DTcoop: Delay Tolerant Cooperative Communications in DTN/WLAN Integrated Networks

In this paper, we consider a DTN/WLAN integrated network where nomadic nodes with high mobility comprise a delay tolerant network (DTN) while local nodes with low mobility reside in the coverage area of wireless local area networks (WLANs). A message dissemination service is considered, where data traffic is generated by a server in the Internet and destined to a group of nomadic nodes. In order to facilitate message dissemination, a delay tolerant cooperative communication (DTCoop) scheme is proposed. The messages for dissemination are first pre-downloaded to a group of storage local nodes within a WLAN before the visit of a nomadic node, and then scheduled for transmission when a nomadic node comes into the transmission range. Analysis and simulation results are presented to evaluate the performance of the proposed DTCoop scheme. It is shown that our proposed scheme can significantly improve the message delivery performance from a WLAN to a nomadic node as compared with existing schemes without message pre-downloading or message scheduling.