Abstract: A wireless terminal device includes a wireless interface part having an interface with a wireless transmission path at a physical layer, a link forming part accessing the wireless transmission path via the wireless interface unit and forming a particular link on the wireless transmission path, and a transmission/reception part transmitting and/or receiving transmission information via the particular link formed by the link forming part. The wireless transmission path is formed as a physical channel to which a CSMA system is applied. The CSMA system secures a given transmission quality with respect to a total of the number of links concurrently formable and the amount of the transmission information. The link forming part forms the particular link on the wireless transmission path when initiated.

Abstract: The present invention is directed to technology relating to a telephone whose settings can be changed and a telephone capable of changing settings of a called telephone. A portable cellular phone includes function setting request receiving means for receiving from the calling telephone a function setting request added to call setting information, setting changing means capable of changing setting details according to the function setting request received by the function setting request receiving means, and control means capable of refusing the function setting request to change the settings received from the setting changing means, when the function setting request is not acceptable.

Abstract: Prior to the sale of a personal communication terminal, a secret key is generated and stored in the personal communication terminal in accordance with an application made from the manufacturer to the carrier. At this time, the communication between the manufacturer and the carrier is performed in the form of secret communication with a signature that conforms to a public key system. After the sale, an identification number encrypted with the same key as the secret key is transmitted to the personal communication terminal in accordance with an application made from the user to the carrier. Using the stored secret key, the personal communication terminal decrypts the received identification number for storage therein.

Abstract: A communication terminal connection system couples at least one source terminals to a destination terminal via a line, and comprises a channel switch connected to the terminals, at least one multiplexer coupled to the channel switch which is coupled between the terminals and the multiplexer, and a control part coupled to the channel switch for switching and controlling a connection of the channel switch.