Sequential handoff algorithm for cellular mobile communication

Sequential handoff algorithms based on the confidence interval are proposed for improving the handoff performance. The decision on handoff is based upon sequential observations, instead of one decision per observation. Conventional algorithms with fixed signal averaging interval and/or fixed hysteresis level lack flexibility under a changing mobile environment. Unlike conventional algorithms which make binary decisions on `handoff´ or `no-handoff´, the sequential algorithm introduces an additional decision option: `no-handoff but accumulate´. With this decision option, the mobile unit will initiate a handoff only if the accumulated sequential samples have sufficient confidence to support such decision. The sequential handoff algorithm is shown to improve the handoff performance by lowering the mean number of handoffs while simultaneously reducing the mean number of drop-calls