Fujitsu Corporation

Fujitus Limited

Yuzo Okuyama

Satoshi Kakuma

Mikio Nakayama

Tetsuo Tachibana

Kazuo Hajikano

Youzou Iketani

Yoshihiro Watanabe

Naotoshi Watanabe

Kazuo Sato

Masami Murayama

Shiro Uriu

Shuji Yoshimura

Kenichi Okabe

Sumie Morita

Jyoei Kamoi

Tomoyuki Yamaguchi

Megumi Shibata

Yamato Tachibana

Ryuhei Motono

Kazuo Takeoka

Yasunori Tonooka

Satoshi Makuma

A UPC process unit judges whether an arrived cell conforms to a declared parameter. When receiving a cell which is transmitted by a GFR service, a frame process unit modifies the judgment result of the UPC process unit taking an AAL5 frame into consideration. A cell process unit discards the arrived cell based on the judgment result of the UPC process unit or the modified result.

Traffic control apparatus and method thereof

A plurality of input lines are respectively connected to separate multiplexing units that are connected in cascade by cascading lines. Select signals are transferred in parallel with fixed length packets over the cascading lines. Each separate multiplexing unit is responsive to a select signal received from the cascading line to select one of fixed length packets received over the corresponding input line and the upstream cascading line and output it over the downstream cascading line. The most downstream separate multiplexing unit provides a multiplexed output of the input lines.

Line multiplexing system

An internal timing information producing portion produces internal timing information IRTS1 to IRTS4 which is the timing information on a data reception clock by using a network clock C.sub.N and the data reception clock C.sub.RU. A calculator calculates the difference between the internal timing information IRTS1 to IRTS4 and the transmission timing information RRTS1 to RRTS4 contained in a received cell, and a data reception clock producing portion adjusts the timing of the data reception clock C.sub.RU so that the difference is zero and outputs the adjusted timing. An ATM cell decomposing portion outputs the user data D.sub.RU in synchronism with the data reception clock C.sub.RU which is input from the data reception clock producing portion.

Interface device

A test cell generating section periodically generates a pass determining test cell at preset timing, multiplexes them with user cells from a user line interface, and transmits the result of multiplexing to an ATM exchange. When no user cell is supplied from the user line interface, the test cell generating section transmits only the pass determining test cell to the ATM exchange. A cell determining section determines whether a cell supplied from the ATM exchange is a user cell or test cell, identifies/determines the pass based on information of the test cell and outputs only the user cell to the user line side when the supplied cell is the test cell.

Preset virtual path determining method and device in ATM exchange system

A delay-in-frames correction system in a switch unit in a PCM transmission line is used for data communication. A channel data storage unit is provided to temporarily store data corresponding to each channel on the output side or the input side of the switch unit in each direction in the PCM transmission line. A data delay control unit delays data among the data corresponding to channels and stored in the channel data storage unit. The data corresponding to a plurality of channels is output in order in the same frame and delayed by the number of frames indicated by the most delayed data corresponding to channels to provide frame correction instruction information for outputting a data string in the same frame.

Delay-in-frames correcting system in a PCM transmission line

The present invention relates to a system for controlling a miscellaneous device such as a remote device associated with an exchange which handles a fixed length cell with a control field and an information field. The object of the invention is to offer a system where an exchange can control a miscellaneous device such as a remote device in accordance with the feature of the exchange. The exchange includes a call processor, a switch and a signal device. In order to control the miscellaneous device, a path is formed between the signal device and the miscellaneous device. Control information from the call processor is cellulated. The path notifies the miscellaneous device of the control information including cell via the switch to control the miscellaneous device by the exchange.

System of controlling miscellaneous means associated with exchange

Interface device between a network and an exchange for assembling

An ATM (asynchronous transfer mode) exchange has a buffer for system #0 and a buffer for system #1 providing P-MEM's for storing data including an A bit and for a VCI/VPI currently in use is set to '1'. Upon detecting a switchover between the systems, every B bit is reset to '0'. When the exchange while changing from a master to a slave receives a cell having a slave indication and while changing from a slave to a master it receives a cell having a master indication, respective systems rewrite B bits for VCI/VPI's of respective cells to '1'. In the meantime, each of the P-MEM's calculates exclusive 'OR' operations between the A bit and the B bit for every VCI/VPI, and further obtains a disjunction among all the exclusive 'OR' operations thus obtained. Then, when both P-MEM's obtain '0' for their respective disjunctions, cells are read out from one of the buffers in the system changing from a slave to a master. This enables the ATM exchange having a switch duplexed by mutually asynchronous active and backup systems to switchover the systems without causing a cell to be duplicated or lost.

Procedure for switching-over systems

A message information terminating system in a switching center is connected to a plurality of remote stations by Derived Data Link interfaces and includes transmission lines connected to the same data terminal unit of the switching center, for transmitting message information containing various information such as subscriber information with communication data by framing bits between the switching center and each of said remote stations, and a message terminating equipment provided with a processing unit for analyzing the message information and disposed in a network at the switching center. The data terminal unit collects the message information from a plurality of the remote stations and transmits the message information to the message terminating equipment through the network. The message terminating equipment separates the message information from each of the remote stations, analyzes the message information, using the processing unit, and sends normal message information to a control processor in the switching center when the message terminating equipment detects a normal message.

Message information terminating system

A multiplexer multiplexes data of data links received from respective digital lines over to an intraoffice link. A terminator extracts data of the data links received from the respective digital lines multiplexed over to a corresponding intraoffice link, and processes them in a batch. When respective data links are configured by using frame synchronization bits, e.g. at a predetermined frame timing for multiframes, the multiplexer multiplexes frame synchronization bits without shedding their synchronization pattern over to the intraoffice link, and the terminator extracts only the received data of the data links by the frame synchronization bits. In this case, on multiplexing only the frame synchronization bits from respective digital lines, the multiplexer multiplexes identification data indicating that the multiplexing timing is at the head end frames of multiframes. The terminator extracts the identification data and identifies the timing for the head end frames of the multiframes.

Data link terminator

An HDB3 code violation detector includes a converting part for receiving positive polarity data and negative polarity data from a PCM line and for converting an HDB3 code received via the PCM line into an NRZ signal, and a first judging part receiving the positive polarity data, the negative polarity data and the NRZ signal, for judging whether or not a pattern of the NRZ signal received from the converting part is possible when the NRZ signal is NRZ '1' and for outputting a judgement result. In addition, the detector includes a second judging part receiving the positive polarity data, the negative polarity data and the NRZ signal, for judging whether or not a pattern of the NRZ signal received from the converting part is possible when the NRZ signal has a maximum of three consecutive NRZ '0's and for outputting a judgement result. Further, the detector includes a third judging part receiving the positive polarity data, the negative polarity data and the NRZ signal, for judging whether or not a pattern of the NRZ signal received from the converting part is possible when the NRZ signal has at least four consecutive NRZ '0's and for outputting a judgement result, and a detecting part for detecting a code violation of the HDB3 code based on the judgement results of the first, second and third judging parts.

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Kawasaki, Japan

Yuzo Okuyama