Resource Optimization Protocol Based on Multicommunity Model for Intermittently Connected Mobile Networks

Abstract

Intermittently connected mobile networks (ICMNs) are kinds of delay-tolerant networks (DTNs) in which the topology of mobile network changes frequently, the network is sparse, and end-to-end connection is hard to establish. However, as nodes in DTNs may often have limited energy, the performance of the network will be inevitably affected. Particularly, the message delivery ratio will be decreased when some of the nodes are out of energy and unable to participate in relay process. In order to make effective use of resources, we take this into consideration and propose the social similarity and optimized resource (SSAOR) protocol. According to the position relationship between the source and the destination nodes, SSAOR uses two different strategies to determine the order of forwarding messages. If they belong to the same community, the source node forwards message, copies to the relay node with the shorter encounter interval and the higher social friendship rank similarity with destination nodes. Otherwise, the source node forwards message copies to the relay node with the higher weight “betweenness” similarity and the shorter waiting encounter time similarity with destination nodes. In addition, we propose a buffer management method for dynamically distributing message copies to reduce network overhead, due to the fact that only a small number of copies can be successfully delivered. Finally, the simulation results show that SSAOR achieves a higher delivery ratio and lower overhead ratio, compared to other protocols within resource-constrained network situations.