Implications of cell planning on handoff performance in Manhattan environments

The handoff performance in a Manhattan-like environment is investigated for the following handoff criteria: received signal strength, uplink SIR or downlink SIR. The performance is evaluated for symmetric cell plans with different interference characteristics. It is found that the most serious threat to reliable handoffs is the risk of making handoffs to out-of-sight base stations on crossing streets. One conclusion is that for acceptable handoff performance in microcellular systems, handoff decisions should be based on a combination of the SIRs in both the uplink and the downlink.