Abstract: When a mobile communication apparatus detects a communication channel in a good channel state, the identification information on a system side communication apparatus providing the communication channel is extracted and stored in relation to the communication channel. At the time of channel switching, a stored communication channel having identification information coincident with the identification information on a communication channel being acquired is selected in preference to other communication channels, whereby the channel search can be completed in a short time.

Abstract: To simplify the operation of a press-to-talk switch, transmission is continued for a set time by an operation relief control unit even when the press-to-talk switch is released after transmission effected by pressing the press-to-talk switch.

Abstract: When the mobile communication apparatus captures a communication channel, it stores the capture time associated with the communication channel. Thereafter, at the time of channel switching, it retrieves the capture time associated with the same communication channel as the communication channel currently captured. The apparatus further retrieves the nearest capture time to the capture time obtained by the above retrieval, so that by selecting the communication channel associated with the thus obtained capture time with priority, it can perform the channel search in a quite short time.

Abstract: The communication device according to the present invention outputs data as to whether position registration to a cellular service has succeeded or failed to a position registration control section using a transmission path. The communication device also outputs data as to whether position registration to a satellite service has succeeded or failed to the control section using a transmission path. The control section receives and records a result of position registration in each service, and then outputs data, when a service to be provided to a user is switched, as to where position registration in the service is required or not, using a transmission path to a multiple service switching communication control section.

Abstract: A multiple-service offering communication terminal and a multiple-service offering apparatus comprise a multiple-service common judgment control unit for judging information on a communication failure or the occurrence of a failure which is provided with a multiple-device informing function to inform a user by controlling accessory terminals according to information to improve the efficiency of the way of informing a plurality of devices of a failure or the like and the operation efficiency of the user.