1. Samsung MAC Proposal Presentation
Aug 2004
doc.: IEEE /0917r2
August 2004
SAMSUNG 11n MAC
Samsung MAC Proposal Presentation
Kyunghun Jang, Samsung, et al
Kyunghun Jang, Samsung, et al

2. Authors and Contributors
August 2004
Authors and Contributors
Kyunghun Jang
Youngsoo Kim
Jin-Bong Chang
Dongjun Lee
Jon Rosdahl
Changyeul Kwon
Chil-Youl Yang
SukJin Yun
Seyoung Shin
Kyungik Cho
Sunghyun Choi
Seongkwan Kim
Tae-Jin Lee
Duck-Yong Yang
Hyung-Wook Yoon
Kyunghun Jang, Samsung, et al

3. Samsung MAC Proposal Samsung MAC Proposal FRCC compliance
August 2004
Samsung MAC Proposal
Samsung MAC Proposal FRCC compliance n
Samsung MAC Proposal Technical Specification n
Samsung MAC Proposal Results n
Samsung MAC Proposal CC Summary n
Kyunghun Jang, Samsung, et al

4. Contents Summary of New MAC Features Two-level Frame Aggregation
Aug 2004
doc.: IEEE /0917r2
August 2004
Contents
Summary of New MAC Features
Two-level Frame Aggregation
MP-Frame: Aggregation Control
Smart Block ACK
Error Recovery Mechanisms
Operating Modes
Kyunghun Jang, Samsung, et al
Kyunghun Jang, Samsung, et al

5. New MAC Features (1) Two-level frame aggregation
August 2004
New MAC Features (1)
Two-level frame aggregation
Supports multiple destinations and multiple rates in a PPDU
MAC header compression
Allows more efficient medium usage when multiple MPDUs are aggregated in a PSDU
A service period for aggregation exchanges
Initiated by MP frame and is combined with dynamic TDM and CSMA/CA without collision and unnecessary backoff delay
Kyunghun Jang, Samsung, et al

6. New MAC Features (2) Smart Block ACK Three error recovery mechanisms
August 2004
New MAC Features (2)
Smart Block ACK
Uses a two-level bitmap with a variable size instead of a fixed 128 octets as in the e Block ACK
Three error recovery mechanisms
Used with the two-level frame aggregation mechanism
Operating modes
For coexistence between legacy STAs and HT STAs
Kyunghun Jang, Samsung, et al

7. Two-level Frame Aggregation
August 2004
Two-level Frame Aggregation
MAC
Header
DA1:TID1
MSDU F C S
MAC
Header
DA1:TID1
MSDU F C S
MAC
Header
DA1:TID2
MSDU F C S
MAC
Header
DA2:TID1
MSDU F C S
MPDU
Aggregate
PSDU M D
PSDU
DATA MPDU M D
CH-type1
MPDU M D
CH-type2
MPDU M D
PSDU
DATA MPDU
Preamble/
PLCP Header P D
PSDU P D
PSDU
Aggregate
PPDU
rate1
rate2
basic rate
MD : MPDU Delimiter, PD : PSDU Delimiter
Kyunghun Jang, Samsung, et al

8. Compressed MAC Header (CH)
August 2004
Compressed MAC Header (CH)
CH-type1 MPDU
CH-type2 MPDU
Octets: ~
Frame
Control
Address 3
Sequence
Control
Address 4
(if needed)
MSDU
FCS
Octets: ~
Frame
Control
Address 3
Sequence
Control
Address 4
(if needed)
QoS
Control
MSDU
FCS
Kyunghun Jang, Samsung, et al

9. MPDU and PPDU Delimiters
August 2004
MPDU and PPDU Delimiters
MD (4 octets)
PD (2 symbols)
Bits:
Reserved
MPDU length
CRC
Unique Pattern
Bits:
Reserved
PSDU length
MCS
CRC
Unique Pattern
Kyunghun Jang, Samsung, et al

