cooperative video streaming on...

Cooperative Video Streaming on Smartphones

Hülya Seferoğlu†, Lorenzo Keller‡, Blerim Cici †, Anh Le †,

Athina Markopoulou †, Christina Fragouli‡

†University of California, Irvine ‡ École Polytechnique Fédérale de Lausanne

Supported by AFOSR MURI, NSF CAREER and by ArmaSuisse W+T

“Unofficial” Motivation

•  Typical practical questions after a talk on network coding: –  “Is it implemented in practice?” –  “How much benefit does it bring?” –  “How much is the overhead”? –  “Can non-network coding approaches do as well?” –  “I don’t believe this is useful!”

•  We decided to implement network coding …

2

Cooperative Video Streaming on Smartphones Scenario

3

The Internet Video Source

Smartphones

Youtube, Netflix,

etc.

Video Proxies

Base Stations

о  Several users, within proximity of each other

о  Interested in viewing the same video at the same time (e.g. a soccer match or lecture)

о  Have Internet connection via cellular or wifi

о  Mobile-to-mobile connections possible via bluetooth or wifi.

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Smartphones

Cooperative Video Streaming on Smartphones Examples

о  Each individual user may not have high enough rate to stream a high quality video (due to bad, time-varying, or no cellular connection)

о  Special case: sharing a video stored on one of the phones Base

Stations

5


Smartphones

Cooperative Video Streaming on Smartphones Question

о  How to best utilize all resources to provide the best performance?

Base Stations

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1. Cooperation: use cellular links and local links 2. Network coding: intra-session, application-layer 3.  Broadcast: use wireless+NC efficiently 4. Implementation on Androids This scenario lends itself naturally to network coding.


Smartphones

Cooperative Video Streaming on Smartphones Key Ingredients

Base Stations

Related Work

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о  Smartphones with NC Implementation о  P. Vingelmann, M. V. Pedersen, F. H. P. Fitzek, and J. Heide, “On-the-fly packet error recovery in a

cooperative cluster of mobile devices,” in Proc. of Globecom, Houston, TX, Dec. 2011. (Univ. of Aalborg) о  Baochun Li’s group: NC implementation in Iphones and Ipad.

о  Wifi devices with NC Implementation о  COPE testbed, … о  Y. Park, C. Jo, S. Yun, H. Kim, “Multi-room IPTV delivery through pseudo-broadcast over IEEE 802.11 links,”

in Proc. of VTC, Taipei, Taiwan, May 2010. о  S. Sen, N. K. Madabhushi, S. Banerjee, “Scalable wifi media delivery through adaptive broadcasts,” in Proc.

of NSDI, San Jose, CA, April 2010.

о  Network Coding-based P2P о  C. Gkantsidis, P. R. Rodriguez, “Network coding for large scale content distribution,” in Proc. of Infocom,

Miami, FL, March 2005. о  M. Wang, B. Li, “R2: random push with random network coding in live peer-to-peer streaming,” in IEEE

JSAC, vol. 25(9), pp. 1655–1666, Dec. 2007. о  Z. Liu, C. Wu, B. Li, S. Zhao, “UUSee: large-scale operational on demand streaming with random network

coding,” in Proc. of Infocom, San Diego, CA, March 2010. о  B. Li, D. Niu, “Random network coding in peer-to-peer networks: from theory to practice,” in Proceedings of

the IEEE, vol. 99(3), pp. 513-523, March 2011.

Related Work

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о  Network Coding & NUM о  D. S. Lun, N. Ratnakar, M. Medard, R. Koetter, D. R. Karger, T. Ho, E. Ahmed, and F. Zhao, “Minimum-cost

multicast over coded packet networks,” in IEEE Trans. on Information Theory, vol. 52(6), June 2006. о  L. Chen, T. Ho, S. Low, M. Chiang, and J. C. Doyle, “Optimization based rate control for multicast with

network coding,” in Proc. of Infocom, Anchorage, AK, May 2007. о  J. Yuan, Z. Li, W. Yu, and B. Li, “A cross-layer optimization framework for multi-hop multicast in wireless

mesh networks,” in IEEE JSAC, vol. 24(11), Nov. 2006. о  Z. Li, B. Li, and M. Wang, “Optimization models for streaming in multihop wireless networks,” in Proc. of

ICCCN, Honolulu, HI, Aug. 2007.

о  Network Coding & NUM & P2P о  M. Chen, M. Ponec, S. Sengupta, J. Li, P. A. Chou, “Utility maximization in peer-to-peer systems,” in Proc. of

ACM Sigmetrics, Annapolis, MD, June 2008. о  S. Liu, R. Z.-Shen, W. Jiang, J. Rexford, M. Chiang, “Performance bounds for peer-assisted live streaming,”

in Proc. of ACM Sigmetrics, Annapolis, MD, June 2008. о  Z. Shao and S.-Y. R. Li, “To code or not to code: rate optimality of network coding versus routing in peer-to-

peer networks,” in IEEE Trans. on Communications, vol. 59(4), pp. 948-954, April 2011. о  C. Liang, M. Zhao, and Y. Liu, “Optimal bandwidth sharing in multiswarm multiparty p2p video-conferencing

systems,” in IEEE/ACM Trans. on Networking, March 2011. о  S. Hua, Y. Guo, Y. Liu, H. Liu, and S. S. Panwar, “Scalable video multicast in hybrid 3g/ad-hoc networks,” in

