Method and apparatus for measurement directed hard handoff in a cdma system

摘要

In a communications network, a network user communicates using a remote unit with another user via at least one base station. The network is comprised of first and second mobile switching control stations respectively controlling communications through a first set of base stations including a first base station and through a second set of base stations including a second base station. To direct communications between the remote unit and the first and second base stations the first base station measures a round trip delay of an active communication signal between the first base station and the remote unit. The remote unit measures a first phase offset of a pilot signal received from a first candidate base station and reports it to the first mobile switching center via the first base station. The first mobile switching center calculates a candidate round trip delay between the remote unit and the first candidate base station based on the first phase offset and the round trip delay of the active communication signal. A active communication control unit accesses a measurement directed hard handoff table to determine a location of the remote unit based on the round trip delay corresponding to the first active communication signal and the candidate round trip delay.