Jim Zyren Mark Webster Steve Halford Intersil Corporation March 2001 TGg Final Statement Jim Zyren Mark Webster Steve Halford Intersil Corporation J. Zyren, M. Webster, S. Halford, Intersil Corp

OFDM for IEEE 802.11g CCK / OFDM Industry Convergence March 2001 CCK / OFDM Fully compliant with TGg requirements Backward compatible with IEEE 802.11b Utilizes 802.11a as a basis for the higher data rates Data rates identical to 802.11a (6,9,12,18,24,36,48,54 Mbps) Industry Convergence OFDM already adopted for 802.11a & HiperLAN2 Uses technology developed by MANY companies Regulatory Issues All TGg proposals require rule change FCC is changing rules Do we want to enable another hi rate technology? Inevitable direct competition with OFDM @ 2.4 & 5 GHz J. Zyren, M. Webster, S. Halford, Intersil Corp

March 2001 Regulatory Status None of the TGg proposals meets the FCC requirements for 2.4 GHz DSSS systems FCC considers spectral efficiency to be a key component Meeting processing gain or CW jammer test alone is not sufficient FCC has compelling reasons to modify 2.4 GHz DSSS rules: WiLan Application for Review TI proposal for PBCC Current proceeding (99-231) regarding DSSS testing Consumer demand for higher data rates FCC is planning to initiate a rule making process to change the rules for DSSS systems in the 2.4 GHz band Expected to redefine “DSSS” to permit higher data rates Likely initiated in the spring timeframe OFDM is coming to the 2.4 GHz band OFDM (Wi-LAN) has been turned down TI has never obtained regulatory approval for PBCC J. Zyren, M. Webster, S. Halford, Intersil Corp

Why OFDM for 2.4 GHz? OFDM is a powerful and proven waveform March 2001 OFDM is a powerful and proven waveform Selected for both 802.11a and HyperLan2 Robust performance against multi-path, AWGN, and in-band interference Real world performance impacts Interleaving and error coding result in very robust performance Data rates to 54 Mbps Industry Convergence Many companies are developing OFDM technology Industry working to develop a single 5 GHz standard for the 5 GHz bands 5 GHz IAG and IEEE 802.11 5GSG Provide graceful migration path from 802.11b to 802.11a CCK-OFDM offers forward & backward compatibility OFDM is being widely adopted TGg should capitalize on this development --- not resist it! J. Zyren, M. Webster, S. Halford, Intersil Corp

Comparison of PBCC and OFDM March 2001 PBCC was adopted by IEEE 802.11 on the same day as CCK but no PBCC based products are on the market Design complexity delays practical implementation WLAN channels are limited by multi-path not AWGN Convolutional codes emphasize AWGN performance but complicate receiver via complex equalization requirements By comparison, CCK block codes are optimized for multi-path properties Block codes are selected for autocorrelation and cross correlation properties Lowers receiver complexity and speeds implementation Similarly, OFDM characteristics are well suited to WLAN applications Robust performance against multi-path, in-band interference and AWGN Receiver scales to higher data rates with no increase in complexity PBCC is more differentiated from CCK than OFDM PBCC is not optimized to address real world WLAN effects PBCC requires the use of an entirely different receiver structure J. Zyren, M. Webster, S. Halford, Intersil Corp

Some Closing Thoughts March 2001 Single carrier systems do not scale well to higher data rates Selection of PBCC will effectively cap data rates and require the standardization of yet another technology TGg should adopt the fastest technology for the HI RATE EXTENSION OFDM provides for data rates to 54 Mbps Complements 802.11a Speeds WLAN adoption in BOTH 2.4 & 5 GHz bands OFDM will likely come into the band regardless of what the IEEE does IEEE should standardize around OFDM OFDM is the right choice for TGg J. Zyren, M. Webster, S. Halford, Intersil Corp