Customer regarding any claim of infringement. Nortel Networks has no
obligation regarding any claim based on any of the following: a) anything
Customer provides which is incorporated into the Hardware or Software; b)
functionality provided by Nortel Networks at the instruction of Customer; c)
Customer's modification of Hardware or Software; d) the combination, operation,
or use of Hardware or Software with other products not provided by Nortel
Networks as a system, or the combination, operation, or use of Hardware or
Software with any product, data, or apparatus that Nortel Networks did not
provide; or e) infringement by a Third Party Vendor Item alone, as opposed to
its combination with Products Nortel Networks provides to Customer as a system.

12. EQUIPMENT IN ACQUIRED LOCATIONS

In the event Customer acquires new locations during the term of this Agreement,
where existing Nortel Networks' hardware is installed which is running or based
on Nortel Networks' current MTX-Software, or within two (2) software releases of
the then current version, Customer hereby agrees that if it replaces any such
Software or hardware, during the term of this Agreement, it will do so with
Products manufactured by Nortel Networks only.

13. LAST BID OPPORTUNITY

a) In the event Section 12 ("Equipment in Acquired Locations") is not
applicable, in each case in which Customer requests one or more wireless
infrastructure equipment vendors to provide a bid or offer to sell with respect
to Customer's purchase of wireless equipment, of a type that is functionality
equivalent for Customer's intended use to the Products and Services sold by
Nortel Networks, Customer shall give Nortel Networks an opportunity to provide a
last bid or offer to sell its equipment after all other vendors have made their
final bid(s) or offer(s) ("Last Bid") in accordance with Section 13(b), below.
Such Last Bid may be Nortel Networks' first opportunity to bid or offer, or may
be a bid or offer by Nortel Networks subsequent to its first bid or offer.
Customer is not required to accept the Last Bid as the winning bid or offer.

b) Subject to Section 13(a) above, at such time as no further bids or offers are
being accepted by Customer from vendors other than Nortel Networks, Customer
shall notify Nortel Networks in writing, with written receipt from Nortel
Networks, that Nortel Networks may make its Last Bid. Within twenty-four (24)
hours after Nortel Networks' receipt of such notice of Last Bid from Customer,
Nortel Networks shall either provide its Last Bid or provide Customer with
written notice declining to make a Last Bid. If Nortel Networks does not respond
to Customer within twenty-four (24) hours after receipt


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of Last Bid notice, Customer may deem that Nortel Networks has declined to offer
such Last Bid.

14. NETWORK EVOLUTION COMMITMENT

a) If, during the first twelve (12) months of the Term or as extended by Nortel
Networks in writing, Customer agrees in writing to purchase a Net Price of no
less than * of the Nortel Networks' Products and Services agreed by the parties
to be required for Customer's Network Evolution Project ("Network Evolution
Commitment"), Nortel Networks shall, upon receipt of the first Order pursuant to
the Network Evolution Commitment ("Initial Network Evolution Order"), provide
Customer with the discount as discussed below. Customer shall issue Orders, as
described herein, to purchase Products and Services in fulfillment of the
Network Evolution Commitment and shall clearly indicate on such Orders that such
Products or Services are being Ordered pursuant to the Network Evolution
Commitment. Customer shall accept full delivery and make full payment (in
accordance with Section 5 "Charges and Payment") for all Products and Services
Ordered pursuant to the Network Evolution Commitment no later than thirty-six
(36) months from issuance of the Network Evolution Commitment ("Network
Evolution Term"). In the event that Customer fails to achieve the Network
Evolution Commitment prior to the expiration or termination of the Network
Evolution Term, Customer shall promptly pay Nortel Networks, as a liquidated
damage and not as a penalty, an amount equal to twenty percent (20%) of that
portion of the Network Evolution Commitment that remains unfulfilled prior to
the expiration or termination of the Network Evolution Term. Such amount shall
be due and payable within thirty (30) days of Nortel Networks' invoice therefor.

b) Upon receipt and acceptance of the Initial Network Evolution Order, Nortel
Networks shall grant to Customer purchase credits in an amount equal to * of the
Net Price paid by Customer for Annex 1 Products purchased/licensed and accepted
within the current calendar year prior to the date of receipt by Nortel Networks
of the Network Evolution Order to be used in accordance with Section 14(c) below
("Purchase Credits"). Additionally, upon the expiration of each three (3) month
period following the acceptance of the Initial Network Evolution Order, Nortel
Networks will provide Customer with Purchase Credits in an amount equal to * of
the Net Price of Annex 1 Products purchased/licensed and accepted by Customer
during the preceding three (3) month period. Example: If Nortel Networks accepts
the Initial Network Evolution Order on July 1, 2002, then Customer would receive
Purchase Credits in an amount equal to * of the Net Price of Annex 1 Products
purchased and paid for by Customer between January 1, 2002 and July 1, 2002.
Additionally, on October 1, 2002, Customer would receive additional Purchase
Credits in an amount equal to * of the Net Price of Annex 1 Products purchased
and accepted between July 1, 2002 and October 1, 2002. Customer would continue
to receive Purchase Credits each quarter thereafter, as described herein, until
the expiration or termination of the Term.

