Exhibit 99.1

      InterDigital Anticipates Filing an Automatic Extension for
                           Form 10-K Filing

    KING OF PRUSSIA, Pa.--(BUSINESS WIRE)--March 11,
2005--InterDigital Communications Corporation (NASDAQ:IDCC), a leading
architect, designer and provider of wireless technology and product
platforms, today announced that it anticipates filing with the
Securities and Exchange Commission (SEC) a Form 12b-25 Notification of
Late Filing pursuant to Rule 12b-25 of the Securities Exchange Act of
1934 to obtain an automatic extension to file its Form 10-K for the
year ended December 31, 2004.
    On March 10, 2005, the Company issued its preliminary financial
results for fourth quarter and full year 2004. The results were
preliminary because the Company is in the process of responding to
comments by the SEC associated with a periodic review of the Company's
Form 10-K for the year ended December 31, 2003 and Form 10-Q for the
quarter ended September 30, 2004. Two principal items remaining in the
review relate to the timing of the expense recognition of the
Company's foreign source withholding taxes and the ten year
amortization period for costs of internally developed patents. The
Company is continuing to address these items with the SEC. The Company
will be unable to finalize its financial results until these items are
resolved which it anticipates will occur after March 16, 2005.
Resolution of these items will have no effect on the Company's cash
flow or underlying economics of the business.
    The Company can make no prediction at this time as to the outcome
of the review with the SEC, any impact the resolution of the review
may have on amounts recorded for foreign source withholding taxes and
amortization of patent costs, and whether or not such resolution will
result in the Company reporting a material weakness in the Company's
internal control over financial reporting as required by Section 404
of The Sarbanes-Oxley Act of 2002.

    About InterDigital

    InterDigital architects, designs and provides advanced wireless
technologies and products that drive voice and data communications.
The Company offer technology and product solutions for mainstream
wireless applications that deliver time-to-market, performance, and
cost benefits, as well as product differentiation advantages, to its
commercial and government/military customers. InterDigital has a
strong portfolio of patented technologies covering 2G, 2.5G, 3G and
802 standards, which it licenses worldwide. For more information,
please visit InterDigital's web site: www.interdigital.com.
InterDigital is a trademark of InterDigital Communications
Corporation.

    CONTACT: InterDigital Communications Corporation
             Media Contact:
             Dawn Goldstein, 610-878-7800
             e-mail: dawn.goldstein@interdigital.com
                 or
             Investor Contact:
             Janet Point, 610-878-7800
             e-mail: janet.point@interdigital.com