1. Response to Call For Proposal for P802.11n
Month 2003
doc.: IEEE /xxxr0
Response to Call For Proposal for P802.11n
Hervé Bonneville, Bruno Jechoux, Romain Rollet
Mitsubishi ITE 1, allee de Beaulieu, Rennes, France
Alexandre Ribeiro Dias, Stéphanie Rouquette-Léveil, Markus Muck, Marc de Courville, Jean-Noël Patillon, Karine Gosse, Brian Classon
Motorola Labs
Parc les Algorithmes – Saint Aubin – Gif sur Yvette Cedex - France
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

2. Mitsubishi ITE - Motorola Joint Proposal Background
Month 2003
doc.: IEEE /xxxr0
Mitsubishi ITE - Motorola Joint Proposal Background
Complete proposal resulting from a joint effort of Mitsubishi Electric ITE and Motorola to make n the system of choice for Consumer Electronics market while enhancing the service for PC/enterprise historical market.
Goal is to provide an efficient MAC handling of QoS sensitive applications taking full benefit of a high throughput MIMO based PHY while keeping compatibility with legacy systems
Various environments supported
Enterprise
Home environment
Hot Spot
Proven and simple solutions
summary deck
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

3. Content Proposal Guide and Overview MAC Description System Performance
Month 2003
doc.: IEEE /xxxr0
Content
Proposal Guide and Overview
MAC Description
System Performance
PHY Description
Link Performance
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

4. Guide to Mitsubishi ITE -Motorola Proposal
Month 2003
doc.: IEEE /xxxr0
Guide to Mitsubishi ITE -Motorola Proposal
The complete proposal submitted by MITSUBISHI ITE and MOTOROLA consists of the following four documents:
n- mitsubishi-ite-motorola-proposal-response
Response to functional requirements, comparison criteria table. Includes also a technical overview
n-mitsubishi-ite-motorola-proposal-detaileddescription
Detailed technical description of the proposal
n-mitsubishi-ite-motorola-proposal-presentation
this document
n-mitsubishi-ite-motorola-proposal-simresults
Detailed system simulation results (Excel spread sheet)
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

5. Proposal Overview: MAC
Month 2003
doc.: IEEE /xxxr0
Proposal Overview: MAC
Full compatibility with legacy stations
QoS support with guarantied throughput and stringent delay constraints support even in heavily loaded system
Centralised on demand resource allocation with Resource announcement,
efficient even with simple per priority Round Robin scheduler
TDMA mode embedded in e superframe
Resource request/grant scheme for allocation in UL
Aggregation at PHY level (1 to several destination)
Fast selective repeat ARQ for low latency and low overhead error correction
summary deck
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

6. Proposal Overview: MAC (Continued)
Month 2003
doc.: IEEE /xxxr0
Proposal Overview: MAC (Continued)
Short and fixed size MAC-PDU with MAC Header compression
Flexible architecture for efficient handling of heterogeneous traffics (Bursty, CBR, Elastic)
Support of multiple environments without context-dependent parameter tuning
High efficiency and Scalable architecture (constant overhead when data rate increases)
Low complexity, low power consumption
summary deck
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

7. Proposal Overview: PHY
Month 2003
doc.: IEEE /xxxr0
Proposal Overview: PHY
Modification of IEEE a-1999 PHY in order to:
provide new OFDM PHY modes for delivering higher data rates meeting the IEEE802.11n PAR
improve also support of lower data rate modes for enhancing range or link quality of IEEE802.11a modes but also supporting services requiring small packet size such as VoIP
allow short term implementation and deployment for mandatory modes
focus on open loop solution to avoid protocol overhead consumed in feedback signalization
Ensure possible operation in enlarged set of scenarios (support of long channel impulse responses)
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

8. Proposal Overview: PHY (Continued)
Key features:
Multi-antenna extension:
MIMO with at least 2Tx/2Rx antennas scaling up to 4Tx
Support for asymmetric antenna configurations to accomodate various classes of devices
Open-loop modulation technique
Second OFDM modulator (optional): 128 carriers in 20MHz with 104 data carriers, and double duration guard interval
8% PHY rate increase
Operate in larger environments, take better into account Tx/Rx filters
New nPLCP preambles (same for 64- and 128-point IFFT/FFT) for MIMO support
Mitsubishi ITE / Motorola Labs