c) Purchase Credits provided pursuant to this Section 14 may only be used by
Customer to pay for Nortel Networks' radio frequency ("RF") optimization
Services ordered pursuant to this Agreement and purchase orders for Nortel
Networks' wireless Services placed pursuant to the Services and Support Plan
Agreement, ("SSP Agreement") originally executed by the parties on or about
September 14, 2000, as amended; provided, however, that Purchase Credits may
only be applied to such orders placed and accepted following receipt of the
Network Evolution Commitment. Such Purchase Credits may not be used to pay for
Orders of Annex 1 Products placed pursuant to this Agreement. Purchase Credits
must be used within one (1) year from the date such Purchase Credits were
provided, after which such Purchase Credits will be forfeited, and shall have no
cash value.

d) In the event that Customer fails to achieve the Network Evolution Commitment
by the end of the Network Evolution Term, Nortel Networks shall invoice Customer
for the amount of credits provided to and used by Customer. Customer agrees to
pay such invoice within thirty (30) days of receipt thereof. This does not limit
Nortel Networks' right to seek any other remedy(s) it may have in law or equity
for Customer's failure to satisfy the Network Evolution Commitment.

e) Customer and Nortel Networks acknowledge and agree that purchases made
pursuant to the Network Evolution Commitment shall not count toward Customer's
fulfillment of the Volume Commitment.

15. LIMITATION OF LIABILITY

In no event shall Nortel Networks or its agents or suppliers be liable to
Customer for more than the amount of any actual direct damages up to the greater
of U.S. $100,000 (or equivalent in local currency) or the charges for the
Product or Services that are the subject of the claim, regardless of the cause
and whether arising in contract, tort (including negligence) or otherwise. This
limitation will not apply to claims for damages for bodily injury (including
death) and damage to real property and tangible personal property for which
Nortel Networks is legally liable and payments as set forth in Section 11
Patents and Copyrights. IN NO EVENT SHALL NORTEL NETWORKS OR ITS AGENTS OR
SUPPLIERS BE LIABLE FOR ANY OF THE FOLLOWING: a) DAMAGES BASED ON ANY THIRD
PARTY CLAIM EXCEPT AS EXPRESSLY PROVIDED HEREIN AND IN SECTION 11; b) LOSS OF,
OR DAMAGE TO, CUSTOMER'S RECORDS, FILES OR DATA; OR c) INDIRECT, SPECIAL,
INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS OR
SAVINGS), EVEN IF NORTEL NETWORKS IS INFORMED OF THEIR POSSIBILITY.

16. TRAINING CREDITS

a) Beginning in calendar year 2002, during each calendar year of the Term and
subject to Section 2(b) ("Orders/Commitment"), Customer shall receive an annual
credit of * to be applied toward tuition fees for Nortel Networks' training
products and services ("Training Bank Dollars"), provided that Customer notifies
Nortel Networks of its intent to apply Training Bank Dollars toward tuition
costs for training prior to Nortel Networks issuance of invoices for such
training. Training Bank Dollars must be used within the calendar year in which
they are provided to Customer, such that Customer shall use no more than * of
Training Bank dollars during any calendar year of the Term.

----------

*Confidential information has been entitled and filed separately with the
Securities and exchange Commission.

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Any Training Bank Dollars not used within the calendar year they are provided
shall be deemed forfeited by Customer and have no cash value. The Training Bank
Dollars may be applied to all training media offerings, including (but not
limited to) Nortel Networks instructor-led classroom training at a Nortel
Networks facility, Nortel Networks instructor-led classroom training at the
Customer location (Customer site training), self- paced training, and eLearning
training medias. Nortel Networks may change, modify, update and/or add training
programs at any time. Customer shall bear the cost of transportation, meals,
lodging or any other incidental expenses of Customer personnel to, from and
during training. Training Bank Dollars may only be used to train people employed
by Customer and not independent contractors, consultants, or the like without
the written consent of Nortel Networks, such consent not to be unreasonably
withheld. The availability of any training shall be subject to any prerequisites
identified by Nortel Networks. Customer agrees that the courseware and
instructional material are confidential information provided by Nortel Networks
and shall hold the courseware and instructional material in confidence in
accordance with the confidentiality provisions of this Agreement.

b) Any charges for training to which Customer does not apply Training Credits
shall be payable by Customer to Nortel Networks at Nortel Networks' then-current
prices and Customer shall render payment thirty (30) days following receipt of
an invoice therefore.

