1. Multiple Frame Exchanges during EDCF TXOP
Month 1998
doc.: IEEE /xxx
November 2001
Multiple Frame Exchanges during EDCF TXOP
Sunghyun Choi1, Javier del Prado1, Atul Garg1, Maarten Hoeben3, Stefan Mangold2, Sai Shankar1, and Menzo Wentink3
Philips1, Aachen University2, and Intersil3
and
S. Choi, Philips & M.M. Wentink, Intersil

2. November 2001
Problem Statement
Per e/D1.3, it is clear that one cannot have multiple frame (i.e., MSDU) exchanges during a non-polled TXOP (or EDCF TXOP).
802.11e/D1.2 was not very clear in that; see 01/534 for related discussion.
However, allowing the multiple frame exchanges (or EDCF TXOP Bursting) looks very attractive.
See the next for the details.
S. Choi, Philips & M.M. Wentink, Intersil

3. Advantages of EDCF TXOP Bursting
November 2001
Advantages of EDCF TXOP Bursting
Will reduce network overhead
Without bursting available, an ESTA must backoff after each MSDU transmission
Will increase bandwidth fairness among the same priority queues, virtually independent from the frame sizes.
Without bursting available, the ESTA with larger MSDUs will use the channel more
Should not affect the rest of HCF as the EDCF TXOP is limited by “CP TXOP Limit” in QoS Parameter Set element anyway.
S. Choi, Philips & M.M. Wentink, Intersil

4. Proposed EDCF TXOP Bursting
November 2001
Proposed EDCF TXOP Bursting
During an EDCF TXOP, ESTA may transmit multiple frames (i.e., MSDUs) from the same queue (i.e., from the same Access Category per 01/565r0).
Once there is a transmission failure, the EDCF TXOP ends, and the ESTA goes into backoff.
Without a transmission failure, the ESTA goes to backoff after the final frame exchange.
S. Choi, Philips & M.M. Wentink, Intersil

5. November 2001
Duration and NAV Rules
EDCF bursting uses Duration rules similar to fragment bursting
Each MPDU protects up to the next frame exchange via Duration.
S. Choi, Philips & M.M. Wentink, Intersil

6. November 2001
EDCF TXOP Limit per AC
Replace the “CP TXOP Limit” in QoS Parameter Set element with four “CP TXOP Limit [AC]’s”
One per Access Category (AC) (ref. 01/565r0)
Desirable along with the EDCF TXOP bursting
Will enable bursting size tuning per AC depending on the traffic types
Can achieve weighted bandwidth sharing among ACs
S. Choi, Philips & M.M. Wentink, Intersil