July 2005 doc.: IEEE 802.11-04/0889r7
Submission page 3 Syed Aon Mujtaba, Agere Systems
1 Executive Summary 1
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The TGn Sync team respectfully submits its complete proposal. The team is comprised of 802.11 WG 3
participants whose companies represent a broad range of markets, including, PC, Enterprise, Consumer 4
Electronics, Handset, Semiconductor and Public Access. Since these companies are based in the US, Europe 5
and Asia Pacific, the team has had the benefit of a worldwide perspective, both in terms of perceived market 6
demand as well as regulatory concerns (including channel bandwidth limitations, limited channel access, 7
restricted transmission times, etc.). 8
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Our goal has been to align (or “sync” with) 802.11n members to a single set of core positions prior to the TGn 10
down selection phase. By aligning before entrenched positions form, we hope to increase the possibility of a 11
more rapid introduction of an 802.11n standard. 12
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The team has worked as a technical group for many months to develop a TGn proposal, recognizing that 14
whatever decisions were made had to ultimately survive the TGn process and therefore be based solely on 15
technical merit. There were no signed agreements involved in joining the TGn Sync team. There was no 16
attempt to develop joint IP and each company was expected to abide by the same reasonable and non-17
discriminatory terms that the IEEE bylaws require. 18
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The technical approach balances market expectations with design practicality. The solution is a robust, scalable 20
architecture targeting the least amount of complexity. In fact, the basic configuration delivers a maximum rate 21
of 243 Mbps using only two antennas. This rate is consistent with the historical trend of 5x with each 22
generation of 802.11 (802.11/2Mbps, 802.11b/11Mbps, and finally 802.11a/ 54Mbps). The proposal also 23
incorporates options for rates up to 720 Mbps. This choice of higher peak data rates was seen as critical for 24
future proofing this next generation of WLAN. 25
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The PHY techniques used to achieve the higher data rates involve a MIMO evolution of 802.11 OFDM PHY 27
with spatial division multiplexing of spatial streams, wider bandwidth options (either 20MHz or 40MHz) and 28
an optimized interleaver for both the 20 MHz and 40MHz channelizations. Additionally, optional 29
enhancements include advanced FEC coding techniques (LDPC), space time block coding (STBC), and 30
transmit beamforming with negligible additional cost in the receiving client device and/or additional RF chains. 31
These options provide extra scalability if additional robustness and/or throughput is required. 32
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The TGn Sync proposal also offers seamless interoperability with 802.11 legacy devices. This interoperability 34
is achieved with an enhanced 802.11 preamble design and efficient PHY and MAC level mechanisms, which 35
also provide robustness and cost-effectiveness. 36
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The features added to improve MAC efficiency − for higher throughput and overall system performance − 38
include aggregation, bi-directional data flow, enhanced Block Ack, channel management (including a receiver 39
assisted channel training protocol) and feedback mechanisms that enable rate adaptation. Protection 40
mechanisms are also added to achieve the seamless interoperability and coexistence with legacy devices 41
mentioned above. The approach supports 802.11e and proposes new features for further enhancement. 42
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1.1 Proposal Structure 45
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The TGn Sync complete proposal meets the IEEE 802.11n PAR, meets all functional requirements, and 47
addresses all mandatory requirements of the comparison criteria. 48
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This document contains a technical specification of the proposed MAC and PHY enhancements. 50
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