摘要:
A hit-less protection switching method and apparatus therefor for ATM transmission lines for selecting first cells from normal received signals and writing the same into a normal cell buffer, selecting second cells from emergency received signals and writing the same into an emergency cell buffer, reading the first cells from the normal cell buffer after a first delay time, reading the second cells from the emergency cell buffer after a second delay time, comparing the contents of the first cell with the contents of the second cell and changing the difference between the first delay time and the second delay time, when a state of discrepancy between the contents of the first cell and the contents of the second cell is continuously detected for a predetermined time, to dissolve the state of discrepancy, and selecting one of the cells read from the normal cell buffer and the emergency cell buffer with a delay as communications information.
摘要:
A communication network system includes a communication line, a plurality of communication stations each having a node coupled to the communication line and a network controller coupled to the stations for controlling routing for communication messages between nodes. In one embodiment, the messages are sent from plural terminals connected with each node along with communication performance prerequisites. The communication performance prerequisites for a communication message are discriminated in the node which receives the message. Traffic in various routes between the nodes is continually measured in the communication stations and the measuring results are stored in a database storage unit. Future traffic in the various routes is predicted on the basis of the information on the continually measured traffic by the use of a predetermined algorithm and stored in the storage unit for use in determination of routes for communication messages on the basis of the result of the communication performance prerequisites discrimination and predetermined criteria with respect to the updated information on the predicted traffic in the storage unit.
摘要:
A method of modifying a virtual path capacity in a communication network which transfers a first cell in an asynchronous transfer mode between node apparatuses. The first cell has a first virtual path identifier indicative of a virtual path which the first cell passes through. A bandwidth allocated to the virtual path is modified. Notification of the modification of the bandwidth is provided to a node apparatus included in the virtual path by passing a second cell through said virtual path. The second cell has information of the modification and a second virtual path identifier same as the first virtual path identifier. The second cell is received by the node apparatus and a third cell having information of confirmation of reception of the second cell is returned by the node apparatus.
摘要:
A method of modifying a virtual path capacity in a communication network which transfers a first cell in an asynchronous transfer mode between node apparatuses. The first cell has a first virtual path identifier indicative of a virtual path which the first cell passes through. A bandwidth allocated to the virtual path is modified. Notification of the modification of the bandwidth is provided to a node apparatus included in the virtual path by passing a second cell through said virtual path. The second cell has information of the modification and a second virtual path identifier same as the first virtual path identifier. The second cell is received by the node apparatus and a third cell having information of confirmation of reception of the second cell is returned by the node apparatus.
摘要:
An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
摘要:
An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
摘要:
An optical repeater for realizing transmission of supervisory information of an optical fiber transmission system without the output power of an optical fiber amplifier being reduced, wherein a supervisory optical transmitter and optical receiver with a wavelength which is similar to the wavelength of the pumping light source of the optical fiber amplifier are mounted, and on the input side of the optical repeater, pumping light is multiplexed in the forward direction and a supervisory optical signal, which is multiplexed in wavelength and transmitted, is demultiplexed simultaneously by the first wavelength multi- and demultiplexer and they are received by the supervisory optical receiver, and on the output side of the optical repeater, pumping light is muitiplexed in the reverse direction and a supervisory optical signal outputted from the supervisory optical transmitter is multiplexed by the second wavelength multi- and demultiplexer.
摘要:
First stage and third stage four-input four-output space division switches are arranged before and after a second stage time division switch, and two outputs of the first stage space division switch and two inputs of the third stage space division switch are connected by bypassing the time division switch. The time division switch has n control memories. A first control memory stores connection information in a normal state of each path set in the transmission line, a second control memory stores connection information of a first alternative path when failures occur in a path, and an n-th control memory (n is any integer equal or greater than 3) stores connection information of an (n-1)th alternative path, and a control memory corresponding the a failure pattern is selected from the n control memories for each path.
摘要:
A cell routing method and apparatus in an ATM processing apparatus. The ATM processing apparatus has two or more routing tables associated with address filters of an ATM switch to store routing information for indicating the destination of cell output, and two or more conversion tables associated with VPI conversion circuits for replacing VPI (Virtual Path Identifier) or VCI conversion circuits for replacing VCI (Virtual Channel Identifier) to store information for indicating the VPI or VCI obtained after conversion. In an input interface circuit, selection information indicating which routing table and conversion table out of the above described two or more routing tables and two or more conversion tables should be selected is written into an occupied area within a cell. In a switch circuit, the selection information is read and one routing table is selected out of the above described two or more routing tables on the basis of the selection information thus read, and cell routing is thus performed based on information in the selected routing table. Further, in an output interface circuit, selection information contained in the cell is read and one conversion table is selected out of the above described two or more conversion tables on the basis of the selection information thus read, and VPI conversion or VCI conversion is thus executed based on information in the selected conversion table.
摘要:
A circuit switching apparatus and method for time division network with various transmission speeds for time-division multiplexing a plurality of circuits including signals at different transmission speeds, transmitting the same onto an input highway, repeatedly recording the transmitted signals in a data memory in a predetermined order, reading respective recorded signals in a predetermined order onto an output highway. An access unit for reading signals from the data memory has an address control memory for storing circuit switching information, a circuit speed control memory for storing transmission speed information for the respective circuits and an address generating section for generating an address for accessing the data memory on the basis of the circuit switching information and the circuit transmission speed information from those memories.