1. 1 Cooperative Inter-stream Rate Control Scheme for Layered Multicast Masato KAWADA, Hiroyuki MORIKAWA, Tomonori AOYAMA, School of Engineering, The University of Tokyo

2. 2 Introduction Sharing streams –If streams pass the same bottleneck link and share the limited bandwidth, we call it sharing streams in the following Design a end-to-end inter-stream control scheme for layered multicast which enables to adjust the allocated bandwidth of sharing streams according to the predefined policy

3. 3 Introduction Use Receiver-driven layered Multicast (RLM) as basic method for receiving layered multicast streams Establish Multiple Streams Controller(MSC) mechanism over RLM at each receiver.

4. 4 Receiver-driven Layered Multicast (RLM) Receiver-driven rate control has tow main mechanism –The probe of empty bandwidth with trial joining to the next layered and loss detection –Rate degradation on congestion by dropping the extended layer to reduce the congestion Join-experiments –A receiver subscribes to an additional layer and observes if the subscription degrades its reception quality as opposed to improving it

5. 5 Receiver-driven Layered Multicast (RLM) Detection time –The time due to the experiment in a certain time Join-timer –The interval to the next join-experiment Subscription Success –No congestion occurs and packet loss rate doesn’t exceed a configured threshold during the detection time

6. 6 Receiver-driven Layered Multicast (RLM) Subscription Fail –Congestion occurs due to the experiment during the detection –Packet loss rate measured in a detection time exceeds a configured threshold A receiver multicasts a join-experiment report identifying the experimental layer to other receivers when doing the experiment

7. 7 Receiver-driven Layered Multicast (RLM) Disadvantages –Receivers can’t adjust the allocated subscription level among streams –If there are streams occupying the bottleneck link, the new stream passing the same link has little available bandwidth

8. 8 Receiver-driven Layered Multicast (RLM) Disadvantages(Cont.) –If join-experiments are overlapped among streams, the experiments are likely to interfere with each other and be failed –If temporary congestions caused by join- experiments of other streams happen continually, a receiver misrepresents this congestion as continuous one and drops the highest layer

9. 9 Overview of Inter-Stream Control RLM++ with MSCRLM

10. 10 Overview of Inter-Stream Control

11. 11 RLM++ Operation Support TjTj

12. 12 RLM++ Operation Support MSC can prevent the wasteful decreasing of the subscription level happening by misrepresenting congestion due the other stream’s join-experiments as continuous congestion

13. 13 Construction of Congestion Table

14. 14 Construction of Congestion Table MSC grasps the sharing state of bandwidth in a bottleneck link both among receivers and among streams from congestion table. The information in the table becomes the clue of performing the adjustment of subscription level among streams

15. 15 Base Layer Protection MSC and RLM++ should guarantee the bandwidth for the base layer by degrading the subscription level of the other stream MSC multicasts the dropping request and the receivers who detect congestion caused by the base layer decrease the subscription level when they receive the request

16. 16 Adjustment of Subscription Level MSC can find the situation of dropping or subscription among streams by analyzing congestion table MSC can adjust the subscription level among streams according to receiver;s request or a predefined rule

17. 17 Simulation and Evaluation 4 Multicast Layer: 100kbps, 100kbps, 200kbps, 400kbps Request sequence: Bottleneck: Topology (1): 5 — 6 (300 kbps) Topology (2): 4 — 5 (600 kbps) Topology: Simulation Parameters:

18. 18 Results and Evaluation Base layer protection: –R2 joins Stream ‘z’ at 100 sec. Base layer join (no protection) Base layer join (protection) Y X Z

19. 19 Results and Evaluation Adjustment of subscription level –R1 changes the subscription level from (x, y) = (2, 1) to (x, y) = (1, 2)

20. 20 Results and Evaluation Scalability –The three senders in topology (2) starts their own session randomly during the first 5sec of simulation time, and receivers start receiving each streams at random time between 5sec and 7sec –Three metrics Convergence time Loss rate Subscription level stability

21. 21 Results and Evaluation Scalability --- Convergence time –The time between when it starts and when it reaches its stable subscription level

22. 22 Results and Evaluation Scalability --- Loss rate

23. 23 Results and Evaluation Scalability --- Stability of subscription level –We use the frequency of missdropping layers as evaluation values of subscription level stability

24. 24 Conclusion MSC and RLM++ can do the base layer protection and the adjustment of subscription level among streams by constructing and analyzing congestion table Effective bandwidth allocation among streams with user’s request and receiving streams with stable quality are possible