This Article 
 Bibliographic References 
 Add to: 
Context-Based Network Estimation for Energy-Efficient Ubiquitous Wireless Connectivity
January 2011 (vol. 10 no. 1)
pp. 54-66
Ahmad Rahmati, Rice University, Houston
Lin Zhong, Rice University, Houston
Context information brings new opportunities for efficient and effective system resource management of mobile devices. In this work, we focus on the use of context information to achieve energy-efficient, ubiquitous wireless connectivity. Our field-collected data show that the energy cost of network interfaces poses a great challenge to ubiquitous connectivity, despite decent availability of cellular networks. We propose to leverage the complementary strengths of Wi-Fi and cellular interfaces by automatically selecting the most efficient one based on context information. We formulate the selection of wireless interfaces as a statistical decision problem. The challenge is to accurately estimate Wi-Fi network conditions without powering up the network interface. We explore the use of different context information, including time, history, cellular network conditions, and device motion, to statistically estimate Wi-Fi network conditions with negligible overhead. We evaluate several context-based algorithms for the estimation and prediction of current and future network conditions. Simulations using field-collected traces show that our network estimation algorithms can improve the average battery lifetime of a commercial mobile phone for an ECG reporting application by 40 percent, very close to the estimated theoretical upper bound of 42 percent. Furthermore, our most effective algorithm can predict Wi-Fi availability for one and ten hours into the future with 95 and 90 percent accuracy, respectively.

[1] A. Rahmati and L. Zhong, "Context-for-Wireless: Context-Sensitive Energy-Efficient Wireless Data Transfer," Proc. ACM MobiSys, pp. 165-178, 2007.
[2] C.V.C. Bouten, K.T.M. Koekkoek, M. Verduin, R. Kodde, and J.D. Janssen, "A Triaxial Accelerometer and Portable Data Processing Unit for the Assessment of Daily Physical Activity," IEEE Trans. Biomedical Eng., vol. 44, no. 3, pp. 136-147, Mar. 1997.
[3] P.S. Hamilton and W.J. Tompkins, "Estimation of Rate-Distortion Bounds for Compression of Ambulatory ECGs," Proc. Int'l Conf. Eng. in Medicine and Biology Soc., vol. 2, pp. 763-764, 1989.
[4] Universal Access Report, GSM Assoc., regulatory-affairsuniversal_access.htm , 2006.
[5] V. Bychkovsky, B. Hull, A. Miu, H. Balakrishnan, and S. Madden, "A Measurement Study of Vehicular Internet Access Using In Situ Wi-Fi Networks," Proc. ACM MobiCom, pp. 50-61, 2006.
[6] Rice Orbit Platform, Rice Efficient Computing Group,, 2010.
[7] A. LaMarca, Y. Chawathe, S. Consolvo, J. Hightower, I. Smith, J. Scott, T. Sohn, J. Howard, J. Hughes, and F. Potter, "Place Lab: Device Positioning Using Radio Beacons in the Wild," Proc. Int'l Conf. Pervasive Computing (Pervasive), pp. 116-133, 2005.
[8] A.J. Nicholson, Y. Chawathe, M.Y. Chen, B.D. Noble, and D. Wetherall, "Improved Access Point Selection," Proc. ACM MobiSys, pp. 233-245, 2006.
[9] P. Eronen, "TCP Wake-Up: Reducing Keep-Alive Traffic in Mobile IPv4 and IPsec NAT Traversal," Nokia technical report, 2008.
[10] M.Y. Chen, T. Sohn, D. Chmelev, D. Haehnel, J. Hightower, J. Hughes, A. LaMarca, F. Potter, I. Smith, and A. Varshavsky, "Practical Metropolitan-Scale Positioning for GSM Phones," Proc. Int'l Conf. Ubiquitous Computing (UbiComp), pp. 157-169, 2006.
[11] P. Bahl and V.N. Padmanabhan, "RADAR: An In-Building RF-Based User Location and Tracking System," Proc. IEEE INFOCOM, vol. 772, pp. 775-784, 2000.
[12] E. Shih, P. Bahl, and M.J. Sinclair, "Wake on Wireless: An Event Driven Energy Saving Strategy for Battery Operated Devices," Proc. ACM MobiCom, pp. 160-171, 2002.
[13] T. Hastie, R. Tibshirani, and J.H. Friedman, The Elements of Statistical Learning: Data Mining, Inference, and Prediction. Springer, 2001.
[14] T. Pering, Y. Agarwal, R. Gupta, and R. Want, "CoolSpots: Reducing the Power Consumption of Wireless Mobile Devices with Multiple Radio Interfaces," Proc. ACM MobiSys, pp. 220-232, 2006.
[15] Y. Agarwal, R. Chandra, A. Wolman, P. Bahl, K. Chin, and R. Gupta, "Wireless Wakeups Revisited: Energy Management for VoIP over Wi-Fi Smartphones," Proc. ACM MobiSys, pp. 179-191, 2007.
[16] C.F. Chiasserini, R.R. Rao, and D. di Elettronica, "Improving Energy Saving in Wireless Systems by Using Dynamic Power Management," IEEE Trans. Wireless Comm., vol. 2, no. 5, pp. 1090-1100, Sept. 2003.
[17] T. Armstrong, O. Trescases, C. Amza, and E. de Lara, "Efficient and Transparent Dynamic Content Updates for Mobile Clients," Proc. ACM MobiSys, pp. 56-68, 2006.
[18] E. Gustafsson and A. Jonsson, "Always Best Connected," IEEE Wireless Comm., vol. 10, no. 1, pp. 49-55, Feb. 2003.
[19] J. Sorber, N. Banerjee, M.D. Corner, and S. Rollins, "Turducken: Hierarchical Power Management for Mobile Devices," Proc. ACM MobiSys, pp. 261-274, 2005.
[20] S. Chakraborty, Y. Dong, D.K.Y. Yau, and J.C.S. Lui, "On the Effectiveness of Movement Prediction to Reduce Energy Consumption in Wireless Communication," IEEE Trans. Mobile Computing, vol. 5, no. 2, pp. 157-169, Feb. 2006.
[21] A.J. Nicholson and B.D. Noble, "BreadCrumbs: Forecasting Mobile Connectivity," Proc. ACM MobiCom, pp. 46-57, 2008.
[22] S. Gitzenis and N. Bambos, "Joint Transmitter Power Control and Mobile Cache Management in Wireless Computing," IEEE Trans. Mobile Computing, vol. 7, no. 4, pp. 498-512, Apr. 2008.
[23] N. Banerjee, A. Rahmati, M.D. Corner, S. Rollins, and L. Zhong, "Users and Batteries: Interactions and Adaptive Energy Management in Mobile Systems," Proc. Int'l Conf. Ubiquitous Computing (Ubicomp), pp. 217-234, 2007.
[24] A. Rahmati and L. Zhong, "Human-Battery Interaction on Mobile Phones," Pervasive and Mobile Computing, vol. 5, no. 5, pp. 465-477, 2009.
[25] N. Ravi, J. Scott, L. Han, and L. Iftode, "Context-Aware Battery Management for Mobile Phones," Proc. Int'l Conf. Pervasive Computing and Comm. (PerCom), pp. 224-233, 2008.

Index Terms:
Network architecture and design, local and wide-area networks.
Ahmad Rahmati, Lin Zhong, "Context-Based Network Estimation for Energy-Efficient Ubiquitous Wireless Connectivity," IEEE Transactions on Mobile Computing, vol. 10, no. 1, pp. 54-66, Jan. 2011, doi:10.1109/TMC.2010.139
Usage of this product signifies your acceptance of the Terms of Use.