Exact File Delivery Time of Bundle Protocol in Delay/disruption-Tolerant Networks

As the data delivery protocol in the Delay/ disruption-Tolerant Networks (DTN), the Bundle Protocol (BP) has gained much interest in its performance analysis. Existing analytic results in terms of the average file delivery time (AFDT) are mainly approximations, which provide reasonably close estimates in some cases but exhibit large discrepancies in other cases. In this paper, we point out a fallacy used in existing work, and, for the first time, provide an exact mathematical solution of the AFDT of the bundle protocol. This result works for both symmetric and asymmetric channel conditions, with either unlimited or limited total number of transmission rounds. Validation via simulation is also provided.