Cost-efficient design for higher capacity hybrid wireless-optical broadband access network (WOBAN)

Noting that the optical part of a hybrid wireless-optical broadband access network (WOBAN) has high capacity, we need to enhance the capacity for wireless access using a low-cost solution. Deploying multiple radios, say two, at each node will improve the performance of wireless access, but this will also increase the cost and power consumption of the solution. However, deploying multiple radios at only a few nodes, especially those that are overloaded with traffic, can lead to a less-costly and less-power-hungry solution, possibly without sacrificing performance. Hence, we propose a mixed-capacity wireless access (MCWA) architecture for WOBAN and study how to optimally place a limited number of additional radios at the wireless nodes to save the overall network cost. We formulate this problem as a Mixed Integer Linear Program (MILP) and solve it using a standard solver such as CPLEX. An efficient channel and radio assignment scheme is essential to utilize MCWA by reducing interference and contention in the wireless front-end of WOBAN. We propose an intelligent channel and radio assignment (ICRA) for MCWA in WOBAN that performs load balancing over different channels to reduce interference and contention. We formulate this problem as another MILP and solve it using CPLEX. Our findings show that, by using a mixed-capacity wireless access design with intelligent channel and radio assignment, we can obtain almost the same performance as a WOBAN with multi-radios at all nodes. (C) 2011 Elsevier B.V. All rights reserved.