Document:

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                                                                   EXHIBIT 10.51

CONFIDENTIAL PORTIONS OF THIS DOCUMENT HAVE BEEN REDACTED AND SEPARATELY FILED
WITH THE COMMISSION.

                       INTERDIGITAL TECHNOLOGY CORPORATION

                            PATENT LICENSE AGREEMENT

THIS IS A PATENT LICENSE AGREEMENT (the "Agreement"), dated May 8, 1995, (the
"Effective Date") between InterDigital Technology Corporation ("ITC"), a
Delaware corporation with a mailing address of 913 Market Street, Suite 802,
Wilmington, DE 19801, and NEC Corporation ("Licensee"), a Japanese corporation
with a mailing address of [**].

                                   BACKGROUND

ITC owns and has the right to license the Licensed Patents (defined below) and
is willing to grant worldwide, non-exclusive licenses thereunder on the terms
set forth below. Licensee desires to obtain such a license.

NOW, THEREFORE, in consideration of the mutual promises contained herein, and
intending to be legally bound, the parties agree as follows:

1    Definitions. As used herein:

(a)  "Affiliate" means IDC, or a corporation or other legal entity fifty percent
     (50%) or more of the voting stock or control of which is owned, directly or
     indirectly, by Licensee, IDC, or ITC, as the case may be.

(b)  "Cellular Unit" means a Covered Subscriber Unit other than a PCS/PHS Unit
     or Wireless Local Loop Subscriber Unit.

(c)  "Covered Infrastructure Unit" means Infrastructure Equipment that is
     designed to operate in accordance with a Covered Standard.

(d)  "Covered Standards" mean IS-54, IS-136, GSM, DCS-1800/1900, PDC, PHS and
     additional standards for digital wireless communications products as added
     pursuant to Paragraph 4, below, and various derivations thereof that do not
     fundamentally alter the character thereof, where the use and operation of
     products in conformity with such standards is covered by one or more claims
     of the Licensed Patents.

(e)  "Covered Subscriber Units" means Subscriber Units that are built to operate
     in accordance with one or more Covered Standards.

(f)  "DCS 1800/1900" means the compatibility standard developed for personal
     communications systems based on GSM but intended for use in the 1.8Ghz
     and/or 1.9 Ghz frequency bands.

       ** Material omitted and filed separately with the Commission.

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(g)  "GSM" means the compatibility standard developed for the 900 MHZ
     PanEuropean digital TDMA cellular mobile radio communication system,
     promulgated by the European Telecommunication Standards Institute, as
     amended from time to time.

(h)  "IDC" means InterDigital Communications Corporation. ITC is a wholly owned
     subsidiary of InterDigital Patents Corporation which is an Affiliate of
     IDC.

(i)  "Infrastructure Equipment" means mobile switching centers, base station
     controllers, base stations, digital transceivers, and similar telephony
     equipment, which are used to interconnect a Covered Subscriber Unit to the
     wired telephone network. Switching equipment may be included in the mobile
     switching center or the base station controller.

(j)  "IS-54" means Cellular Dual Mode Mobile Station - Base Station
     Compatibility Standards, promulgated by the Electronics Industry
     Association and the Telecommunications Industry Association, as amended
     from time to time.

(k)  "IS-136" means an improved version of 15-54 which includes, among other
     things, a digital control channel.

(l)  "Licensed Patents" means every issued patent derived from a patent
     application which bears a first effective filing date on or before February
     28, 2002 and owned at any time by ITC or its Affiliates or for which ITC
     has the right to grant the licenses conveyed hereunder, (including utility
     models but excluding design patents and design registrations) in any
     country of the world, which covers the manufacture, use, sale or lease of
     Subscriber Units and/or Infrastructure Equipment for use in TDMA based
     digital wireless telecommunications systems. Licensed Patents shall also
     include published patent applications which, but only to the extent that
     ITC would have the right, under the laws of the nation in which said
     applications are published, to recover damages for infringement of said
     application during the period of publication. Licensed Patents shall not
     include patents of an entity that acquires IDC. Appendix B contains a
     complete listing of the existing patents and patent applications relating
     to TDMA based digital wireless telecommunications systems owned by ITC
     (including the expiration date of each such patent). ITC shall update such
     list annually or as otherwise requested by Licensee during the term of this
     Agreement to add newly filed or issued patent applications or patents. The
     identity and contents (if provided) of any patents applications shall be
     maintained in confidence by Licensee; provided that Licensee shall have no
     confidentiality obligation with respect to any information which:

     (i)   is already publicly available, or becomes publicly available except
           by Licensee's breach of the confidentiality obligation herein,

     (ii)  is already known to Licensee at the time of the disclosure,

     (iii) is legitimately obtained by Licensee from a third party without
           confidentiality obligation, or

     (iv)  is independently developed by Licensee at any time.

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(m)  "Licensed PDC Infrastructure Equipment" means PDC Infrastructure Equipment
     licensed under this Agreement.

(n)  "Licensee" means the company identified as "Licensee" on page 1 of this
     Agreement, and its Affiliates.

(o)  "Manufacturer's Average Selling Price" means the average price at which a
     Covered Subscriber Unit is sold by the manufacturer in an arms' length
     transaction after deducting the following items to the extent actually
     paid: (i) usual trade discounts, (ii) packing costs, (iii) costs of
     insurance and transportation, and (iv) import, export, excise, sales and
     value added taxes and custom duties. The determination of the
     Manufacturer's Average Selling Price shall be made once each calendar year
     and shall be based on sales of the applicable model of Covered Subscriber
     Unit in the immediately preceding calendar quarter.

(p)  "Net Selling Price" means the amount actually invoiced to the customer for
     a Covered Infrastructure Unit less packing, insurance and shipping costs,
     applicable import, export and excise duties, returns, trade discounts
     given, insurance and installation costs, to the extent included in the Net
     Selling Price, [**]. If base stations or other Infrastructure Equipment
     contain integrated switching equipment, royalties shall be payable with
     respect to the entire cost of such base stations or other Infrastructure
     Equipment, provided, however, [**].

(q)  "PCS Unit" means a Covered Subscriber Unit that (i) complies with DCS
     1800/1900 and (ii) whose Manufacturer's Average Selling Price is fifty
     percent (50%) or less of the Manufacturer's Average Selling Price of a
     typical GSM Subscriber Unit in the country in which such Subscriber Unit is
     sold. Any DCS 1800/1900 Subscriber Unit that does not satisfy both of the
     foregoing conditions shall be treated as a Cellular Unit for purposes of
     this Agreement.

