A Hierarchical Hybrid Network Model

Wireless Hybrid Networks (WHNs) represent the merging of two different network paradigms: ad hoc and infrastructure-based systems. The many services, terminal types and air interfaces that will be available to the user in the B3G arena will naturally make current wireless networks evolve towards the WHN scenario, where gateway terminals, implementing both cellular or hot spot technologies and infrastructure-less air interfaces, will allow integration of the two separate paradigms. This scenario opens many novel research issues. In this paper we study a hierarchical network where wireless nodes at different levels are uniformly distributed over the bi-dimensional plane with different densities, path loss and shadowing are included with different propagation parameters, different air interfaces are used, and different hard capacities characterise the nodes at the different levels. Given this scenario, a mathematical description of the distribution of active links at the different levels is given, through the application of statistical theory results already obtained for a simpler two-level network. This provides a means to allow proper access control, depending on the maximum number of radio resource units available at each node. The statistical model, which assumes an infinite plane, is compared to simulation results in order to assess how much the model is robust when investigating smaller, limited square scenarios.