Doctoral Thesis Performance Studies for Mobile Ad Hoc Networks with Erasure Coding and f-cast Relay

The mobile ad hoc networks (MANETs) are a class of infrastructure-less self-organizing networks consisting of mobile devices communicating with each other over peer-topeer wireless links. Due to their distinctive features of robustness, self-organization, quick deployment and reconfiguration, MANETs hold great promises for many important application scenarios, like disaster relief, battle field communications, and wide area sensing, and are thus increasingly becoming an indispensable component for the next generation (5G) networks. To efficiently support these critical applications with stringent performance requirements, it is of great importance to thoroughly understand the fundamental performance of such networks, like the delivery delay and throughput capacity. This work focuses on the performance studies of an important class of MANETs with erasure coding and packet redundancy (f -cast), i.e., each coded packet at source node is transmitted to at most f distinct relay nodes. The erasure coding and packet redundancy are two promising techniques that have been extensively studied in the literature for improving the packet delivery performance in MANETs. On one hand, previous studies showed that erasure coding technique can considerably reduce the delay variance in MANETs, while it may lead to a relatively large packet delivery delay, since the early arrived coded packets in destination node have to wait a long time for the arrivals of other coded packets from distinct relay nodes. On the other hand, packet redundancy technique can efficiently reduce the packet delivery delay due to the fact that multiple relays will carry redundant copies of a packet, increasing the chance of the packet being received by its destination; however, it usually incurs high variance of packet delivery delay. Thus, we consider a combination of erasure coding and packet redundancy in MANETs to have a flexible trade-off between packet delivery delay and delay variance. We combine these two techniques together and study the packet delivery delay and throughput capacity in MANETs, under a general two-hop relay routing algorithm with unicast traffic pattern, i.e., a source node has only a destination node, which covers available routing algorithms with pure erasure coding or pure packet redundancy as special cases. To analyze the packet delivery delay, we propose a Markov chain model to depict the packet delivery process under this routing algorithm, with which we derive the analytical expressions for the mean value and variance of packet delivery delay. To analyze the throughput capacity, we propose two Markov chain models to depict the fastest packet distributing process and fastest packet receiving process at source and destination nodes, respectively, with which we derive the analytical expression for the throughput capacity. Extensive simulation and theoretical results are provided to validate the accuracy of our theoretical performance analysis as well as our findings. Then, we study packet delivery delay of MANETs adopting a two-hop relay routing algorithm with packet redundancy, and multicast traffic pattern, where a source node has multiple destination nodes. To this end, we propose a Markov chain model to capture the packet delivery process under the routing algorithm, with which we derive the analytical expressions for the mean value and variance of packet delivi ery delay. Extensive simulations demonstrate the efficiency of our theoretical delay results.