(r)  "PCS/PHS Unit" means a (i) Subscriber Unit that complies with PHS, or (ii)
     a PCS Unit.

(s)  "PDC" means the RCR STD 27 compatibility standard developed in Japan known
     as PDC or Personal Digital Cellular or PanAsian Digital Cellular for TDMA

______________
     ** Material has been omitted and filed separately with the Commission.

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     digital wireless mobile radio communication systems, as amended from time
     to time.

(t)  "PHS" means the RCR STD 28 compatibility standard developed in Japan and
     known as the Personal Handyphone Standard, as amended from time to time.

(u)  "PDC Infrastructure Equipment" means Infrastructure Equipment designed for
     use in conjunction with PDC Subscriber Units.

(v)  "PDC Infrastructure Unit" means a PDC base station which is used as the
     method of tracking the royalties payable for PDC Infrastructure Equipment.

(w)  "Subscriber Unit" means a radiotelephone, whether fixed, mobile,
     transportable, vehicular, portable or hand-held, adapted for use by a
     single person. A Subscriber Unit may be a Wireless Local Loop Subscriber
     Unit.

(x)  [**]

(y)  TDMA" means time division multiple access.

(z)  "Unlicensed Subscriber Unit" means a Subscriber Unit built in accordance
     with a Covered Standard by a third party that is not licensed under the
     Licensed Patents for the manufacture, use and sale of such Subscriber Unit.

(aa) "Wireless Local Loop Subscriber Unit" means a Subscriber Unit, other than a
     PHS Subscriber Unit, used in a digital wireless communication system that
     is specifically designed for the purpose of providing fixed wireless
     telephone service.

2    License Grant. ITC hereby grants to Licensee a non-exclusive, worldwide,
     royalty bearing license under the Licensed Patents to make, have made,
     import, use, sell, lease and/or otherwise distribute Covered Subscriber
     Units and Covered Infrastructure Units.

3    Limitations on License Grant.

(a)  Third party purchasers of Covered Subscriber Units or Covered
     Infrastructure Units purchased directly or indirectly from Licensee shall
     have the right to use and sell such purchased products for their normal or
     expected uses without obligation under patents to ITC or its Affiliates.

(b)  Notwithstanding the terms of subparagraph (a), no license is granted by
     estoppel or implication to any third party customer of Covered Subscriber
     Units to make, use or sell Infrastructure Equipment, and no license is
     granted by estoppel or implication to any third party customer of Covered
     Infrastructure Units to make, use or sell Subscriber Units, and any claims
     that ITC may have against a third party manufacturer of Unlicensed
     Subscriber Units that the use of such Unlicensed Subscriber Units with
     Infrastructure Equipment licensed hereunder

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     ** Material has been omitted and filed separately with the Commission.

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     contributorily infringe or induce the infringement of any claims of any of
     the Licensed Patents are expressly reserved by ITC hereunder.

(c)  Notwithstanding the terms of subparagraph (b), in no event shall Licensee
     be held liable for contributory infringement or inducing infringement (or
     under any similar theory of liability), based on the uses made of Covered
     Subscriber Units or Covered Infrastructure Units by direct or indirect
     purchasers, regardless of the manner in which such Covered Subscriber Units
     or Covered Infrastructure Units are sold, marketed or promoted by Licensee.

4    Additional Covered Standards.

(a)  ITC and Licensee shall each have the right to designate additional
     standards (including, without limitation, Licensee product architectures,
     even if such architectures are not the subject of an industry standard) as
     candidates for adoption as Covered Standards, by giving written notice to
     the other. Any such designation shall include a full description of the
     standard, and a list of those patent claims which are deemed to cover the
     use and operation of Licensee's products in conformity with that standard.

(b)  If candidates for adoption as additional Covered Standards are designated
     by ITC, Licensee shall retain the right to object to such designation on
     the ground that such candidate is not a Covered Standard. If the parties
     are unable to reach agreement on this issue, this dispute will be resolved
     under the dispute resolution provisions of Paragraph 18.

(c)  If a candidate for adoption as an additional Covered Standard is adopted as
     such, either by agreement of the parties or through the Paragraph 18
     dispute resolution process, the parties shall enter into good faith
     negotiations to determine an appropriate royalty applicable to Covered
     Subscriber Units or Covered Infrastructure Units which comply with such
     additional Covered Standard. Such negotiations shall take into
     consideration the Manufacturer's Average Selling Price of such product, the
     Licensed Patents covering such product and the royalty rates and terms
     contained herein.

(d)  In the event that an additional Covered Standard is adopted prior to the
     exhaustion of prepaid royalties, Licensee shall have the option to apply
     prepaid royalties towards products compliant with such additional Covered
     Standard. Such prepaid royalties will be applied at a rate consistent with
     the ratio between the royalty rate applicable to already covered products
     and the royalty rate applicable to newly covered products. For example, if
     a 1995 royalty rate of $[**] per unit were applied to a Subscriber Unit
     covered by an additional Covered Standard, sales of such Subscriber Unit
     would be applied against the prepaid royalty credit at a rate of two such
     Subscriber Units for every PCS/PHS unit which would otherwise be applicable
     against the royalty credit, reflecting the ratio between $[**] and $[**].

(e)  In no event shall the adoption of additional Covered Standards increase the
     royalty payable on any Covered Infrastructure Unit or Covered Subscriber
     Unit

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     ** Material has been omitted and filed separately with the Commission.

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         which is or would be already subject to payment of royalties hereunder,
         or affect the allocation of the prepaid royalties to such a product.
         Thus, if a particular Licensee product is already subject to royalty
         payments based on the compliance of that product with an existing
         Covered Standard, the royalty payable on current and future sales of
         such product will not be affected by the adoption of an additional
         Covered Standard with which that product is compliant. In addition, if
         Licensee introduces a product in the future, and if that product is
         compliant with a Covered Standard listed in the originally executed
         version of this Agreement, the adoption of an additional Covered
         Standard with which that product is compliant will not increase the
         royalties otherwise payable on that product.

5        Payment of License Fees.

(a)      Advance Payment.

   (i)   Licensee shall pay ITC Twenty Three Million, Five Hundred and Thirty
         One Thousand, Two Hundred and Sixty Six U.S. Dollars ($23,531,266) as
         the unconditional irrevocable payment in full for the license granted
         under Paragraph 2 hereof on the sale of the first [**] Cellular Units,
         net of credits and returns.

