scalable on-demand media streaming with packet loss recovery
DESCRIPTION
Scalable On-Demand Media Streaming with Packet Loss Recovery. A. Mahanti, D. L. Eager, (USask) M. K. Vernon, D S-Stukel (Wisc) Presented by Cheng Huang 04.08.2004. Introduction. VOD is cool, but might also be expensive Naïve implementation: connection per user - PowerPoint PPT PresentationTRANSCRIPT
Scalable On-Demand Media Streaming with Packet Loss Recovery
A. Mahanti, D. L. Eager, (USask) M. K. Vernon, D S-Stukel (Wisc)
Presented by Cheng Huang
04.08.2004
2
Introduction
VOD is cool, but might also be expensive Naïve implementation: connection per user Fortunately, users favor a few “hot” movies. It is possible to have inexpensive approach to effectively
share resources (server, network, etc.) and serve lots of requests.
Target of the on-demand streaming scheme Scalable and reliable Fundamental trade-offs
Server bandwidth (network bandwidth), startup delay and client bandwidth
Client buffer requirement (might be of less concern)
3
Outline
Periodic Broadcast Schemes Bandwidth Skimming Scheme Conclusion
4
Outline
Periodic Broadcast Schemes Bandwidth Skimming Scheme Conclusion
5
Pyramid Broadcast
t i me
1 . . . . . .2 6543 7
1
b
2b
2b
2b
1 1 1 1 1 1 1 1 1 1 1 1 1
2 3 2 3 2 3 2 3 2 3 2 3 2 3
4 5 6 7 4 5 6 7 4 5 6 7 4 5
cl i entarri val
s1 s2 s3
start recei vi ng and pl ayi ng s1
start recei vi ng s2
start recei vi ng s3
vi deo sequence
serverbandwi dth
1
2
6
S. Viswanathan, T. Imielinski 1996
6
Skyscraper Broadcast
t i me
1 . . . . . .2 6543 7
1
b
b 11 1 1 1 1 1 1 1 1 1 1 1
cl i entarri val
s1 s2 s4
start recei vi ng and pl ayi ng s1
vi deo sequence
serverbandwi dth
1
1098 11 12 13 1514
s3 s5
2b 23 3 2 3 2 3 2 3 2 3 2 3 2
4b 45 54 5 4 5 4 5 4 5 4 5 4
6b 87 9 10 6 7 8 9 10 6 7 8 9 10
11b 1312 14 15 11 1312 14 15 11 1312 14 15
group 2 group 3
group 1
group 2
group 3
K. A. Hua, S. Shen 1997
7
Fibonacci Broadcast
t i me
1 . . . . . .2 6543 7
1
b
b 1 1 1 1 1 1 1 1 1 1 1 1 1
cl i entarri val
s1 s2 s4
start recei vi ng and pl ayi ng s1
vi deo sequence
serverbandwi dth
1
1098 11 12 13 1514
s3 s5
2b 2 33 2 3 2 3 2 3 2 3 2 3 2
4b 55 66 4 4 5 6 4 5 6 4 5 6
7b 98 10 11
b 1312 14 15 16 1817 19
16 1817 19
7 98 10 11 7 98 10 11 7 98 10 11
4 5 6 4 5
3 2 3 2 3
1 1 1 1 1
1312 14 15 16 1817 19 1312 14 15
8
Optimized Periodic Broadcast
t i me
1 . . .2 6543 7
1
b
b 1 1 1 1 1 1 1 1 1 1 1 1 1
cl i entarri val
s1 s2 s4
start recei vi ng s1
vi deo sequence
serverbandwi dth
1
1098 11 12 13 1514
s3 s5
2b 2 33 2 3 2 3 2 3 2 3 2 3 2
4b 55 66 4 4 5 6 4 5 6 4 5 6
7b 98 10 11
b 1312 14 15 16 1817 19
16 1817 19
7 98 10 11 7 98 10 11 7 98 10 11
4 5 6 4 5
3 2 3 2 3
1 1 1 1 1
