Dr. Hatim Zaghloul Chairman and CEO

Who are the OFDM Forum’s Principal Members?

The Evolution of W-OFDM Technology May 1998: Wi-LAN is the preferred supplier to Tele2(UK) to build a national network at 3.6GHz November 1998: Wi-LAN’s patented W-OFDM technology is brought to life with functioning 30 Mbps prototype June 1999: Wi-LAN breaks industry barriers with launch of high-speed 30 Mbps wireless networking product at 2.4GHz (not FCC certified) January 2000: Wi-LAN demonstrates first mobile application of W-OFDM technology June 2000: Prototype ASIC chips using W-OFDM technology developed February 2001: Wi-LAN signs a contract for national networks in six European countries and ships 3GHz W-OFDM units

Channel Estimation and Erasure Locating Channel Estimation Equalization Vector –The complex reciprocal of each subcarrier in the average OFDM training symbol. Erasure Locating –The magnitudes vector created by the channel estimator is used to determine which Reed Solomon symbols within an RS codeword are likely to be in error. These suspect errors can be removed from the FEC in the receiver thus improving its performance by an order of magnitude. Phase Whitening –The signal vector is multiplied times a random phase before the IFFT in the transmitter which reduces the peak to average ratio requirement. Phase whitening is superior to data scrambling since scrambling only assures that the data does eventually make it through.

Typical Channel Response Multipath Channel Response (dB)

Channel Estimation and Erasure Locating Channel Estimation With Noise, Equalized Channel, and Erasures

Summary of Benefits to IEEE FWA OFDM is spectrally efficient OFDM can be used in TDD or FDD modes OFDM is scalable for various channel requirements OFDM is robust to channel impairments caused by multipath FEC with erasures compliment OFDM very well, especially when the channel is Non-ideal.Errors due to multipath/jammers may be predictable and erasable

W-OFDM Permits Obstructed LOS (OLOS) Base Site.47 Miles, –67 dBi RSSI, 3 dB Null Depth, Nominal Data Rate

W-OFDM Permits Non Line of Site (NLOS) Base Station Behind Obstruction.6 Miles, -70 dB RSSI, 6 dB Null Depth, Nominal Throughput

Other Technologies for Non- Line of Sight Routed Mesh Network Architecture Traffic can be routed around obstructions rather than needing to deploy additional base stations that can simplify line-of-sight problems in densely populated diverse geographical locations.

US Patent 5,282,222 W-OFDM Wide-band Orthogonal Frequency Division Multiplexing (US patent and Canadian Patent ) “A Method and Apparatus for Multiple Access Between Transceivers in Wireless Communications Using OFDM Spread Spectrum” By Virtue of these patents, two-way high speed communications using any form of OFDM requires a license from Wi-LAN. Wi-LAN is committed to enabling and promoting IEEE and ETSI standards activities and has agreed to license its patents, when and if required, to companies developing products complying with their standards.