1. Frame-Specific Retry Limit for Intra-Stream Prioritization
Authors:
Name
Affiliation
Address
Phone
Philippe Valembois
ENSIIE
1, square de la Résistance Evry, FR
Yacine
Ghamri-Doudane
Marwen Abdennebi
Yacine Ghamri-Doudane et al.

2. Abstract
This proposal fulfils two of the PAR objectives of the 11aa task group:
Graceful degradation of audio video streams when there is insufficient channel capacity, by enabling packet discarding without any requirement for deep packet inspection,
Intra-Access Category prioritization of transport streams by modifying EDCA timing and parameter selection without any requirement for deep packet inspection
This proposal enables a STA to specify a frame specific retry limit using the Intra Acess Priority field and ADDTS/SCS configuration frames
Yacine Ghamri-Doudane et al.

3. Stream Classification Service
History
Stream Classification Service
IEEE /0725r1
Implementation for Intra-AC Differentiated Services
IEEE /0022r0
Using packet drop precedence for graceful degradation
IEEE /0764r1
Yacine Ghamri-Doudane et al.

4. Prioritize some packets in a video stream when the media is busy
Use Cases
Prioritize some packets in a video stream when the media is busy
Give a better chance for important packets to be delivered
Some packets are more important than other (I-frames vs P-frames, B-frames or SVC improvement layers)
More retry limits than with DEI to make difference between I, P, B frames and additional SVC layers
STA can adjust (dynamically) the retry count without the need to change the AP configuration
Yacine Ghamri-Doudane et al.

5. Simulation AP Non-AP STA Yacine Ghamri-Doudane et al. Video Stream
Wired source node which sends the video stream
AP forwards video stream to a STA and applies different retry limits on packets
Non-AP STA receives video stream and evaluates it
Ad-hoc nodes are hidden from the AP and disturbs the reception of the non-AP STA
Bulk transfer
Yacine Ghamri-Doudane et al.

6. Simulation results Yacine Ghamri-Doudane et al. (1) = D:7
(2) = D:7 I:9 P:6 B:3
(3) = D:7 I:12 P:7 B:4
(4) = D:7 I:12 P:8 B:4
Yacine Ghamri-Doudane et al.

7. Used by STA to prioritize important packets
Frame Retry Limit
Used by STA to prioritize important packets
Integration with ADDTSPEC and SCS configuration services
Extension of the Intra-Access Priority Field
B0-B2 B3 B4
B5-B7
B8-B11
B12-B15
User Priority
Alternate Priority
Drop Eligibility
Reserved
Frame Retry Limit
Bits: 3 1 4
Yacine Ghamri-Doudane et al.

8. Example AP Non-AP STA Yacine Ghamri-Doudane et al. AV Stream AV Stream
AP uses SCS to classify packets and determine which Retry Limit it should apply to packets
SCS Requests
Source device tags UDP packets using DiffServ
Wired connection to AP.
Non-AP STA sends SCS requests to specify retry limits for each frame types according to their importance
Yacine Ghamri-Doudane et al.

9. Another example AP Non-AP STA Yacine Ghamri-Doudane et al. AV Stream
AP setup TSPECs to classify packets and determine which Retry Limit it should apply to packets
Source device tags UDP packets using DiffServ
Wired connection to AP.
Non-AP STA receives important packets and other ones if possible
Yacine Ghamri-Doudane et al.

10. Conclusion
This proposal fulfils two of the PAR objectives of the 11aa task group:
Graceful degradation of audio video streams when there is insufficient channel capacity, by enabling packet discarding without any requirement for deep packet inspection
Less important packets are discarded more quickly
Intra-Access Category prioritization of transport streams by modifying EDCA timing and parameter selection without any requirement for deep packet inspection
More important packets are kept while less important ones are dropped when channel is full
Yacine Ghamri-Doudane et al.

11. Motion
Move to incorporate the text changes in XXXX-00-00aa-frame-specific-retry-limit- normative-text.doc into the TGaa draft
Moved:
Seconded:
Result:
Yacine Ghamri-Doudane et al.

12. 11-09-0725r1 “Stream Classification Service”
References
11-10-XXXXr0 “Frame-Specific Retry Limit for Intra-Stream Prioritization”
r1 “Stream Classification Service”
11-09/0022r1 “Implementation for Intra-AC Differentiated Services”
11-08/0764r1 “Using packet drop precedence for graceful degradation”
Yacine Ghamri-Doudane et al.