Changes between Version 6 and Version 7 of WiMAX/WiMAX-Tutorial/Dash/00
- Timestamp:
- 07/22/13 00:11:32 (11 years ago)
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WiMAX/WiMAX-Tutorial/Dash/00
v6 v7 15 15 == The Scenario == 16 16 17 We will run a series of experiments trying to evaluate 3 primitive dash rate adaptation policies. 18 * Policy 1: When the buffer is less than 30% full, the bit-rate is becomes 0 ==> The client requests the video at the lowest available bit-rate.19 * Policy 2: No provision for the bit-rate.20 * Policy 3: When the buffer is less than 30% full, the bit-rate is halved.17 We will run a series of experiments trying to evaluate 3 primitive dash rate adaptation policies. In all of these policies, the client selects the highest available bitrate for a segment that is lower than some perceived available bitrate. The perceived available bitrate is first estimated as the actual bitrate observed over the download of the last segment. Then, it is adjusted according to one of the following policies: 18 * Policy 1: When the buffer is less than 30% full, the perceived available bitrate is zero, and the client requests the lowest available bitrate. 19 * Policy 2: The perceived available bitrate is not adjusted, i.e. it is always equal to the actual bitrate observed over the download of the last segment. 20 * Policy 3: When the buffer is less than 30% full, the perceived available bitrate is equal to half of the actual bitrate observed over the download of the last segment. 21 21 22 These experiments will be conducted in a cellular environment using the WiMAX Base Station and nodes at Winlab.22 These experiments will be conducted in a cellular environment using the WiMAX Base Station and nodes on the {{{outdoor}}} testbed at WINLAB. The experiment scenario is as follows: 23 23 24 24 * A node loaded with the video chunks, the MDP file and an Apache HTPP server running will serve the media content. 25 * Another node will run an OML-ized VLC client requesting the media. Also it will monitor the link quality. 26 * After the end of the experiment the measurements collected will be archived in iRODS where the experimenter can plot and evaluate each adaptation policy used. 25 * Another node will run an instrumented VLC client requesting the media, which will be downloaded over the WiMAX link. 27 26 28 == Further Reading == 27 After the end of the experiment the measurements collected will be archived in iRODS, where you can plot and compare the three rate adaptation policies. 28 29 == DASH References == 29 30 30 31 * [http://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=79041 What is MPEG DASH] 31 32 * [http://dashif.org/mpeg-dash/ Overview MPEG DASH] 32 33 * [http://en.wikipedia.org/wiki/Dynamic_Adaptive_Streaming_over_HTTP Dynamic Adaptive Streaming over HTTP] 34 * [http://www-itec.uni-klu.ac.at/dash/ DASH implementation and dataset] 33 35 34 36