Limiting the client bandwidth Limiting the client bandwidth of broadcasting protocols for of broadcasting protocols for

video on demandvideo on demand

Jehan-Francois Paris and Darrell D.E. LongJehan-Francois Paris and Darrell D.E. Long

Proceedings of the Euromedia 2000 Conference

OutlineOutline

Previous SchemesPrevious Schemes Skyscraper broadcasting Skyscraper broadcasting Fast data broadcasting Fast data broadcasting Pagoda broadcastingPagoda broadcasting Approach in this paper (improving FB and Approach in this paper (improving FB and

Pagoda)Pagoda) Result and my experimentResult and my experiment ConclusionConclusion

Patching1998, 53

Batching1994, 154

Skyscraper1997, 101

PPB1996, 61

Harmonic1997, 34

Stream Tapping1997, 27

Piggyback1996, 20

Fast Data Broadcast1996, 19

Pyramid1995, 19

DSB1998, 25

Pagoda1999, 4

New Pagoda1999, 4

CHB, QHB1998, 12

PHB1998, 17

StaggeredBroadcasting

Universal Distribution2000

HMSM2001

SAM(VCR)1997

Seamless Channel Transition (FB)2001

Adaptive Fast Data Broadcasting2001

…

Adding VCR …

Current Paper

Low I/O Bandwidth

ObjectiveObjective

Bandwidth (delay time)Bandwidth (delay time) Ex: FB -> Pagoda -> New Pagoda

StorageStorage Ex: PB -> PPB

Scalable (wide range)Scalable (wide range) Ex: Ex: FB -> UD

VCR FunctionalityVCR Functionality Ex: Staggered Broadcast -> SAM

Channel AdjustmentChannel Adjustment Ex: FB -> Seamless Channel Transition

I/O BANDWIDTH Ex: FB -> SB , current paper

Skyscraper BroadcastsSkyscraper Broadcasts

ConstraintConstraint For any initial unit segment broadcast , For any initial unit segment broadcast ,

there must be a sequence of segments there must be a sequence of segments that the client can receive that will that the client can receive that will support support continuous playback to the continuous playback to the viewerviewer

Clients are required to receive data on Clients are required to receive data on no more than no more than two channelstwo channels simultaneouslysimultaneously

Skyscraper BroadcastsSkyscraper Broadcasts

ProgressionProgression

we use we use WW to restrict the segments from becoming too to restrict the segments from becoming too large. large.

EXEX：：W= 12W= 12 [ 1 , 2 , 2 , 5 , 5 , 12 , 12 , [ 1 , 2 , 2 , 5 , 5 , 12 , 12 , 12 , 1212 , 12…]…]

Transmitting and Receiving of Segments (SB)

Channel 1

Channel 2

Channel 3

Playback

Channel 4

Channel 5

Fast data broadcastingFast 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 S2

k-1 of equal duration d The channel i broadcasts S2

i-1 to S2i-1

Transmitting and Receiving of Segments (FB)

Channel 1

11 111 1 1 1 1 1 1 1

Channel 2

2 3

Channel 3

2 3 2 3 2 3 2 3 2 3

4 5 6 7 4 5 6 7 4 5 6 7

1 2 3 4 5 6 7

New Pagoda broadcastingNew 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

Transmitting and Receiving of Segments (NPB)

Channel 1

11 111 1 1 1 1 1 1 1

Channel 2

2 4

Channel 3

2 5 2 4

3 6 8 7 9

2 5 2 4 2 5

3 6 3 7 9

1 2 3 4 5 6 7 8 9

3 8

Approach in the paperApproach in the paper

Allow to receive data from Allow to receive data from the first m of tthe first m of these k channelshese k channels..

Downloading data from the k-m remainiDownloading data from the k-m remaining channels will be progressively alloweng channels will be progressively allowed as d as STB starts dropping some of the firsSTB starts dropping some of the first m channelst m channels.. The STB will start receiving data from chann

el m + 1 when it is finished with the first channel.

Approach in the paperApproach in the paper

The segments in the The segments in the first m channelsfirst m channels Segment SSegment Sii repeated at least once every i slot repeated at least once every i slot

s s The segments in the The segments in the remaining (k – m)remaining (k – m) ch ch

annelsannels After slots nAfter slots nk-mk-m, the channel k-m can be downl, the channel k-m can be downl

oaded data.oaded data. Segment SSegment Sii repeated at least once every repeated at least once every (i -n(i -nk-k-

mm) slots) slots

In Fast broadcasting (FB-3)In Fast broadcasting (FB-3)

8-1=7

15-2=13

28-4=24

52-8=44

In Fast broadcasting (FB-4)In Fast broadcasting (FB-4)

In NPB (NPB-3)In NPB (NPB-3)

Channel 4 (NPB-3)Channel 4 (NPB-3)

a) segments S10 to S12 once every 9 slots

b) segments S13 to S16 once every 12 slots

c) segments S17 to S21 once every 15 slots

Channel 5 (NPB-3)Channel 5 (NPB-3)

a) segments S22 to S27 once every 18 slots b) segments S28 to S35 once every 24 slots c) segments S36 to S40 once every 30 slots d) segments S41 to S46 once every 36 slots

In NPB (NPB-4)In NPB (NPB-4)

Result 1Result 1

Result 2Result 2

My Experiment 1My Experiment 1

0

100

200

300

400

500

600

1 2 3 4 5 6 7 8 9

number of channels

num

ber o

f seg

men

ts

FB-2

Skyscraper

FB

Channel

FB-2Skyscra

perFB

1 1 1 1

2 3 3 3

3 6 5 7

4 11 10 15

5 19 15 31

6 32 27 63

7 53 39 127

8 87 64 255

9 142 89 511

My Experiment 2 (FB-2)My Experiment 2 (FB-2)

ChannelDelay

(slots)

Segmentsnumber of

segmentsTotal number of

segmentsnumber of

bufferBuffer /

total

1 0 S1 1 1 0 0%

2 0 S2 ~ S3 2 3 1 33%

3 1 S4 ~ S6 3 6 2 33%

4 2 S7 ~ S11 5 11 3 27%

5 4S12 ~

S198 19 5 26%

6 7S20 ~

S3213 32 8 25%

7 12S33 ~

S5321 53 13 25%

My Experiment 3My Experiment 3

FB-2 FB-3 FB-4 FB

bufferbuffer/

totalbuffer

buffer/total

bufferbuffer/

totalbuffer buffer/total

Original 12 38% 23 45% 31 53% 31 49%

Ours 8 25% 15 29% 18 31% 16 25%

Total 32 51 59 63

ConclusionConclusion

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.