17. CO-MARKETING FUND

a) Subject to this Section 17, during the Term of the Agreement, Nortel Networks
will provide Customer with a sum of money to be used for Customer's marketing
and/or advertising wherein Nortel Networks' equipment is featured and/or
referenced ("Co-Marketing Funds"). In consideration for such Co-Marketing Funds,
Customer agrees to Order, pay for and accept Products with a minimum Net Price
of i) * of the Volume Commitment over the first two (2) calendar years of the
Term and, ii) * during the third year of the Term for a total of * over the
entire Term; provided that any purchases made in excess of * in the first two
(2) years shall count toward Customer's fulfillment of the second commitment
(""Co-Marketing Purchase Commitments"). Nortel Networks will submit Co-Marketing
Fund payments based on the following schedule:

<Table>
<Caption>
                             Co-Marketing Fund Payment
<S>                          <C>
Year 1:
     January 15, 2002               $*
     July 15, 2002                  $*
Year 2:
     January 15, 2003               $*
     July 15, 2003                  $*
Year 3:
     January 15, 2004               $*
     July 15, 2004                  $*
</Table>

b) In the event Customer does not fulfill either and both of its Co-Marketing
Purchase Commitments, Nortel Networks will determine the amount of the unearned
Co-Marketing Funds relative to the percentage of the commitment not met and
invoice Customer for the amount of the unearned Co-Marketing Funds accordingly.
Customer agrees to pay such invoice within thirty (30) days of receipt. By way
of example, if Customer purchases a Net Price of * of Nortel Networks Products
over the first two (2) calendar years of the Term, then Nortel will invoice
Customer for an amount equal to one-half of the Co-Marketing Funds or *.
Additionally, if at the end of the Term Customer's total purchases equal *, then
Nortel shall invoice Customer for an amount equal to forty percent of the
Co-Marketing funds provided during the third calendar year of the Term or *.

c) The total amount of Co-Marketing Funds that Nortel Networks shall be
obligated to provide pursuant to this Agreement shall not exceed a total of *
during any calendar year. Any Co-Marketing Funds not used within the Term will
be forfeited upon termination or expiration of this Agreement and shall have no
cash value.

d) As a condition to receiving Co-Marketing Funds, as set forth above, Customer
shall provide Nortel Networks with the following: i) payment in full for any
invoices issued by Nortel Networks for Orders received and accepted during the
applicable calendar year period which may have become due; ii) a written,
detailed description of Customer's marketing and/or advertising plan for use of
such applicable Co-Marketing Funds; and iii) a written request for payment of
such previously deposited Co-Marketing Funds; provided, however, prior to
Customer's use of any Co-Marketing Funds, Nortel Networks shall provide approval
of such marketing and/or advertising, such approval not to be unreasonably
withheld.

e) Customer hereby acknowledges and agrees to use Co-Marketing Funds in
accordance with Nortel Networks' standard trademark and advertising guidelines,
that it shall use Nortel Networks' trademarks only as specifically permitted by
Nortel Networks, and that it shall not engage in any activity that jeopardizes
the value and/or validity of Nortel Networks' name or trademarks. Nortel
Networks shall have an absolute veto right to Customer's use of Nortel Networks'
name and trademarks in any advertising sponsored by Customer. Customer shall
obtain approval of all proposed advertising activities that feature and/or
reference Nortel Networks and/or its products prior to running such advertising.
Nortel Networks may withdraw approval of any advertisement/promotional activity
at any time and if it does so, Customer shall use commercially reasonable
efforts to cancel or change such advertising. Nortel Networks approval of any
advertisements or marketing activities shall in no way construe, or be
construed, as an endorsement of Customer's products/services.

f) Subject to Section 17 (h) and in consideration of Customer's past purchases
of Nortel Networks' Products and Services, Nortel Networks agrees to contribute
to Customer's internal appreciation and other approved programs scheduled for
the remainder of calendar year 2001 (pertains to the Circle of Excellence
Program, only) and for calendar year 2002. The contributions shall be used for
the events listed below or other similar programs in amounts no less than those
indicated:

----------

*Confidential information has been entitled and filed separately with the
Securities and exchange Commission.



Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION

                                                                    Page 6 of 10
<PAGE>

PURCHASE AND LICENSE AGREEMENT                            [NORTEL NETWORKS LOGO]
================================================================================


         1) Customer's Circle of Excellence Program- * ;

         2) Customer's President's Club Program- * ;

         3) Customer's Invitational Program (limited to one event per calendar
         year)- * .

g) If, during each calendar year of 2002 and 2003, Customer purchases and makes
full payment for Products with a minimum total Net Price of * per year, Nortel
Networks shall contribute to Customer's internal appreciation and other approved
programs, as discussed in Section 17 (f), for the following calendar year, 2003
and 2004 respectively, unless the conditions of Section 17(h) have not been
satisfied. During the fourth quarter of each calendar year, Nortel Networks will
determine the amount of purchases Customer has made during such year. If
Customer has satisfied its obligations set forth above and is not in breach of
this Agreement, Nortel Networks will make the contributions referenced in
Section 17(f) above available to Customer in the following calendar year. For
example, if Customer purchases * in calendar year 2002, Nortel Networks will
make the contributions during calendar year 2003. In the event that Customer
fails to make purchases at the levels discussed above, Nortel Networks shall not
be obligated to make any contributions.

h) As a condition to receiving the contributions, as set forth above, Customer
shall provide Nortel Networks with a written request for payment of such no less
than thirty (30) days prior to the commencement of the internal appreciation or
other approved event. In the event that a specific program is cancelled and
therefore not held during an applicable calendar year, the amounts for such
program may, upon Customer's request and Nortel Networks' written approval, be
used by Customer for a significantly similar program or event within the same
calendar year as the cancelled event or program.

i) Customer and Nortel Networks acknowledge and agree that purchases made toward
fulfillment of the purchase requirement of Section 17(g) above shall count
toward Customer's fulfillment of the Volume Commitment.