   (ii)  Licensee shall pay ITC Three Million, Four Hundred Eight Thousand
         Fourteen U.S. Dollars ($3,408,014) as the unconditional irrevocable
         payment in full for the license granted under Paragraph 2 hereof on the
         anticipated revenue associated with the sale of Covered Infrastructure
         Units listed in Appendix A, net of credits and returns.

   (iii) Five Million U.S. Dollars ($5,000,000) of the advance payment specified
         in subparagraphs (i) and (ii) has already been paid by Licensee. The
         remaining amount of the advance payment specified in subparagraphs (i)
         and (ii), less any Japanese withholding taxes required to be withheld,
         will be paid by wire transfer on or before May 25, 1995.

   (iv)  At Licensee's option, advance payments may be applied to any product
         licensed hereunder.[**] Thus, Licensee shall have the right to apply
         payments made under subparagraph (i) to Covered Infrastructure Units,
         and the right to apply payments made under subparagraph (ii) to
         Cellular Units.

   (v)   The amount of the prepayment made under this subparagraph 5(a) has been
         determined on the basis of the sales projections set forth on the
         spreadsheet attached hereto as Appendix A, using the royalty rates set
         forth in paragraph 5(b) with an interest rate of [**] percent [**]%
         used to compute present value and with a discount of [**] percent [**]%
         for economic uncertainty and as consideration for prepayment of
         royalties. Licensee represents that its sales projections are fair and
         reasonable, and represent its best current estimates of its sales of
         Covered Subscriber Units and Covered Infrastructure Units. In the event
         that the actual number of Covered Subscriber Units or Covered
         Infrastructure Units sold by Licensee in a given year are more than 25%
         greater or less than the estimate set out in the Appendix A hereto, the
         number of such units covered by such prepaid

____________
        ** Material has been omitted and filed separately with the Commission.

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         royalties shall be recalculated to take into account the shorter or
         longer time for which the [**]% interest rate is being applied. Any
         dispute regarding any such adjustment shall be resolved under the terms
         of Paragraph 18.

(b)      Running Royalties.

   (i)   Royalty rate. After exhaustion of the payment under subparagraph 5(a),
         Licensee shall pay royalties to ITC on each sale (exclusive of returns
         and credits) of a Covered Subscriber Unit or a Covered Infrastructure
         Unit as follows:

         Cellular Units:            Sold Prior to December 31, 1995 - $[**]
                                    Sold Prior to December 31, 1996 - $[**]
                                    Sold thereafter - $[**]

         PCS/PHS Units:             Sold Prior to December 31, 1995 - $[**]
                                    Sold Prior to December 31, 1996 - $[**]
                                    Sold thereafter - $[**]

         Covered Infrastructure
         Units:                     [**]% of the Net Selling Price of Covered
                                    Infrastructure Equipment

   (ii)  Cap on royalties.

               (1)  The royalty rates set forth in subparagraph (i) above for
                    Cellular Units and PCS/PHS Units are not intended to exceed
                    [**]% of the Manufacturer's Average Selling Price for the
                    applicable type of Covered Subscriber Units. Accordingly,
                    once the advance payment is exhausted, Licensee shall have
                    the option of providing ITC with information sufficient to
                    determine the Manufacturer's Average Selling Price for each
                    model of Covered Subscriber Unit. If the royalty provided
                    for hereunder exceeds [**]% of the Manufacturer's Average
                    Selling Price for a model of Covered Subscriber Unit, the
                    royalty associated with such model of Covered Subscriber
                    Units shall thereafter be reduced to [**]% of the
                    Manufacturer's Average Selling Price for such Covered
                    Subscriber Units. In each succeeding year, Licensee shall
                    provide ITC with sufficient information to determine the
                    Manufacturer's Average Selling Price of any Covered
                    Subscriber Units for which the royalty has been reduced as
                    described in this subparagraph, and the royalty for such
                    Covered Subscriber Units shall be adjusted to take into
                    account any subsequent price changes, with such royalty
                    always to be maintained at the lower of (1) the rate
                    specified in subparagraph (i), above, or (2) [**]%.

               (2)  If required for purposes of subparagraph (ii)(1), above,
                    Licensee shall make sufficient information available to ITC
                    to enable it to independently verify the Manufacturer's
                    Average Selling Price. If such information is not available,
                    the parties shall jointly determine

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         **  Material has been omitted and filed separately with the Commission.

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                    a temporary Manufacturer's Average Selling Price to be used
                    for one calendar quarter until an actual average
                    Manufacturer's Average Selling Price can be determined as
                    provided for in this Paragraph. ITC shall hold in confidence
                    all Manufacturer's Average Selling Price supporting
                    information provided hereunder.

(c)      For purposes of this Agreement, the manufacture, sale, lease and/or use
         of a Covered Subscriber Unit or Covered Infrastructure Equipment shall
         apply against the applicable prepaid royalty credit of Paragraph 5(a)
         or the applicable running royalties of Paragraph 5(b), as the case may
         be, if manufactured, used, sold or leased in (i) the United States,
         (ii) any country where a valid foreign counterpart of U.S. Patent No.
         [**] has issued or been published for opposition at the time in
         question, but only if said counterpart contains claims which do not
         differ materially from those of the [**] Patent, or (iii) any country
         where a foreign counterpart application to U.S. Patent No. [**] has
         been published if, under the law of the applicable country, ITC is or
         shall be entitled to recover damages based on such publication, but
         only if said counterpart contains claims which do not differ materially
         from those of the [**] Patent. At the adjustment meetings provided for
         in Paragraph 7 hereof, if requested by Licensee, the parties shall
         consider whether and which Covered Subscriber Units or Covered
         Infrastructure Equipment of Licensee are within the scope of the issued
         claims of any non-U.S. patent of the type referred to in subparagraph
         5(c)(ii) or (iii), above. Nothing herein shall be construed as
         affecting in any manner the territorial scope of the license set forth
         in Paragraph 2, above.

(d)      Neither ITC nor its Affiliates currently have any issued Japanese
         patents or published Japanese patent applications for opposition which
         relate to TDMA digital wireless communications systems. Nothing herein
         contained shall be deemed to require that royalties be paid on, or a
         portion of the prepayment be allocated to, Licensee products
         manufactured, used and sold in Japan which are compliant with PHS, PCS
         or PDC, until and unless ITC acquires one or more Licensed Patents in
         Japan covering these standards.

