Mobile-service switching center, base station controller, multicall communication mode supporting terminal and method of changing number of calls in multicall communication mode

A base station controller comprising:

• holding section capable of holding a plurality of calls communicating with each of base stations located near the base station controller at a time;
• detecting section for detecting at least a status that a handover is requested and determining a status that all of the calls held by the holding section cannot be handled upon handover in the multicall communication mode based on the number of calls held by the holding section;
• notifying section for transmitting a special message regarding the number of calls allowable to continue to the multicall communication mode supporting terminal which has generated a handover request detected by the detecting section;
• reply receiving section capable of receiving a reply designating a desired call to continue which the multicall communication mode supporting terminal selects from the plurality of calls notified by the notifying section;
• and
• transmitting section for transmitting data indicative of the desired call to continue which is designated by the message received by the reply receiving section, to a mobile-service switching center.

A multicall communication mode supporting terminal comprising:

• receiving section for receiving a special message regarding the increases and decreases of a plurality of calls and extracting call-number change information from the special message;
• presenting section for displaying the plurality of calls under communication which is identified by the call-number changing information extracted by the receiving section, to the user of the multicall communication mode supporting terminal in a visual manner or an audible manner in accordance with the call-number change information extracted by the receiving section;
• input section arranged to permit the user of the multicall communication mode supporting terminal to carry out input operation for selecting a desired call to continue from the plurality of calls presented by the presenting section;
• and
• transmitting section for transmitting information regarding the desired call to continue which is selected by the input section to a corresponding base station.

A method of changing the number of calls in a multicall communication mode for use in a switching center system which comprises a first multicall communication mode supporting terminal for transmitting and receiving a radio signal, a base station controller for controlling a base station, and a mobile-service switching center for transmitting and receiving information regarding a plurality of calls so that a communication status is settled between the first multicall communication mode supporting terminal and the base station controller, the method comprising:

• a step of detecting an event caused by an occurrence of handover and a fluctuation in congesting state of a network;
• a step of notifying a special message having inserted therein call-number changing information regarding the increases and decreases of call-numbers to a switching center as a connection destination connected by the handover when the event is detected at the event detecting step;
• a step of receiving a reply regarding a desired call to continue selected by the first multicall communication mode supporting terminal from the plurality of calls notified by the special message created at the special message notifying step;
• and
• a step of rearranging the handover in such a manner that the desired call to continue designated by the reply received at the reply receiving step is maintained in connection and an undesired call to continue, the undesired call is not selected from the plurality of calls by the first multicall communication mode supporting terminal.

A method of changing the number of calls in a multicall communication mode for use in a switching system which comprises a first multicall communication mode supporting terminal for transmitting and receiving a radio signal, a base station controller for controlling a base station, and a mobile-service switching center for transmitting and receiving information regarding a plurality of calls so that a communication status is settled between the first multicall communication mode supporting terminal and the base station controller, the method comprising:

• a first transmitting step for transmitting a handover request from the mobile-service switching center to a mobile-service switching center as a connection destination to be connected by the handover;
• a second transmitting step for transmitting a message containing data indicative of a number of calls allowable to continue based on the capacity and the congesting state of the mobile-service switching center as a connection destination, the message is transmitted from the mobile-service switching center as a connection destination at the first transmitting step;
• and
• a call-number notifying step for transmitting a message indicative of an additional number of calls allowable to continue from the mobile-service switching center to the first multicall communication mode supporting terminal, if the number of calls, the number is contained in the message sent at the second transmitting step, allowable to continue is larger than the current number of calls supported by the first multicall communication mode supporting terminal.