Home Gateway for Three-Screen TV Using H.264 SVC and Raptor FEC

1. Home Gateway for Three-Screen TV Using H.264 SVC and Raptor FEC IEEE Transactions on Consumer Electronics, Vol. 57, No. 4, November 2011 Eun-SeokRyu and NikilJayant

2. Outline • Background • Introduction • Proposed Method • Experimental Results • Recent Research • Conclusion

3. Background • Home Gateway • The home gateway is an intelligent network interface device located at the consumer premises. • It enables residential user to access the internet services delivered to home and also to access the different services offered by various smart devices located within home. • Three-screen Service • is a multimedia service and provides the right solution for consumers to access rich multimedia resources on any device, anytime, and anywhere.

4. Background • Scalable Video Coding • H.264/SVC is in particular of importance because it envisions methods for controlling video characteristics such as resolution, quality, and frame rate according to the network condition. For this purpose, SVC uses a layered coding approach to provide combined spatial, temporal, and quality scalabilities.

5. Background • Scalable Video Coding • SVC coding has several advantages : • reduce total bandwidth, storage, and computational complexity by supporting many clients with a single video content file. • applicable to many unequal error protection (UEP) methods using priorities of each layer. • SVC approach is inherently more robust because of its error resilient tools.

6. Background • Raptor FEC • The Raptor FEC was developed by Amin Shokrollahi as one of fountain codes in 2001 and is also called a rateless code. • Several standards have adopted Raptor code as a standard: • Multimedia broadcast and multicast services (MBMS) in the 3rd generation partnership project (3GPP) • DVB-H • Reliable multicast transport (RMT) working group within the internet engineering task force (IETF). • The Raptor FEC can be designed with both the systematic and non-systematic approaches.

7. Background • Raptor FEC • Encode

8. Outline • Background • Introduction • Proposed Method • Experimental Results • Recent Research • Conclusion

9. Introduction • According to the annual Cisco visual networking index (VNI) forecast: • 2009-2014, the sum of all forms of videos will continue to exceed 91 percent of global consumer traffic. • TV • VoD • internet video • peer-to-peer • These show the importance of home multimedia technology in near future.

10. Introduction • Video service providers (VSP) are preparing premium services. • The home gateway and three-screen clients are as followed.

11. Introduction • A traditional solution for source coding is to prepare separate pre-encoded video streams according to the capability of each targeted device. • Another advanced solution is transcoding one high resolution and high bit rate video sequence for targeted screen sizes and bit rates of TV clients.

12. Introduction • This paper proposes an elastic video streaming solution for 3STV and home gateway. • SVC source coding technology to support various device capabilities with single bitstream. • Raptor forward error correction technology to achieve strong packet loss recovery feature in application layer.

13. Introduction • This paper proposes optimized video streaming methods with SVC and Raptor FEC. • adaptive SVC layer-switching method, which enables the server to perform selecting appropriate according to bandwidth. • adaptive Raptor FEC method, which controls the overhead of Raptor FEC according to PLR. • The advantage of an efficient combination of (1) and (2) is that • the optimal layer numbers to be sent under permitted bandwidth. • the overhead of Raptor FEC to protect the packets of selected layers according to link quality.

14. Outline • Background • Introduction • Proposed Method • Experimental Results • Recent Research • Conclusion

15. Adaptive SVC Layer-switching with Raptor FEC Overhead Control • Conceptual procedures of the proposed method • Received Signal Strength Indicator (RSSI)-based feedback

16. Adaptive SVC Layer-switching with Raptor FEC Overhead Control • System architecture of implemented home gateway

17. Adaptive SVC Layer-switching with Raptor FEC Overhead Control • Adaptive SVC Layer-switching • is a reliable method for automatic switching between the several spatial/temporal layers. • is the easiest natural bandwidth adaptation method in the middle of streaming.

18. Adaptive SVC Layer-switching with Raptor FEC Overhead Control • Adaptive Raptor FEC • Raptor FEC shows excellent packet loss recovery results in various PLR conditions, for any given overall FEC overhead rate. • The proposed method determines the Raptor overhead according to feedback of channel condition based on these experimental results as an overhead adaptation method.

