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TGn Sync Proposal Date: Aug 13, 2004 Month 2002
doc.: IEEE /xxxr0 August 2004 TGn Sync Proposal Date: Aug 13, 2004 Aon Mujtaba, Agere Systems Inc., Adrian P Stephens, Intel Corporation, Alek Purkovic, Nortel Networks Andrew Myles, Cisco Systems Brian Johnson, Nortel Networks Corporation, Daisuke Takeda, Toshiba Corporation, Darren McNamara, Toshiba Corporation, Dongjun (DJ) Lee, Samsung Electronics Co. Ltd., David Bagby, Calypso Consulting, Eldad Perahia, Cisco Systems, Huanchun Ye, Atheros Communications Inc., Hui-Ling Lou, Marvell Semiconductor Inc., James Chen, Marvell Semiconductor Inc., James Mike Wilson, Intel Corporation, Jan Boer, Agere Systems Inc., Jari Jokela, Nokia, Jeff Gilbert, Atheros Communications Inc., Joe Pitarresi, Intel Corporation, Jörg Habetha, Royal Philips Electronics, John Sadowsky, Intel Corporation, Jon Rosdahl, Samsung Electronics Co. Ltd., Luke Qian, Cisco Systems, Mary Cramer, Agere Systems summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Authors (continued) Month 2002 doc.: IEEE 802.11-02/xxxr0 August 2004
Masahiro Takagi, Toshiba Corporation, Monisha Ghosh, Royal Philips Electronics, Nico van Waes, Nokia, Osama Aboul-Magd, Nortel Networks Corporation, Paul Feinberg, Sony Electronics Inc., Pen Li , Royal Philips Electronics Peter Loc, Marvell Semiconductor Inc., Pieter-Paul Giesberts, Agere Systems Inc., Richard van Leeuwen, Agere Systems Inc., Ronald Rietman, Royal Philips Electronics, Seigo Nakao, SANYO Electric Co. Ltd., Sheung Li, Atheros Communications Inc., Stephen Shellhammer, Intel, Takushi Kunihiro, Sony Corporation, Teik-Kheong (TK) Tan, Royal Philips Electronics, Tomoko Adachi, Toshiba Corporation, Tomoya Yamaura, Sony Corporation, Tsuguhide Aoki, Toshiba Corporation, Won-Joon Choi, Atheros Communications Inc., Xiaowen Wang, Agere Systems Inc., Yasuhiko Tanabe, Toshiba Corporation, Yasuhiro Tanaka, SANYO Electric Co. Ltd., Yoshiharu Doi, SANYO Electric Co. Ltd., Yuichi Morioka, Sony Corporation, Youngsoo Kim, Samsung Electronics Co. Ltd., summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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TGn Sync Proposal Team - Background
Month 2002 doc.: IEEE /xxxr0 August 2004 TGn Sync Proposal Team - Background Team operated as a technical group to help motivate a rapid introduction of the n standard Participating companies from a broad range of markets PC Enterprise Consumer Electronics Semiconductor Handset Public Access Solution incorporates a worldwide perspective of perceived market demand and regulatory concerns Team has representation from the US, Europe and the Pacific Rim summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Proposal Overview High throughput and minimal design complexity
Month 2002 doc.: IEEE /xxxr0 August 2004 Proposal Overview High throughput and minimal design complexity Superior robustness for a broad range of applications Low cost, low power consumption Scalable architecture Seamless interoperability with legacy devices Flexible architecture offering regulatory compliance in all major regulatory domains while preserving interoperability summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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PHY Summary of TGn Sync Proposal
Month 2002 doc.: IEEE /xxxr0 August 2004 PHY Summary of TGn Sync Proposal Basic configuration delivers 243 Mbps using only two antennas Follows historical trend of 5x for (.11 .11b .11a/g) Higher optional PHY data rate rates (>600 Mbps) for future generation devices MIMO evolution of OFDM PHY with spatial division multiplexing of spatial streams Multiple antennas (2 mandatory, greater than 2 optional) Preamble designed for seamless interoperability with legacy a/g Wider bandwidth options with fully interoperable 20 MHz and 40 MHz* channel capability Support for licensed 10 MHz modes Optional enhancements Advanced FEC coding techniques (RS, LDPC) Transmit beamforming with negligible additional cost in receiving client device 1/2 guard interval Rate 7/8 coding summary deck *Not required in regulatory domains where prohibited. Aon Mujtaba, Agere Systems, et al John Doe, His Company
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MAC Summary of TGn Sync Proposal
Month 2002 doc.: IEEE /xxxr0 August 2004 MAC Summary of TGn Sync Proposal Supports .11e Frame aggregation, single and multiple* destinations Bi-directional data flow Feedback mechanisms that enhance rate adaptation Protection mechanisms for seamless interoperability and coexistence with legacy devices Channel management (including receiver assisted channel training protocol) Power management summary deck * Optional Aon Mujtaba, Agere Systems, et al John Doe, His Company
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PHY Month 2002 doc.: IEEE 802.11-02/xxxr0 August 2004 summary deck
Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Basic Tx Data Path FEC coding Spatial stream parsing
Month 2002 doc.: IEEE /xxxr0 August 2004 Basic Tx Data Path FEC coding Conventional K = 7 convolutional code Rates: 1/2, 2/3 and 3/4 Supports legacy operation Optional LDPC/RS Optional rate 7/8 code Spatial stream parsing Frequency interleaving Block interleaver w/ QAM bit rotation (like 11a) 20 MHz 16 columns freq. sep. = 3 subcarriers 40 MHz 18 columns freq. sep. = 6 subcarriers QAM modulation BPSK, QPSK, 16 QAM and 64 QAM Optional 1/2 guard interval summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Basic Tx Data Path 2 antenna 20 MHz 2 antenna 40 MHz Month 2002
doc.: IEEE /xxxr0 August 2004 Basic Tx Data Path 2 antenna 20 MHz summary deck 2 antenna 40 MHz Aon Mujtaba, Agere Systems, et al John Doe, His Company
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+ Duplicate Format, BPSK R = ½ provides 6 Mbps for 40 MHz channels
Month 2002 doc.: IEEE /xxxr0 August 2004 Basic MCS Set Modulation Code Rate Data Rates* 20 MHz (Mbps) (1,2,3,4 spatial streams) Data Rates* 40 MHz (Mbps) BPSK 1/2 6, 12, 18, 24 13.5, 27, 45.5, 54 QPSK 12, 24, 36, 48 27, 54, 81, 108 3/4 18, 35, 54, 72 40.5, 81, 121.5, 162 16 QAM 24, 48, 72, 96 54, 108, 162, 216 36, 72, 108, 144 81, 162, 243, 324 64 QAM 2/3 48, 96, 144, 192 108, 216, 324, 432 121.5, 243, 364.5, 486 7/8 63, 126, 189, 252 141.75, 283.5, , 567 summary deck + Duplicate Format, BPSK R = ½ provides 6 Mbps for 40 MHz channels * Optional short GI (0.4 sec) increases rates by 11.1% for maximum data rate of 640 Mbps Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Only 2 RF chains => Cost effective & low power
Month 2002 doc.: IEEE /xxxr0 August 2004 2x2 – 40 MHz Only 2 RF chains => Cost effective & low power Lower throughput => Low cost RF Throughput Overhead => Robust delivery of 100 Mbps Sweet Spot for 100 Mbps top-of-MAC summary deck Standard 0.8 sec GI Aon Mujtaba, Agere Systems, et al John Doe, His Company
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PPDU Format Legend L- Legacy, HT- High Throughput
Month 2002 doc.: IEEE /xxxr0 August 2004 PPDU Format Legend L- Legacy, HT- High Throughput STF = Short Training Field LTF = Long Training Field SIG = Signal Field Legacy Compatible Can be decoded by any legacy a or g compliant device for interoperability summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Spoofing RATE and LENGTH PPDU length in OFDM symbols Spoofing
Month 2002 doc.: IEEE /xxxr0 August 2004 Spoofing RATE and LENGTH PPDU length in OFDM symbols Spoofing Spoofing means that the legacy RATE and LENGTH fields are falsely encoded in order to determine a specified length L-SIG RATE = 6 Mbps spoofing duration up to ~3 msec summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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HT-SIG Contents MCS = Modulation Coding Scheme Length
August 2004 HT-SIG Contents MCS = Modulation Coding Scheme Number of spatial streams Modulation Code rate Length Up to 262 kbytes PPDU option flags Support for advanced features Scrambler initialization Robust scrambler init required for packet aggregation Strong 8-bit CRC protection Aon Mujtaba, Agere Systems, et al
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HT PPDU Detection Auto-detection scheme on HT-SIG
August 2004 HT PPDU Detection Auto-detection scheme on HT-SIG Q-BPSK modulation (BPSK w/ 90-deg rotation) Pilot reversal Combined methods provide speed and reliability Aon Mujtaba, Agere Systems, et al
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Training Fields Design priorities
Month 2002 doc.: IEEE /xxxr0 August 2004 Training Fields Design priorities Backward compatibility with a/g Robust performance Cost effective implementation Low overhead summary deck These space-time diagrams apply to both 20 and 40 MHz channels Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Legacy Compatible Preamble
Month 2002 doc.: IEEE /xxxr0 August 2004 Legacy Compatible Preamble CDD The L-STF, L-LTF, L-SIG and HT-SIG are transmitted as a single spatial stream. This may be either transmitted on all Tx antennas via a method such as Cyclic Delay Diversity (CDD), or on a single antenna. These are implementation options. Requirement: These fields must be transmitted in an omni-directional mode that can be demodulated by legacy receivers. or single antenna summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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HT Training Fields HT-STF HT-LTF Tone interleaving of spatial streams
Month 2002 doc.: IEEE /xxxr0 August 2004 HT Training Fields HT-STF Used for 2nd AGC HT-LTF Used for MIMO channel estimation Additional frequency or time alignment Tone interleaving of spatial streams summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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HT Short Training Field
