Agere Sues Intersil

By Eric Griffith

October 18, 2002

UPDATE: Agere has filed a patent infringement suit against WLAN chip rival Intersil for monetary damages and seeks an injunction against Intersil using patented technology.

Agere Systems of Allentown, PA, has filed a patent infringement law suite against Irvine, CA-based Intersil in the United States District Court in Delaware. Both company's are incorporated under Delaware law.

The suit regards six patents Agere owns. Three of the patents are said, in the company statement, to be "essential in order to comply with the IEEE 802.11b wireless local area networking (WLAN) standard." Agere made these patents available for use "on reasonable terms and conditions" -- but the suit alleges Intersil has not paid for the use. The other three patents cover wireless technology regarding the OSI Model Physical Layer (PHY) and radio components which Agere says it developed and that Intersil is using in its WLAN chips and reference designs.

According to the complaint filed by Agere, the major patents in question include:

  • Patent No. 5,862,182 -- "OFDM Digital Communications System Using Complimentary Codes," a method and apparatus for encoding and decoding data using complementary codes, issued January 19, 1999.
  • Patent No. 6,404,732 -- "Digital Modulation System Using Modified Orthogonal Codes to Reduce Autocorrelation," a method and apparatus for encoding and decoding data with a symbol produced from orthogonal symbols and complementary codes, issued June 11, 2002
  • Patent No. 6,452,958 B1 -- "Digital Modulation System Using Extended Code Set," a method and apparatus for encoding and decoding data with a code set having an extended number of codes and a complementary code; issued just last month, on September 17, 2002.
The other three patents are No. 5,128,960 on recovering a clock signal from a data symbol in a wireless channel; No. 5,420,599 that grounds inactive antennas so they don't interfere with active antennas; and No. 6,067,291 for establishing variable carrier detect threshold and defer threshold.

Agere wants monetary damages from Intersil, wishes to be "awarded for all attorney fees, costs and expenses it incurs" and is seeking an injunction against Intersil so it can no longer use the patents in its products. The complaint alleges that Agere previously notified Intersil of the infringement on all counts, and that Intersil's infringement "was, and continues to be, willful."

Intersil's official stance is that the suit is "wholly without merit." The company believes that its PRISM WLAN chips do not infringe on any of Agere's patents. The company plans to defend itself against the claims and will continue to sell its chips as per usual.

In May 2001, Agere similarly sued Proxim for infringing on three of its WLAN patents and sought monetary damages and an injunction against further infringement; this was in response to a suite Proxim had itself filed against 3Com, Cisco, Intersil, SMC Networks, Symbol Technologies and Wayport in March of that year to protect its own patented WLAN technology. Agere and Proxim settled their suit as part of the sale of ORiNOCO product line to Proxim this summer.

Eric Griffith is the managing editor of 802.11 Planet.

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