COADA

Abstract

This paper argues that Dynamic Coalition Peer-to-Peer (P2P) Network exists in numerous scenarios where mobile users cluster and form coalitions, and the relationship between sizes of coalitions and distances from mobile nodes to their Point of Interest (PoI) follows exponential distributions. The P2P coalition patterns of mobile users and their exponential distribution behavior can be utilized for efficient and adaptive content file download of cellular users. An adaptive protocol named COADA (COalition-aware Adaptive content DownloAd) is designed that (a) blends cellular and P2P (e.g., WiFi or Bluetooth) wireless interfaces, (b) leverages the clustering of people into P2P coalitions when moving towards PoI, and (c) utilizes exponential-coalition-size function of the Dynamic Coalition P2P Network to minimize the cellular download and meet content file download deadline. With COADA protocol, mobile nodes periodically sample the current P2P coalition size and predict the future coalition size using the exponential function. In order to decide how much file data is available in P2P coalition channels versus how much file data must be downloaded from the server over the cellular network, Online Codes techniques are used and tune cellular download timers to meet the file download deadline. The simulation results show that COADA achieves considerable performance improvements by downloading less file data from the cellular channel and more file data over the P2P coalition network while meeting the file download deadline.