9. Proposal Overview: PHY (End)
High order modulation (optional): 256-QAM
20MHz bandwidth
Modification can be used with 40MHz and advanced coding (turbo/LDPC codes)
Space/frequency interleaver
IEEE a convolutional code with code rates 1/2, 2/3, 3/4 and 5/6
Mitsubishi ITE / Motorola Labs

10. Typical system performances
PER target:
All QoS flows satisfied
Scenario XVI: Use the most efficient PHY mode (3x3 256QAM3/4, Ns=3)
(*) bis stands for: “with fully backlogged TCP sources”
Mitsubishi ITE / Motorola Labs

11. MAC Description Month 2003 doc.: IEEE 802.11-03/xxxr0 summary deck
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

12. Our vision
Ethernet:
Topology had to change for 100 Mbit/s and above
No more a shared bus
Collisions shall be avoided to get performances
Physical layer enhancements might be sufficient to compensate MAC lack of efficiency on TGn simulation scenarios
but at which cost in terms of complexity?
AND Customers and applications evolution are not limited to IEEE simulation scenarios!
Let’s anticipate these needs right now!
Mitsubishi ITE / Motorola Labs

13. System Objectives QoS support Efficient resource usage Compatibility
Versatile and Flexible
No added complexity
Mitsubishi ITE / Motorola Labs

14. Derived MAC enhancements
TDMA frame embedded in e superframe
Centralised on demand resource allocation with Resource announcement,
efficient even with simple Round Robin scheduler per priority
Fast selective repeat ARQ with Buffer management
Short and fixed size MAC-PDU with MAC Header compression
Aggregation at PHY level (1 to several destination)
Mitsubishi ITE / Motorola Labs

15. Stack overview
MAC layer is enhanced with the “Extended Centralised Coordination Function” mode (ECCF).
Functions are distributed over 4 sub-layers
802.2 LLC
802.2 LLC
ECCF MAC
Legacy MAC
Packet Sequence Number Assignments
MAC Header Compression
LLCCS
Sequence Number Assignments
Fragmentation
Encryption
MDU Header + CRC
Segment Sequence Number Assignments
Segmentation/Re-Assembly
SAR
MIS
Error and Flow Control
MLS
Encryption
MPDU Header
Signalling Insertion
PHY
PHY
Mitsubishi ITE / Motorola Labs

16. Frame structure and timing
MAC Super Frame & Beacon kept for compatibility.
A part of the Contention Free Period (CFP) divided into MAC Time Frame (MTF) of fixed duration (for example 2 ms).
Resource scheduling performed on a per MTF basis. Time Intervals (TI) of variable duration dynamically allocated to STAs within an MTF.
MAC Super Frame
CFP CP
CFP
MTF
Period for ECCF
Period for
PCF/HCCA
access
Period for
DCF/EDCA
access
Period for ECCF
Beacon
Beacon
Beacon
Information CF
Parameter Set
ECCF
Parameter Set
Mitsubishi ITE / Motorola Labs

17. Frame structure and timing (cont.)
ECCF insertion into CAP: CAP generated by the HC using CF-Poll data frame as defined in the e extension.
CF-Poll contains the RRM MAC address (HC and RRM can be distinct) as destination address, and allocates a reserved time period for ECCF.
CAP is split by the RRM into successive MTFs of fixed duration, each being described by a PGPM broadcast at the beginning of the MTF.
SIFS
PIFS
MTF
DIFS
CF-Poll
PGPM
PGPM
Data
Data
CAP
Legacy MAC frame
ECCF MAC frame
Mitsubishi ITE / Motorola Labs

18. Frame structure and timing (cont.)
TI constituted of one MPDU = data unit exchanged with the PHY layer as in legacy
MPDU contains two parts: signalling and data
contents defined by the emitter (source STA)
data and signalling can be intended for one or more destination STAs
Possible long PHY bursts
MTF composition defined in a specific MPDU = PGPM
MTF
MPDU
MPDU
MPDU
MPDU
PGPM
Data
Data
Data
Data
PGPM
TI#0
TI#1
TI#2
TI#3
TI#4
Mitsubishi ITE / Motorola Labs

19. MTF structure (detailed)
An MPDU may aggregate all data blocks sent by a station
MPDU signalling part (variable length):
Has a dedicated protection (HSCS)
Includes resource requests, Error Control signalling,...
Includes description of data blocks (if any)
MTF structure example
PGPM
Header
HSCS
Signalling
Signalling
MPDU
Header
HSCS
Data
STA#2
STA#1
MPDU
RRM, STA#3
STA#4
TID STA#1
->STA#2
TID STA#4
->RRM,STA#3
DPD
STA#2
Data Block
to STA#2
MPDU
Header
HSCS
Signalling RR
->RRM FB
->STA#3
Fixed size segments (2 possible lengths)
CRC
MIS-PDU
HDR
...
Sent by
RRM
All
(TI #0)
(TI #1)
(TI #2)
Mitsubishi ITE / Motorola Labs