(e)      Only one royalty shall be payable by Licensee to ITC under this
         Agreement based on any Covered Subscriber Unit or Covered
         Infrastructure Unit. If Licensee incorporates into a Covered Subscriber
         Unit or a Covered Infrastructure Unit apparatus obtained from a third
         party, for which a license under the Licensed Patents already exist,
         the value of such apparatus shall be excluded from the royalty base for
         such product. In the event the relevant product is a Covered Subscriber
         Unit, such exclusion shall take the form of reducing the unit royalty
         payment required for such Covered Subscriber Unit.

(f)      Any royalties payable on a published application shall be paid, or
         amounts subtracted from the prepayment, upon the issuance of the patent
         corresponding to said application, subject to the provisions of
         Paragraphs 5(c)(iii) and 7(e)(iii).

6        Wireless Local Loop Subscriber Units.

(a)      If Licensee makes, uses or sells Covered Subscriber Units which are
         Wireless

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      ** Material has been omitted and filed separately with the Commission.

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         Local Loop Subscriber Units, ITC shall have the option of (1) treating
         such Wireless Local Loop Subscriber Units the same as other Covered
         Subscriber Units for royalty purposes or (2) imposing a royalty on such
         Wireless Local Loop Subscriber Units of [**] of the Manufacturer's
         Average Selling Price for each model of Wireless Local Loop Subscriber
         Unit.

(b)      In the event that ITC elects to impose a royalty on Wireless Local Loop
         Subscriber Units which is greater than the royalty which would
         otherwise be payable on such units as Covered Subscriber Units,
         Licensee shall have the option of terminating the royalty-free license
         which is granted pursuant to Paragraph 13 hereof. In such an event, the
         parties shall negotiate a cross-license, with or without royalties, as
         appropriate, for Wireless Local Loop Subscriber Units and UltraPhone
         products. Such cross-license may include a modification of the royalty
         rate which would be otherwise payable by Licensee on Wireless Local
         Loop Subscriber Units, and may include the payment of royalties by IDC
         or its Affiliates on UltraPhone sales. In the event the parties are
         unable to agree on the terms of such a cross-license, the dispute will
         be submitted to the dispute resolution process of Paragraph 18.

7        Adjustments to Royalties.

(a)      If requested by either party, the parties shall meet not more than
         annually during the term of this Agreement to discuss possible downward
         adjustments to royalties payable hereunder or other adjustments which
         may be required hereunder. Such adjustments may take the form of
         credits for additional units under the prepayment, or an adjustment of
         the running royalty rate, or both.

(b)      Adjustment meetings shall take place during the first calendar quarter
         of each year and shall alternate between Wilmington, DE and Tokyo,
         Japan. In the event the parties are unable to agree on adjustments, the
         dispute shall be submitted to the dispute resolution procedures of
         Paragraph 18 hereof.

(c)      Any adjustment pursuant to this Paragraph shall be effective on the
         date of the event giving rise to the right to have such an adjustment.

(d)      If Licensee is entitled to an adjustment of royalties as a result of
         the operation of this Paragraph, and Licensee has at the time of such
         entitlement not utilized all of the prepayment, Licensee shall receive
         a credit of additional Cellular Units and/or Covered Infrastructure
         Units which shall be determined pursuant to good faith negotiations
         between the parties, or pursuant to Paragraph 18 if such good faith
         negotiations are not successful. A credit under the prepayment will not
         preclude an additional adjustment of the running royalty rate. A credit
         under the prepayment will take into account a reasonable interest rate
         under the circumstances used for purposes of computing present value.

(e)      [**]

         [**]

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      ** Material has been omitted and filed separately with the Commission.

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         (ii)  The expiration of any Licensed Patent.

   (iii) The failure of any published application which constitutes a Licensed
         Patent to issue within two (2) years of ITC's identification of such
         application as a Licensed Patent, or the issuance of a patent from such
         application with claims materially different from those present in the
         application as published.

         (iv)  The entry of any agreement, judgment, litigation settlement,
               arbitration award or the like, pursuant to which a third party
               obtains the right to a prospectively lower royalty payment under
               Licensed Patents for the manufacture, use or sale of Covered
               Subscriber Units or Covered Infrastructure Equipment. In such an
               event, the royalty rates under this Agreement shall be reduced
               by[**]. In evaluating whether Licensee is entitled to any
               reduction in royalty fees under these provisions for most favored
               licensee treatment, the economic values of all relevant factors
               (including but not limited to acquisitions of products by or from
               IDC, joint development projects with IDC, joint venture
               relationships with IDC, royalty advances, and royalty guarantees)
               will be taken into account. For purposes of this subparagraph,
               Covered Subscriber Units shall be deemed to be equivalent to
               products manufactured by third parties which are designed to
               operate in accordance with the same Covered Standards as
               particular Covered Subscriber Units. This subparagraph shall not
               apply to license agreements executed prior to the Effective Date.
               Any adjustment under this subparagraph will take into account the
               royalty rates applicable to the third party, determined, if
               relevant,[**] and the rate of sale of Cellular Units and/or
               Covered Infrastructure Units compared to the applicable rate set
               forth in Appendix A.

(f)      ITC shall be required to promptly inform Licensee of any event which
         might give rise to an adjustment under this Paragraph. In the event of
         an agreement, judgment, litigation settlement, arbitration award or the
         like, ITC shall promptly provide Licensee (or its independent outside
         counsel, if disclosure of the applicable document to Licensee is
         prohibited) with a copy of the relevant sections of the applicable
         documents.

(g)      [**]

         [**]

         [**]

         [**]

8        Payments. All running royalties payable shall be paid to ITC in U.S.
         Dollars on a quarterly basis, within forty-five (45) days after the end
         of each calendar quarter on products sold by Licensee during such
         calendar quarter. All applicable taxes which are required by law to be
         deducted from amounts payable to ITC (including deductions for Japanese
         withholding tax) shall be deducted from the royalties payable hereunder
         and paid to the relevant government authority by

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      ** Material has been omitted and filed separately with the Commission.

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     Licensee on ITC's behalf. If any such deduction is required by the elevant
     government, Licensee will furnish ITC with appropriate documentation
     evidencing the payment of such tax as issued by the appropriate authority
     of such government.

9    Japanese Withholding Tax Provision.

(a)  For purposes of the applicability of Japanese withholding tax on the
     royalty advance, at Licensee's option, Licensee may either (i) pay on
     behalf of ITC the withholding tax on up to [**] of the advance royalties
     paid pursuant to Paragraph 5(a) hereof, or (ii) declare that at least [**]%
     of the anticipated manufacturing and sales plans of Licensee shall be
     allocated to non-Japanese source income, with the balance being allocated
     to Japanese source income.