August 2004 HT Short Training Field 24 tones – interleaved across spatial streams Excellent space-frequency observability 1.6 sec period 2nd AGC Reduces ADC requirement by 1 bit Significant cost & power reduction Eliminates MIMO AGC mismatch Robust packets for aggregation Aon Mujtaba, Agere Systems, et al
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HT Long Training Fields
August 2004 HT Long Training Fields Aon Mujtaba, Agere Systems, et al
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Spatial Stream Tone Interleaving
August 2004 Spatial Stream Tone Interleaving Color indicate spatial stream Each HT-LTF has equal representation from all spatial streams Eliminates avg. power fluctuation across LTFs HT-LTS symbols are selected to control PAPR Distinct symbol designs for different number of spatial streams Aon Mujtaba, Agere Systems, et al
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Why Tone Interleaving on HT-LTF?
August 2004 Why Tone Interleaving on HT-LTF? No tone interleaving Clipping in Rx ADC? Even if all spatial streams are transmitted with equal power, they can create power differences at the receiver. For Model B (15 n sec delay spread) this can result in frequent power differentials of ~6dB between spatial streams. Tone interleaving of spatial streams results in averaging power levels across all spatial streams on each training symbol. The result is essentially no Rx power fluctuation of the STS and LTS with respect to the data symbols. Aon Mujtaba, Agere Systems, et al
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40 MHz Channel 108 data + 6 pilot subcarriers
Month 2002 doc.: IEEE /xxxr0 August 2004 40 MHz Channel 108 data + 6 pilot subcarriers Duplicate format on legacy part Provides interoperability between 20 MHz and 40 MHz transmissions Aon Mujtaba, Agere Systems, et al John Doe, His Company
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40 MHz PPDU Format Duplicate format preamble HT part
Month 2002 doc.: IEEE /xxxr0 August 2004 40 MHz PPDU Format Duplicate format preamble Provides interoperability with 20 MHz legacy STAs Data, pilot and training tones in each 20 MHz subchannel are identical to corresponding 20 MHz format 90 deg phase shift on upper sub-channel controls PAPR HT part 108 data tones + 6 pilots 3 center nulls (not shown) summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Duplicate Receiver Combining Equalizer: Simple MRC combining
August 2004 Duplicate Receiver Combining Equalizer: Simple MRC combining Note: If upper sub-channel is not present, combining weights are zero Aon Mujtaba, Agere Systems, et al
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40/20 MHz Interoperability
Month 2002 doc.: IEEE /xxxr0 August 2004 40/20 MHz Interoperability 20 MHz PPDU 40 MHz receiver Combine modulation symbols from upper & lower sub-channels 20 MHz PPDU in lower sub-channel Zero combining weights in upper subchannel No loss in performance relative to a 20 MHz receiver Use differential sub-channel energy to detect 20 vs. 40 MHz signals 40 MHz PPDU 20 MHz receiver One sub-channel is sufficient to decode the L-SIG Detects only half of the 40 MHz signal 3 dB performance penalty for 20 MHz clients See MAC slides for additional information on 40/20 inter-op summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Transmit Beamforming Basic Beamforming
Month 2002 doc.: IEEE /xxxr0 August 2004 Transmit Beamforming Basic Beamforming Cost, complexity, and power consumption contained in the AP Enterprise AP, media server AP, set-top box, or desktop PC Very low overhead for BF receive only client Low client cost, essentially zero overhead Low power consumption – battery operated Basic MCS set Channel sounding PPDU provides capability to estimate the channel from all Tx antennas Receiver does not need to know the beamforming specifics at the transmitter Simple packet exchange for calibration Optional Advanced Beamforming (ABF) Extended MCS Set Provides independent modulation/coding across spatial streams Support for unequal spatial stream power loading Support for bi-directional beamforming summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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=> cost effective server-client
Month 2002 doc.: IEEE /xxxr0 August 2004 4 Tx AP => 2 Rx Client ~10 dB gain over Basic 2x2! => cost effective server-client summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Optional Advanced Coding Modes
Month 2002 doc.: IEEE /xxxr0 August 2004 Optional Advanced Coding Modes Low Density Parity Check (LDPC) Superior performance at high code rates (7/8) Reed-Solomon (RS) Outer code concatenated with inner convolutional code Very low cost, mature technology summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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LDPC yields a 2x2 20 MHz high throughput solution at reasonable SNR!
