Fujitsu Corporation

Nippon Telegraph and Telephone Corporation

Toshio Shimoe

Jyoei Kamoi

Kazuo Hajikano

Satoshi Kuroyanagi

Ryuichi Takechi

Takeshi Kawasaki

Satoshi Kakuma

Masami Murayama

Tetsuo Tachibana

Hiroshi Tomonaga

Tadahiro Takase

Teruaki Hagihara

Yuji Kato

Shunji Abe

Toshio Soumiya

Michio Kusayanagi

Hichiro Hayami

Haruo Mukai

Koso Murakami

Yoshihiro Watanabe

Ippei Sawaki

Junichi Yamazaki

Yoshiharu Sato

Tomohiro Shinomiya

Norihito Nishimoto

Hiroshi Takeo

Yoji Tsuboi

Masayuki Kumazaki

The object of the present invention is accomodating local connectionless information (data that is immediately transferred without establishing a path to a receive side), such as LAN data in a local area network, by an asynchronous transfer mode (ATM) network using a connection-oriented communication system (which makes data transfers after verifying that a path to the receive side has been established), thereby performing efficient, fast routing of connectionless information. A connectionless communication system of the present invention is equipped with connectionless information cell assembly/deassembly means for bi-directional conversion between variable-length connectionless information and fixed-length connectionless cells, routing control means for analyzing a destination address of information in connectionless cells and controlling the routing of the connectionless cells; and an ATM network for connecting the connectionless information cell assembly/deassembly means and the routing control means by a permanent virtual channel serving as a fixed path and connecting the routing control means together by a virtual channel serving as a semi-fixed path, whereby connectionless information is segmented into connectionless cells and the connectionless information is exchanged within the ATM network in connectionless cell units.

Connectionless communication system

A communication system for use with a network for transmitting fixed-length cells from a transmitting terminal via a virtual connection in the network to a receiving terminal. The communication system includes a converting device, connected to the transmitting terminal or the receiving terminal, for performing a bi-directional conversion between a variable-length packet and the fixed-length cells, the transmitting terminal or the receiving terminal outputting the variable-length packet, a buffer capacity monitoring device in the receiving terminal for monitoring a capacity of a buffer in the receiving terminal receiving the fixed-length cells and for outputting an alarm signal at the time of detecting a congestion state of the capacity of the buffer, a congestion state alerting device in the receiving terminal responsive to the alarm signal from the buffer capacity monitoring device for outputting an alert signal to the transmitting terminal, and a traffic transmission control device in the transmitting terminal responsive to the alert signal from the congestion state alerting device in the receiving terminal for controlling a transmission of the fixed-length cells to the receiving terminal.

A communication system for transmitting a fixed-length cell converted from a variable-length information including data and a destination of the data. The system includes a cell assembly/disassembly device for performing bi-directional conversion between the variable-length information and the fixed-length cell, a routing control device for receiving the fixed-length cell converted from the variable-length information by the cell assembly/disassembly device, for analyzing the destination of the data and for controlling a routing of the fixed-length cell based on the analyzed destination, and having an error detecting device for detecting an error of the variable-length information in the fixed-length cell, and a network for connecting the cell assembly/disassembly device and the routing control device by a fixed capacity path and for connecting the routing control device to another routing control device by the fixed capacity path or a variable capacity path.

An Asynchronous Transfer Mode (ATM) cell error processing system includes a plurality of error detectors for respectively detecting predetermined cell errors and for respectively generating decision signals and an error editing unit which is operatively coupled to the error detector and determines, based on the decision signals, whether or not a cell related to the decision signals should be discarded. A buffer, which is coupled to at least one of the error detectors, temporarily stores the cell. An error cell discarding unit, which is coupled to the error editing unit and the buffer, discards the cell from the buffer when the error editing unit determines that the cell should be discarded and relays the cell when the error editing unit determines that the cell should not be discarded.

Asynchronous transfer mode (ATM) cell error processing system

A call admission control system in an asynchronous transfer mode exchange includes a unit for describing attribute parameters of a cell from the subscriber terminal; a unit for calculating, based on the attribute parameters, the average and the dispersion of the traffic speeds of the call; a unit for managing data of the average and the dispersion on each output route and data relating to each subscriber; and a unit for calculating the total average and the total dispersion of the data speeds on the selection output route; and a unit for calculating prediction values of cell abandon rate and end-to-end delay based on the average and the dispersion on the selected output route calculated by the total average and dispersion calculating unit, and for comparing the prediction values with the required service quality of cell discard rate and end-to end delay, for determining whether or not the requesting call may be connected.

Traffic control system for asynchronous transfer mode exchange

A switch includes a plurality of memories respectively having write terminals connected to input ports and output terminals, each of the memories including an input acknowledgement signal generating block for generating an input acknowledgement signal when data is received thereto. A multiplexer, which is coupled between the read terminals of the memories and an output port, connects one of the memories to the output port in response to a port number signal. An output controller, which is coupled to the memories and the multiplexer, receives the input acknowledgement signal from each of the memories in order of receipt and generating the port number signal so that data stored in the memories is selected by the multiplexer in order of receipt of the input acknowledgement signal.

Switch coupled between input and output ports in communication system

A call admission control system in an asynchronous transfer mode exchange includes a unit for describing attribute parameters of a call from the subscriber terminal; a unit for calculating, based on the attribute parameters, the average and the dispersion of the traffic speeds of the call; a unit for managing data of the average and the dispersion on each output route and data relating to each subscriber; and a unit for calculating the total average and the total dispersion of the data speeds on the selected output route; and a unit for calculating prediction values of cell abandon rate and end-to-end delay based on the average and the dispersion on the selected output route calculated by the total average and dispersion calculating unit, and for comparing the prediction values with the required service quality of cell discard rate and end-to-end delay, for determining whether or not the requesting call may be connected.

A transmission line control processor performs various processes in response to requests of a call processor for capture, allotment, and release of a subscriber line or an inter-station line. Additionally, in response to requests of the call processor for a reservation, connection, and disconnection of a path, the transmission line control processor instructs an ATM switch to connect or disconnect the path. These processes can be performed using with the existing functions of ordinary call processors, and such complicated processes as the management of bands at ATM switches are executed exclusively by a transmission line control processor.

ATM switching unit

Non-blocking optical space switch

A switching system having a tone trunk which stores, in the digital memory thereof, a predetermined digital tone signal in the form of digital codes for supplying the corresponding analog tone signal to telephone sets of subscribers. The digital codes have been coded in such a way that the analog tone signal is accompanied by a quantizing noise having a characteristic of white noise.

Switching system having tone trunk

Growing community of inventors

Kawasaki, Japan

Toshio Shimoe