10. Preamble/PLCP header Structure
August 2004
Preamble/PLCP header Structure
Symbols : / TBD
Legacy-STF
Legacy-LTF
Legacy-SIG
HT-SIG
HT-STF
HT-LTF
Bits:
Bits:
Rate
reserved
Length
Parity
Tail
Antenna
Config.
reserved
Parity
Tail
Kyunghun Jang, Samsung, et al

11. Format of MultiPoll Frame
August 2004
Format of MultiPoll Frame
Dur/ID
BSSID
Frame
control
octets : 2 2 6
D/L
Count(n)
U/L
Count(m)
D/L MAP
5 * n
U/L MAP
4 * m
AID
Length
MCS
14bit
16bit
6bit
Antenna
Config
4bit
QoS Control
Recommended
Rate
TID
No TID
3bit
1bit
AAI
TxOPLimit
8bit
FCS 4
* MCS: Modulation Coding Scheme
* AAI: Aggregated ACK Indicator
Kyunghun Jang, Samsung, et al

12. MP-Frame: Aggregation Control
August 2004
MP-Frame: Aggregation Control
D/L MAP
AID
LENGTH
MCS
HT STA1
length1
rate1
HT STA2
length2
rate2
U/L MAP
AID
QoS ctrl
Recom. Rate
HT STA1
qos1
rate1
HT STA2
qos2
rate2
HT STA3
qos3
rate3
Dynamic TDM
CSMA/CA MP
Aggregate
PSDU
Aggregate
PSDU
CF-
END
HT AP
Aggregate PPDU
Aggregate
PSDU
HT STA 1
TXOP Limit 1
HT STA 2
Aggregate
PSDU 2 1
HT STA 3
TXOP Limit
DATA
NAV 4 3
Non-polled (HT) STA 4 2 1
Service Period
PIFS
PIFS
DIFS
DIFS
PIFS
AIFS[AC]
Kyunghun Jang, Samsung, et al

13. Long NAV for Aggregation Exchanges
August 2004
Long NAV for Aggregation Exchanges
Dynamic TDM
CSMA/CA MP
Aggregate
PSDU
Aggregate
PSDU
CF-
END
HT AP
Aggregate
PPDU
Aggregate
PSDU
HT STA 1
Set NAV
TXOP Limit
Reset NAV 1
HT STA 2
Aggregate
PSDU
HT STA 3 2 1
TXOP Limit
Non-polled (HT) STA 4
NAV
Shrinking 4 3
Service Period
PIFS
PIFS
DIFS
DIFS
PIFS
AIFS[AC]
Kyunghun Jang, Samsung, et al

14. Smart Block ACK Frames Smart Block ACK Request (SBAR) MPDU
August 2004
Smart Block ACK Frames
Smart Block ACK Request (SBAR) MPDU
Smart Block ACK (SBA) MPDU
2 octets
2 octets
6 octets
6 octets
2 octets
2 octets
4 octets
Frame
Control
Duration RA TA
BAR Control
Block Ack Starting
Sequence Control
FCS
Reserved
SSBAR
TID
SSBAR: Selective SBAR
SSBAR=1 : Implicit Error Recovery
11 bits
1 bits
4 bits
2 octets
2 octets
6 octets
6 octets
2 octets
2 octets
8 octets
2*n octets
4 octets
Frame
Control
Duration RA TA
BA Control
BA Starting
Sequence Control
BA MSDU
Bitmap
BA Erroneous
MSDU Bitmap
FCS A
Last SN NA
Reserved
TID
Bits :
Kyunghun Jang, Samsung, et al

15. August 2004
SBA MPDU
First bit, “A”, in the BA control field, indicates whether all MSDUs have been successfully received, up to the MSDU with 6 bits of a sequence number in the Last SN subfield.
“NA” bit in the BA control field, indicates no packet has been successfully received.
Bm bit, in 8 octet BA MSDU Bitmap field, indicates whether all the fragmented MPDUs with SN = (BA Starting Sequence Control + m) have been successfully received or not.
The total number (n) of following BA erroneous MSDU Bitmap equals to the number of zero bits in BA MSDU Bitmap field. The order of subsequent BA erroneous MSDU Bitmap follows the order of zero bits in the BA MSDU Bitmap.
Kyunghun Jang, Samsung, et al

