Cost Comparison between SISO and MIMO Deployments in Future Wide Area Cellular Networks

Future cellular networks are expected to provide significantly higher capacity than today's systems. To support this higher capacity a denser deployment might be necessary. An alternative way is to deploy Multiple-Input-Multiple-Output (MIMO) base stations (BSs), called advanced BSs, so that the system capacity is improved without increasing the BSs density. This paper compares Single-Input-Single-Output (SISO) BS deployments with MIMO BS deployments from a cost perspective. We use a deployment methodology starting with a sparse density of BSs. By deploying additional BSs sequentially the number of BSs is increased until the traffic demand in the network area is supported. Providing equal service level, i.e., supporting the same traffic demand, by means of different deployment realizations enables a relevant comparison between the alternative single and multiple antenna systems. With the models and assumptions used here, results show that in order to support the same users' service level, the cost of deploying MIMO BSs is significantly less compared to increasing the density of SISO BSs. The cost gain is due to the reducing of the number of required BSs for the case of MIMO deployment.