January 2011
doc.: IEEE 802.11-11/0026r0
VHT Supported MCS Field
Date: 2011-01-17
Authors:
Name
Affiliations
Address
Phone
email
Sameer Vermani
Qualcomm
San Diego, CA
858-845-3115
[email protected]
Santosh Abraham
Qualcomm
San Diego, CA
858-651-6107
[email protected]
Youhan Kim
Atheros
Hongyuan Zhang
Marvell
Eldad Perahia
Intel
Vinko Erceg
Broadcom
San Diego, CA
+1-858-521-5885
[email protected]
Brian Hart
Cisco Systems
San Jose, CA
408-526-3346
[email protected]
Daewon Lee
LG Electronics
Korea
+82-31-450-7897
[email protected]
Minho Cheong
ETRI
Korea
+82 42 860 5635
[email protected]
Uikun Kwon
Samsung
Korea
+82-31-280-9513
Vish Ponnampalam
MediaTek
San Jose, CA
+1-408-526-1899
vish.ponnampalam@mediate
k.com
Bo Sun
ZTE
China
+86-29-88724130
[email protected]
Sean Coffey
Realtek
Irvine, CA
[email protected]
Tianyu Wu
Huawei
China
[email protected]
Submission
San Jose, CA
+1-408-830-5835
Santa Clara, CA
+1-408-222-1837
Hillsboro, OR
[email protected]
[email protected]
[email protected]
Slide 1
[email protected]
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Abstract
This document proposes a design of the VHT
Supported MCS Set Field of the VHT Capabilities
element
Submission
Slide 2
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Introduction
•
Goal is to design “The Supported MCS Set field” that indicates which
MCSs a STA supports
– Different from 11n
• In 11n, an MCS was identified by an MCS index, which was represented by an integer in
the range 0 to 76 (included the different Nss possibilities)
• In 11ac, MCS and Nss are disjoint quantities
– Aim to reduce the number of options available and remove possibility of “holes”
in supported MCS table
• Cleans up the standard and rate adaptation
•
Assumptions
– Transmit and receive support for MCS 0 through 7 in all the supported (BW, Nss)
combinations unless
• It is a restricted MCS
• Data rate cut-off of a device forbids such a support (only allowed in highest BW)
– Allowance for optional modes
• Support of MCSs 8 and 9
• Support for more than 1 spatial stream.
Submission
Slide 3
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Proposed Contents of VHT Supported
MCS field
•
Rx MCS Map
– This consists of a 16 bit field which specifies max MCS supported for every Nss
•
2 bit number for each Nss value
–
–
–
–
00 will denote support for up to MCS 7
01 will denote support for up to MCS 8
10 will denote support for up to MCS 9
11 will denote no support for that Nss
2 bits
Max MCS for
Nss=1
Max MCS for
Nss=2
Max MCS for
Nss=3
Max MCS for
Nss=8
16 bits
Rx MCS map
•
Rx Highest Supported Data Rate
– This field is needed to place a limit on the max data rate (13 bits)
• In units of Mb/s where 1 represents 1 Mb/s, and incrementing in steps of 1 Mb/s
– This cutoff can over-ride a claim for support of a certain (MCS, Nss) combination
for the highest supported BW
Submission
Slide 4
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Proposed Contents of VHT Supported
MCS field
•
Tx MCS Set Defined
– 1 bit specifying whether the Tx is advertising its MCS capability or not
– Subsequent fields on this slide are irrelevant if this bit is set to 0
– When set to 1
• Subsequent fields help the STA in choosing a more powerful AP or an AP more
commensurate with its own capability
•
Tx MCS Map
– Exactly same as Rx MCS map defined in slide 3
•
Tx Highest Supported Data Rate
– This field is needed to advertise the max data rate a device can transmit (13 bits)
• In units of Mb/s where 1 represents 1 Mb/s, and incrementing in steps of 1 Mb/s
– This cutoff can over-ride a claim for support of a certain (MCS, Nss) combination
for the highest BW
Submission
Slide 5
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Frame Format: VHT Supported MCS
• Proposed frame format for the VHT Supported MCS
field
B0
B15 B16
B28
Rx Highest
Rx MCS map
Supported Data
Rate
Bits
Submission
16
13
B29
B58 B59
B63
B45 B46
Tx Highest
Reserved
Tx MCS Map
Supported Data
Rate
B30
Tx MCS Set
Defined
1
16
Slide 6
13
5
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Conclusion
• We proposed a simple way to convey the supported
MCS set for 11ac
Submission
Slide 7
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
Pre-motion
• Do you agree with the VHT Supported MCS Set Field proposed in
this presentation and agree to add it to the spec framework
document ?
Submission
Slide 8
Sameer Vermani, Qualcomm
January 2011
doc.: IEEE 802.11-11/0026r0
References
[1] IEEE 802.11 document 09/0992r18 , “Proposed Specification Framework for
TGac”, Robert Stacey et al
Submission
Slide 9
Sameer Vermani, Qualcomm