(b)  With respect to any additional royalties which may be payable in the future
     to ITC by Licensee, if, and to the extent, permitted by Japanese tax law,
     no withholding shall be made with respect to Covered Subscriber Units or
     Covered Infrastructure Units manufactured outside of Japan, or manufactured
     in Japan but intended for sale outside of Japan, provided, however that ITC
     shall indemnify Licensee against underpayment of withholding.

10   Reports.

(a)  Until the exhaustion of the prepayment made hereunder, Licensee will
     provide to ITC an annual written report, setting forth the quantity of
     sales of each type of Covered Subscriber Unit and the number of Covered
     Infrastructure Units sold during such year, to the extent reasonably
     necessary for calculation of the amount of the prepayment applied to
     royalties hereunder.

(b)  Following the exhaustion of the prepayment, Licensee shall accompany each
     payment with a written report setting forth the quantity of each type of
     Covered Subscriber Unit and Covered Infrastructure Unit sold during the
     prior calendar quarter, to the extent reasonably necessary for calculation
     of royalties payable hereunder, and, if applicable, additional information
     sufficient to determine the royalties payable for units which are subject
     to royalty percentages.

(c)  All reports required under this paragraph will be certified to be complete
     and accurate by an officer of Licensee.

(d)  All information contained in any reports furnished under this paragraph
     shall be held in confidence by ITC.

11   Audits.

(a)  Licensee shall keep books and records adequate to accurately determine the
     payments due under this Agreement. The books and records must be retained
     for five (5) years after the delivery of the royalty report to which they
     relate. ITC shall have the right, no more than once per calendar year, to
     have an independent certified public accountant, who shall enter into an
     appropriate

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      ** Material has been omitted and filed separately with the Commission.

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     nondisclosure agreement with Licensee, inspect all relevant books and
     records of Licensee on seven (7) business days notice and during regular
     business hours to verify the reports and payments required to be made
     hereunder. The auditor shall disclose to ITC no more information than is
     reasonably necessary to determine any royalties owed hereunder. Should an
     underpayment in excess of [**] percent ([**]%) be discovered, Licensee
     shall pay the cost of the audit. In any event, Licensee shall promptly pay
     any underpayment together with interest at the annual rate of [**] percent
     ([**]%). All information obtained through such audit shall be held in
     confidence by ITC.

(b)  Licensee shall have the right, no more than once per calendar year, to have
     a mutually acceptable independent certified public account, who shall enter
     into an appropriate nondisclosure agreement with ITC, inspect all relevant
     agreements, books and records, agreements, judgements, litigation
     settlements, arbitration awards and the like, relating to the Licensed
     Patents on seven (7) business days notice and during regular-business hours
     to verify the most favored licensee status of Licensee, taking into account
     the economic value of all relevant factors. The auditor shall disclose to
     Licensee no more information than is reasonably necessary for Licensee to
     verify its most-favored licensee status, and except in those extraordinary
     circumstances where the identity of a third party to an agreement or
     adjudication with ITC is essential information for the purposes of
     evaluating such agreement or adjudication, the auditor shall not disclose
     the identity of any such third party to Licensee. All information obtained
     through such audit shall be held in confidence by Licensee.

12   No Set Off. Licensee agrees and acknowledges that it has no right to, and
     shall not, attempt to set off amounts claimed to be owed based on any claim
     that it has or may have in the future against IDC or its Affiliates other
     than ITC, against amounts owed hereunder.

13   License Grant to IDC. Licensee hereby grants to IDC a worldwide, royalty
     free, paid-up, perpetual license under patents owned by it and its
     Affiliates, such license authorizing ITC and IDC to manufacture, use or
     sell any digital wireless telecommunications products based on the existing
     UltraPhone product line (including improvements thereof) manufactured and
     designed by or for IDC which are first offered for sale prior to one year
     from the Effective Date.

14   Additional Patent Licenses. With respect to any patents relating to digital
     wireless telephone systems owned by either party, or either party's
     Affiliates, which patents are not otherwise licensed hereunder, the owning
     party agrees to negotiate a reasonable license to make, have made, use,
     sell, lease and/or otherwise distribute Subscriber Units and Infrastructure
     Equipment on reasonable terms and conditions, taking into consideration the
     nature of the patent and the overall importance of the patent to the
     product. If no agreement can be reached on the nature of such terms, any
     dispute will be resolved under the dispute resolution procedures of this
     Agreement.

15   License Term. The term of this Agreement shall commence on the Effective
     Date and terminate upon the last-to-expire of the Licensed Patents
     applicable to

____________
      **  Material has been omitted and filed separately with the Commission.

                                       12

<PAGE>

     any Covered Standard, unless sooner terminated as provided herein.

16   Patent Marking. All Licensee Covered Subscriber Units intended for sale
     within the United States shall include a statement that they are licensed
     under U.S. Patents, including up to five patent numbers to be provided by
     ITC; provided that ITC shall represent and warrant that such patents cover
     such products and that all of its other licensees in the United States are
     also required to mark their corresponding products with such patent
     numbers.

17   Termination.

(a)  This Agreement may be canceled by either party, upon forty-five (45) days'
     prior written notice, if the other party is in breach of any of its
     material obligations hereunder and the breach is not remedied within the
     notice period. In the event that the other party submits the underlying
     dispute to the dispute resolution procedures of this Agreement, the
     termination shall be held in abeyance until such procedures are completed,
     and shall only take effect if said procedures result in a determination
     that the other party is in material breach. In such event, the other party
     shall be given forty-five (45) days after such determination to remedy such
     breach, with the termination to take effect only if the breach has not been
     remedied during said period.

(b)  This Agreement may be terminated without cause by Licensee upon written
     notice to ITC on thirty (30) days prior written notice, or at any time
     after the expiration, unenforceability, or invalidation of all of the
     Licensed Patents; provided, however, upon such termination, ITC shall have
     the right to take any action that it deems appropriate to collect royalties
     on products manufactured by Licensee after the termination and/or
     manufactured by Licensee before termination, but for which royalties due
     hereunder were not paid, which it believes are covered by the Licensed
     Patents.

18   Dispute Resolution.

(a)  Negotiation of Disputes. In the event of any dispute arising under this
     Agreement (including, without limitation, failure of the parties to agree
     on royalty rates, number of Licensee's products covered by the prepaid
     royalties, royalty reductions for patent invalidity, non-coverage,
     unenforceability or expiration or most favored license provisions, or other
     matters concerning royalty rates), senior executives of the parties with
     decision making authority will meet in Wilmington, DE, Tokyo, Japan or such
     other city as may be agreeable to the parties as soon as reasonably
     possible (but no later than sixty (60) days after notice) and will enter
     into good faith negotiations aimed at resolving the dispute. If they are
     unable to resolve the dispute in a mutually satisfactory manner within an
     additional sixty (60) days, the matter may be submitted to mediation and
     arbitration as provided for below.