20. MTF structure (cont.) MTF structure example with flow aggregation:
Station 1 transmits data to stations 2 and 3 in one MPDU (PHY burst) only
PHY mode may be different for each pair
PGPM
Header
HSCS
Signalling
MPDU
Header
HSCS
Signalling
Data
STA#2,#3
STA#2
STA#3
STA#1
TID STA#1
->STA#2;#3
DPD
STA#2
STA#3
Data Block
to STA#2
Data Block
to STA#3
Fixed size segments (2 possible lengths)
CRC
MIS-PDU
HDR
...
Fixed size segments (2 possible lengths)
CRC
MIS-PDU
HDR
...
Sent by
RRM
Received by
All
(TI #0)
(TI #1)
Mitsubishi ITE / Motorola Labs

21. Data Segmentation Short and fixed-size segments
better robustness against errors remaining above PHY layer
Segmentation and Re-assembly (SAR) sub-layer introduced to perform adaptation between LLC and MAC.
Simulations have been made with two segment sizes (Long and Short, 128 and 61 octets of payload). Good trade-off between:
MAC signaling overhead added to each segment
Segmentation overhead due to padding added to reach a predetermined size in the last segment
LLC
Long
Short
Segmentation overhead
MAC signalling overhead
SAR-SDU
SAR
Sub-Layer
(MAC)
Data
Segment
Segment
Segment
MIS
(MAC)
CRC
MIS-PDU
HDR
CRC
MIS-PDU
HDR
HDR
MIS-PDU
CRC
Mitsubishi ITE / Motorola Labs

22. Power Saving Inherent power saving facilities Long-term power saving:
An active STA doesn’t need to listen to all MPDUs
Only resource grants announcements and traffic it is destined to
STA may be on a low power scheme otherwise
Long-term power saving:
RRM allows an STA to enter sleep mode when it has no more traffic to schedule for it
RRM will grant resource to that STA after the sleeping period
During sleep mode, traffic is buffered in any source STA as there is no resource granted for it
Compatible with direct link communication
Mitsubishi ITE / Motorola Labs

23. System Performance Month 2003 doc.: IEEE 802.11-03/xxxr0 summary deck
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

24. Simulations
Unique MAC configuration (no knob activation nor parameter tuning depending on the context or scenario)
Simulation conditions:
MAC, EC and segmentation overhead fully taken into account
Dynamic resource allocation based on requests from STA
Simple Round Robin scheduler (per priority level), 2 priority classes
No contention period, 2 ms long MTF
PHY modes
MIMO (2x2 up to 3x3), 20 MHz (from 6 Mbit/s up to 216 Mbit/s)
PHY abstraction in system simulation (preliminary configuration)
Uniform PER in the BSS (all the STA see the same PER)
Simulated PER: 0, , up to (equivalent to 0; ; for 1500 bytes packets)
Mitsubishi ITE / Motorola Labs

25. ECCF Scalability
Goodput at MAC SAP vs PHY data rate (point-to-point scenario)
linear variation
Slight impact of the PER on MAC efficiency
retransmission with low signalling SR-ARQ
MAC efficiency:
Constant vs PHY rate
High level: [76% ; 86%]
Fully scalable for high bit rates
Results valid whatever the application packet size (c.f.segmentation)
Mitsubishi ITE / Motorola Labs

26. Mixed traffic handling
Capacity usage at MAC-SAP vs. Number of VoIP sessions
1 TCP data flow transmitted using MIMO 128Mbit/s
VoIP: 120-byte packets emitted every 10 ms (2x96kbit/s)
n VoIP sessions, using MIMO or SISO
30 VoIP sessions + at least 70 Mbit/s of TCP traffic
Mitsubishi ITE / Motorola Labs

27. Delay performances IEEE TGn Usage models : Scenario I (Home)
Traffic classification based on priority level (VoIP > TCP)
Delay comparison for different error rate [cdf(d>D)]
Strong QoS constraints of VoIP reached:
with a simple centralised scheduling
an efficient ARQ
Max delay below 20 ms for QoS traffic
Mitsubishi ITE / Motorola Labs