18. SWITCH SOFTWARE LICENSE FEES

a) Each calendar year during the Term, Nortel Networks shall invoice Customer
for license fees for each DMS-MTX Software load (as described in Subsection d)
herein) on a per Switch basis. Each calendar year, Nortel Networks shall invoice
Customer an amount equal to the product of  *   times the greater of the number
of subscribers on an applicable Switch at Turnover or at the time of the audit,
as described herein ("Software License Fee"); provided, however, that such fee
shall not exceed   *   per Switch per calendar year. Subject to Subsection c)
below, Nortel Networks shall invoice Customer for the Software License Fees
after its completion of the audit described in Subsection b) below.

b) Except for the instances described in Subsection c) below, commencing in
2001, during the month of December of each calendar year during the Term, Nortel
Networks shall audit each Switch acquired and owned by Customer, including any
Switch(es) acquired by Customer in accordance with Section 12 (Equipment in
Acquired Locations) (each a "Newly Acquired Switch") to determine the number of
subscribers per Switch for purposes of calculating the applicable Software
License Fee. Customer hereby gives Nortel Networks the right to conduct at its
discretion such audit either remotely or on-site. If Nortel Networks elects to
perform such audit on-site, Customer shall provide free and safe access.

c) In the event Turnover of a Newly Acquired Switch occurs after Nortel Networks
has conducted its annual audit described in Subsection b) above, Nortel Networks
may invoice Customer for the Software License Fee defined in Subsection a)
above, such initial Software License Fee being prorated for the remainder of the
calendar year in which such Newly Acquired Switch is installed.

d) For the Software License Fee, Customer shall be provided with one (1) DMS-MTX
standard, commercially available Software release per Switch, as offered by
Nortel Networks to its customers for 800 MHz AMPS/TDMA and 1900 MHz AMPS/TDMA
Equipment application during the applicable calendar year. Customer may license
additional Software releases offered by Nortel Networks to its customers for
each such Switch in a given calendar year during the Term in addition to the
Software release included in such Software License Fee by paying Nortel Networks
for all applicable fees and charges including, but not limited to, all service
fees incurred for the installation of such Software on a per Switch basis
("Software Application Service Fee"). All Software releases licensed by Customer
hereunder shall include all Software, whether base or optional features,
contained in the standard, commercially available DMS-MTX Software ("DMS-MTX
Core Software"). Such DMS-MTX Core Software shall not include the following:

         1) all CDMA-specific Software features, including, but not limited to,
         IS-634 open interface and all other CDMA-specific interfaces; and,

         2) Software operating on an adjunct platform.

In all cases, the applicable Software License Fee and/or Software Application
Service Fee are exclusive of any Hardware required to operate the Software.

e) In the event Customer makes the Network Evolution Commitment by the end of
the Network Evolution Term as described in Section 14 in the Agreement, Nortel
Networks will reduce the Software License Fee from * per subscriber to * per
subscriber as described in Subsection a) above for all audits taking place
following Nortel Networks' receipt of the Network Evolution Commitment.
Notwithstanding the foregoing, Customer shall continue to be responsible for any
and all Software Application Service Fees incurred. In the event that Customer
fails to achieve the Network Evolution Commitment by the end of the Network
Evolution Term, Nortel Networks shall invoice Customer for the amount of
additional Software License Fees due for calculation periods taking place after
Customer makes the Network Evolution Commitment. By way of example, if during
calendar year 2002 Customer were to make the Network Evolution Commitment,
Nortel Networks would calculate the Software


----------
* Confidential information has been omitted and filed separately with the
  Securities and Exchange Commission.




Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION

                                                                    Page 7 of 10
<PAGE>

PURCHASE AND LICENSE AGREEMENT                            [NORTEL NETWORKS LOGO]
================================================================================


License Fee using * per subscriber going forward from such time. If Customer
were to fail to meet the Network Evolution Commitment, Nortel Networks would
invoice Customer for a Software License Fee in an amount equal to the product of
* times the number of subscribers per Switch calculated following the date that
the Network Evolution Commitment was made. This does not limit Nortel Networks'
right to seek any other remedy(s) it may have in law or in equity for Customer's
failure to satisfy the Network Evolution Commitment.

f) Customer shall pay any applicable invoice described herein within thirty (30)
days of the date of such invoice.

19. DISPUTE RESOLUTION

If any disagreement, including payment disputes under Section 5 ("Charges and
Payment"), cannot be resolved by the representatives of the parties with
day-to-day responsibility for this Agreement within thirty (30) days of written
notice of a dispute, then such matters shall be referred to an executive level
representative of each of the parties. The executive representatives shall
conduct fact-to-face negotiations at a neutral location or such other location
as shall be mutually agreed upon. If these executive representatives are unable
to resolve the dispute within ten (10) business days after either party requests
the involvement of the executive representatives, then either party may, but is
not required to, avail itself of any remedies available at law or equity. Each
party agrees that during such negotiation, it will faithfully continue
performance as outlined herein.

