When using a first wireless communication system to facilitate at least a first
wireless communication and in response to detecting at least one handover condition,
a mobile station can automatically use a second wireless communication system to
establish a communication link to a private branch exchange that is associated
with the first wireless communication system and automatically transmit a pre-established
message to the private branch exchange to trigger a handover of the first wireless
communication from the first wireless communication system to the second wireless
communication system.