(b)  Mediation of Disputes. The parties agree to submit any unresolved dispute
     to a sole mediator selected by the parties as soon as reasonably possible
     but no later than sixty (60) days after notice). Any such mediation shall
     be non-binding. If not thus resolved, the parties will proceed as specified
     in subparagraph (c).

(c)  Arbitration. Any disputes arising under this Agreement which are not
     resolved as

                                       13

<PAGE>

     provide for in subparagraphs 18(a) and (b) shall be submitted to an
     arbitration proceeding which shall take place in Washington, D.C. The
     proceeding shall be conducted under the then prevailing rules for
     commercial arbitration (or, if the matter involves issues of patent
     validity, infringement or enforceability, the patent arbitration rules) of
     the American Arbitration Association, by a panel of three (3) arbitrators
     reasonably acceptable to both of the parties, one of whom must have
     substantial experience in the field of telecommunications. The arbitrators
     shall have the authority to permit limited discovery to the extent required
     by a party in order to establish its position. The decision of the
     arbitrators shall be final and binding and may be entered and enforced in
     any court of competent jurisdiction. Any monetary award shall be payable in
     U.S. dollars, free of any tax, offset or other deduction. Any determination
     of the arbitration shall be confidential to the parties hereto and binding
     solely on the parties hereto. The parties, their counsel, and the
     arbitrators shall take all reasonable steps to conclude the arbitration
     within six (6) months after it is instituted.

19   Miscellaneous.

(a)  Notices. All notices or other communications required or permitted under
     this Agreement shall be in writing and shall be delivered by personal
     delivery, registered mail, return receipt requested, or a qualified "Next
     Day Air" delivery service addressed as follows:

     If to ITC:   InterDigital Technology Corporation
                          [**]
                          Wilmington, Delaware 19801
                          Attention: President

     If to Licensee:   NEC Corporation
                          [**] Japan
                          Attention: [**]

(b)  ITC warrants that it owns the patents and patent applications identified in
     Appendix B hereto and that such patent and applications include all those
     of ITC and its Affiliates concerning Covered Subscriber Units or Covered
     Infrastructure Units, that by Agreement with IDC, ITC will own all patents
     and patent application filed on or before February 28, 2002 for inventions
     made by IDC and its Affiliates and that it has the right to grant this
     license to the Licensed Patents. IDC shall confirm to Licensee in writing
     its agreement to assign all such patents and patent application to ITC.

(c)  Nothing in this Agreement shall be construed as:

     (i)    Requiring the maintenance of the Licensed Patents;

     (ii)   A warranty as to the validity or scope of the Licensed Patents;

     (iii)  A warranty or representation that any product will be free from
            infringement of patents of third parties;

____________
         ** Material has been omitted and filed separately with the Commission.

                                       14

<PAGE>

     (iv)   An agreement to bring or prosecute actions against third party
            infringers of the Licensed Patents;

     (v)    Conferring any license or right under any patent other than the
            Licensed Patents; or

     (vi)   Conferring any right to use the Licensed Patents outside the field
            of use defined by the license grant of Paragraph 2.

(d)  This Agreement is personal to Licensee and may not be assigned or
     transferred, nor may any license granted hereunder be assigned or
     transferred, whether by operation of law or otherwise, and any attempt to
     make any such assignment or transfer shall be null and void; provided,
     however, this Agreement may be transferred in connection with the sale of
     all or substantially all of the business or assets of Licensee to which
     this Agreement relates. The license granted hereunder to Licensee shall
     survive any transfer by operation of law or otherwise of the Licensed
     Patents or otherwise of the Licensed Patents or this Agreement by ITC.

(e)  Licensee and ITC agree to hold in confidence and not to disclose, except
     under a requirement of confidentiality or an appropriate protective order,
     any of the terms of this Agreement, except as required by law or government
     regulation, or except to the party's outside counsel. The press release
     attached as Appendix C shall be issued by ITC on or after the Effective
     Date, but not before the ratification of this Agreement by Licensee's Board
     of Directors; provided that ITC shall first provide to Licensee an opinion
     of counsel that disclosure of the amount of the prepaid royalty under
     Paragraph 5 is required by U.S. securities laws. The per-unit royalties
     pursuant to Paragraph 5 will not be disclosed. Such press release, when and
     if issued, and shall be the basis for any further disclosures concerning
     this Agreement by IDC.

(f)  The validity and interpretation of this Agreement shall be governed by
     Delaware law, without regard to conflict of laws principles and the parties
     submit to the jurisdiction of the state and federal courts of the State of
     Delaware solely for the purpose of enforcing the dispute resolution clause
     set forth in Paragraph 18. Process may be served on either party by U.S.
     Mail, postage prepaid, or by a recognized "Next Day Air" service.

(g)  This Agreement contains the complete and final agreement between the
     parties, and supersedes all previous understandings relating to the subject
     matter hereof whether oral or written. This Agreement may only be modified
     by a written agreement signed by duly authorized representatives of the
     parties.

                                       15

<PAGE>

IN WITNESS WHEREOF, the parties have executed this Agreement by their duly
authorized representatives.

INTERDIGITAL TECHNOLOGY                    NEC CORPORATION
  CORPORATION

By:                                        By:    /s/[**]
                                                  ------------------------------

                                                  General Manager
Title:                                     Title: Mobile Communications Division
                                                  ------------------------------

Dated: 5/2/95                              Dated: 5/8/95
       -------------------------                  ------------------------------

                                     ATTEST:

                                           By:    /s/ [**]
                                                  ------------------------------

                                                  [**]
                                                  Mobile Communications
                                           Title: Systems Division
                                                  ------------------------------

                                           Dated: 5/8/95
                                                  ------------------------------

____________
         **  Material has been omitted and filed separately with the Commission.

                                       16

<PAGE>

                               Index of Appendices

Appendix A - NEC Corporate Sales Projections

Appendix B - ITC Patents

                                       17<PAGE>

                                                                   EXHIBIT 10.52

CONFIDENTIAL PORTIONS OF THIS DOCUMENT HAVE BEEN REDACTED AND SEPARATELY FILED
WITH THE COMMISSION.