20. GENERAL

a) With the exception of (i) an assignment or transfer to Customer's
successor-in-interest in connection with a transfer (or other termination) of
Customer's ownership of the FCC License to provide wireless telecommunications
in any specific market; provided, that such successor-in-interest is not a
Direct Competitor of Nortel ("Sale") or (ii) an assignment or transfer to which
Nortel Networks has consented in writing, such consent not to be unreasonably
withheld, Customer agrees not to assign, or otherwise transfer this Agreement or
Customer's rights under it, or delegate Customer's obligations, to a
successor-in-interest without giving Nortel Networks prior written notice and
any attempt to do so is void. Any successor-in-interest or assignee must sign a
Software license agreement with Nortel Networks and be subject to any Software
license fees prior to any assignment or transfer of the Software license rights
conferred thereunder. Upon Customer's Sale of Products, Customer shall give
Nortel Networks notice of such sale, transfer or assignment.

b) Customer represents and warrants that it is buying Products and/or Services
for its own internal use and not for resale. Customer agrees to comply with all
applicable laws including all applicable export and import laws and regulations.
Neither Customer nor Nortel Networks will bring a legal action under this
Agreement more than two years after the cause of action arose.

c) Neither party is responsible for failure to fulfill any obligations due to
causes beyond its control. In the event that any provision of this Agreement or
portions thereof are held to be invalid or unenforceable, the remainder of this
Agreement will remain in full force and effect.

d) The terms and conditions of this Agreement, including the Services Supplement
and Supplemental Terms Annexes 1 and 2, attached hereto and contained herein,
form the complete and exclusive agreement between Customer and Nortel Networks
and replace any prior oral or written proposals, agreements, correspondence or
communications regarding the subject matter hereof. The parties hereby agree to
terminate the existing DMS-MTX Cellular Supply Agreement dated on or about
December 6, 1995, as amended ("Supply Agreement"), as of the Effective Date of
this Agreement; provided that, the terms of the Supply Agreement shall continue
to apply to any outstanding and unfulfilled purchase orders and any unresolved
claims thereunder. Notwithstanding the preceding, the following terms and
conditions shall survive such termination: Sections 7 (" Warranties, Remedies
and Limitation of Warranties and Remedies and Disclaimers of Warranties and
Liability"), 9 ("Patent or Copyright Infringements"), 10 ("Software License"),
12 ("Remedies"), 15 ("Coverage, Interference and Third-Party Facilities"), 16
("Regulatory Compliance"), 19 ("Release of Information"), 20
("Confidentiality"), 21 ("Interconnection to Switch"), and 24 ("General").

e) In the event of a conflict between this Purchase and License Agreement and a
Supplement, the terms in any Supplement(s) prevail. Any changes to this
Agreement must be made by mutual agreement in writing.

f) All Customer's rights and all of Nortel Networks' obligations are valid only
in the country in which the Products and Services were supplied.

g) the laws of the State of New York govern this Agreement, exclusive of its
conflict of laws provisions; and nothing in this Agreement affects any statutory
rights of consumers that cannot be waived or limited by contract.

----------
* Confidential information has been omitted and filed separately with the
  Securities and Exchange Commission.




DOBSON COMMUNICATIONS CORPORATION

By: Signature on file
   ----------------------------------------------------
Name: Timothy J. Duffy
     --------------------------------------------------
Title: Vice President and Chief Technical Officer
      -------------------------------------------------
Address:
        -----------------------------------------------
State of Incorporation: Oklahoma
                       --------------------------------
Tax I.D. Number: 73-1513309
                ---------------------------------------
Date: 11-20-01
     --------------------------------------------------

NORTEL NETWORKS INC.

By: Signature on File
   ----------------------------------------------------
Name: Walt Megura
     --------------------------------------------------
Title: RVP Western Region
      -------------------------------------------------
Address: 2221 Lakeside Blvd., Richardson, TX 75082
        -----------------------------------------------
Date: 11-21-01
     --------------------------------------------------


Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION

                                                                    Page 8 of 10
<PAGE>

SERVICES SUPPLEMENT TO THE PURCHASE AND LICENSE AGREEMENT [NORTEL NETWORKS LOGO]
================================================================================


The various Services that Customer may obtain from Nortel Networks, associated
pricing, and the manner in which they will be provided are governed by this
Services Supplement ("Supplement"). The terms and conditions provided in this
Supplement will apply solely to the provision of Services.

1. DEFINITIONS

(a) "Deliverables" means all Materials and Software delivered to Customer
pursuant to an Order, but specifically excluding Tools.

(b) "Materials" means any and all designs, documentation and other work product
prepared by Nortel Networks and delivered to Customer pursuant to an Order (and
specifically excluding Software).

(c) "Statement of Work" is a document, prepared by Nortel Networks, describing
the scope of work, estimated schedule, prices, Deliverables, and other relevant
terms specific to a Service, which may, from time to time, be mutually agreed to
in writing by Customer and Nortel Networks. A Statement of Work shall be
governed by the terms and conditions of, and constitute a part of, this
Supplement.

