Performance of a Hierarchical Cellular Network with Mobility-dependent Hand-over Strategies

Abstract—This contribution deals with the blocking probability in a hierarchical network with two mobility behaviors. A continuous coverage is achieved with micro-cells that accommodate both fresh calls and handover requests. Over this micro-cell coverage umbrella-cells, which only accept handover, are implemented. At every handover, the sojourn time of the terminal in the cell is measured. If it is lower than a threshold, the terminal is considered as rapid and directed towards an umbrella cell. Otherwise the communication stays at the microcell level. Furthermore, if there is no available channel in a micro-cell, the call is handed over the corresponding umbrella-cell. The strategy tends to favor handover to umbrella-cells for high-speed terminals. An analytical model for the telefraffic performance is developed and used to calculate the forced t e r m i n a t i o n p r o b a b i l i t y i n d i f f e r e n t configurations. The performance of the strategy is then studied.