Summary
International Conference on Emerging Technologies for Communications
2020
Session Number:IB1
Session:
Number:IB1-2
Interaction between Protocol Layers in Adaptive Video Steaming
Miki Yamamoto,
pp.-
Publication Date:2020/12/2
Online ISSN:2188-5079
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Summary:
MPEG-DASH(Dynamic Adaptive Streaming over HTTP) is an international standard for video streaming services over HTTP. In MPEG-DASH, an ABR(Adaptive BitRate) algorithm selects adequate bit rate for each short-period fragmentation of video file, called a segment. It dynamically adjusts video bit rate to available network bandwidth which is estimated from measured download throughput of previous segments. There are many factors which affect application layer estimation, e.g. TCP congestion control in the transport layer and caching at a router in the network layer. In this paper, we present some interesting performance evaluation results of interaction between protocol layers in MPEG-DASH. Caching in the network layer is generally expected to improve user performance because cached content can be obtained with higher throughput. However, our evaluation results show that in some cases segments obtained from router cache might degrade user-perceived QoE because of misunderstanding of download throughput on the congested path to the server. The other interesting result presented in this paper is interaction between ABR in the application layer and TCP in the transport layer. Different TCP versions are well known to have unfair throughput, which causes unfairness in ABR bit rate selection. We also present our proposed fairness improvement method of application layer approach.