(d) "Services Descriptions" means Nortel Networks published specifications for
certain Services in effect at the time Nortel Networks accepts an Order.

(e) "Tools" mean any diagnostics, documentation, test equipment or other items
used by Nortel Networks in the performance of the Services.

2. CHARGES AND PAYMENT

Fees for Services may be based on a fixed price, time and materials, time and
materials with deliverables or other commercial arrangement, as specified in an
Order. Unless otherwise included as part of a fixed price, Customer will
reimburse Nortel Networks for all reasonable out-of-pocket expenses incurred by
Nortel Networks in performing the Services (including, without limitation, all
reasonable travel, meal, lodging and mileage expenses) plus standard and
applicable administration fees. All fees for Services are subject to annual
review and adjustment by Nortel Networks. Unless otherwise provided in a valid
Nortel Networks quotation, proposal or Statement of Work, Nortel Networks shall
invoice Customer one hundred percent of the price of the Services upon
completion unless the Service continues beyond thirty days, in which case Nortel
Networks shall invoice Customer at the end of each month for the Services
performed in that month. Certain ongoing Services (for example maintenance and
managed services) ordered by Customer may be invoiced in advance of the
performance of such Services by Nortel Networks.

3. CHANGES TO ORDERS

The parties may, by mutual agreement, make changes to the scope of work,
schedule, prices, deliverables or other substantive aspects of the Services
("Change"). The party asking for a Change shall describe in writing the details
of the requested Change ("Change Order Request"). The prices are based on Nortel
Networks providing the Services only as herein specified or as specified in an
accepted Order or statement of work. Should any factors (e.g., changed site
conditions) cause a material change in scope or an increase in the Services to
be provided, Nortel Networks may, without liability, suspend performance of such
Services and request a change to the applicable Order to reflect the increased
costs of Nortel Networks' performance and/or Nortel Networks' performance of
additional Services. Nortel Networks shall be granted an equitable extension in
the time for performance due to the occurrence of any such changed conditions or
other factors outside Nortel Networks' control. Nortel Networks shall provide in
writing to Customer a summary of any and all adjustments to the charges and
other changes resulting from the Change Order Request. In no event shall any
Change be effective or acted upon in any way until such time as (i) an
authorized representative of both parties has agreed to the terms of the Change
Order Request in writing and (ii) Nortel Networks receives an Order from
Customer for any additional amounts resulting from the Change Order Request.

4. CUSTOMER RESPONSIBILITIES

Customer agrees to cooperate with Nortel Networks in the performance by Nortel
Networks of the Services, including, without limitation, providing Nortel
Networks with sufficient, free and timely access and availability as required by
Nortel Networks to facilities, data, information and personnel of Customer;
including the recovery by Nortel Networks of any Tools. In addition, Customer
shall be responsible for the accuracy and completeness of all data and
information that it provides or causes to be provided to Nortel Networks. In the
event that there are any delays by Customer in fulfilling its responsibilities
as stated above, or there are errors or inaccuracies in the information
provided, Nortel Networks shall be entitled to appropriate schedule and pricing
adjustments. It is understood and agreed that the Services provided by Nortel
Networks may include the advice and recommendations of Nortel Networks, but all
decisions in connection with the implementation of such advice and
recommendations shall be the sole responsibility of, and made by, Customer.

5. PERSONNEL

Nortel Networks and Customer are each responsible for the supervision,
direction, compensation and control of their own employees and subcontractors.
Nortel Networks may subcontract any portion or all of the Services to
subcontractors selected by Nortel Networks. Neither party shall knowingly
solicit to hire employees of the other party with whom it had contact as a
result of the performance of the Services for a period ending six months after
completion of the Services. Neither party shall be precluded from conducting
generalized searches for employees (and hiring those employees who respond to
generalized searches) either through the use of search firms or advertisements
in the media, provided that searches are not specifically targeted to employees
providing Services.

6. PATENTS AND COPYRIGHTS

Nortel Networks will indemnify Customer against any third party claims that any
Materials infringe such third party's patents or copyrights. Such indemnity will
be in accordance with Section 11, Patents and Copyrights, as set forth in the
Purchase and License Agreement. In the event Customer is required to return to
Nortel Networks any Materials in accordance with that provision, Nortel Networks
will give Customer a credit equal to the amounts paid by Customer for the
infringing Materials returned.


Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION

                                                                    Page 8 of 10
<PAGE>

SERVICES SUPPLEMENT TO THE PURCHASE AND LICENSE AGREEMENT [NORTEL NETWORKS LOGO]
================================================================================


7. INTELLECTUAL PROPERTY RIGHTS

(a) Nortel Networks, on behalf of itself and its subcontractors, reserves all
proprietary rights in and to (i) all methodologies, designs, engineering
details, and other data pertaining to the Services and the Materials delivered,
(ii) all original works, computer programs, updates developed in the course of
providing the Service (except Customer's developed programs), (iii) discoveries,
inventions, patents, know-how and techniques arising out of the Services and
(iv) any and all products (including software and equipment) developed as a
result of the Services. The performance by Nortel Networks of Services shall not
be deemed work for hire.