1312 14 15 16 1817 19 1312 14 15
start pl ayi ng s1
A. Mahanti, D. L. Eager, M. K. Vernon, D. S.-Stukel 2001
9
Optimized Periodic Broadcast (cont.) General segment length
2
22
12
1
k
k
ll
ll
kkk
10
Generalized OPB
Given the client reception bandwidth as constraint b: maximum client reception bandwidth r: bandwidth of each stream s: number of streams client listen to concurrently
b = r*s
sk
sk
l
lr
l
r
lk
skjj
k
jj
k
1
1
1
1
1
11
Performance of OPB
12
Optimized Periodic Broadcast
t i me
1 . . .2 6543 7
1
b
b 1 1 1 1 1 1 1 1 1 1 1 1 1
cl i entarri val
s1 s2 s4
start recei vi ng s1
vi deo sequence
serverbandwi dth
1
1098 11 12 13 1514
s3 s5
2b 2 33 2 3 2 3 2 3 2 3 2 3 2
4b 55 66 4 4 5 6 4 5 6 4 5 6
7b 98 10 11
b 1312 14 15 16 1817 19
16 1817 19
7 98 10 11 7 98 10 11 7 98 10 11
4 5 6 4 5
3 2 3 2 3
1 1 1 1 1
1312 14 15 16 1817 19 1312 14 15
start pl ayi ng s1
13
Optimized Periodic Broadcast
t i me
1 . . .2 6543 7
1
b
b 1 1 1 1 1 1 1 1 1 1 1 1 1
cl i entarri val
s1 s2 s4
start recei vi ng s1
vi deo sequence
serverbandwi dth
1
1098 11 12 13 1514
s3 s5
2b 2 33 2 3 2 3 2 3 2 3 2 3 2
4b 55 66 4 4 5 6 4 5 6 4 5 6
7b 98 10 11
b 1312 14 15 16 1817 19
16 1817 19
7 98 10 11 7 98 10 11 7 98 10 11
4 5 6 4 5
3 2 3 2 3
1 1 1 1 1
1312 14 15 16 1817 19 1312 14 15
start pl ayi ng s1
pari ty
l oss
14
Loss Recovery Strategy
Digital Fountain approach Use Error Correction Codes to generate n
symbols from k original symbols (n >> k) Symbol: frame, packet, etc.
Recover the k original symbols from any k out of n coded symbols
1 52 63 4 1 2 3
a eb fc d g h i
ori gi nalsequence
codedsequence
start recei vi ng
5 64
j k l
15
Generalized RPB
Reliable Periodic Broadcast (RPB) Maximum tolerable loss rate p
need L/(1-p) packets in order to receive L packets Segment length (a = 1/(1-p))
sk
sk
l
lr
la
r
la k
skjj
k
jj
k
1
1
1
1
1
16
Performance of RPB
17
Outline
Periodic Broadcast Schemes Bandwidth Skimming Scheme Conclusion
18
Bandwidth Skimming Scheme
19
Bandwidth Skimming Scheme (cont.)
t i me
a1
cl i entarri val
mul t i cast starts
b1c1
substream asubstream bsubstream c
a2b2c2
a3b3c3
a4b4c4
a1b1c1
a2b2c2
a3b3c3
a5b5c5
substream asubstream bsubstream c
20
Reliable Bandwidth Skimming Pros
Bandwidth decreases as the client request rate decreases
VCR functionality – fast forward Protocol
Primary stream is transmitted at rate 1 Secondary stream is transmitted at rate p/(1-p) Merging happens between primary streams, as w
ell as secondary streams Real system in Univ. of Wisconsin
21
Reliable Bandwidth Skimming (cont.)
22
Conclusions
Propose two reliable on-demand streaming schemes RPB RBS
Schemes investigate the fundamental trade-offs of on-demand streaming service