Month 2002 doc.: IEEE /xxxr0 August 2004 LDPC yields a 2x2 20 MHz high throughput solution at reasonable SNR! summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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August 2004 MAC Aon Mujtaba, Agere Systems, et al
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MAC Challenges in HT Environment
Month 2002 doc.: IEEE /xxxr0 August 2004 MAC Challenges in HT Environment HT requires an improvement in MAC Efficiency HT requires effective Rate Adaptation HT requires Legacy Protection summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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New MAC Features Aggregation Format Aggregation Exchanges
Month 2002 doc.: IEEE /xxxr0 August 2004 New MAC Features Aggregation Format Aggregation Exchanges Protocol for training Protocol for reverse direction data Single and multiple responder Header Compression Protection Mechanisms Coexistence & Channel Management MIMO Power Management summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Aggregation Framing Robust Structure
Month 2002 doc.: IEEE /xxxr0 August 2004 Aggregation Framing Robust Structure Aggregation Framing is a purely-MAC function (PHY has no knowledge of MPDU boundaries) summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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MAC Header Compression
August 2004 MAC Header Compression MHDR MPDU carries repeated Header fields CHDATA MPDU refers to previous MHDR MPDU HID field ties the two together Context only within current aggregate Aon Mujtaba, Agere Systems, et al
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Aggregate Exchange Sequences
Month 2002 doc.: IEEE /xxxr0 August 2004 Aggregate Exchange Sequences MPDU or frame exchange sequences now extended to aggregate exchange sequences in which groups of frames are exchanged “at a time” Allows effective use of Aggregate Feature Allows control, data and acknowledgement to be sent in the same PPDU An initiator sends a PPDU and a responder may transmit a response PPDU Either PPDU can be an aggregate (“Initiator” / “responder” are new terms relating to roles in aggregate exchange protocol) summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Basic Aggregate Exchange
Month 2002 doc.: IEEE /xxxr0 August 2004 Basic Aggregate Exchange summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Reverse Direction Data Flow
August 2004 Reverse Direction Data Flow Gives an opportunity for a responder to transmit data to an initiator during the initiator’s TXOP Aggregates data with response control MPDUs Reduces Contention Effective in increasing TCP/IP performance Aon Mujtaba, Agere Systems, et al
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Reverse Direction Protocol
Month 2002 doc.: IEEE /xxxr0 August 2004 Reverse Direction Protocol summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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August 2004 Training Protocol Support for PHY closed-loop modes with on-the-air signalling Request for training and feedback are carried in control frames Rate feedback supported Transmit beamforming training supported sounding packet calibration exchange Timing of response is not constrained permitting a wide range of implementation options Aon Mujtaba, Agere Systems, et al
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Training Protocol Month 2002 doc.: IEEE 802.11-02/xxxr0 August 2004
summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Multiple Receiver Aggregation
August 2004 Multiple Receiver Aggregation Aggregates can contain MPDUs addressed for multiple receiver addresses (MRA) MRA may be followed by multiple responses from the multiple receivers MRA is effective in improving throughput in applications where frames are buffered to many receiver addresses Aon Mujtaba, Agere Systems, et al
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Periodic Multi-Receiver Aggregation
Month 2002 doc.: IEEE /xxxr0 August 2004 Periodic Multi-Receiver Aggregation summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Multiple Responses MRA contains multiple IAC for
August 2004 Multiple Responses MRA contains multiple IAC for One per response At most one per receiver IAC specifies response offset and duration Aon Mujtaba, Agere Systems, et al
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Protection Mechanisms
August 2004 Protection Mechanisms LongNAV An entire sequence is protected by NAV set using MPDU duration field or during contention-free period CF-end packet at end of EDCA TXOP sequence may be used to return unused time by resetting NAV Pairwise Spoofing Protection of pairs of PPDUs sent between an initiator and a single responder Uses Legacy PLCP header duration spoofing Single-ended Spoofing Protection of aggregate and any responses using legacy PLCP spoofing at the initiator only Can be used to protect multiple responses Aon Mujtaba, Agere Systems, et al
