Abstract — In multi-hop ad hoc networks, the efficiency of a medium access control protocol under heavy traffic load depends mainly on its ability to schedule a large number of simultaneous non-interfering transmissions. However, as each node has only a local view of the network, it is difficult to globally synchronize transmission times over the whole network. How does the lack of global coordination affect spatial reuse in multi-hop wireless networks? We show that in a de-centralized network the spatial reuse does not benefit from global clock synchronization. On the contrary, we demonstrate that non-slotted protocols using collision avoidance mechanisms can achieve a higher spatial reuse than the corresponding slotted protocols. By means of a simple backoff mechanism, one can thus favor the spontaneous emergence of spatially dense transmission schedules. I.

We review the theory of loss networks, including recent results on their dynamical behaviour. We give also some new results.

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We consider equilibrium analysis of several dynamic resource sharing policies for multiclass loss networks with acyclic topologies. The policies of interest are based on the principle of prioritizing classes via thresholding or reservation. We show that under each policy the equilibrium network state is a Markov random field and we obtain closed form expressions for the conditional probabilities therein. Such representations drastically reduce the computational complexity of blocking probability and revenue calculations. We provide revenue comparison of the considered policies and several extensions of the applied analytical technique.