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Proceedings of the Euromedia 2000 Conference. Limiting the client bandwidth of broadcasting protocols for video on demand. Jehan-Francois Paris and Darrell D.E. Long. Outline. Previous Schemes Skyscraper broadcasting Fast data broadcasting Pagoda broadcasting
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Proceedings of the Euromedia 2000 Conference Limiting the client bandwidth of broadcasting protocols for video on demand Jehan-Francois Paris and Darrell D.E. Long
Outline • Previous Schemes • Skyscraper broadcasting • Fast data broadcasting • Pagoda broadcasting • Approach in this paper (improving FB and Pagoda) • Result and my experiment • Conclusion
HMSM 2001 Piggyback 1996, 20 Batching 1994, 154 Stream Tapping 1997, 27 Adding VCR … Patching 1998, 53 Universal Distribution 2000 Adaptive Fast Data Broadcasting 2001 Fast Data Broadcast 1996, 19 Pagoda 1999, 4 New Pagoda 1999, 4 Low I/O Bandwidth Seamless Channel Transition (FB) 2001 Staggered Broadcasting Pyramid 1995, 19 PPB 1996, 61 Skyscraper 1997, 101 Current Paper DSB 1998, 25 Harmonic 1997, 34 CHB, QHB 1998, 12 PHB 1998, 17 SAM(VCR) 1997 …
Objective • Bandwidth (delay time) • Ex: FB -> Pagoda -> New Pagoda • Storage • Ex: PB -> PPB • Scalable (wide range) • Ex: FB -> UD • VCR Functionality • Ex: Staggered Broadcast -> SAM • Channel Adjustment • Ex: FB -> Seamless Channel Transition • I/O BANDWIDTH • Ex: FB -> SB , current paper
Skyscraper Broadcasts • Constraint • For any initial unit segment broadcast , there must be a sequence of segments that the client can receive that will support continuous playback to the viewer • Clients are required to receive data on no more than two channels simultaneously
Skyscraper Broadcasts • Progression • we use Wto restrict the segments from becoming too large. • EX:W= 12 • [ 1 , 2 , 2 , 5 , 5 , 12 , 12 , 12 , 12…]
Transmitting and Receiving of Segments (SB) Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Playback
Fast data broadcasting • Allocates to each video to be broadcast k data channels whose bandwidths are equal to the video consumption rate b • Partitions the video into 2k-1 segments S1 to S2k-1 of equal duration d • The channel i broadcasts S2i-1 to S2i-1
1 2 3 4 5 6 7 Transmitting and Receiving of Segments (FB) Channel 1 1 1 1 1 1 1 1 1 1 1 1 1 Channel 2 2 3 2 3 2 3 2 3 2 3 2 3 4 5 6 7 4 5 6 7 4 5 6 7 Channel 3
New Pagoda broadcasting • Using a more complex segment-to-channel mapping • The NPB protocol can pack nine segments into three channels whereas the FB protocol could only pack seven segments • Si means Si must be broadcasted once every i slots • FB:S7 is broadcasted once every 4 slots • New Pagoda:S7 is broadcasted once every 6 slots
1 2 3 4 5 6 7 8 9 Transmitting and Receiving of Segments (NPB) Channel 1 1 1 1 1 1 1 1 1 1 1 1 1 Channel 2 2 4 2 5 2 4 2 5 2 4 2 5 3 6 8 3 7 9 3 6 8 3 7 9 Channel 3
Approach in the paper • Allow to receive data from the first m of these k channels. • Downloading data from the k-m remaining channels will be progressively allowed as STB starts dropping some of the first m channels. • The STB will start receiving data from channel m + 1 when it is finished with the first channel.
Approach in the paper • The segments in the first m channels • Segment Si repeated at least once every i slots • The segments in the remaining (k – m) channels • After slots nk-m, the channel k-m can be downloaded data. • Segment Si repeated at least once every (i -nk-m) slots
In Fast broadcasting (FB-3) 8-1=7 15-2=13 28-4=24 52-8=44
Channel 4 (NPB-3) • a) segments S10 to S12 once every 9 slots • b) segments S13 to S16once every 12 slots • c) segments S17 to S21 once every 15 slots
Channel 5 (NPB-3) • a) segments S22 to S27 once every 18 slots • b) segments S28 to S35once every 24 slots • c) segments S36 to S40 once every 30 slots • d) segments S41 to S46once every 36 slots
Conclusion • We have shown how to modify existing broadcasting protocols so that their client bandwidth would never exceed three to four channels. • Most broadcasting protocols require a customer set-top box capable of simultaneously capturing data from five to eight video channels.