A handoff control process for microcellular systems

A handoff control process, which can handle frequent cell-boundary crossings by mobile radio users in microcellular systems, is presented. Handoff determination criteria are investigated under microcellular propagation models. As a result, it is shown that relative field strength measurement should be applied because of its almost twice higher spectrum efficiency than that of relative distance measurement. In application, measurement frequency greatly increases due to not only cell size reduction but also microcellular propagation characteristics. In order to solve this problem, a mobile-station-originated handoff process is proposed. This process becomes feasible in a TDMA (time-division multiple-access) system because mobile stations can be easily equipped with a measurement function