March 2014
doc.: IEEE 802.11-14/0340-00-0hew
A Simplified Simultaneous Transmit and
Receive MAC Proposal
Date: 2014-03-17
Authors:
Name
Affiliations
Raja Banerjea
CSR
[email protected]
Jim Lansford
CSR
[email protected]
Naveen Kakani
CSR
[email protected]
Submission
Address
Slide 1
Phone
email
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
Abstract
In band STR (Full Duplex) transmission allows 100%
increase in Network throughput. Traditional STR
transmission require STR AP and STR capable STA.
Earlier we presented a mechanism which supports In
Band STR using a STR AP and Half Duplex STAs.
In this presentation we propose a simplified MAC
mechanism which supports In Band STR
Submission
Slide 2
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
Topics
• A simplified STR mechanism
• High Level MAC Requirements for In Band STR
• A Simplified MAC Proposal for In Band STR
• Conclusion
Submission
Slide 3
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
Proposed STR in WLAN
• Leverage attenuation and path loss between STAs to develop a
simplified STR solution. The increased complexity is only at the
Access Point.
• Access Point uses knowledge of path loss between STAs to Group
STAs for In band STR transmission.
Traditional WLAN:
Half Duplex
transmission
Submission
In Band STR
Slide 4
Proposed Solution
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
Benefits of simplified In Band STR
• 100 % increase in network throughput
•
No increase in complexity at the STA
•
Compatible with legacy deployments
• Takes advantage of Wall attenuation and Path Loss
Submission
Slide 5
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
High Level MAC Requirements for In
Band STR
• EDCA based
•
Coexistence with legacy STAs
• Same BSS
• OBSS
•
Simplified solution at the STA
•
High MAC Efficiency
Submission
Slide 6
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
In Band STR MAC Protocol – Use EDCA
Legacy Preamble
STR Preamble
Payload
STA-1
Legacy
STR Preamble
Payload
AP
STA-2
 Allows legacy stations to defer based on L-SIG Length
Allows OBSS STAs to defer
 Indicates duration of PPDU to STA which would simultaneously
transmit
Provides time when the STAs should transmit Acknowledgement
Submission
Slide 7
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
In Band STR MAC Protocol – Use EDCA
(opportunistic transmit)
Legacy Preamble
STR Preamble
Payload
STA-1
Legacy
STR Preamble
AP
Payload
STA-2
• In-Band STR AP can receive packet transmission from STA-1, then it
could decide to opportunistically transmit to STA-2.
Submission
Slide 8
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
In Band STR MAC Protocol –
Simultaneous Transmit and Receive
Legacy Preamble
STR Preamble
Payload
STA-1
STA-2
AP
Legacy
STR Preamble
Payload
– Partial AID in the VHT-SIGA1 indicates recipient of PPDU
– Group ID / Partial AID of STA2 indicates STA-2 should also transmit
– STA-2 should end PPDU transmission before L_LENGTH Duration
Submission
Slide 9
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
In Band STR MAC Protocol – ACKs
SIFS
Legacy Preamble
STR Preamble
Payload
L_LENGTH_DUR + SIFS
ACK
STA-1
SIFS
STA-2
AP
Legacy
STR Preamble
Payload
ACK
• Acknowledgement scheme remains unchanged for STA-1
• STA-2 waits for L_LENGTH_DUR + SIFS to receive ACK
• In Band STR capable AP can transmit and receive ACK simultaneously
• AP Transmit ACK SIFS after end of PPDU transmission
Submission
Slide 10
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
STA Transmit Buffer Status Feedback
• AP needs status of transmit buffer at STAs to enable scheduling UL
transmission. This could be done using a “1” bit indication in the UL to
indicate Tx Buffer Empty or by indicating number of bytes in Tx Buffer.
Submission
Slide 11
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
Conclusion
• In band STR can increase the network throughput by 100 %
• The simplified In band STR mechanism leverages wall attenuation
and path loss between STAs and enables STR where only the Access
Point is STR capable.
• In Band STR can be used along with MU-MIMO and SU-MIMO
and provides increased throughput
• The simplified InBand STR MAC scheme proposed uses EDCA
mechanism and maintains backward compatibility
• In Band STR MAC need not be a complex MAC
Submission
Slide 12
Raja Banerjea, CSR
March 2014
doc.: IEEE 802.11-14/0340-00-0hew
References
[1]11-13-1421-01-hew-str-radios-and-str-media-access.pptx
[2] 11-13-0765-02-0hew-co-time-co-frequency-full-duplex-for802.11-wlan.pptx
[3] 11-13-1122r0-considerations for In-Band Simultaneous
Transmit and Receive (STR) feature in HEW
Submission
Slide 13
Raja Banerjea, CSR