A cost model for ad hoc extended cellular systems

The use of ad hoc/multihop as an extension to the cellular system has been proposed in the literature as a candidate architecture for providing lower infrastructure costs. In this paper the base station and wireless relay density are used as the main measures for the infrastructure cost. An analytical expression is deduced for the relation between the base station and the wireless relay densities. It is shown that, under some circumstances, the same service can be provided to the end-user with a reduced base station density if wireless relays (routers) are used for multihopping, thus reducing the infrastructure cost. However, the base station density can not be made arbitrarily low due to the increase in the transport traffic and the well-known Shannon limit on the channel capacity.