Joint Base Station and Relay Station Placement for IEEE 802.16j Networks

In this paper, the network deployment problem for IEEE 802.16j networks is studied. We consider jointly deploying a number of base stations and relay stations to serve mobile stations distributed arbitrarily in a given geographic area such that the cost is within the budget and the system capacity is maximized. This problem is formulated as an integer linear programming (ILP) model. We analyze the complexity of the problem and design an efficient two-stage network deployment algorithm which tackles both user fairness and capacity enhancement. Computational experiments are conducted to show the effect of network deployments in different traffic distribution scenarios. We also show the impact of different deployment profiles on network capacity and fairness and discuss the cost-efficiency tradeoffs between base stations and relay stations. Our numerical results indicate that deploying relay stations can enhance system capacity and fairness under the condition that the number of base stations deployed is not too small. The degree of enhancement is higher when the traffic demand distribution is concentrated in hotspots.