Intermittent connection effect in the Message Ferry Delay Tolerant Network

Abstract

Delay Tolerant Networks (DTN) give a base of communication that permits the delivery of data within harsh environments or even between networks without interconnection. The connection between networks happens when some nodes cross between them and carry information. Our model consists of the Message Ferry Mobility Model (MFMM) where all nodes in the network are confined to their village except one mobile node (the message ferry). In order to reduce the energy consumption the wireless interface is not always on. We aim to study how much does the on/off state of the wireless interface reduces the total connection time available in the MFMM. To answer this question, we created a simulator that uses the MFMM. The simulator generated mobility traces of all nodes and measured the contact time under different patterns of the on/off cycle. As expected the contact time are longer when the interface is active more often. However we found an unanticipated reduction in contact time vs active wireless interface ratio. Hence, we concluded that in the MFMM, the on/off duty-cycle of the wireless interface influences the total contact times.