                      AMENDMENT TO PATENT LICENSE AGREEMENT

THIS AMENDMENT TO THE PATENT LICENSE AGREEMENT dated May 8, 1995, is entered
into this 15th day of January 2002 ("Effective Date") between InterDigital
Technology Corporation ("ITC"), a Delaware corporation with a mailing address of
[**], Wilmington, DE 19801, and NEC Corporation ("Licensee"), a company
organized and existing under the laws of Japan, with a mailing address [**],
Japan.

                                    PREAMBLE

WHEREAS, ITC and Licensee are parties to an existing Patent License Agreement,
dated May 8, 1995, covering certain TDMA-based products manufactured and sold by
Licensee (the "Prior Agreement");

WHEREAS, a substantial dispute (the "Dispute") has arisen between Licensee and
ITC as to whether royalties are owed by Licensee for its sale in Japan of
Covered Infrastructure Equipment/1/ and Covered Subscriber Units compliant with
PHS and PDC Covered Standards;

WHEREAS, the parties have engaged in both a mediation and an arbitration dispute
resolution process pursuant to the Prior Agreement with respect to such dispute,
and are desirous of settling the dispute amicably;

WHEREAS, the parties have agreed upon a settlement of the dispute, wherein the
settlement provides:(i) for certain amendments to the Prior Agreement, the
principal amendment providing for certain payments to ITC in lump sum amounts in
exchange for a paid-up license for Covered Subscriber Units and Covered
Infrastructure Equipment compliant with PHS and PDC Covered Standards, and (ii)
for a new license agreement

_______________
** Material has been omitted and filed separately with the commission.

/1/ Capitalized terms undefined herein shall have the meaning ascribed to them
in the Prior Agreement.

<PAGE>

involving Covered Subscriber Units and Covered Infrastructure Equipment
compliant with Narrowband CDMA and Third Generation (as defined in such new
agreement) ("3G Agreement"); and

WHEREAS, the lump sum amounts provided for under the settlement referenced
herein are based upon the existing rights and obligations of the parties under
the Prior Agreement, including without limitation the [**] provision of Section
7(g) of the Prior Agreement.

NOW, THEREFORE, in consideration of the mutual promises contained herein, and
intending to be legally bound, the parties agree as follows:

     1.   Paid Up License for PHS and PDC. Licensee irrevocably and
          unconditionally agrees to pay to ITC the non-refundable lump sum
          amount of $53,000,000. Payment of such amount shall be made on the
          following installment basis by wire transfer to ITC's bank account to
          be designated by ITC in advance:

            .  On or before April 10, 2002:           $US 13,250,000
            .  On or before December 31, 2002         $US 13,250,000
            .  On or before April 10, 2003            $US 13,250,000
            .  On or before December 31, 2003         US$ 13,250,000

          In consideration of such payment and in recognition of the fact that
          the $26,939,280 was previously paid under the Prior Agreement, the
          license granted under Section 2 of the Prior Agreement, with respect
          to Covered Subscriber Units and Covered Infrastructure Equipment
          compliant with PHS and/or PDC Covered Standards ("Covered PHS/PDC
          Products"), shall be considered fully paid up and irrevocable and
          shall survive any termination of the Prior Agreement; provided,
          however, that the royalty obligation as regards

____________
** Material has been omitted and filed separately with the commission.

                                       2

<PAGE>

          any Covered PHS/PDC Products also compliant with Third Generation or
          Narrowband CDMA (each as defined in the 3G Agreement) shall be
          determined in accordance with the terms of the 3G Agreement. In
          addition, with respect to any other Covered Subscriber Unit or Covered
          Infrastructure Equipment also compliant with Third Generation or
          Narrowband CDMA (e.g., GSM/FDD Covered Subscriber Unit), no royalty
          shall be payable under the Prior Agreement for such other product, so
          long as Licensee has paid, or is to pay, a royalty in accordance with
          the terms of the 3G Agreement with respect to such other Covered
          Subscriber Unit or Covered Infrastructure Equipment. Licensee may
          deduct applicable Japanese source withholding taxes from the payments
          hereunder, it being understood that both parties agree that the entire
          amount of US$53,000,000 is subject to the Japanese source withholding
          taxes. Licensee shall furnish ITC with the evidence that any such
          withholding tax has been paid.

          It is understood that if the Prior Agreement is substituted at
          Licensee's election by another patent license agreement as a result of
          the operation of the most favored licensee rights provisions of the
          Prior Agreement, any royalty obligation under such substitute
          agreement relating to Covered Subscriber Units and Covered
          Infrastructure Equipment compliant with only PHS and PDC shall not
          apply.

     2.   (Reserved).

     3.   Infrastructure. With regard to Infrastructure Equipment compliant with
          GSM and IS-54/136, Licensee agrees to pay ITC a royalty of [**]% of
          the Net Selling Price of each such sale, if any, of said
          Infrastructure Equipment from May 8, 1995 through December 31, 2006.
          Such royalty payments shall be made on each such sale, if any, by
          Licensee or its Affiliates anywhere in the

______________
** Material has been omitted and filed separately with the commission.

                                       3

<PAGE>

          world, without regard to the provisions of Section 5(c) or Section 7
          (other than Section 7(e)(iv)) of the Prior Agreement. Thereafter, any
          royalty obligations with regard to such Infrastructure Equipment shall
          be governed by the terms of the Prior Agreement.

     4.   Meaning of Paragraphs 5(c)(ii) and (iii) of Prior Agreement. The
          parties agree that, as used in Paragraphs 5(c) (ii) and (iii) of the
          Prior Agreement, the clause "but only if said counterpart contains
          claims which do not differ materially from those of the [**] Patent"
          shall in each occurrence, for the purpose of settlement, be hereafter
          deemed to refer to substantial differences between the issued non-U.S.
          patent claim(s), which issue from non-U.S. [**] patent applications
          that share a common specification with the U.S. patent, and Licensee's
          products compliant with a Covered Standard, such that infringement of
          such non-U.S. claims cannot be found. The parties further agree that,
          based on the audit conducted as part of the Dispute, Licensee has
          correctly accounted for use of the pre-paid units, including the
          application of credits under the [**] clause of the Prior Agreement,
          and that such credits shall continue to be available to Licensee with
          regard to its royalty obligations under the Prior Agreement.