19. Adaptive SVC Layer-switching with Raptor FEC Overhead Control • The flow chart of algorithm for SVC layer and Raptor overhead adaptation

20. Outline • Background • Introduction • Proposed Method • Experimental Results • Recent Research • Conclusion

21. Experimental Results • Implementation • The implemented environment for the 3STV home gateway includes: • two laptops with one large size TV, and one personal digital assistant (PDA). • 802.11b wireless LAN is used for the in-home wireless network. • TCP is used for sending control messages such as the feedback of channel condition. • Real-time Transport Protocol over UDP is used for streaming video sequence.

22. Experimental Results • Sample video sequences for three-screen TV

23. Experimental Results • Overall bit rate gains

24. Experimental Results • Performance of adaptive Raptor FEC and SVC layer-switching

25. Experimental Results • Comparison of video quality by streaming methods (from left 3%, 5%, 10%, and 15% PLR condition).

26. Experimental Results • Moving traces with mobile TV on building map

27. Experimental Results • Reactions of the proposed method in real moving experimentation using implemented home gateway system

28. Outline • Background • Introduction • Proposed Method • Experimental Results • Recent Research • Conclusion

29. Multilevel Diversity Coding via Rateless Codes for Reliable and Scalable Video Multicasting IEEE Communications Letters, Vol. 17, No. 5, May 2013 Mohsen Sardari, Eun-SeokRyu, FaramarzFekri, and NikilJayant

30. Multi-gateway Structure • Clients in different coverage regions can connect to a number of gateways (top). • Association of each client to more gateways result in higher quality (bottom).

31. Multi-gateway Optimization • Benefit : reducing the load on the backbone network. • This paper formulates the problem as an optimization problem with the objective of minimizing the total bandwidth of the scalable video delivery.

32. Multi-gateway Optimization • This paper first introduces an abstract model and describe the optimal solution for multi-gateway multicast of scalable content. • And demonstrates that traditional multicast, which requires all the gateways in the network fully deliver all the layers of a SVC content, is not optimal.

33. Multi-gateway Optimization • Consider a source node S which provides scalable video with L layers l1, . . . , lL . • This paper optimize for the total output rate of the S such that connection to any Nα number of gateways should enable the client to successfully receive layers {l1, . . . , lα}.

34. Multi-gateway Optimization • Consider the n-th gateway and let r1n, r2n , . . . , rLnbe the rate of the layers 1 through L provided by S to the n-thgateway. • The total rate sent to n-thgateway :

35. Multi-gateway Optimization • To successfully recover a layer α, the sum of the rates rα ≥ 0 received by a client from all the gateways should be lα. • Therefore, constraints on successful recovery of layers result in the following optimization problem :

36. Multi-gateway Optimization • Thus, the dual problem of optimization with variables p1, . . . , pL, is

37. Multi-gateway Optimization • The solution of the optimization problem :

38. Multi-gateway Optimization • In [10], it is shown that given enough budget for storing a file in a distributed network, spreading of the budget maximizes the recovery probability for a collector with random access to a set of storage nodes. [10] D. Leong, A. Dimakis, and T. Ho, “Distributed storage allocations,” IEEE Trans. Inf. Theory, vol. 58, no. 7, pp. 4733–4752, July 2012.

39. Achieving the Optimal Solution with Rateless Coding • Source Sshould provide every gateway the whole of layer 1, and 1/i of the layer i. • The property of ratelesscoding provides the flexibility to encode data on the fly and proves to be useful in achieving the optimal solution.

40. Comparison of the Optimal Solution with Simple Multicast • Gain of various layer growths

41. Experimental Results • Performance evaluation • Overhead r = 12%

42. Conclusion • Adaptive SVC layer-switching selects appropriate layers to be sent according to ABW by RSSI-based feedback. • Raptor FEC overhead control method controls its overhead according to PLR. • The proposed method outperforms traditional methods and enhances video quality from 2dB to 5dB while simultaneously reducing bitrates from 28% to 36% .