POEM: Minimizing Energy Consumption for WiFi Tethering Service

Despite the rapidly increasing number of public WiFi hotspots, their coverage is still limited to indoor and office/business environments. WiFi tethering is thus a useful and economic means of providing on-the-go mobile users' Internet connection. One of the main problems of WiFi tethering is the excessive power consumption of mobile access points (APs), or tethered smartphones. Since the power-saving mechanism, defined and deployed in the IEEE 802.11 standard, is intended for clients only, the WiFi interface of a mobile AP never enters the sleep mode. In this paper, we propose a simple but effective system, called power-efficient mobile (POEM), which reduces energy consumption of a mobile AP by allowing its WiFi interface to sleep even during data transfer. The POEM exploits the inherent bandwidth asymmetry between the WiFi and the WWAN interfaces of a mobile AP by buffering the data packets received via the WWAN interface at the mobile AP, thereby allowing the WiFi interface to enter the sleep mode. Compared with the other power-saving solutions for WiFi tethering, the POEM is able to handle various types of applications, such as video steaming and file download, designed to support legacy clients (i.e., clients without POEM), and is also efficient in reducing the clients' energy consumption. We have implemented and conducted an extensive evaluation of the POEM's effectiveness in an android/linux-based test bed. Our experimental results show that the POEM can allow the WiFi interface of a mobile AP to sleep for up to 90% of the total transfer time without significantly affecting system throughput or end-to-end delay.

[1]  Surendar Chandra.  Wireless network interface energy consumption , 2003, Multimedia Systems.

[2]  Oliver Spatscheck,et al.  Accurate, scalable in-network identification of p2p traffic using application signatures , 2004, WWW '04.

[3]  Konstantina Papagiannaki,et al.  Toward the Accurate Identification of Network Applications , 2005, PAM.

[4]  Yi Xie,et al.  Centralized PSM: An AP-centric power saving Mode for 802.11 infrastructure networks , 2009, 2009 IEEE Sarnoff Symposium.

[5]  Pedro Cuenca,et al.  Cross-layer architecture for adaptive video multicast streaming over multirate wireless LANs , 2007, IEEE Journal on Selected Areas in Communications.

[6]  Yunxin Liu,et al.  DozyAP: power-efficient Wi-Fi tethering , 2012, MobiSys '12.

[7]  Ramachandran Ramjee,et al.  NAPman: network-assisted power management for wifi devices , 2010, MobiSys '10.

[8]  Ramesh Govindan,et al.  Snooze: energy management in 802.11n WLANs , 2011, CoNEXT '11.

[9]  Renata Teixeira,et al.  Traffic classification on the fly , 2006, CCRV.

[10]  Catherine Rosenberg,et al.  Energy Efficient Schedulers in Wireless Networks: Design and Optimization , 2006, Mob. Networks Appl..

[11]  Michalis Faloutsos,et al.  BLINC: multilevel traffic classification in the dark , 2005, SIGCOMM '05.

[12]  Rong-Hong Jan,et al.  A power-saving scheduling for infrastructure-mode 802.11 wireless LANs , 2006, Comput. Commun..

[13]  Konstantina Papagiannaki,et al.  Catnap: exploiting high bandwidth wireless interfaces to save energy for mobile devices , 2010, MobiSys '10.

[14]  Janne Riihijärvi,et al.  Experimental study on performance of IEEE 802.11n and impact of interferers on the 2.4 GHz ISM band , 2010, IWCMC.

[15]  Hari Balakrishnan,et al.  Minimizing Energy for Wireless Web Access with Bounded Slowdown , 2002, MobiCom '02.

[16]  Songqing Chen,et al.  PSM-throttling: Minimizing Energy Consumption for Bulk Data Communications in WLANs , 2007, 2007 IEEE International Conference on Network Protocols.

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

[18]  Surendar Chandra,et al.  Wireless network interface energy consumption implications of popular streaming formats , 2001, IS&T/SPIE Electronic Imaging.

[19]  Suchendra M. Bhandarkar,et al.  A client-side statistical prediction scheme for energy aware multimedia data streaming , 2006, IEEE Transactions on Multimedia.