Abstract: A mobile communication system which performs a handover operation with high-reliability, while the system can flexibly cope with various circumstances in which a mobile station is used, without changing a hardware structure. A plurality of radio base stations form respective radio communication cells. Each of the radio base stations performs a radio channel setting control including a handover with respect to a call originated for the mobile station located in one of the cells. An exchange is connected to each of the radio base stations via a communication link so that the exchange performs a call process of the call in association with the radio channel setting control performed by the radio base stations.

Abstract: In addition to an array of basic call modules each containing a description of a procedure for causing a call state transition from current stable state to next stable state, IN call modules are provided that are activated as tasks independently of the basic call modules. Of the IN call modules, modules equipped with a message generation function contain a description of a procedure necessary for the transmission of a message to a service control point (SCP), and modules equipped with a message analysis function contain a description of a procedure necessary for the analysis of a message from the SCP. When it is determined that a call requires an additional service as a result of DP processing in the basic call processing performed in a basic call module, the basic call processing is interrupted, and an appropriate IN call module is activated. When the IN call processing performed by the IN call module is completed, the basic call module is reactivated to resume the basic call processing.

Abstract: A network element managing system includes a management control section for maintaining and managing network elements such as an exchange or a telecommunication line and a communication control section for controlling the communication processing of the network so that an interface is commonly used between the management control section and the communication control section, thereby satisfying a required performance in both of a processing request relating to maintenance, management and operation and a processing request relating to communication. That is, the system of the invention includes a scheduling section for determining execution order on the basis of the attribute of the processing request, and the loads of the communication control section and the management control section. Also, the communication control section and the management control section have a function for scheduling the processing request on the basis of the attribute of the object to be processed, respectively.

Abstract: In an accounting system for a multimedia communications system, an additional information storage unit stores additional information to be supplied to subscriber terminals in the multimedia communications system by one or a plurality of additional information suppliers. An additional information adding unit adds the additional information to communication information transmitted between subscriber terminals communicating with each other. A measurement unit measures a degree of supply of the additional information supplied to at least one of the subscriber terminals communicating with each other. A database unit stores accounting information used to calculate a fee for a communication between the subscriber terminals communicating with each other. A control unit calculates the fee for the communication between the subscriber terminals communicating with each other on the basis of the accounting information and the degree of supply of the additional information measured by the measurement unit.

Abstract: A diagnostic expert system is set up with a first diagnostic subsystem based on a maintenance technician's knowledge and a second diagnostic subsystem based on a design engineer's knowledge. If a fault cannot be located under the first diagnostic subsystem, the second diagnostic subsystem, which operates by using the result obtained from the first diagnostic subsystem is started so as to determine the location of the fault.