Utility-based adaptive resource allocation in hybrid wireless networks

Service availability in wireless networks is highly dependent on efficient resource allocation and guaranteed quality of service (QoS) amid overloads and failures. This paper addresses optimal bandwidth allocation in a hybrid network (cellular and ad hoc), where added reach through an ad hoc overlay is combined with the stability and essential services of a cellular network. The paper builds on a near optimal approach in which resource-utility functions are used as a means of adaptive delivery of QoS, user differentiation, and maximisation of system level utility. It distinguishes between non-adaptive, semi-adaptive, and fully adaptive applications. First, the global cellular bandwidth allocation (in the presence of multiple routes through ad hoc relays) is cast in terms of a linear programming problem. Second, a heuristic algorithm that has far lower computational overhead and accrues at worse 12% less than the utility of the optimal solution is presented. Both algorithms are implemented within a model of a hybrid network on top of the J-Sim simulation environment. Comparative studies are made to show effective load balancing and crash tolerance in the presence of a high traffic overload