Time scales and delay-tolerant routing protocols.

ABSTRACTNumerous routing protocols have been proposed for Delay Tolerant Networking. One class of routing protocols aims at optimizing the delivery performance by using knowledge of previous encounters for forecasting the future contacts to determine suitable next hops for a given packet. Protocols pursuing such an approach face a fundamental challenge of choosing the right protocol parameters and the right time scale for estimation. These, in turn, depend on the mobility characteristics of the mobile nodes which are likely to vary within one scenario and across different ones. We characterise this issue, which has been overlooked in this field so far, using PROPHET and MaxPROP as two representative routing protocols and derive mechanisms to dynamically and independently determine routing parameters in mobile nodes.