Fundamental Mobility Properties for Realistic Performance Analysis of Intermittently Connected Mobile Networks

Traditional mobile ad hoc routing protocols fail to deliver any data in intermittently connected mobile ad hoc networks (ICMN's) because of the absence of complete end-to-end paths in these networks. To overcome this issue, researchers have proposed to use node mobility to carry data around the network. These schemes are referred to as mobility-assisted routing schemes. A mobility-assisted routing scheme forwards data only when appropriate relays meet each other. The time it takes for them to first meet each other is referred to as the meeting time. The time duration they remain in contact with each other is called the contact time. If they fail to exchange the packet during the contact time (due to contention in the network), then they have to wait till they meet each other again. This time duration is referred to as the inter meeting time. A realistic performance analysis of any mobility-assisted routing scheme requires a knowledge of the statistics of these three quantities. These quantities vary largely depending on the mobility model at hand. This paper studies these three quantities for the three most popularly used mobility models: random direction, random waypoint and random walk models. Hence, this work allows for a realistic performance analysis of any routing scheme under any of these three mobility models