Nec Corporation

Nec Infrontia Corporation

Minako Takai

Kiyokazu Otsuka

Takanori Hiroshima

A network includes Internet protocol (IP) terminals for establishing communication using an initiation protocol used in connection-oriented communication in which connection to a destination is confirmed over an IP network for the communication; and a server apparatus constituting the network along with the IP terminals. The server apparatus includes a detecting unit for detecting a speech quality between the IP terminals; a calculating unit for calculating an optimal speech quality based on the detected speech quality information; and a notifying unit for notifying the IP terminals establishing communication of the calculated optimal speech quality. The IP terminals establish communication with the speech quality being set to the optimal speech quality, which the server apparatus notifies to the IP terminals.

Network, server apparatus, IP corresponding terminal device, and speech-quality control method used in the same

There is disclosed a private branch exchange in which an SIP terminal is capable of receiving great variety of services provided by the private branch exchange without upgrading version of software of the SIP terminal itself. A standard SIP protocol control moduleand an expanded SIP protocol control moduleare disposed for SIP corresponding terminals, convert signals from an SIP system protocol corresponding terminal into signals of a protocol inside an IP-PBX 1 to transmit the signals to a PBX basic connection process providing module, and convert signals from the PBX basic connection process providing moduleinto signals of an SIP system protocol to transmit the signals to the SIP system protocol corresponding terminal. A PBX additional service providing moduleand the PBX basic connection process providing moduleprovide additional services in response to an hooking operation from the SIP corresponding terminal or an input of a number for starting the service.

Network, private branch exchange, and PBX additional service starting method

The invention provides a private branch mobile communication apparatus and method which allows hand-over without interruption of communication and makes it possible to allow a service from a private branch exchange of a home node to be utilized as it is even if a radio terminal moves from the private branch exchange of the home node to another private branch exchange. A network common database, a local database and a memory section are stored in each of private branch exchanges. When a radio terminal forwards a position registration request to a radio base station belonging to a second private branch exchange other than the home node to the radio terminal, the second private branch exchange refers to the network common database to access the local database and the memory section of the private branch exchange of the home node, and then refers to the network common database to perform position registration into the private branch exchange of the home node and extract service data of an additional service to be performed by the private branch exchange which has received the position registration request other than the home node.

Private branch mobile communication system and method

The present invention provides a private branch exchange which allows the same system call sign (SYS-ID) to be shared with other private branch exchanges for allocating it to general cell stations. The private branch exchange (PBX), to which a control cell station (CS) is allocated, communicating with mobile stations (PS) reads the system call sign from the control cell station where the system call sign is stored in advance. The system call sign is stored into cell stations in a plurality of private branch exchanges connected to each other when the cell stations belong to the same group as that of the control cell station of the first mentioned private branch exchange.

Growing community of inventors

Tokyo, Japan

Minako Takai