1. Samsung MAC Proposal Presentation
August 2004
SAMSUNG 11n MAC
Samsung MAC Proposal Presentation
Kyunghun Jang, 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, et al

3. Contents New MAC Feature Two-level Frame Aggregation New HT Frame
August 2004
Contents
New MAC Feature
Two-level Frame Aggregation
New HT Frame
Aggregation Exchange
Acknowledgement
Operating Modes
Kyunghun Jang, et al

4. August 2004
New MAC Features (1)
Two-level frame aggregation that supports multiple destinations and multiple rates in a PPDU.
A service period for aggregation exchanges that is commenced by MP frame and is combined with dynamic TDM and CSMA/CA without collision and unnecessary backoff delay.
Three acknowledgement mechanisms that are suitably selected in aggregation exchange transfer according to each HT STA or each HT STA’s TID.
Kyunghun Jang, et al

5. August 2004
New MAC Features (2)
Smart Block ACK that uses two-level bitmap with variable size instead of fixed 128 octets in e Block ACK.
MAC Header compression that allows more efficient medium usage when multiple MPDUs are aggregated in a PSDU.
Operating modes for coexistence with legacy STAs and HT STAs
Usage of legacy ACK for solving unfairness
Kyunghun Jang, et al

6. Two-level Frame Aggregation
August 2004
Two-level Frame Aggregation
MAC
Header
( DA 1 /
TID 1 )
MSDU
MAC
Header
( DA 1 /
TID 1 )
MSDU
MAC
Header
( DA1 /
TID 2 )
MSDU
MAC
Header
( DA 2 /
TID 1 )
MSDU
MPDU M D
PSDU
DATA MPDU M D
CHDATA – 1
MPDU M D
CHDATA – 2
MPDU M D
PSDU
DATA MPDU
PSDU
Preamble/
PLCP Header P D
PSDU P D
PSDU
PPDU
rate1
rate2
MD : MPDU Delimiter, PD : PSDU Delimiter
Kyunghun Jang, et al

7. MAC Header Compression
August 2004
MAC Header Compression
CHDATA-1 MPDU
CHDATA-2 MPDU
Octets: ~
Frame
Control
Address 3
Sequence
Control
Address 4
Frame
Body
FCS
Octets: ~
Frame
Control
Address 3
Sequence
Control
Address 4
QoS
Control
Frame
Body
FCS
Kyunghun Jang, et al

8. Smart Block ACK (SBA) SBA MPDU SBAR(SBA Request) MPDU August 2004
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 MSDUs’
Bitmap
BA Erroneous
MSDUs’ Bitmap
FCS A
Last SN
Reserved
TID
Bits : RA
BAR Control
Duration
Frame
Control TA
Block Ack Starting
Sequence Control
FCS
Reserved
TID
2 octets
6 octets
4 octets
4 bits
11 bits
SSBAR
1 bits
SSBAR: Selective SBAR
SSBAR=1 : Implicit acknowledgment is applied.
Kyunghun Jang, et al

9. August 2004
SBA MPDU
B0 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.
B(m - 1) bit, in 8 octet BA MSDUs’ 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 MSDUs’ Bitmap equals to the number of zero bits in BA MSDUs’ Bitmap field. The order of subsequent BA erroneous MSDUs’ Bitmap follows the order of zero bits in the BA MSDUs’ Bitmap.
Kyunghun Jang, et al

10. 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
16it
6bit
Antenna
Config
4bit
QoS Control
Recommended
Rate
TID
No TID
3bit
1bit
AAI
TxOPLimit
8bit
FCS 4
* AAI: Aggregated ACK Indicator
Kyunghun Jang, et al

11. Aggregation Exchanges
August 2004
Aggregation Exchanges
Kyunghun Jang, et al

12. Acknowledgement Mechanisms in a Service Period
August 2004
Acknowledgement Mechanisms in a Service Period
Pair Acknowledgement
Phase Acknowledgement
Implicit Acknowledgement
Kyunghun Jang, et al

13. Pair Acknowledgement August 2004 HC STA1 AAI=0 STA2 Within TXOP limit
MP-Frame
Preamble
PLCP
Data MPDU
SBAR MPDU
SBA MPDU
CF-END frame
DIFS
SIFS
PIFS HC
STA1
STA2
AAI=0
Kyunghun Jang, et al

14. Phase Acknowledgement
August 2004
Phase Acknowledgement
MP-Frame
Preamble
PLCP
Data MPDU
SBAR MPDU
SBA MPDU
CF-END frame
If Service Period is remaining (Error Recovery Phase) HC
STA1
STA2
AAI=1
DIFS
PIFS
Kyunghun Jang, et al

15. Implicit Acknowledgement
August 2004
Implicit Acknowledgement
PIFS
DIFS
SIFS
MP-Frame
Preamble
PLCP
Data MPDU
SBAR MPDU HC
STA 1
STA 2
STA 3
SBA MPDU 1
AAI=0
Backoff count 2
CF-END frame
SSBAR =1
Kyunghun Jang, et al

16. Protection mechanisms(1)
August 2004
Protection mechanisms(1)
Long NAV for aggregation exchanges
Kyunghun Jang, et al

17. Protection mechanisms(2)
August 2004
Protection mechanisms(2)
CTS-to-Self or RTS/CTS for Contention Period(CP)
Kyunghun Jang, et al

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

19. August 2004
Managed Mode
Kyunghun Jang, et al

20. Usage of legacy ACK Solution for unfairness August 2004
Kyunghun Jang, et al

21. August 2004
Discussion
Kyunghun Jang, et al