(b) Nortel Networks grants to Customer a perpetual, non-exclusive, world-wide,
paid up license to use, copy and modify the Materials produced by Nortel
Networks and delivered to Customer in the performance of Services solely for
Customer's internal business purposes.

(c) It is understood between the parties that Nortel Networks will employ its
know-how, techniques, concepts, experience and expertise, as well as all other
intellectual property, including that to which it reserves its rights hereunder,
to perform services the same as or similar to the Services for others.

8. MAINTENANCE SERVICES

Nortel Networks provides Product maintenance Services either at Customer's
location or at a service center to keep Products in, or restore them to,
conformance with published specifications.

(a) To be eligible for maintenance Services, the Products must be in good
operating condition and at revision levels supported by Nortel Networks.

(b) Relocation of Products under maintenance Services may result in adjustments
to the price and response times. Continued maintenance Services for such
Products are subject to reasonable availability from Nortel Networks or an
authorized maintenance service provider.

(c) The warranty service terms in Section 7 Warranty Service and exclusions in
Section 6(e) of the Purchase and License Agreement shall also apply to post
warranty Product maintenance Services.

9. GENERAL

In the event of a conflict between this Supplement and any other documents
attached hereto or referenced herein, the terms in this Supplement prevail.

10. PRICING AND AVAILABLE SERVICES

The Services to be provided and/or the applicable pricing shall be as set forth
in (i) an accepted Nortel Networks' proposal, (ii) a Statement of Work or (iii)
the Services Descriptions.


Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION

                                                                   Page 10 of 10
<PAGE>

WARRANTY MATRIX                                           [NORTEL NETWORKS LOGO]
================================================================================


Products may be purchased only in countries where Nortel Networks makes these
products available for purchase and use.

The following Hardware and Software items shall have the corresponding warranty
periods:

<Table>
<Caption>
     CARRIER PRODUCTS                                          HARDWARE                        SOFTWARE
     ----------------                                          --------                        --------
<S>                                                            <C>                             <C>
     DMS, Optical Networks, and Wireless product families      12 months from ship date        12 months from ship date

     CVX, SS7 Gateway, UE IMAS, Alteon and Shasta              12 months from ship date        90 days from ship date
     products

     Carrier Data Products (Passport; Bay and Micom            See current Nortel Networks     See current Nortel Networks
     products)                                                 price list.                     price list.

     All other product families not listed (unless specified   90 days from ship date          90 days from ship date
     otherwise in writing)
</Table>

The following Products require an Enterprise Supplement to enable purchase.

<Table>
<Caption>
     ENTERPRISE PRODUCTS                                       HARDWARE                        SOFTWARE
     -------------------                                       --------                        --------
<S>                                                            <C>                             <C>
     Data Products (e.g., Access CN, Advanced Video,           See current Enterprise Data     See current Enterprise Data
     Backbone CN, Baystack, Business Communications            Products Product Catalog        Products Product Catalog
     Manager, Contivity, Instant Internet, Net ID, Passport
     LAN and WAN Solutions)

     Portal Products                                           90 days from ship date          90 days from ship date
</Table>

The following Products require an eBusiness Solutions Supplement to enable
purchase.

<Table>
<Caption>
     eBUSINESS PRODUCTS                                        HARDWARE                        SOFTWARE
     ------------------                                        --------                        --------
<S>                                                            <C>                             <C>
     Clarify ECRM and eBusiness Service Provider Products      As quoted                       As quoted
</Table>

This Warranty Matrix may be revised from time to time.


                                                 Nortel Networks Warranty Matrix
                                                             Version 2 - 05/2001


<PAGE>

SUPPLEMENTAL TERMS ANNEX 1                                [NORTEL NETWORKS LOGO]
================================================================================


                           SUPPLEMENTAL TERMS ANNEX 1
                                       TO
                         PURCHASE AND LICENSE AGREEMENT
                                     BETWEEN
                              NORTEL NETWORKS INC.
                                       AND
                        DOBSON COMMUNICATIONS CORPORATION


The supplemental terms and conditions below, including defined terms, take
precedence over any conflicting terms and conditions specified in the Section(s)
noted below or elsewhere in the Purchase and License Agreement, with respect to
the wireless Products identified in this Supplemental Terms Annex 1 ("Annex 1
Products"), attached hereto and incorporated herein.

1. With respect to Section 5 (Charges and Payments) of the Purchase and License
Agreement, amend such Section as follows:

     a)   Renumber the existing Section 5 as Section 5(a); and

     b)   Add the following sections:

          "5(b) In consideration of the Volume Commitment set forth in the
                Agreement, for Annex 1 Products purchased/licensed during the
                Term, Nortel Networks grants to Customer the following discounts
                to be applied against Nortel Networks' then-current list price:

<Table>
<Caption>
                        Product                                              Discount
                        -------                                              --------
<S>                                                                         <C>
                        Switch/TDMA Hardware                                   *
                        Cell Site Hardware (exclusive of radios/amplifiers)    *
                        BSC/BTS                                                *
                        CDMA Software                                          *
                        Services are not discountable.
                        (Note: This discount level applies to either 800 MHZ or 1900 MHZ equipment)
</Table>

          5(c) Customer may purchase TRU-III/SCLPA(s) or TRU-II/SCLPA(s) for the
               Net Price per radio/amplifier unit of * for either 800 MHZ or
               1900 MHZ radios."

