November 2000 doc IEEE 802 11 00386 Suggested

November 2000 doc. : IEEE 802. 11 -00/386 Suggested Options to the Texas Instruments Proposal for IEEE 802. 11 g High-Rate Standard Anuj Batra Ph. D, Chris Heegard Ph. D, Eric Rossin Ph. D, and Matthew B. Shoemake Ph. D Texas Instruments 141 Stony Circle, Suite 130 Santa Rosa California 95401 (707) 521 -3060, heegard@ti. com Submission 1 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Increasing Throughput with a High Performance Preamble Submission 2 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Current Preamble and Header (P/H) • Long PLCP PPDU Format: PLCP PREAMBLE 144 BITS @ 1 Mbps PLCP HEADER 48 BITS @ 1 Mbps PSDU 192 ms • Short PLCP PPDU Format: SHORT PLCP PREAMBLE 72 BITS @ 1 Mbps SHORT PLCP HEADER 48 BITS @ 2 Mbps PSDU 96 ms • Note that the preamble and header contain no information Submission 3 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Percent Overhead for Long P/H PSDU size (bytes) Submission 4 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Percent Overhead for Short P/H PSDU size (bytes) Submission 5 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Motivation for a Shorter P/H • For short PSDUs, preamble and header spans a large portion of the packet • Large P/H wastes valuable resources and decreases the network throughput • Can reduce overhead by: – defining a new preamble, and – increasing the data rate for the header Submission 6 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 New High Performance P/H PREAMBLE TIMING SYNC FRAME SYNC CHANNEL EST 96 symbols @ 11 Msps 64 symbols @ 11 Msps 168 symbols @ 11 Msps HEADER 48 BITS @ 5. 5 Mbps PSDU 38. 55 ms • Timing Synchronization Sequence: – tone that alternates between (1+j) and (-1 -j) – allows for easy detection of packet, timing, carrier frequency offset – need clocks to be locked • Frame Synchronization Sequence: composed of PN sequences – fix location within packet • Channel Estimation Sequence: deterministic sequernce – example: first 168 symbols of a length 255 PN sequence Submission 7 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Simulation: Network Throughput Total time P/H PSDU SIFS P/H ACK DIFS BACKOFF P/H PSDU time to transmit information network throughput = total time • Assumed a back-off time of zero to demonstrate the effect that the preamble size has on network throughput • Calculated increase in throughput for new P/H over Long P/H and Short P/H for various data rates Submission 8 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Throughput Increase for 5. 5 Mbps Submission 9 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Throughput Increase for 11. 0 Mbps Submission 10 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Throughput Increase for 16. 5 Mbps Submission 11 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Throughput Increase for 22. 0 Mbps Submission 12 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Throughput Increase for 33. 0 Mbps Submission 13 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Summary • Proposed a new preamble and header, which: – decreases overhead, and – increases network throughput for short packets • Results: – – – Submission 5. 5 Mbps: 120%+ over Long P/H , 40%+ over Short P/H 11. 0 Mbps: 150%+ over Long P/H, 60%+ over Short P/H 16. 5 Mbps: 165%+ over Long P/H, 65%+ over Short P/H 22. 0 Mbps: 180%+ over Long P/H , 70%+ over Short P/H 33. 0 Mbps: 200%+ over Long P/H , 75%+ over Short P/H 14 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Increasing the Data Rate to 33 Mbps in Wireless Ethernet via Clock Switching Submission 15 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Introduction • The existing IEEE 802. 11 b standard, and the TI proposed 22 Mbps extension to the standard, is based upon an 11 Msps symbol rate and a bandwidth occupancy of 20 MHz. In terms of modern digital communications techniques such as pulse shaping and adaptive equalization, a more aggressive symbol rate in the same bandwidth is practical. However, in order to deal with inter-operability with existing networks, the structure of the preamble, including the symbol rate of the preamble, must not change. A viable method to address these issues is to transmit an 11 Msps preamble followed by a higher symbol rate encoded data rate. Means and issues involving the switch in the clock are addressed in this presentation. The suggested increase in rate by 50% to 16. 5 Msps yields a data rate of 33 Mbps. Submission 16 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Pulse Shaping Submission 17 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Eye Diagram Submission 18 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Clock Switching Submission 19 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Clock Switching from 11 MHz to 16. 5 MHz with no (0//0) Guard Band Submission 20 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Clock Switching from 11 MHz to 16. 5 MHz with (2//3) Guard Band Submission 21 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Clock Switching from 11 MHz to 16. 5 MHz with (4//6) Guard Band Submission 22 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Packet Structure • Packet Structure without Clock Switching Submission 23 Anuj Batra et al. , Texas Instruments

November 2000 doc. : IEEE 802. 11 -00/386 Packet Structure (cont. ) • Packet Structure with Clock Switching Submission 24 Anuj Batra et al. , Texas Instruments