High-Speed Broadband Wireless LAN Solution March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 High-Speed Broadband Wireless LAN Solution Date: 2007-03-13 Authors: Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair stuart@ok-brit.com as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

High-Speed Broadband Wireless LAN Solution March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Abstract High-Speed Broadband Wireless LAN Solution Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Contents Inadequacy in 802.11a/g Nufront solution March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Contents Inadequacy in 802.11a/g Nufront solution (1) Subchannel-modulation mode (2) PHY superframe (3) Advantages and benefits Simulation and computation results Conclusion Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Inadequacy in 802.11a/g Low speed in data transmission March 2007 doc.: IEEE 802.11-07/0402r0 Inadequacy in 802.11a/g March 2007 Low speed in data transmission Two factors that limit 802.11a/g data transmission speed: (1) The ordinary OFDM is affected by the frequency-selective fading of channel (2) Overhead in MAC access as well as in PHY frame Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Frequency selective fading in 802.11a/g channel March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Frequency selective fading in 802.11a/g channel Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Nufront solution Subchannel-modulation mode: March 2007 doc.: IEEE 802.11-07/0402r0 Nufront solution March 2007 Subchannel-modulation mode: Each chosen subchannel modulation mode is based on the gain of subchannel PHY Superframe: A PHY superframe is composed of several PHY frames Advantages and benefits Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Subchannel-modulation mode March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Implementation steps: 1. Transmit station transmits a packet to receive station; 2. Receive station makes channel estimation with this packet, and then chooses modulation mode for each subchannel; 3. Receive station feeds back reference data of subchannel-modulation mode to transmit station; 4. Transmit station transmits data packets to receive station based on the chosen subchannel-modulation mode. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Subchannel-modulation mode March 2007 doc.: IEEE 802.11-07/0402r0 Subchannel-modulation mode March 2007 Innovations in the implementation: 1. Make use of MAC layer’s interaction (for example, RTS-CTS) to compute and feed back reference data of the subchannel-modulation mode In the RTS-CTS interaction, the receive station uses RTS to estimate channel, and then uses CTS to feed back reference data of the subchannel-modulation mode. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Subchannel-modulation mode March 2007 doc.: IEEE 802.11-07/0402r0 Subchannel-modulation mode March 2007 2. “Reflexive” channel estimation When a MAC frame is proved correct through FCS checking, it is transformed into a baseband signal sequence. This sequence is then taken as a new lengthened training sequence to get a much more accurate channel estimation. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Subchannel-modulation mode March 2007 doc.: IEEE 802.11-07/0402r0 Subchannel-modulation mode March 2007 3. Reconstruct the SIGNAL symbol of the PHY frame using subchannel-modulation mode Swap Field “Duration” in MAC frame and Field “LENGTH” in PHY frame Maximum PHY data rate: 72 Mbps (256QAM) Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Implementation steps: March 2007 doc.: IEEE 802.11-07/0402r0 PHY Superframe March 2007 Implementation steps: 1. Concatenating SIGNAL symbols and data symbols of different PHY frames to construct a superframe; 2. Adding a preamble to the superframe. PREAMBLE DATA 1 …… SIGNAL 2 K Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

March 2007 doc.: IEEE 802.11-07/0402r0 PHY Superframe March 2007 Group acknowledgement mechanism Whenever a receive station gets a chance to respond, it responds to all the packets received since its last response. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Advantages and benefits March 2007 doc.: IEEE 802.11-07/0402r0 Advantages and benefits March 2007 (1) High data transmission speed See “Simulation and computation results” (2) Low complexity It can be implemented by only replacing the 802.11a/g DSP unit with the DSP unit based on Nufront solution while keeping the existing RF unit unchanged (3) Compatibility with 802.11a/g The PHY and MAC frame structures of Nufront solution are almost as same as 802.11a/g Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Simulation and computation results March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Simulation and computation results (1) PHY data rate achieved by the subchannel-modulation mode (2) MAC throughput achieved by the PHY superframe (3) Data transmission speed achieved Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Achieved PHY data rate comparison among different modes March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Achieved PHY data rate comparison among different modes Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Comparison of achieved MAC throughput between superframe and 802.11a/g system Achieved data rate in PHY layer (Mbps) Achieved MAC throughput (Mbps) 802.11a/g system Superframe system(K=10) Superframe system(K=20) 36 28.89 34.32 34.67 48 36.53 45.33 45.94 54 39.80 50.73 51.53 72 49.08 66.72 68.06 Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Data transmission speed achieved March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Data transmission speed achieved SNR (dB) Data transmission speed(Mbps) (802.11a/g) Data transmission speed (Mbps) (Nufront) Number of HDTV and SDTV that can work 15 11.0 23.1 1 HDTV or 5 SDTV 20 18.7 35.9 1 HDTV, 3 SDTV 25 20.7 49.8 2 HDTV, 2 SDTV Or 1HDTV,7 SDTV (K=10) Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Conclusion Nufront solution proposes the subchannel-modulation mode and the PHY superframe in 802.11a/g WLAN to improve the network’s PHY data rate and MAC throughput, respectively. Simulation and computation results indicate that, based on Nufront solution, a much higher data transmission speed in comparison with the 802.11a/g system can be achieved. Thus HDTV can be transmitted through WLAN. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

March 2007 doc.: IEEE 802.11-07/0402r0 March 2007 Conclusion By only replacing the 802.11a/g baseband DSP unit with the DSP unit based on Nufront solution while keeping the existing RF unit unchanged, a high-speed WLAN system compatible with 802.11a/g can be achieved. At the beginning of our R&D, we found an economic improvement and upgrade to 802.11 is very important. We also found a chip with Nufront solution can be easily made through existing SoC technology. Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software

Thank You Very Much! March 2007 March 2007 doc.: IEEE 802.11-07/0402r0 Hamilton Young, Beijing Nufront Software Hamilton Young, Beijing Nufront Software