Fujitsu Corporation

Kohei Ueki

Satoshi Takahashi

Yoshihiro Watanabe

Jun Ito

Masami Murayama

Takashi Hatano

Yoshihiro Kubota

Hidehiko Suzuki

Takashi Tabu

Akinori Kamijo

Akira Orita

Sachiko Inoue

Kazuya Ito

Noriko Hayashi

A hybrid exchange which exchanges the STM data to be transmitted periodically to realize an exchange in unit of the ATM data to be transmitted asynchronously includes asynchronous transmission terminal interface as the interface with an STM terminal, an synchronous transmission terminal interface as the interface with an ATM terminal, an ATM exchange interface as the interface with an ATM exchange, a transmitting unit for transmitting the STM time slot and ATM time slot, and a control unit for controlling the interfaces. The synchronous transmission terminal interface assigns the STM data to be transmitted periodically to the STM time slot, while the asynchronous transmission terminal interface assigns the ATM data to be transmitted asynchronously to the ATM time slot. The STM time slot and ATM time slot are identified by the STM/ATM identifier. The STM time slot is stored by multiplexing a plurality of STM data.

Hybrid exchange, an exchange, and a re-arrangement method for STM data in an exchange

Disclosed is an ATM switching apparatus capable of reducing a probability an IAM acceptance being rejected due to a difference in bandwidth acquiring algorithm. The ATM switching apparatus is constructed such that when receiving an IAR due to the difference in bandwidth calculation algorithm for the IAM indicating a use of a certain VPC, a calculated bandwidth value is set in an estimated free bandwidth value about the VPC within a bandwidth management table, a value given by Calculation Bandwidth Value/Free bandwidth Value is set in a ratio, and the VPC is selected by using not the free bandwidth value but the estimated free bandwidth value (&equals;Free Bandwidth Value&times;Ratio) when transmitting the IAM. It is another contrivance that when the free bandwidth value changes, the estimated free bandwidth value is also changed to establish &ldquo;Estimated Free Bandwidth Value&equals;Free Bandwidth Value&times;Ratio&rdquo; without changing the ratio.

ATM switching apparatus and ATM communications network

The present invention relates to a technique for a method of checking virtual-path-connection selection rights of fixed-length cell handling exchanges. For each of the virtual path connections, a second fixed-length cell handling exchange notifies, as first message information, a first fixed-length cell handling exchange of the status as to which of the first fixed-length cell handling exchange or the second fixed-length cell handling exchange has a selection right for the virtual path connection. The first fixed-length cell handling exchange that has received the first message information checks whether or not an inconsistency is present in the setting of the virtual-path-connection selection rights, and sends back to the second fixed-length cell handling exchange the result of the check, as second message information. This structure makes it possible to prevent the reduction in efficiency of use of virtual path connections and to efficiently and effectively utilize network resources.

Method of checking and correcting virtual path connection selection

A billing data is relieved by a relief method of billing data when a failure occurs on SVC (Switched Virtual Connection) calls which subscribers connect and disconnect. The relief method of billing data on an asynchronous transfer mode switching system includes an asynchronous transfer mode switch, a terminator provided on an input side of said asynchronous transfer mode switch for counting the number of cells sent from subscribers or other switching system, and a call controller for controlling paths on said asynchronous transfer mode switch, collecting a count value of the numbers of cells on said terminator, and creating billing data according to the count value of the collected cell number and call control data, wherein only the count value of the number of the cells counted on said terminator is removed from the values to be initialized on initialization caused by a failure.

Relief method of billing data in ATM switching system

In control system for communication between units, each unit stores an adjacent-unit identifying number fixedly corresponding to each unit adjacent to one of the units, and forms a relative address, the relative address of the originating unit being 'nil' and the relative address of the destination unit being expressed by a set of adjacent-unit identifying numbers of all units provided on the communication path between the originating unit and the destination unit, excluding the originating unit and including the destination unit, the signal message routing being executed in such a way that, when the received destination address is 'nil', the unit receiving the message is determined to be the destination unit, and when the received destination address is not 'nil', the unit receiving the message transfers the message to the next-stage unit, whereby a simple addressing process is realized.

Control system for communication between units

Growing community of inventors

Kawasaki, Japan

Kohei Ueki