when david helps goliath: the case for 3g onloading
DESCRIPTION
HotNets'12 Access link can often be the bottleneck for application performance. In this paper, we propose to augment wired connections using cellular ones, that we term “3G onloading (3GOL)". 3GOL utilizes available mobile devices and alreadypaid-for data volumes to augment and improve performance of applications on wired network. We motivate 3GOL by understanding bottlenecks present in the wired and the cellular networks. In order to understand the potential benefits of 3GOL, we conduct active experiments using mobile devices. We show that capacity gains can scale linearly with the number of devices on the downlink while also seeing improvements on the uplink. Using real traces we show how video on demand can benefit with 3GOL, even when volume caps are in place. We design 3GOL as an over the top service, and highlight research challenges.TRANSCRIPT
When David helps Goliath: The case for 3G Onloading Narseo Vallina-Rodriguez, Vijay Erramilli, Yan Grunenberger,
Laszlo Gyarmati, Nikos Laoutaris, Rade Stanojevic,
Dina Pagagiannaki
University of Cambridge
Telefonica Research / Telefonica Digital
HotNets 2012, Redmond, WA
David and Goliath
100x
47 Mbps downlink 5.6 Mbps uplink
Cellular Network
200m
Wired Network (DSL)
5.8 Gbps downlink 2.3 Gbps uplink
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Can David help Goliath?
YES! ¤ For 1 ADSLà the entire BS is not David
¤ For all ADSLs à David can become Goliath FOR SHORT PERIODS OF TIME
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
3G Onloading
¤ Offload traffic from the wired network onto the cellular network ¤ Speed up wired connections
¤ Improve applications’ performance
¤ Limitations: ¤ 3GOL cannot assist all wired connections ¤ Cannot help applications at all times
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Scenario 1: David helps Goliath
A
3.4 Mbps
4.7 Mbps
¤ Video-streaming application
¤ Well provisioned area
¤ Spare capacity on cellular network ¤ Powerboost ¤ Use-and-release
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Scenario 2: David becomes Goliath
2 Km 2.8 Mbps
A
¤ Constrained wired networks
¤ Cellular network can provide more capacity than wired networks
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4.7 Mbps
Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Design Considerations
¤ The Network ¤ 3G throughput is highly variable ¤ Control-plane latency
¤ The User Economics: volume caps in data plans ¤ 40 % of the mobile users use less than 10% of their
cap
¤ The Service ¤ Network integrated service ¤ Over the top
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Preliminary results
¤ How much additional throughput?
¤ Performance improvement?
¤ Increase in cellular traffic?
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
How much additional throughput?
¤ The Network ¤ 3G throughput depends on a number of factors
¤ Limited 3G network backhaul capacity
¤ Signaling delay
¤ The Economics ¤ Data volume caps
¤ The Service ¤ Network integrated service
¤ Over the top
Scenario Time DSL (d/u) Mbps
1. Densely populated residential area (city center)
1 am 3.44 / 0.30
2. Office area rush hour 4 pm 4.51 / 0.47
3. Residential Area in tourist hotspot
10 pm 6.72 / 0.84
4. Sparsely populated residential area (suburbs)
1 am 2.84 / 0.45
5. Popular shopping center in peak time
2 pm n/a
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Upstream Downstream
0
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15000
1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10Cluster Size
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ted
Thro
ughp
ut (K
bps)
location Location1 Location2 Location3 Location4 Location5
How much additional throughput?
Upstream Downstream
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ughp
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location Location1 Location2 Location3 Location4 Location5Densely populated area
Upstream Downstream
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ughp
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location Location1 Location2 Location3 Location4 Location5Office area
Upstream Downstream
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location Location1 Location2 Location3 Location4 Location5Residential area. Tourist hotspot
Upstream Downstream
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bps)
location Location1 Location2 Location3 Location4 Location5Suburbs
Upstream Downstream
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bps)
location Location1 Location2 Location3 Location4 Location5Shopping center (city center)
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
How much additional throughput?
Scenario Time DSL (d/u) Mbps
Cellular (d/u) Mbps
3GOL/DSL (d/u)
1. Densely populated residential area (city center)
1 am 3.44 / 0.30 4.37 / 1.64 2.3 / 6.5
2. Office area rush hour 4 pm 4.51 / 0.47
4.56 / 5.18 2.0 / 12.0
3. Residential Area in tourist hotspot
10 pm 6.72 / 0.84 1.92 / 1.53 1.3 / 2.8
4. Sparsely populated residential area (suburbs)
1 am 2.84 / 0.45 4.67 / 3.89 2.7 / 9.7
5. Popular shopping center in peak time
2 pm n/a 5.31 / 2.64
n/a
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Performance improvement: Video-streaming
0 5 10 15 200
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
dsl/3GOL
fract
ion
of v
ideo
s
Empirical CDF
1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.60
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
dsl/3GOl(40MB)fra
ctio
n of
use
rs
Empirical CDF
Unlimited Capped
50% of the videos have a speed up factor of 10 and below
40% of users have a speed up around 20%
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
0 2 4 6 8 10 12 14 16 18 20 22 24
101
102
103
104
105
time (5min bins)
loa
d o
n n
wk
(Mb
s)
3GOL(20Mb budget)
3GOL(Unlim)
Cell capacity
Increase in 3G traffic
Available Bandwidth
Overload
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Prototype implementation
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
¤ Decide when to use 3GOL ¤ Which apps and when!
¤ Use the right devices ¤ Cell Nets are best effort! ¤ Pre-fetching radio channel
¤ How much data to onload
¤ How to aggregate different connections: ¤ Same Wi-Fi AP ¤ ClubDSL [Mobicom 2011]
Research challenges
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Related Work
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
¤ Wired networks performance. ¤ Sundaresan et al. Broadband internet performance: a view from the
gateway. ACM SIGCOMM 2011. ¤ Kreibich et al. NetAlyzr, IMC 2010
¤ 3G Offloading ¤ Badam et al. The hare and the tortoise: taming wireless losses by exploiting
wired eliability. In MobiHoc, 2011. ¤ Lee et al. Mobile data offloading: how much can wifi deliver? CoNext 2010
¤ Mobile networks ¤ Ha et al. Tube. ACM Sigcomm, 2012 ¤ Huang et al. A close examination of performance and power
characteristics of 4G/LTE networks ¤ Qiang et al. Characterizing radio resource allocation for 3g networks ¤ Vallina-Rodriguez et al. Breaking for commercials (To appear) IMC 2012
Summary
¤ David can help Goliath
¤ Powerboost-like service ¤ Constrained wired networks
¤ Overhead in cellular network can be controlled ¤ Use and release ¤ Data caps
¤ Better performance expected with LTE deployment
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12
Questions?
Narseo Vallina-Rodriguez [email protected] University of Cambridge / Telefonica Research
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Narseo Vallina-Rodriguez, University of Cambridge/Telefonica Research, HotNets'12