Abstract: An optical ring system having: a wavelength demultiplexer to which wavelength-multiplexed optical signal to be sent through an optical fiber from a previous node of multiple nodes is input and in which optical signal with each wavelength assigned to itself is demultiplexed; an optical ring device which is disposed in a predetermined node of the multiple nodes to the each wavelength assigned and which is composed of a failure existence judging part which terminates an overhead of each optical signal with a wavelength demultiplexed by the wavelength demultiplexer and judges whether a failure occurs in regard to a wavelength in a previous section through which optical signal with the assigned wavelength is sent, and a switching part which, when the failure existence judging means determines the occurrence of failure, selects a path that allows optical signal with the wavelength to be transmitted to the previous node while avoiding the previous section incurring the failure; and a wavelength multiplexer which mul

Abstract: In a switch network system which has a plurality of network input terminals and a plurality of network output terminals and a plurality of switch matrices between the network input terminals and the network output terminals, network connection data signals which specify paths between the network input terminals and the network output terminals are renewed or regenerated together with interconnection data signals of the switch matrices when any disorder takes place in the network connection data signals and the interconnection data signals. Such regeneration is carried out by retrieving or monitoring actual paths from the network output terminals towards the network input terminals by the use of a route-search and renewal processing unit and switch-search and renewal units. The switch network system may be either a unidirectional network system or a bidirectional network system.

Abstract: In a cross connect apparatus, a switch section includes a plurality of switches and having n input terminals and m output terminals. A control section reads a current connection information indicative of a current connection state of the switch section in response to a connection command, and determines based on the read connection information, whether it is allowed to establish a connection state of the switch section designated by the connection command. When it is determined to be allowed, the control section establishes a new connection state of the switch section designated by the connection command.

Abstract: A digital cross-connect system has a network management system for designating input and output terminals and delivering one-to-one connection and one-to-many branch connection request signals, and a plurality of cross-connect devices each including a multistage switch for switching connections between the input and output terminals over former, intermediate, and latter stages, and a switch control device for controlling switched connections between the input and output terminals. The network management system designates a switch in the latter stage and delivers a one-to-many connection request signal. The switch control device instructs a switch in the former stage to make a one-to-one connection only and inhibits the switch from making a one-to-many branch connection in response to the one-to-many connection request signal, and also instructs the designated switch in the latter stage to inhibit signals from being supplied from input terminals other than one designated input terminal.

Abstract: A cross-connection device installed in a node of a transmission network. Each of a plurality of memories stores particular connection information. To replace a transmission path, a selector selectively connects one of the memories to a group of switches. The device, therefore, replaces connection information to be used in a moment and adapts itself to changes in environment immediately.

Abstract: A data updating system includes a current data storage unit for storing a current data. The current data includes a plurality of data rows, each of which is a set of data elements required to achieve a function. Each of the data elements is assigned with an identifier. A back-up section executes a back-up process, i.e., reads out data elements of a data row associated with an update instruction and stores it in a buffer memory. An update section overwrite new data elements designated by the update instruction on the associated data row in the storage unit in units of data elements after the back-up. When the overwrite is unsuccessful on a particular one of the new data elements, a recover section executes a recover process, i.e., reads the data elements from the buffer memory and writes them in the storage unit to recover the whole current data.

Abstract: A cross-connecting module includes a demultiplexing unit, a first replacing unit, a cross-connecting unit, a second replacing unit, and a multiplexing unit. The demultiplexing unit sequentially byte-interleave-demultiplexes multiplexed transmission data into a plurality of demultiplexed data. The first replacing unit replaces pointer information indicating a leading address of a data storage area of each of the second and subsequent demultiplexed data, which are byte-interleave-demultiplexed by the demultiplexing means, with pointer information indicating a leading address of a data storage area of the first demultiplexed data. The cross-connecting unit cross-connects the first demultiplexed data from the demultiplexing unit with the second and subsequent demultiplexed data from the first replacing unit. The second replacing unit replaces the pointer information of each of the second and subsequent demultiplexed data from the cross-connecting unit with a preset specific value.

Abstract: When setting a branch route in a three-stage cross-connect switch system having a non-blocking three-stage Clos switch configuration having input stage switches, intermediate stage switches and output stage switches, the output stage switches, the intermediate stage switches and the input stage switches are searched first, second and third, respectively, for points of branching connection with existing routes in order to avoid, as far as practicable, the use of the output terminals of input stage switches having the same switch number. The blocking of any route setting request newly emerging for one-to-one connection or branching connection can be thereby restrained.

Abstract: An electronic device has a rack accommodating a mother board and a first and a second printed circuit board (PCB) group mounted on the mother board. The PCBs belonging to one of the first and second groups are mounted on the mother board in an upper half of the rack while having the surfaces thereof positioned substantially parallel to the side walls of the rack. The PCBs belonging to the other group are mounted on the mother board in a lower half of the rack while having the surfaces thereof held substantially horizontal. If necessary, a third group of PCBs are positioned above one of the first and second PCB groups and mounted on the mother board with their surfaces held substantially horizontal. The wiring network between the first and second (and third) PCB groups is formed on the surface of the mother board by printing. Two electric fans may be respectively located between the first and second PCB groups and between the third and first (or second) PCB groups.

Abstract: In a switching module for a digital cross-connect system, N input terminals of the module are divided into first and second groups and N output terminals are likewise divided into first and second groups. First and second N.times.N space switches and a first group of N selectors are provided. Each of the first-group selectors has a first input coupled to an associated one of the N input terminals of the first group and an output coupled to an associated one of N inputs of the first N.times.N space switch. A first group of N splitters are connected respectively to the N input terminals of the second group, each of the splitters having a first output coupled to a second input of an associated slector of the first group and a second output coupled to an associated input of the second N.times.N space switch. A second group of N selectors is provided, each having a first input coupled to an associated output of the first N.times.

Abstract: N/n first-stage switches of an existing N.times.N three stage network are decomposed into 2N/n virtual switches having n inlets and 2n outlets, and N/n third-stage switches are likewise decomposed into 2N/n virtual switches having 2n inlets and n outlets. The outlets of each first-stage virtual switch are connected respectively to the inlets of different second stage existing switches, the inlets of each third-stage virtual switch being connected respectively to the outlets of different second stage existing switches. When expansion stages are installed, existing connections from the outlets of the N/n first-stage virtual switches are removed and new connections are established therefrom to the inlets of different expansion second-stage switches, and existing connections to the inlets of the N/n third-stage virtual switches are removed and new connections are established therefrom to the outlets of different expansion second-stage switches.