Hitachi, Ltd.

Kokusai Electric Co., Ltd.

Nippon Telegraph and Telephone Corporation

Tetsuo Takemura

Yutaka Fukushima

Hiroshi Kuwahara

Takao Kato

Yoshihiro Kondo

Arata Nakagoshi

Mitsuhiro Wada

Shinichi Iwaki

Yoshinobu Yamamoto

Yumiko Watanabe

Isao Shimbo

Kouichi Ohta

Hirofumi Udaki

Masao Wanami

Mitsuyoshi Hashida

Toshiaki Suzuki

Shinobu Gohara

Akio Amano

Kenji Kawakita

Toshiyuki Odaka

Nobuo Hataoka

Jiro Kashio

Noboru Watanabe

Masao Kunimoto

Akira Horiki

Takeshi Harakawa

Ryujiro Muramatsu

Tatsuo Yoshie

Fumito Sato

Duplicate optical fibers connect between a base station controller and a radio base station for each route. The duplicate optical fiber is connected to each of the radio base stations for each route through a star coupler. The radio base stations are arranged in each of areas so that the radio base stations for different routes are arranged adjacent to each other.

Portable telephone system

A telephone exchange enables subscribers to use voice dialing more easily with existing telephone systems. The voice dialing does not require special input operations or preregistration of called parties. Rather, a subscriber can make a telephone call easily without having to perform multiple operations. The telephone exchange includes structure for discriminating dial pulse information, push-button tone information, and spoken information so that one or more of these types of information can be input by a caller to achieve connection to the called party.

Telephone exchange network using telephone exchanges with speech

In a network system in which an interconnection is achieved between an LAN terminal connected to an LAN and an ISDN terminal linked with an ISDN via at least an LAN/ISDN inter-working unit coupling the LAN with the ISDN, the ISDN terminal develops a function to multiplex data link connections (communication paths) identified with respective data link connection identifiers (DLCIs) on ISDN channels. After conducting a call establishment to the ISDN terminal, the inter-working unit supplies the LAN terminal with an ISDN channel number and a DLCI designating an ISDN communication path. Thereafter, the LAN terminal sends an LAN frame having an OSI layer 2 header loaded with the communication path information to the inter-working unit. On receiving the LAN frame, the inter-working unit executes a format conversion to convert the LAN frame into an ISDN frame based on the ISDN communication path information.

Interconnection system and method for heterogeneous networks

When one module provides service while using a service providing function of other module, the service requesting module sends out a service request to other modules in a broadcast fashion. Each module receives and detects the service request, and when there is a corresponding service providing function in its own module, it sends a response back to the requesting module. Among a plurality of nodes, a selection function module which stores service providing function arrangement information of other nodes and determines a node which has the function for the corresponding service request is provided. The selection function module sends back a response to the service request.

Method for providing network service in a communication system

A time switch for a time division switch has a function to exchange time slots as well as functions of bit are conversion and multiplexing or demultiplexing. A first stage time switch comprises a channel memory capable of sequential writing and random reading and a converter for converting a data read from the channel memory to a universal signal in accordance with a conversion mode designation. A final stage time switch comprises a channel memory capable of random writing and sequential reading and a control circuit for designating a write bit position of the channel memory in accordance with a write mode designation. An economic time switch having a high flexibility to a traffic variation among bearer signals is provided.

Time switch in a time division switching network

A digital data transmission system with a transmultiplexer arrangement for interconnection of a time division multiplex line and a packet multiplex line. The transmultiplexer has a section which converts data for each of a plurality of terminals on the time division multiplex line in the unit of a packet, for allocation on the packet multiplex line, and a section which identifies the time position of each data unit on the time division multiplex line, prepares a specific packet containing the position information and allocates the specific packet before the data packet on the packet multiplex line. The transmultiplexer also has a section which periodically allocates data on the packet multiplex line allotted with a specific packet containing position information of a terminal before a data packet corresponding to the terminal on the time division multiplex line in accordance with the position information of the terminal.

Digital data transmission system with time division/packet

A voice signal converting device is adapted for a digital communication network which handles digitized voice signals and data signals simultaneously or equally. A bit for discriminating whether a signal in communication is a voice signal or a data signal is applied in a digital signal channel. The voice signal converting device is connected to a digital communication path to detect the discrimination bit from the incoming signal in such a manner that when a bit group corresponding to the discrimination bit represents the voice signal, the bit group is converted into a predeterminedly correlated bit group and delivered out and when the bit group corresponding to the discrimination bit represents the data signal, this bit group is delivered out in its original form. Consequently, even when the voice signal and the data signal coexist in one communication, speech quality of the voice signal and bit integrity of the data signal can be guaran

Voice signal converting device

Growing community of inventors

Yokohama, Japan

Tetsuo Takemura