     5.   Adjustment.
          (1) If, after the Effective Date of this Amendment Agreement,
              Licensee or its Affiliates acquires any entity which, prior to
              such acquisition, sold PDC or PHS Covered Subscriber Units or
              Covered Infrastructure Equipment without a license from ITC for
              the Licensed Patents, then Licensee shall pay ITC royalties of
              (i) $[**] for each PDC Covered Subscriber Unit and PHS Covered
              Subscriber Unit, and (ii) [**]% of the Net Selling Price of PDC
              or PHS Covered Infrastructure Equipment sold by such entity prior
              to such acquisition by Licensee; provided, however, that if such

_____________
** Material has been omitted and filed separately with the commission.

                                       4

<PAGE>

              acquisition occurs later than twelve (12) months after the
              Effective Date of this Amendment, Licensee shall have the option,
              to be exercised via written notice to ITC within sixty (60) days
              of the completion date of such acquisition, to have such sales be
              construed as unlicensed. In such situation, ITC shall have
              recourse to seek damages and/or royalties from any entity,
              including Licensee or its Affiliates, against whom legal action
              may be brought. In addition, provided such entity, at the time of
              being acquired by Licensee, had annual sales of PDC and/or PHS
              Covered Subscriber Units in excess of [**] units, in the
              aggregate, or had annual sales of PDC or PHS Covered
              Infrastructure Equipment of [**] U.S Dollars ($US [**]), the
              parties shall negotiate in good faith an equitable adjustment to
              the lump sum amount provided in Article 1 herein for sales after
              the date of the acquisition, provided that in lieu of adjustment
              to the lump sum amount provided in Article 1 herein, Licensee
              shall have the option to pay royalties to ITC at the royalty rates
              provided for in (i) and (ii) above with respect to PDC or PHS
              Covered Subscriber Units or Covered Infrastructure Equipment sold
              by, or ascribed to, the acquired entity after the date of the
              acquisition. Such negotiated adjustment amount will be based upon
              the ratio of Licensee and its Affiliates' total sales of the PDC
              and PHS Covered Subscriber Units and Covered Infrastructure
              Equipment from the period January 1, 1995 through December 31,
              2001 and the acquired entities sales of the PDC and PHS Covered
              Subscriber Units and Covered Infrastructure Equipment over the
              same period, less any royalties, if any, paid by Licensee for
              sales by the acquired entity prior to the date of acquisition
              pursuant to the first sentence of this Article 5. Any dispute as
              to the adjustment amount owed shall be made subject to resolution
              under the Dispute Resolution Procedures of the Prior Agreement.
              The parties shall also negotiate such an adjustment amount if
              Licensee acquires, over time, a number of

________________
** Material has been omitted and filed separately with the commission.

                                       5

<PAGE>

              entities, such that, in the aggregate, there existed annual sales
              of at least [**] Covered Subscriber Units or [**] U.S Dollars
              ($[**] US) of Covered Infrastructure revenue at the time of being
              acquired by Licensee. Sales by the acquired entities of non-PDC
              and non-PHS Covered Subscriber Units and Covered Infrastructure
              Equipment after the time of being acquired by Licensee, shall be
              controlled by the Prior Agreement. For sales by the acquired
              entities of non-PDC and non-PHS Covered Subscriber Units and
              Covered Infrastructure Equipment prior to the time of being
              acquired by Licensee, then Licensee shall pay ITC royalties of (i)
              $[**]US for each non-PDC Covered Subscriber Unit and non-PHS
              Covered Subscriber Unit, and (ii) [**]% of the Net Selling Price
              of non-PDC or non-PHS Covered Infrastructure Equipment; provided,
              however, that if such acquisition occurs later than twelve (12)
              months after the Effective Date of this Amendment, Licensee shall
              have the option, to be exercised via written notice sent to ITC
              within sixty (60) days of the conclusion date of such acquisition,
              to have such sales be construed as unlicensed.

          (2) To the extent Licensee or its Affiliates acquires an entity
              already licensed by ITC to the Licensed Patents, for the first
              twelve (12) months after the acquisition, the royalty obligation
              of such entity for royalty obligated sales volumes related to such
              entity shall be defined in such other license agreement with ITC.
              After the 12 month period, royalty obligations for all PDC and PHS
              Covered Subscriber Units and Covered Infrastructure Equipment
              sales made by, or ascribed to, the previously licensed acquired
              entity shall be determined as set forth in paragraph (1) above (as
              for unlicensed entities, either as an adjustment to the lump sum
              or running royalties, at Licensee's option); and royalty
              obligations for all non-PDC and non-PHS Covered Subscriber Units
              and Covered Infrastructure Equipment sales made by, or ascribed
              to, the previously licensed acquired

____________
** Material has been omitted and filed separately with the commission.

                                       6

<PAGE>

              entity after such acquisition shall be controlled by the terms of
              the Prior Agreement.

          (3) The above paragraphs (1) and (2) shall not apply in cases Licensee
              or its Affiliates acquires Licensee or any entity which is already
              Licensee's Affiliates at the time immediately prior to the
              acquisition.

     6.   Confidentiality/Press Release. Unless otherwise required by law,
          government regulations, stock exchange listing rules or court order,
          the parties shall maintain as strictly confidential the royalty terms
          of this Amendment Agreement and any proprietary information disclosed
          under, or as a result of the negotiation of, this Amendment Agreement,
          provided that each party may disclose in confidence the royalty terms
          to (i) its outside counsel or accountant, or (ii) its financial
          advisors or prospective acquiring or acquired entity in connection
          with its prospective M&A transactions. Further, ITC and/or IDC may
          issue a press release having the content shown in Exhibit 1, attached
          hereto. Licensee may also issue a press release regarding the fact of
          the execution of this Amendment Agreement and the settlement of the
          arbitration. To the extent ITC and/or IDC desires to modify an agreed
          upon press release, or Licensee desires to issue a press release, such
          desiring party shall provide the other party with an advance copy of
          its respective proposed press release for review, consent and comment;
          whereby consent by the other party shall not be unreasonably withheld
          or delayed.

     7.   Prior Agreement. Except as provided herein, all other terms and
          conditions of the Prior Agreement remain unaltered and in full force
          and effect.

                          Signatures on following page.

                                       7

<PAGE>

IN WITNESS WHEREOF, the parties have executed this Agreement by their duly
authorized representatives.

INTERDIGITAL TECHNOLOGY CORPORATION

By: /s/ William J. Merritt
   ------------------------------------

Dated: January 14, 2002
      ---------------------------------

NEC CORPORATION

By: /s/ [**]
   ------------------------------------

Dated: January 15, 2002
      ---------------------------------

____________
** Material has been omitted and filed separately with the commission.

                                       8

<PAGE>

                                Index of Exhibits

EXHIBIT 1:     PRESS RELEASE

                                       1

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