Experimental digital cellular system for microcellular handoff

An experimental digital cellular system composed of a private branch exchange (PBX)-based MSC (mobile switching center), three base stations, two mobile stations, and a radio channel simulator, is developed. The system uses a mobile originated handoff process; i.e. a mobile station requests a handoff to the MSC based on signal strength from surrounding base stations. All control channels are multiplexed on the same carrier so that mobile stations can monitor signal strength quickly. Experimental results show that a handoff decision can be made within a second, even under slow fading (such as walking speed), which agrees with the theoretical calculation very well. It is shown that the whole handoff procedure works reliably under a typical microcell propagation condition.<>