16. Example of Smart Block ACK (1)
August 2004
Example of Smart Block ACK (1)
Fragmented MSDU
with SN = 10
Fragmented MSDU
with SN = 11
Fragmented MSDU
with SN = 12
10-1
10-2
10-3
10-4
11-1
11-2
11-3
12-1
12-2
12-3
12-4
12-5
Corresponding Smart Block ACK
Octets: 2 2 6 6 2 2 4
Frame
Control
Duration RA TA
BA Control
SN = 10
FCS 1 12
reserved
TID
Bits :
Kyunghun Jang, Samsung, et al

17. Example of Smart Block ACK (2)
August 2004
Example of Smart Block ACK (2)
Fragmented MSDU
with SN = 10
Fragmented MSDU
with SN = 11
Fragmented MSDU
with SN = 12
10-1
10-2
10-3
10-4
11-1
11-2
11-3
12-1
12-2
12-3
12-4
12-5
Corresponding Smart Block ACK
Octets: 2 2 6 6 2 2 8 2 2 4
Frame
Control
Duration RA TA
BA Control
SN = 10 1 …
BA Erroneous
MSDU Bitmap
of SN = 11
BA Erroneous
MSDU Bitmap
of SN = 12
FCS
BA MSDU Bitmap 12
reserved
TID 1 1 … 1 1 1 …
BA control
BA Erroneous
MSDU Bitmap of SN = 11
BA Erroneous
MSDU Bitmap of SN = 12
Kyunghun Jang, Samsung, et al

18. Example of Smart Block ACK (3)
August 2004
Example of Smart Block ACK (3)
Fragmented MSDU
with SN = 10
Fragmented MSDU
with SN = 11
Fragmented MSDU
with SN = 12
10-1
10-2
10-3
10-4
11-1
11-2
11-3
12-1
12-2
12-3
12-4
12-5
Corresponding Smart Block ACK
Octets: 2 2 6 6 2 2 8 2 4
Frame
Control
Duration RA TA
BA Control
SN = 10 1 …
BA Erroneous
MSDU Bitmap of SN =11
FCS
BA MSDU Bitmap 1 … 11
reserved
TID
BA Erroneous
MSDU Bitmap of SN = 11
BA control
Kyunghun Jang, Samsung, et al

19. Error Recovery Mechanisms
August 2004
Error Recovery Mechanisms
MP-Frame: Immediate Error Recovery
MP-Frame: Coordinated Error Recovery
MP-Frame: Implicit Error Recovery
Kyunghun Jang, Samsung, et al

20. MP-Frame: Immediate Error Recovery
August 2004
MP-Frame: Immediate Error Recovery
Within TXOP limit
Within TXOP limit 1 2 1 2 1
Preamble
PLCP
MP-Frame
Preamble
PLCP
Data MPDU
Data MPDU
SBAR MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
SBA MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
SBA MPDU
Preamble
PLCP
SBA MPDU
Preamble
PLCP
CF-END frame
HT AP
Retransmission 11 12
Preamble
PLCP
SBA MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
SBA MPDU
STA1
AAI = 0
Retransmission 21 22 21
Preamble
PLCP
SBA MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
Data MPDU
SBAR MPDU
STA2 1
AAI = 0
PIFS
DIFS
SIFS
SIFS
DIFS
SIFS
SIFS
SIFS
PIFS
Kyunghun Jang, Samsung, et al

21. MP-Frame: Coordinated Error Recovery
August 2004
MP-Frame: Coordinated Error Recovery
Error Recovery Phase 1 2 1 2 2
Preamble
PLCP
MP-Frame
Preamble
PLCP
Data MPDU
Data MPDU
SBAR MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
MP-Frame
Preamble
PLCP
SBA MPDU
Data MPDU
SBAR MPDU
SBA MPDU
Preamble
PLCP
SBA MPDU
Preamble
PLCP
CF-END frame
HT AP
Retransmission 11 12
Preamble
PLCP
SBA MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
SBA MPDU
STA1
AAI = 1
Retransmission 21 22 21
Preamble
PLCP
SBA MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
Data MPDU
SBAR MPDU
STA2 1 1
AAI = 1
PIFS
DIFS
DIFS
PIFS
PIFS
DIFS
DIFS
PIFS
PIFS
Kyunghun Jang, Samsung, et al