28. Simulation results for Scenario 1
all data flow transmitted using MIMO 3x2 64QAM 3/4 (Ns=2) or 2x2 16QAM 3/4 (Ns=1)
Modified scenario 1bis:
Infinite TCP sources + Multiple PHY modes ( Mbit/s)
QoS requirements can be achieved with 105 Mbit/s at PHY
> 74% MAC efficiency
102 Mbit/s available at MAC-SAP (140 Mbit/s avg at PHY)
Mitsubishi ITE / Motorola Labs

29. Simulation results for Scenario 4
Multiple PHY modes ( Mbit/s)
> 69% MAC efficiency
129 Mbit/s available at MAC-SAP (186 Mbit/s avg at PHY)
Mitsubishi ITE / Motorola Labs

30. Simulation results for Scenario 6
all data flow transmitted using MIMO 3x3 64QAM2/3 (Ns=2) or 2x2 64QAM5/6 (Ns=1).
Modified scenario 6bis:
Infinite TCP sources + Multiple PHY modes ( Mbit/s)
QoS requirements can be achieved with 92 Mbit/s at PHY
> 65% MAC efficiency
90 Mbit/s available at MAC-SAP (137 Mbit/s avg at PHY)
Mitsubishi ITE / Motorola Labs

31. Results conclusion QoS requirements supported (throughput and delay)
High level MAC efficiency for all scenarios
Flexibility ensured, without context-dependent tuning
Overall support of 11n simulations scenarios with a 120 Mbps PHY layer
Mitsubishi ITE / Motorola Labs

32. Feasibility Nothing futuristic Proven technologies
TDMA has been used for years
Present in many systems (GSM, , …)
Just one step further than HCCA
Proven technologies
Centralised RRM
Simple scheduler
Classical ARQ
Moderate complexity implementation
not more complex than e (HCCA)
Mitsubishi ITE / Motorola Labs

33. PHY Description Month 2003 doc.: IEEE 802.11-03/xxxr0 summary deck
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

34. Multi-antenna aspects of the proposal
Transmission of 1, 2 or 3 parallel streams using:
Space-Time Block Coding (STBC)
Spatial Division Multiplexing (SDM)
or robust hybrid solutions (STBC/SDM)
optimize the rate vs link budget trade-off
2, 3 or 4 transmit antennas
2 Tx is mandatory (with 2Rx antennas)
A terminal with 2Rx has to have the capability to decode all 2 streams STBC/SDM schemes (same for 3Rx)
Use of STBC mandatory when a terminal transmits Nflows < NTx
2 or more receive antennas
With STBC or STBC/SDM, asymmetric antenna configurations can be supported
Mitsubishi ITE / Motorola Labs

35. 2 antenna transmit schemes proposed
spatial stream #1 * 2 s - 1 1 s
spatial stream #1
spatial stream #1 2 s
spatial stream #2
spatial stream #2
Transmission of 1 spatial stream (STBC)
Transmission of 2 spatial streams (SDM)
Mitsubishi ITE / Motorola Labs

36. 3 antenna transmit schemes proposed
spatial stream #1
spatial stream #2
spatial stream #3 1 s 3 2
Transmission of 2 spatial streams (STBC)
Transmission of 3 spatial streams (SDM)
Mitsubishi ITE / Motorola Labs

37. 4 antenna transmit schemes proposed
spatial stream #1
spatial stream #2
Transmission of 2 spatial streams (STBC)
Transmission of 3 spatial streams (STBC)
Mitsubishi ITE / Motorola Labs

38. OFDM modulation 1st OFDM modulation based on IEEE802.11a parameters:
48 data subcarriers, 64-point IFFT/FFT
180Mbps maximum PHY rate (120Mbps mandatory)
2nd OFDM modulation:
128-point IFFT/FFT
104 data subcarriers
8 pilots on subcarriers -49, -35, -21, -7, 7, 21, 35 and 49
Guard interval duration: 0.8s
Symbol interval: 7.2s
234Mbps maximum PHY rate
Mitsubishi ITE / Motorola Labs

