Multi-tier wireless networks for PCS

We investigate some aspects of the optimal design of multi-tier wireless cellular networks. The need for multi-tier networks arises when there are multitude of traffic types with clearly different parameters, such as mobility patterns, and/or different requirements, such as quality-of-service requirements. In such situations, it may be cost effective to build a multitude of cellular infrastructures, each serving a particular traffic type. The network resources (e.g., the radio channels) are then partitioned among the multitude of tiers. In general terms, we are interested in quantifying the cost reduction due to the multi-tier network, as opposed to a single-tier network. We present our general cell-design methodology and concentrate on the example of a two-tier network; i.e., one which integrates the micro- and the macro-cellular infrastructures.