A First Look at Traffic on Smartphones

Hossein FalakiDimitrios Lymberopoulos

Ratul MahajanSrikanth KandulaDeborah Estrin

2

Exponential growth in mobile traffic

CISCO VNI 2010http://www.totaltele.com

ratul | IMC | Nov 2010

http://www.readwriteweb.com

3

Two ways to understand smartphone traffic

ratul | IMC | Nov 2010

1. Capture at a link in the network

2. Capture on the devices

4

Preliminary findings

Browsing, email, media, and maps dominate traffic

Small connection sizes lead to high overhead

Throughput is bottlenecked by path loss and socket buffers at servers

Tuning 3G radio timeout can significantly reduce power use with minimal performance impact

ratul | IMC | Nov 2010

5

Datasets in our study

ratul | IMC | Nov 2010

Dataset1 Dataset2

# users 10 33

Platform 8 WM6, 2 Android Android

Traffic granularity Packet-level App-level

Duration (days/user) 26-84 49-147

6

Traffic exchanged per day

ratul | IMC | Nov 2010

MB per day

% ofusers(CDF)

7

Traffic composition

ratul | IMC | Nov 2010

Bytes (%)

Browsing 58.0

Media 10.8

Messaging (email, IM) 10.3

Maps 8.5

System 5.8

Social networking 4.2

Games 0.4

Productivity 0.2

Other 1.8[Dataset2]

8

Transfer sizes are small

ratul | IMC | Nov 2010

Transfer size (KB)

% of transfers

(CDF)

[Dataset1]

9

Lower-layer protocols have high overhead

ratul | IMC | Nov 2010

Header overhead (% of bytes)

% ofxfers(CDF)

% ofxfers(CDF)

Handshake overhead (% of time)[Dataset1][Dataset1]

10

Traffic throughput is low

ratul | IMC | Nov 2010

Throughput (kbps)

% ofxfers(CDF)

[Connections in Dataset1 with 10+ data packets in a direction]

11

Throughput bottlenecks

ratul | IMC | Nov 2010

Uplink (%)

Downlink (%)

Packet loss 81.0 61.5Sender window 4.1 27.4

Receiver window 6.8 3.4Bandwidth 5.1 2.9Transport 0.7 0.0

Application 0.0 0.0Unknown 2.4 4.8

[Connections in Dataset1 with 50+ data packets in a direction]

12

Conclusions

Capturing traffic on smartphones provides a rich, detailed view of device traffic

Findings from our preliminary analysis• Browsing, email, media, and maps dominate traffic• Small transfer sizes lead to high overhead• Throughput is limited by loss and socket buffers• Judicious radio timeouts can cut power consumption

ratul | IMC | Nov 2010