IEEE Trans. on Multimedia, vol. 13(2), pp. 402-413, April 2011. о  M. Ponec, S. Sengupta, M. Chen, J. Li, P. A. Chou, “Multi-rate peerto-peer video conferencing: a distributed

approach using scalable coding,” in Proc. of ICME, New York, NY, July 2009. о  D.-C. Tomozei and L. Massoulie, “Flow Control for Cost-Efficient Peer-to-Peer Streaming,” in Proc. of

Infocom, San Diego, CA, March 2010.

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1. Cooperation: use cellular links and local links 2. Network coding: intra-session, application-layer 3.  Broadcast: use wireless+NC efficiently 4. Implementation on Androids


Smartphones

MicroCast Key ingredients - revisited

Outline

•  NUM formulation

•  Implementation and demo on androids

•  Work in progress..

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NUM Formulation Cooperation & Unicast

11

Smartphones

The Source

∑ ∑

∑

∈ −∈

∈

≤

−∈∈∀−≤

∈∈∀−≤

−∈∈∀≥−

∈∀≥−

Ni iNjji

jijijiji

iiji

jiji

Niji

x

iNjNipCgNjNipCxiNjNixg

Njxxts

xU

}{,

,,,,

,

,,

,

}{,,)1(

,),1(

}{,,0

,0..

)(max

γτ

τ

Optimize video rate: x

Flow conservation constraints

Capacity constraints

Interference

Downlink 3g/4g Ci

pi

x

Ci,j, pi,j

xi,j

i gi,j

NUM Formulation Cooperation & Broadcast

12

∑∑

∏

∑

∑

∈ ∈

∈∈

∈

∈

≤

∈∈∀−≤

−∈∈∀≤

∈∈∀−≤

−∈∈∀≥−

∈∀≥−

Ni HJJi

JiJj

jijiJjJi

JjJJiji

iiji

jiji

Niji

x

HJNipCf

iNjNifg

NjNipCxiNjNixg

Njxxts

xU

γτ

τ

,

,,,,

|,,

,

,,

,

,,)1(}{min

}{,,

,),1(

}{,,0

,0..

)(max Optimize video rate: x


Downlink and local area capacity

constraints

Interference

Smartphones

The Source

Downlink 3g/4g Ci

pi

x

Ci,j, pi,j

xi,j

i gi,j

NUM Formulation Cooperation & Broadcast & NC

13

Smartphones

The Source

∑∑

∑

∑

∈ ∈

∈

∈

∈

≤

∈∈∀−≤

−∈∈∀≤

∈∈∀−≤

−∈∈∀≥−

∈∀≥−

Ni HJJi

JijijiJjJi

JjJJiji

iiji

jiji

Niji

x

HJNipCf

iNjNifg

NjNipCxiNjNixg

Njxxts

xU

γτ

τ

,

,,,,

|,,

,

,,

,

,,)}1({min

}{,,

,),1(

}{,,0

,0..

)(max Optimize video rate: x


Downlink and local area capacity

constraints

Interference

Downlink 3g/4g Ci

pi

x

Ci,j, pi,j

xi,j

i gi,j

NUM Solution

14

)()'( 1 ∑∈

−=Jj

jUx λRate Control at the Source

NjNipCxts

x

iiji

Ni Njjijjix

∈∈∀−≤

−∑∑∈ ∈

,),1(..

)(max

,

,, ηλDownlink Rate Control

γτ

ηττ

≤

−

∑∑

∑∑ ∑

∈ ∈

∈ ∈ ∈∈

Ni HJJi

Ni HJ JjjijiJjjiJi

ts

pC

,

,,,,

..

))}1({min(max

Local Area Rate Control/Scheduling

Queue Update at the Source

Queue Update at Smartphones

Njtxtx

tt

Nijit

jj

∈∀−

+=++

∈∑ ,]})()([

)({)1(

,β

λλ

NjNitgtx

tt

jijit

jiji

∈∈∀−

+=++ ,,)]}()([

)({)1(

,,

,,

β

ηη

Cooperation & Broadcast & NC

γτ

ηττ

≤

−

∑∑

∑∑ ∑ ∏

∈ ∈

∈ ∈ ∈ ∈∈

Ni HJJi

Ni HJ Jj JjjijiJjjiJi

ts

pC

,

,,,,

..

)})1(}{min(maxCooperation & Broadcast & No-NC

γτ

τητ

≤

−

∑∑

∑∑

∈ ∈

∈ ∈

Ni Njji

Ni Njjijijiji

ts

pC

,

,,,,

..

)1(maxCooperation & Unicast & NC/No-NC

Performance Evaluation Numerical Results: throughput vs # of users

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Ci=1, pi=0, Ci,j=1, pi,j=0 Ci=1, pi=0, Ci,j=1, pi,j=0.2

о  What do we learn?

