Poster: SoftOffload: A Programmable Approach TowardCollaborative Mobile Traffic Offloading

Aaron Yi Ding§, Jon Crowcroft†, Sasu Tarkoma§

§University of Helsinki, Helsinki, Finland †University of Cambridge, Cambridge, UK{aaron.ding , sasu.tarkoma}@cs.helsinki.fi; jon.crowcroft@cl.cam.ac.uk

Categories and Subject Descriptors

C.2.1 [Network Architecture and Design]: Network com-munications

Keywords

Software Defined Networking; Mobile Data Offloading

ABSTRACT

The fast increase of mobile traffic from smartphone-like de-vices has created a huge pressure for the cellular opera-tors to manage the network infrastructure and resources.Offloading the mobile traffic to alternative networks suchas WiFi is sought as a promising direction to solve thisproblem cost-effectively. According to our study and ex-perimental findings [1], existing research proposals are lackof concern for the complexity of network deployment anddevice limitations, which impedes the solution deployment.To overcome such challenge, we propose SoftOffload, a pro-grammable framework for collaborative mobile traffic off-loading. SoftOffload takes the advantage of software definednetworking (SDN) paradigm in terms of openness and exten-sibility. We have implemented the first prototype utilisingthe open source Floodlight platform [2].

1. DESIGN AND IMPLEMENTATIONThe design principle of SoftOffload is to improve the open-

ness and deployability by adopting the open standard soft-ware defined solutions. As illustrated in Figure 1, the keyelements include the SDN-based SoftOffload controller andthe SoftOffload local agents. The central SoftOffload con-troller is built on top of the open source Floodlight platformon which we integrate our offloading algorithm and control-ling logic [1] as an extension module to guide the mobiletraffic offloading. The SoftOffload local agents utilise themodular Click router [3] where we implement a set of moni-toring and sampling elements to assist the offloading proce-dure.

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MobiSys ’14, Bretton Woods, NH, USA

ACM 978-1-4503-2793-0/14/06.

http://dx.doi.org/10.1145/2594368.2601462.

SDN Controller with

SoftOffload Module

Cellular

Access

WiFi

Access

SDN-enabled

Switches

SoftOffload

Programmable

Local Agent

SoftOffload

Programmable

Local Agent

OpenFlow

Protocol

SoftOffload

Protocol

Mobile

Wireless

Access

Figure 1: SoftOffload Architecture

SoftOffload aims at improving the offloading efficiencyand the system responsiveness to the dynamic changes in awireless mobile environment. The hierarchical design makesthe system scalable by distributing the offloading function-ality between the central controller and the local agents.This function splitting reduces the redundant signalling andthe processing overhead comparing to the centralised app-roach. SoftOffload uses the OpenFlow protocol to managethe SDN-enabled switches and adopts our customised pro-tocol to communicate with the local agents. In our test-ing environment, we utilise commodity hardware with OpenvSwitch installation to enable OpenFlow support.

The beauty of SoftOffload comes from its open and pro-grammable design which improves the extensibility and de-ployability. SoftOffload facilitates the adding of new exten-sions such as traffic inspecting and rate shaping for variousaccess environment with different requirements. Our opensource oriented approach combined with standardised SDNsolutions can bring community contributions to drive theSoftOffload development further. We are planning to releasethe project package after thorough testing and evaluation.

2. REFERENCES

[1] A. Y. Ding, B. Han, Y. Xiao, P. Hui, A. Srinivasan,M. Kojo, and S. Tarkoma. Enabling Energy-AwareCollaborative Mobile Data Offloading for Smartphones.In Proceedings of IEEE SECON 2013.

[2] Floodlight OpenFlow Controller:http://www.projectfloodlight.org/

[3] Project Click: http://read.cs.ucla.edu/click/

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