Hitachi, Ltd.

Hitachi Software Engineering Company, Ltd.

Taihei Suzuki

Eiichi Amada

Hiroshi Kuwahara

Shirou Tanabe

Shinobu Gohara

Yoshito Sakurai

Takao Kato

Kenichi Ohtsuki

Hirotoshi Shirasu

Yukihito Maejima

Takashi Morita

Toshiki P Tanaka

Yoshihiro Takiyasu

Shiro Tanabe

Matsuaki Terada

Mitsuhiro Yamaga

Takuji Mukaemachi

Kunio Hiyama

Yukiji Yamauchi

Katsuyuki Imoto

Kensuke Inoue

Kouichi Yamamoto

Yoshiaki Tokita

Akinori Kubo

Mitsuyuki Masui

Mituyuki Masui

Toshiaki Yamamoto

Yasuyoshi Kaneko

Susumu Kawaguchi

Hikaru Nakatani

Yoshiaki Mijioka

A packet switching system including at least one switching node or local unit each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch based on a logic channel on a packet circuit, a self-routing switch for performing switching based on the output port information, and a control unit for terminating a control packet and performing the call processing function. A switching node or tandem unit is provided including at least one self-routing switch for interconnecting the local units. A device is provided for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating-side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device.

Packet switching system having self-routing switches

In a packet switching system-made up of a single or a plurality of switching nodes or local units each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch on the basis of a logic channel on a packet circuit, a self-routing switch for performing switching on the basis of the output port information, and a control unit for terminating a control packet and performing the call processing function, and a switching node or tandem unit including a single or a plurality of self-routing switches for interconnecting the local units, there are provided a device for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating, side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of the self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit, whereby in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating side local unit arrives at the tandem unit, the packet is transferred to the destination side local unit without undergoing termination of packet and concomitant call processing control.

Packet switching system having-having self-routing switches

In a packet switching system made up of a single or a plurality of switching nodes or local units each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch on the basis of a logic channel on a packet circuit, a self-routing switch for performing switching on the basis of the output port information, land a control unit for terminating a control packet and performing the call processing function, and a switching node or tandem unit including a single or a plurality of self-routing switches for interconnecting the local units, there are provided a device for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating-side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device, operable in the originating side local unit for information transfer, for inserting output port information of the self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit, whereby in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating-side local unit arrives at the tandem unit, the packet is transferred to the destination-side local unit without undergoing termination of packet and concomitant call processing control.

In a packet switching system made up of a single or a plurality of switching nodes or local units each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch on the basis of a logic channel on a packet circuit, a self-routing switch for performing switching on the basis of the output port information, and a control unit for terminating a control packet and performing the call processing function, and a switching node or tandem unit including a single or a plurality of self-routing switches for interconnecting the local units, there are provided a device for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating, side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of the self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit, whereby in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating-side local unit arrives at the tandem unit, the packet is transferred to the destination-side local unit without undergoing termination of packet and concomitant call processing control.

Time-division channel arrangement

A packet switching system which includes a device for setting, between a tandem unit and a destination local unit, the same logic channel as that between an originating local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than the originating local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of a self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit; in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating local unit arrives at the tandem unit, the packet is transferred to the destination local unit without undergoing termination of packet and concomitant call processing control.

A packet switching system which includes a device for setting, between a tandem unit and a destination local unit, the same logic channel as that between an originating local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than the originating local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of a self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit. In the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating local unit arrives at the tandem unit, the packet is transferred to the destination local unit without undergoing termination of packet and concomitant call processing control.

In a packet network having a plurality of local switching units each connected to a plurality of packet lines and at least one cross-connect unit connected to each local switching unit through at least one transit line having a predetermined transmission capacity, a plurality of virtual paths for interconnecting the plurality of local switching units through the cross-connect unit are defined on each transit line, without fixedly assigning communication bandwidths to individual virtual paths and, in respect of the individual transit lines, values of communication bandwidths assigned to virtual channels which have already been established in virtual paths present on the transit lines are stored. When a request for setting a new call is originated, communication bandwidths of first and second transit lines on which exists a virtual path to form thereon a virtual channel for the call are checked for their margin enough to accept assignment of a bandwidth requested by the call, the first transit line lying between the cross-connect unit and an originating local switching unit and the second transit line lying between the cross-connect unit and a terminating local switching unit. If the first and second transit lines have a margin enough to accept the assignment of a bandwidth requested by the call, the virtual channel for the call is established on the virtual path and values of communication bandwidths assigned to the first and second transit lines are updated.

Packet switching method and system with self-routing switch

An apparatus for supporting development of a graphic data driven program includes a data driven mechanism enabling instructions of the data driven program to be executed whenever all input data necessary for executing the instructions is available. The apparatus includes a terminal device for inputting and displaying a graphic data driven program, an input transforming section for transforming the inputted graphic data driven program into an intermediate file by referring to an instruction information data base, a wiring table transforming section for transforming the inputted graphic data driven program into a wiring table of instructions expressed in text which is independent of a target machine by referring to the intermediate file, a compile section for transforming the wiring table into an instruction template described with a language depending on the target machine, an instruction execution section for executing the instruction template, an instruction execution displaying section for displaying results of executing the instruction template superposed on the displayed graphic data driven program, and an instruction information tracing section for comparing actual results of executing the instruction template stored in a traced information file with correct results of executing the instruction template stored in a correct data base.