о  How to determine source video rate? о  Optimal downlink rates? о  Optimal mobile-to-mobile rates о  Which mobile should transmit? о  What information needs to be exchanged?

о  Implementation should mimic the optimal solution

о  Can use the numerical results to check real experiments, understand the effect of various parameters, and for provisioning

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From NUM to implementation

Implementation Hardware

о  Hardware platform о  Google Nexus S

о  1 GHz Cortex A8, 512 MB RAM

о  Network connections о  cellular (3G) о  802.11b о  Bluetooth 2.1+EDR

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о  Software platform о  Android 2.3 о  Application written in Java runs on

о  Android (mobile phones, tablets) о  Java 2 SE (laptops, etc.)

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Implementation Software

Application Architecture

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GUI and Video player

Segment reordering and caching

Download segments from source

Downlink: Wifi/3G

Local link: Bluetooth/WiFi

Local CollaboraFon

Network layer

AbstracFon layer

Requester

Collaborative SegmentRequester

HTTP Segment Producer

Segment Producer

Segment Consumer

SegmentConsumer

StoredStreamImpl

NCPeer

StoredStream StorageEventListener

NetworkLayer

Channel

NetworkLayerImpl

MessageListener

MessageListener

Bluetooth Endpoint Manager

UDP Endpoint Manager

Bluetooth Connecti

on

BluetoothLinkLayer

Connection Endpoint Manager

Datagram Endpoint Manager

Multicast Endpoint Manager

Broadcast Endpoint Manager

Bluetooth Peer

Directory

Link Layer

Link Layer

Listener Connection

Link Layer

Directory Entry

Listener

PeerDirectory

Neighbor Listener

NC Peer

Factory

Collaborative SegmentRequester

Factory

StreamStorage

Impl

HTTP Stream Publisher

StoredStream StreamStorage

StreamControllerImpl

Stream Storage

Segment Distributor

Factory

Segment Producer Factory

SegmentRequester Segment Requester

Factory

StreamPublisher

Multiplexer

NetworkLayer

Channel

MessageListener

MessageListener

Multiplexer

NeighborListener

GUI

StreamController

TCP/IP

Andorid Media Player HTTP

3G

Bluetooth stack (RFCOMM)

Coding: not a challenge

l  We used NCUtils l  Java ( and C ) library available at: http://arni.epfl.ch/software/ l  Multiplication and inverse done with table lookup, addition done with XOR

l  Encoding/Decoding: l  RNC encoding, early decoding l  could support rates >6Mbps

l  Parameters (not optimized) l  Symbol: 1B (efficient to implement) l  Generation size 10. ~ 10KB RAM to decode each generation l  Payload size 1000 bytes l  Coding coefficient overhead 1%

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Multiple Interfaces: a challenge

•  Android is optimized for space and battery –  3G, WiFi, Bluetooth

•  Simultaneously using multiple interfaces: –  Bluetooth and 3G: ok –  Bluetooth and wifi: on the same chip –  3G and WiFi: one sleeps while the other is active –  (use WiFi for both downlink and local links: MAC contention) –  We had to re-implement a network layer to provide routing and

datagram communication at the application layer

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Broadcast: a major challenge

о  WiFi Broadcast: not the best

option (base rate, reliability) о  WiFi Pseudo-broadcast on

androids (vs. PCs) is challenging: –  Have to root the phone –  Driver for overhearing not

available on all devices –  Does not work in ad-hoc mode –  Sniffer: we had to extend the

Android API to support overhearing

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A B

C

о  Bluetooth: currently not supported о  WiFi: doable but difficult

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1 2

3 4

HTTP Server

Testbed

Base staFon NC Proxy ….

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1 2

Base staFon

HTTP Server

1 2

Base staFon

HTTP Server

1 2

Base staFon

HTTP Server

NC Proxy

Cooperation 3G downlinks,

pull-based cooperation no NC

3G alone 3G downlinks,

independent pull

Cooperation+NC 3G downlinks,

push+NC cooperation push+NC proxy

55 secs, 239 kbps 40 secs, 329 kbps 32 secs, 411 kbps

Demo #1: The value of (1) Cooperation and (2) NC by Anh Le @UCI: Users 1 and 2 download a 1.57MB file

Demo #2: The Value and Feasibility of (3) Pseudobroadcast by Blerim Cici @UCI: A downloads a 4.92MB mp3 and sends it to B and C over UDP

A

B C

A

B C

Unicast WiFi downlik

independent pull no overhearing

Pseudo-broadcast WiFi downlik

independent pull NC+overhearing

40 sec (on avg) 2.5 segments lost at B, 0.5 segments lost at C

56 sec (on avg) 12.2 segments lost at B, 8.48 segments lost at C

Next Steps •  Analysis

–  bridge the gap between the NUM formulation and the practical implementation

•  Implementation –  incorporate WiFi pseudobroadcast with Cooperation+NC –  make MicroCast publicly available as:

•  Android application •  PC/laptop application •  Java library

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Thank you.

http://odysseas.calit2.uci.edu/doku.php/public:network-coding http://odysseas.calit2.uci.edu/doku.php/public:muri09

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