Mobile data offloading: how much can WiFi deliver?

This paper presents a quantitative study on the performance of 3G mobile data offloading through WiFi networks. We recruited 97 iPhone users from metropolitan areas and collected statistics on their WiFi connectivity during a two-and-a-halfweek period in February 2010. Our trace-driven simulation using the acquired whole-day traces indicates that WiFi already offloads about 65% of the total mobile data traffic and saves 55% of battery power without using any delayed transmission. If data transfers can be delayed with some deadline until users enter a WiFi zone, substantial gains can be achieved only when the deadline is fairly larger than tens of minutes. With 100-s delays, the achievable gain is less than only 2%-3%, whereas with 1 h or longer deadlines, traffic and energy saving gains increase beyond 29% and 20%, respectively. These results are in contrast to the substantial gain (20%-33%) reported by the existing work even for 100-s delayed transmission using traces taken from transit buses or war-driving. In addition, a distribution model-based simulator and a theoretical framework that enable analytical studies of the average performance of offloading are proposed. These tools are useful for network providers to obtain a rough estimate on the average performance of offloading for a given WiFi deployment condition.

[1]  Elizabeth M. Belding-Royer,et al.  Cool-Tether: energy efficient on-the-fly wifi hot-spots using mobile phones , 2009, CoNEXT '09.

[2]  L. Nelson.  Data, data everywhere. , 1997, Critical care medicine.

[3]  Kyunghan Lee,et al.  On the Levy-Walk Nature of Human Mobility , 2008, IEEE INFOCOM 2008 - The 27th Conference on Computer Communications.

[4]  Arun Venkataramani,et al.  Energy consumption in mobile phones: a measurement study and implications for network applications , 2009, IMC '09.

[5]  Ramesh Govindan,et al.  Energy-delay tradeoffs in smartphone applications , 2010, MobiSys '10.

[6]  Sivan Toledo,et al.  VTrack: accurate, energy-aware road traffic delay estimation using mobile phones , 2009, SenSys '09.

[7]  M. Frans Kaashoek,et al.  A measurement study of available bandwidth estimation tools , 2003, IMC '03.

[8]  Carl M. Harris,et al.  Fundamentals of Queueing Theory: Gross/Fundamentals of Queueing Theory , 2008 .

[9]  Kuo-Hsiung Wang,et al.  Cost analysis of a finite M/M/R queueing system with balking, reneging, and server breakdowns , 2002, Math. Methods Oper. Res..

[10]  Jean-Yves Le Boudec,et al.  Power Law and Exponential Decay of Intercontact Times between Mobile Devices , 2010, IEEE Trans. Mob. Comput..

[11]  Deborah Estrin,et al.  Diversity in smartphone usage , 2010, MobiSys '10.

[12]  Injong Rhee,et al.  Towards Mobile Phone Localization without War-Driving , 2010, 2010 Proceedings IEEE INFOCOM.

[13]  D. Y. Barrer.  Queuing with Impatient Customers and Indifferent Clerks , 1957 .

[14]  Ahmad Rahmati,et al.  Context-for-wireless: context-sensitive energy-efficient wireless data transfer , 2007, MobiSys '07.

[15]  Samir Ranjan Das,et al.  Understanding traffic dynamics in cellular data networks , 2011, 2011 Proceedings IEEE INFOCOM.

[16]  Brian D. Noble,et al.  BreadCrumbs: forecasting mobile connectivity , 2008, MobiCom '08.

[17]  Pan Hui,et al.  Impact of Human Mobility on the Design of Opportunistic Forwarding Algorithms , 2006, Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications.

[18]  Albert-László Barabási,et al.  The origin of bursts and heavy tails in human dynamics , 2005, Nature.

[19]  Christophe Diot,et al.  An Experimental Performance Comparison of 3G and Wi-Fi , 2010, PAM.

[20]  Abdolreza Abhari,et al.  Workload generation for YouTube , 2009, Multimedia Tools and Applications.

[21]  F. James.  Statistical Methods in Experimental Physics , 1973 .

[22]  Jean-Yves Le Boudec,et al.  Power Law and Exponential Decay of Intercontact Times between Mobile Devices , 2007, IEEE Transactions on Mobile Computing.

[23]  Deborah Estrin,et al.  A first look at traffic on smartphones , 2010, IMC '10.

[24]  Injong Rhee,et al.  Mobile data offloading: how much can WiFi deliver? , 2010, SIGCOMM '10.

[25]  Guohong Cao,et al.  Win-Coupon: An incentive framework for 3G traffic offloading , 2011, 2011 19th IEEE International Conference on Network Protocols.

[26]  Marcel F. Neuts,et al.  Matrix-Geometric Solutions in Stochastic Models , 1981 .

[27]  Srinivasan Seshan,et al.  Mark-and-sweep: getting the "inside" scoop on neighborhood networks , 2008, IMC '08.

[28]  Arun Venkataramani,et al.  Augmenting mobile 3G using WiFi , 2010, MobiSys '10.

[29]  T. Friedman,et al.  Characterizing pairwise inter-contact patterns in delay tolerant networks , 2007, AUTONOMICS 2007.

[30]  D. Y. Barrer.  Queuing with Impatient Customers and Ordered Service , 1957 .