The Minimal Delay Path and its evolving properties in intermittently connected mobile networks

We study the Minimal Delay Path (MDP) of message delivery and its evolving properties in social opportunistic networks where the connectivity is intermittent and evolving over time. Through in-depth analysis of the public released trace dataset from CRAWDAD community, our results show that the network connectivity is highly depended on some rare nodal contacts that occurred only few times rather than those frequently occurred nodal contacts in whole trace dataset. By constructing the Time Evolving Graph (TEG) and computing its MDPs using our modified version of the Shortest Path algorithm we illustrate how those rare contacts impact on the delay of message delivery in opportunistic network. Our results is in sharp contrast to previous work that choose the most frequent contact node as next hop forwarder (e.g. PROPHET), and we imply that the algorithms identifying those occur less frequently but important nodes as next hop will achieve better message delivery performance.