MOBILE DIVERSITY HANDOVER AND BRANCH CONTROL

摘要

When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the netwo rk checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If t he mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile stati on and stops the current communication. In communication, the network and the mobil e station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current bran ch is replaced by new branches capable of executing the diversity handover. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used. Therefore, the mobile communications system is suitable for transmission of various sorts of data in accordance with the development of multimedia.