This paper addresses the delay analysis and resource consumption in mobile ad hoc networks (MANETs) equipped with throwboxes. Throwboxes are stationary, wireless devices that act as relays, and that are deployed to increase the connectivity between mobile nodes. Our objective is to quantify the impact of adding throwboxes on the performance of two routing protocols, namely the Multicopy Two-hop Routing protocol and the Epidemic Routing protocol, in the cases where the throwboxes are fully disconnected or mesh connected. To this end, we use a Markovian model where the successive meeting times between any pair of mobile nodes (resp. any mobile node and any throwbox) are represented by a Poisson process with intensity λ (resp. µ). We derive closed-form expressions for the distribution of the delivery delay of a packet and for the distribution of the total number of copies of a packet that are generated, the latter metric reflecting the overhead induced by the routing protocol. These results are then compared to simulation results. Through a mean-field approach we also provide asymptotic results when the number of nodes (mobile nodes and/or throwboxes) is large.

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For the last twenty years, mobile communications have experienced an explosive growth. In particular, one area of mobile communication, the Mobile Ad hoc Networks (MANETs), has attracted significant attention due to its multiple applications and its challenging research problems. On the other hand, the nodes mobility in these networks has introduced new challenges for the routing protocols, especially when the mobility induces multiple disconnections in the network. In this survey, we present an overview of this issue and a detailed discussion of the major factors involved. In particular, we show how messages can be efficiently disseminated in different types of MANETs.

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Abstract. This paper presents an adaptive backoff algorithm for the contentionbased Distributed Coordination Function (DCF) of the IEEE 802.11 standard. Relying on on-line measurements of the number of sources, the algorithm, called Adaptive BEB, judiciously sets the size of the minimal contention window to adapt to the congestion level in the shared medium. The paper also provides an extension to Adaptive BEB for enhancing its performance over noisy channels. In this extension, a simple EWMA filter is used to derive a Packet Error Rate estimator. The performance evaluation of our proposal is addressed via simulations.