----------
* Confidential information has been omitted and filed separately with the
  Securities and Exchange Commission.





Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION

<PAGE>

SUPPLEMENTAL TERMS ANNEX 2                                [NORTEL NETWORKS LOGO]
================================================================================


                           SUPPLEMENTAL TERMS ANNEX 2
                                       TO
                         PURCHASE AND LICENSE AGREEMENT
                                     BETWEEN
                              NORTEL NETWORKS INC.
                                       AND
                        DOBSON COMMUNICATIONS CORPORATION

Each of the following companies has been identified by Dobson Communications
Corporation as a potential purchaser (hereafter referred to as "Affiliate")
under the terms of the Agreement. Each Affiliate agrees that terms and
conditions specified in the Agreement, including, but not limited to, Section 4
("Licensed Use of Software"), Section 10 ("Confidential Information"), Section
12 ("Equipment in Newly Acquired Markets") and Section 13 ("Last Bid
Opportunity"), shall govern all Orders submitted by such Affiliate and accepted
by Nortel Networks during the Term of the Agreement. During their participation
in this Agreement, Dobson Communications Corporation absolutely, irrevocably and
unconditionally guarantees the performance and payment of every Affiliate
issuing Orders and/or otherwise acting under this Agreement and any contract
created thereby. With respect to American Cellular Corporation ("ACC"), if
Dobson or one of its majority owned subsidiaries neither manages nor owns a
controlling interest in ACC, and Dobson notifies Nortel Networks of such in
writing, and there remains an unfilled purchase commitment under the Agreement,
Dobson and Nortel Networks agree to assign and allocate up to thirty-three
percent (33%) of the unfulfilled commitment to ACC upon a new agreement between
Nortel Networks and ACC being entered into with substantially similar terms to
those contained within the Agreement. Upon ACC's written acceptance of such
assignment, Nortel Networks will reduce Dobson's remaining commitment by such
assigned amount.

Affiliate Name:
Dobson Cellular Systems, Inc.
Santa Cruz Cellular Telephone, Inc.
Sygnet Communication, Inc.
American Cellular Corporation

This annex may be executed by one or more of the parties hereto on any number of
separate counterparts, and all of said counterparts taken together shall be
deemed to constitute one and the same instrument.

<Table>
<S>                                                     <C>
DOBSON COMMUNICATIONS CORPORATION                       SYGNET COMMUNICATIONS, INC.

By: /s/ TIMOTHY J. DUFFY                                By: /s/ TIMOTHY J. DUFFY
   -----------------------------------------------         -----------------------------------------------
Name: Timothy J. Duffy                                  Name: Timothy J. Duffy
     ---------------------------------------------           ---------------------------------------------
Title: Vice President and Chief Technical Officer       Title: Vice President and Chief Technical Officer
      --------------------------------------------            --------------------------------------------
Address:                                                Address:
        ------------------------------------------              ------------------------------------------
State of Incorporation: Oklahoma                        State of Incorporation: Ohio
                       ---------------------------                             ---------------------------
Tax I.D. Number: 73-1513309                             Tax I.D. Number: 04-3239455
                ----------------------------------                      ----------------------------------
Date:                                                   Date:
     ---------------------------------------------           ---------------------------------------------

DOBSON CELLULAR SYSTEMS, INC.                           AMERICAN CELLULAR CORPORATION

By: /s/ TIMOTHY J. DUFFY                                By: /s/ TIMOTHY J. DUFFY
   -----------------------------------------------         -----------------------------------------------
Name: Timothy J. Duffy                                  Name: Timothy J. Duffy
     ---------------------------------------------           ---------------------------------------------
Title: Vice President and Chief Technical Officer       Title: Vice President and Chief Technical Officer
      --------------------------------------------            --------------------------------------------
Address:                                                Address:
        ------------------------------------------              ------------------------------------------
State of Incorporation: Oklahoma                        State of Incorporation: Delaware
                       ---------------------------                             ---------------------------
Tax I.D. Number: 73-1364699                             Tax I.D. Number: 22-3043811
                ----------------------------------                      ----------------------------------
Date:                                                   Date:
     ---------------------------------------------           ---------------------------------------------

SANTA CRUZ CELLULAR TELEPHONE

By: /s/ TIMOTHY J. DUFFY
   -----------------------------------------------
Name: Timothy J. Duffy
     ---------------------------------------------
Title: Vice President and Chief Technical Officer
      --------------------------------------------
Address:
        ------------------------------------------
State of Incorporation: California
                       ---------------------------
Tax I.D. Number: 94-3051213
                ----------------------------------
Date:
     ---------------------------------------------
</Table>


Dobson-dsf-11.12.01

                            CONFIDENTIAL INFORMATION