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LongNAV protection Provides protection of a sequence of multiple PPDUs
Month 2002 doc.: IEEE /xxxr0 August 2004 LongNAV protection Provides protection of a sequence of multiple PPDUs Provides a solution for .11b Comes “for free” with polled TXOP Gives maximum freedom in use of TXOP by initiator summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Pairwise Spoofing Protection
Month 2002 doc.: IEEE /xxxr0 August 2004 Pairwise Spoofing Protection Protects pairs of PPDUs (current and following) Very low overhead, suitable for short exchanges Places Legacy devices into receiving mode for spoofed duration Spoofing is interpreted by HT devices as a NAV setting summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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Single-Ended Spoofing Protection
August 2004 Single-Ended Spoofing Protection Protects MRA and all responses Very low overhead, suitable for short exchanges Places legacy devices into receiving mode for spoofed duration Same level of protection as initiator CTS-to-Self Assuming CTS is sent at the lowest rate Aon Mujtaba, Agere Systems, et al
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Following Packet Descriptor (FPD) Protocol
August 2004 Following Packet Descriptor (FPD) Protocol Aon Mujtaba, Agere Systems, et al
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Operating Mode Selection
Month 2002 doc.: IEEE /xxxr0 August 2004 Operating Mode Selection BSS operating mode controls the use of protection mechanisms and 40/20 width switching by HT STA Supports mixed BSS of legacy + HT devices HT AP-managed modes If only the control channel is overlapped, managed mixed mode provides a low overhead alternative to mixed mode If both channels are overlapped, 20 MHz base mode allows an HT AP to dynamically switch channel width for 40 MHz-capable HT STA summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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20 MHz-base Managed Mixed Mode
August 2004 20 MHz-base Managed Mixed Mode 20 MHz period Transition period 40 MHz period Transition period 20 MHz period Analogue switching time Analogue switching time Channel access time in extension channel ch_a (control) PIFS SIFS PIFS IDLE >=PIFS PIFS >=PIFS busy Bcn/ ICB CF- End <40 MHz frame exchange> DCB CF- End <20 MHz frames> t ch_b (extension) busy CTS self /Bcn CF- End <20 MHz frames> t PIFS PIFS 40 MHz analogue/ 20 MHz digital mode >= PIFS NAV ch_a NAV NAV ch_b NAV NAV ch_a+ch_b NAV NAV Aon Mujtaba, Agere Systems, et al
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August 2004 Channel Selection Support 40/20 MHz and 20 MHz operating modes of whole BSS In 40/20 MHz mode, all legacy PPDUs are 20 MHz, all HT PPDUs exchanged between HT STA are either 40 MHz or 20 MHz depending on operating mode and STA capability Channel selection constraints Partial overlap between HT systems is not allowed Legacy STAs are only allowed in the control sub-channel except in 20 MHz-base managed mixed mode An HT AP responds to changes in environment to maintain channel selection constraints Aon Mujtaba, Agere Systems, et al
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August 2004 MIMO Power Management Timed Receive Mode Switching (TRMS) allows a STA to operate with only 1 of its receive chains enabled most of the time Switch to fully enabled when the STA transmits a frame Hold-on timer keeps the STA fully enabled for a known period of time Good for bursty traffic reduced latency compared to other methods of power saving Aon Mujtaba, Agere Systems, et al
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MAC Architecture Month 2002 doc.: IEEE 802.11-02/xxxr0 August 2004
summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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CC 28/29 Performance Mandatory features only Month 2002
doc.: IEEE /xxxr0 August 2004 CC 28/29 Performance summary deck Mandatory features only Aon Mujtaba, Agere Systems, et al John Doe, His Company
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MAC Selected CC Performance
Month 2002 doc.: IEEE /xxxr0 MAC Selected CC Performance August 2004 CC# Name Result HCCA 2x2x20 2x2x40 CC3 List of goodput results for usage models 1, 4 and 6. SS1 (Mbps) 55.2 76.8 SS4 45.1 74.1 SS6 44.9 62.1 CC18 HT Usage Models Supported (non QoS) SS1 (Mbps/ratio) 2.76/0.09 24.4/0.8 36.0/0.07 65.0/0.14 0.1/0.005 17.24/0.86 CC19 HT Usage Models Supported (QoS) 17/17 18/18 39/39 CC58 HT Spectral Efficiency bps/Hz 5.4 6.075 summary deck Aon Mujtaba, Agere Systems, et al John Doe, His Company
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