Apparatus for supporting graphic data driven program development and for

A high-speed ring LAN capable of accommodating at least one public network having a signal transmission rate of 155.57 MHz, and at least one sub-LAN having a signal transmission rate of 100 MHz. The high-speed LAN has a signal transmission rate of 155.52 Mbps .times.n (n is an even number). SONET (Synchronous Optical NETwork) subframes each comprising a 9 bytes .times.9 section overhead area and a 261 bytes .times.9 virtual container 4 (VC-4) area flow in a time-divisional n-multiplexed format. The respective node devices inserted in the transmission path have one or more ports to accommodate sub-LANs or public networks. Information is exchanged in units of a fixed-length packet between a received SONET subframe and an asynchronous port whereas information is exchanged in units of a byte between the SONET subframe and a synchronous port.

High-speed ring lan system

A data driven type instruction execution method for controlling execution of instructions by using a memory storing an input data available source, an output message destination to which the results of the operation performed are sent and an input data number counters for indicating availability of the input data to each of the instructions. A flag indicating the number of input data required for each instruction is not less than two, an input data number counter for the instruction requiring two or more input data and an initialization table for setting an initial value of the counter. The content of the flag is referred and deciding that the instruction can be executed when the flag indicates the input data number of one. The input data counter is decremented when the input data number is two or more, and deciding that the instruction can be executed when the decrement of the input data counter results in zero. Operation is executed starting from the instruction which the input data are complete, the result of the operation being informed to the output message destination. The instruction is registered in the queue when executable. Execution of the instruction is performed by taking out it from the queue.

Control system with flag indicating two or less data inputs and counter

A method of converting with the aid of a computer a data flow description chart containing a plurality of process elements each receiving a plurality of inputs and outputting one or plural data according to the result of processing and data lines interconnecting the plural process elements into a function design chart showing an outline of the data flow. A source program list corresponding to the data flow description chart is inputted to the computer. A statements analyzing program then consults a first description rule table prepared previously to thereby convert each statement of the source program describing the relation between each of the process elements and the plural input information inputted to each process element into an output data record including a graphic symbol to be displayed on the function design chart and comment. The comment imparted to each graphic symbol of the process element is the respresentative input information of those inputted to the process element. When the input information originates in other process element, a second description rule table prepared previously is then referred to for searching the source process element in which the input information originates. The name of the inherent information found as the result of the search constitutes the comment. Each output data record is added with linkage information between the process elements in consideration of the representative data governing the execution of each process element. A drawing program draws the function design chart on the basis of the output data records.

Method for automatically converting a data flow description of a source

When the subscribers are connected with the switching system by the optical fibers, in order to realize the signal exchange without converting the optical signals sent by the optical fibers into the electric signal, the optical switching system is constituted by: an optical time division multiplexer for time division multiplexing the optical signals which were sent by a plurality of fiber optic cables corresponding to a plurality of subscribers; an optical time switch for changing the time arrangement of the output signals of the optical time division multiplexer; and an optical time division demultiplexer for distributing the time sequential signal of the output signals of the optical time switch to the optical fibers of a plurality of subscriber lines.

Optical switching system

A high-speed ring LAN capable of accommodating at least one public network having a signal transmission rate of 155.57 MHz, and at least one sub-LAN having a signal transmission rate of 100 MHz. The high-speed LAN has a signal transmission rate of 155.52 Mbps.times.n (n is an even number). SONET (Synchronous Optical NETwork) subframes each comprising a 9 bytes.times.9 section overhead area and a 261 bytes.times.9 virtual container 4 (VC-4) area flow in a time-divisional n-multiplexed format. The respective node devices inserted in the transmission path have one or more ports to accommodate sub-LANs or public networks. Information is exchanged in units of a fixed-length packet between a received SONET subframe and an asynchronous packet whereas information is exchanged in units of a byte between the SONET subframe and a synchronous port.

High-speed ring LAN system

An I/O prescription table (I/O PTBL) is associated with a processing program module that is executed by a conventional sequential execution type processor. Each processing program module fetches the input data according to its associated I/O PTBL and stores the output data in the same table. An execution control program makes reference to the I/O PTBL associated with the processing program module, updates the designated I/O PTBL so as to indicate that the corresponding input data is prepared, and starts the processing program module associated with the I/O PTBL which is furnished with all of the necessary input data.

Method and system for data driven information processing

In a digital and electronic switching apparatus, each subscriber's circuit is provided with a loop back circuit which selectively return a downward channel signal to an upward channel in order that a ring back tone informing a calling telephone set of the fact that a called telephone set is being dialed can be synchronized with a ringing tone dialing a called telephone set. Upon dialing a called subscriber, the loop back circuit is ON-OFF controlled in synchronism with the ON-OFF control of the ringing tone so that a tone signal generated from a common continuous ring back tone source can be transmitted to the loop back circuit and the calling telephone set via a speech path of a switching network.

Growing community of inventors

Kodaira, Japan

Taihei Suzuki