Hitachi, Ltd.

Kokusai Electric Co., Ltd.

Nippon Telegraph and Telephone Corporation

Hitachi Communication Systems, Inc.

Shinichi Iwaki

Masao Kunimoto

Satoshi Shimizu

Kenji Kawakita

Hiroshi Kuwahara

Yoshihiro Kondo

Arata Nakagoshi

Tetsuo Takemura

Mitsuhiro Wada

Yoshinobu Yamamoto

Yumiko Watanabe

Yutaka Fukushima

Isao Shimbo

Kouichi Ohta

Hirofumi Udaki

Masao Wanami

Mitsuyoshi Hashida

Shinobu Gohara

Jiro Kashio

Haruo Shibata

Koji Hirayama

Akio Kawase

Hiroyuki Ichikawa

Tetsuya Suzuka

A switching system for realizing integration of existing communication networks or interconnections thereof, and a switching control method. After a call is originated from an ATM communication networkto an STM communication network, an ATMIFthat has received a connection request signal (control signal) converts the control signal into a format of an ATM cell, adds a header destined to one of SIG-to n for processing control signals, and then output the same. An ATMSWperforms self-routing based on header information. The selected one of the SIG-to n performs conversion for the ATM cellby a specified protocol, makes an ATM cellhaving a header destined to one of CLP-to k for processing control signals, and then output the same. Upon having received the ATM cell, the CLPlinks up with other processors to perform call connection control, functions having been dispersed among the other processors.

Switching system and switching control method

A signal processing method for an ATM switching network formed by connecting a plurality of ATM switching networks in which header conversion tables of line interfaces can be rewritten by control cells, includes in response to occurrence of an abnormality in a call control processor of a ATM switching system A, informing an ATM switching system B of the occurrence of the abnormality, transferring call control information in the ATM switching system A to the ATM switching system B, rewriting header conversion tables included in a plurality of line interfaces of the ATM switching system A by using control cells generated by the ATM switching system A and thereby transferring signal channel cells arriving at the ATM switching system A after occurrence of the abnormality to the ATM switching system B, and rewriting header conversion tables included in a plurality of line interfaces of the ATM switching system A by using control cells generated by the ATM switching system B and thereby making a call control processor of the ATM switching system B effect route control of information channel cells within the ATM switching system A.

ATM switching network and ATM switching system in which the transfer of inputted cells is controlled by control cells, and signal processing method in ATM switching network

ATM switching network and ATM switching system in which the transfer of

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 communication control apparatus connected between a transmission path and a processing unit which apparatus includes a table memory for storing the number of received frames which are in the state waiting for protocol processing in correspondence with connection identifiers, a first processor responsive to reception of a new frame from the aforementioned transmission path for making decision by referencing the memory table mentioned above as to whether or not the number of the received frames corresponding to the connection identifier of the newly received frame and waiting for the protocol processing has reached a threshold value for thereby abandoning the aforementioned newly received frame when that number has reached the threshold value and, if otherwise, placing the newly received frame in the state waiting for the protocol processing, and a second processor for executing a predetermined protocol processing on the received frame in the state waiting for the protocol processing.

Communication control apparatus having function for limiting frame

An adaptation processing apparatus for assembling received data units of a fixed length to provide variable length data units and transmitting the variable length data units to a plurality of variable length data unit processors while assembling variable length data units received from said plurality of the variable length data unit processors to provide fixed length data units for transmission thereof. An ATM switching system includes the adaptation processing apparatus, a signal processing unit including the plurality of variable length data unit processors mentioned above, and first-in first-out mechanisms for the variable length data units provided in the adaptation processing apparatus in association with every one of the plural variable length data unit processors.

ATM switching system and adaptation processing apparatus

Growing community of inventors

Kamakura, Japan

Shinichi Iwaki