22. MP-Frame: Implicit Error Recovery (1)
August 2004
MP-Frame: Implicit Error Recovery (1) 1 2 1 2 1 2 2
Preamble
PLCP
MP-Frame
Preamble
PLCP
Data MPDU
Data MPDU
SBAR MPDU
Data MPDU
Data MPDU
SBAR MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
Data MPDU
SBAR MPDU
Preamble
PLCP
CF-END frame
HT AP
SSBAR = 1
SSBAR = 0
STA 1
AAI = 0
Preamble
PLCP
SBA MPDU
Preamble
PLCP
SBA MPDU
STA 2 1
AAI = 0
Backoff count
STA 3 2 1
AAI = 0
PIFS
DIFS
SIFS
SIFS
DIFS
Kyunghun Jang, Samsung, et al

23. MP-Frame: Implicit Error Recovery (2)
August 2004
MP-Frame: Implicit Error Recovery (2) 1 2 1 2 1 2 1 2
Preamble
PLCP
MP-Frame
Preamble
PLCP
Data MPDU
Data MPDU
SBAR MPDU
Data MPDU
Data MPDU
SBAR MPDU
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
Data MPDU
Data MPDU
SBAR MPDU
Preamble
PLCP
CF-END frame 1
HT AP
Preamble
PLCP
SBA MPDU
Preamble
PLCP
SBA MPDU
SSBAR = 1
SSBAR = 0
STA 1
AAI = 0
NA = 1
STA 2 1
AAI = 0
STA 3 2 1
AAI = 0
PIFS
DIFS
SIFS
SIFS
DIFS
PIFS
Kyunghun Jang, Samsung, et al

24. Operating Modes Pure mode Mixed mode Managed mode
August 2004
Operating Modes
Pure mode
There are only HT STAs without any legacy STAs
Mixed mode
There are legacy STAs and HT STAs together
Protection mechanisms (CTS-to-Self, RTS/CTS) are used in the CP
Managed mode
HT AP can manage the access control between HT STAs and legacy STAs
CP for HT STAs is assigned in CFP.
Kyunghun Jang, Samsung, et al

25. CTS-to-Self or RTS/CTS for Contention Period (CP)
August 2004
CTS-to-Self or RTS/CTS for Contention Period (CP)
Legacy
CTS
HT Data 1
Backoff slots
HT STA1
ACK
Backoff slots
HT STA2
NAV
Backoff slots
HT Others
NAV
Legacy STAs
Backoff slots
NAV
AIFS[AC]
SIFS
SIFS
AIFS[AC]
Kyunghun Jang, Samsung, et al

26. Benefits of Legacy ACK During CP in mixed and managed mode August 2004
AIFS[AC]
SIFS
AIFS[AC]
HT Data
HT STA SRC 1
Backoff slots
Legacy ACK
Backoff slots
HT STA DEST
Legacy STAs
don’t know HT Data,
thus set the EIFS
Backoff slots
Legacy STAs
EIFS
In case of successful reception of legacy ACK,
the EIFS is not used
Kyunghun Jang, Samsung, et al

27. Contention-Free Period Contention-Free Repetition Interval
August 2004
Managed Mode
SIFS
Beacon
HT AP
HT STAs
Sub-CFP
HT CP
Contention Period
NAV
MaxCFPDuration
MaxCFPDuration - HTCPDuration
HT Data
ACK
CF-
End ….
LagacySTAs
Contention-Free Period
Contention-Free Repetition Interval
Reset NAV
HT transmission
Legacy transmission
Kyunghun Jang, Samsung, et al

28. August 2004
Thank You
Kyunghun Jang, Samsung, et al