39. Data rates for 2 transmit antennas and 48 data subcarriers
Month 2003
doc.: IEEE /xxxr0
Data rates for 2 transmit antennas and 48 data subcarriers
288
384 8
3/4
256QAM 2
144Mbps
240 6
5/6
64QAM
120Mbps
216
108Mbps
192
2/3
96Mbps
144 4
16QAM
72Mbps 1
60Mbps
48Mbps
36Mbps 96
1/2
24Mbps 72
QPSK
18Mbps 48
12Mbps 24
BPSK
6Mbps
Data bits per OFDM symbol (NDBPS)
Coded bits per OFDM symbol (NCBPS)
Coded bits per subcarrier per stream (NBPSC)
Coding rate (R)
Modulation
Number of spatial streams (NS)
Data rate (Mbits/s)
Mitsubishi ITE / Motorola Labs
H.Bonneville, B.Jechoux, Mitsubishi ITE

40. Data rates for 2 transmit antennas and 104 data subcarriers
624
832 8
3/4
256QAM 2
156Mbps
520 6
5/6
64QAM
130Mbps
468
117Mbps
416
2/3
104Mbps
312 4
16QAM
78Mbps 1
65Mbps
52Mbps
39Mbps
208
1/2
26Mbps
156
QPSK
19.5Mbps
104
13Mbps 52
BPSK
6.5Mbps
Data bits per OFDM symbol (NDBPS)
Coded bits per OFDM symbol (NCBPS)
Coded bits per subcarrier per stream (NBPSC)
Coding rate (R)
Modulation
Number of spatial streams
(NS)
Data rate (Mbits/s)
Mitsubishi ITE / Motorola Labs

41. Data rates for 3 or 4 transmit antennas and 48 data subcarriers
288
384 8
3/4
256QAM 3
216Mbps
240 6
5/6
64QAM
180Mbps
216
162Mbps
192
2/3
144Mbps 2
120Mbps
96Mbps
144 4
16QAM
72Mbps 96
1/2
48Mbps 72
QPSK
36Mbps 48
24Mbps 24 1
BPSK
12Mbps
Data bits per OFDM symbol (NDBPS)
Coded bits per OFDM symbol (NCBPS)
Coded bits per subcarrier per stream (NBPSC)
Coding rate (R)
Modulation
Number of spatial streams
(NS)
Data rate (Mbits/s)
Mitsubishi ITE / Motorola Labs

42. Data rates for 3 or 4 transmit antennas and 104 data subcarriers
624
832 8
3/4
256QAM 3
234Mbps
520 6
5/6
64QAM
195Mbps
468
175.5Mbps
416
2/3
156Mbps 2
130Mbps
104Mbps
312 4
16QAM
78Mbps
208
1/2
52Mbps
156
QPSK
39Mbps
104
26Mbps 52 1
BPSK
13Mbps
Data bits per OFDM symbol (NDBPS)
Coded bits per OFDM symbol (NCBPS)
Coded bits per subcarrier per stream (NBPSC)
Coding rate (R)
Modulation
Number of spatial streams
(NS)
Data rate (Mbits/s)
Mitsubishi ITE / Motorola Labs

43. Frequency and space interleaver
IEEE802.11a based frequency interleaver defined for both 48 and 104 data subcarriers
Spatial division:
NSD : number of data subcarriers
Mitsubishi ITE / Motorola Labs

44. nPLCP preamble (1/3) nSTS
Each STS1, …, STS10 corresponds to the legacy short training defined over indexes -28,28
S-28,28 = {0, 0, 0, 0, -1-1j, 0, 0, 0, -1-1j, 0, 0, 0, 1+1j, 0, 0, 0, 1+1j, 0, 0, 0, 1+1j, 0, 0, 0, 1+1j, 0, 0, 0, 0, 0, 0, 0, 1+1j, 0, 0, 0, -1-1j, 0, 0, 0, 1+1j, 0, 0, 0, -1-1j, 0, 0, 0, -1-1j, 0, 0, 0, 1+1j, 0, 0, 0, 0}
Duration of the nSTS short training sequence: 10×0.8=8µs.
Mitsubishi ITE / Motorola Labs

45. nPLCP preamble (2/3) nLTS
Each LTS1, LTS2 is based on the legacy long training, but defined over indexes -28,28:
L-28,28 = {1, 1, 1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, 1, 1, 1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, 1, 1, 0, 1, -1, -1, 1, 1, -1, 1, -1, 1, -1, -1, -1, -1, -1, 1, 1, -1, -1, 1, -1, 1, -1, 1, 1, 1, 1, -1, -1}
Duration of the nLTS long training: 1.6+2×3.2=8µs
Mitsubishi ITE / Motorola Labs

46. nPLCP preamble (3/3) nPLCP preamble structure:
Keep only rows corresponding to number of transmit antennas
Mitsubishi ITE / Motorola Labs