Many networked applications that run in the background on smartphones incur significant energy drains when using the cellular radio interface(3G/LTE) for communication. This is mainly due to the radio-tail, where the cellular radio remaining in a high energy state for up to 20s after each communication spurt. In order to cut down energy consumption, many recent devices employ fast dormancy, a feature that forces the client radio to quickly go into a low energy state after a fixed short idle period. However, aggressive idle timer values for fast dormancy can increase signaling overhead due to frequent state transitions, which negatively impacts the network. In this talk, I'll describe RadioJockey, a system that uses program execution traces to predict the end of communication spurts, thereby accurately invoking fast dormancy without increasing network signaling load. RadioJockey achieves 20-40% energy savings with negligible increase in signaling overhead compared to fixed idle timer-based approaches. This work was recently published in Mobicom 2012.
Vishnu Navda is a researcher in the Mobility, Networks, and Systems group at Microsoft Research India. Prior to this, he received his PhD from Stony Brook University. His research interests are in the area of wireless networking and mobile systems. He won the best paper award at Mobisys in 2007 for his work on the use of steerable beam antennas for vehicular communication. Recently, he organized a networking workshop in Agra titled "Connecting the next billion" which focused on technical and public policy issues pertaining to expanding data connectivity in India and other emerging regions. He co-chaired WiNTECH workshop held in conjunction with Mobicom 2012, which focused on experimental evaluation of wireless networks.