Leveraging Social Networks For P 2 P Content-Based File Sharing In Disconnected MANETs

Over a fifth of the 5.5 billion active mobile phones today have “broadband” data service, and this fraction is rapidly growing. Smart phones and tablets with wide-area cellular connectivity have become a significant, and in many cases, dominant, mode of network access. Improvements in the quality of such network connectivity suggest that mobile Internet access will soon overtake desktop access, especially with the continued proliferation of 3G networks and the emergence of LTE and 4G. Wide-area cellular wireless protocols need to balance a number of conflicting goals: high throughput, low latency, low signalling overhead (signalling is caused by mobility and changes in the mobile device’s state), and low battery drain. The 3GPP and 3GPP2 standards (used in 3G and LTE) provide some mechanisms for the cellular network operator and the mobile device to optimize these metrics but to date; deployed methods to minimize energy consumption have left a lot to be desired. The 3G/LTE radio consumes significant amounts of energy; on the iPhone 4, for example, the stated talk time is “up to 7 hours on 3G” (i.e., when the 3G radio is on and in “typical” use) and “up to 14 hours on 2G”. 1 On the Samsung Nexus S, the equivalent numbers are “up to 6 hours 40 minutes on 3G” and “up to 14 hours on 2G”. 2 That the 3G/LTE interface is a battery hog is well-known to most users anecdotally and from experience, and much advice on the web and on blogs is available on how to extend the battery life of your mobile device.3 Unfortunately, essentially all such advice says to “disable your 3G data radio” and “change your fetch data settings to reduce network usage”. Such advice largely defeats the purpose of having an “always on” broadband-speed wireless device, but appears to be the best one can do in current deployments. Show the measured values of 3G energy consumption for multiple Android applications. This bar graph shows the percentage of energy consumed by different 3G radio states. For most of these applications (which are all background applications that can generate traffic without user input, except for Facebook), less than 30% of the energy consumed was during the actual transmission or reception of data. Previous research arrived at a similar conclusion about 60% of the Abstract: 3G technology has stimulated a wide variety of high band width applications on smart phones, such as video streaming and content-rich web browsing. Although having those applications mobile is quite appealing, high data rate transmission also poses huge demand for power. It has been revealed that the tail effect in 3G radio operation results in significant energy drain on smart phones. Recent fast dormancy technique can be utilized to remove tails but, without care, can degrade user experience. Implement Tail Theft in the Network Simulator with a model for calculating energy consumption that is based on parameters measured from mobile phones. When allowing for delays of a few seconds (acceptable for background applications), the energy savings increase to between 62% and 75% for 3G, and 71% for LTE. The increased delays reduce the number of state switches to be the same as in current networks with existing inactivity timers.