The impact of mobility on UMTS network planning

Abstract

In this paper the impact of terminal mobility on UMTS radio network planning is investigated. This impact stems from (i) the more severe signal-to-interference ratio requirements that apply in case of higher velocities, due to the combined effects of multipath propagation, Doppler shifts and power control imperfections; and (ii) the greater radio resource reservation regarding handovers that is required in case of higher velocities, in order to keep the dropping probability below a prespecified target value; as a consequence, fresh call blocking increases, inducing a need for denser site planning. An analytical approach is presented to evaluate the impact of both mobility-related aspects on network planning, performance and investment costs. The principal strength of the presented model and approach lies therein that it is simple enough to allow a computationally relatively inexpensive performance evaluation and optimisation, yet sufficiently realistic to provide valuable qualitative insight for network planning purposes. Numerical results identify terminal mobility as a key property that must not be disregarded in the radio network planning process, while the deployment of radio resource reservation is shown to be very effective in reducing both call dropping and investment costs.