| 摘要 |
PURPOSE:To reduce the load of a portable equipment and to further improve speech quality by processing a TCH switching request signal and a TCH reservation signal between a base station and an exchange by containing the information on privacy such as a secret key, etc., in the signals. CONSTITUTION:A portable equipment determines a base station (CS) to be a channel switching destination. At this time, the portable equipment is calling with a base station CS 1 and a privacy function is in use. The portable equipment sends a call channel (TCH) switching request signal to the base station CS 1. The base station CS 1 continuously adds privacy information such as a secret key, etc., to information if the privacy function is in use at this time and sends the TCH switching request signal to an exchange. The exchange performs the reservation of a new TCH with a base station CS 2 to be a switching destination, and at the same time, privacy information is sent from the exchange to the base station CS 2. The switching operation for the new TCH is performed between the portable equipment and the base station CS 2, but privacy information is already passed to the base station CS 2. Therefore, the privacy function can be immediately resumed. |
