Abstract: 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.

Abstract: 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.

Abstract: An LAN interface unit and an ATM switch unit cooperate to perform traffic control. A QoS unit monitors circumstances of an input buffer from a multiplexer of the ATM switch by means of a system controller and when an overflow of the input buffer is expected, the LAN interface unit of the multiplexer is instructed to perform traffic control. The LAN interface unit performs traffic control such as limitation of ATM cells inputted in the ATM switch.

Abstract: 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, 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.

Abstract: 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-toelectric 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.

Abstract: In a switching system connected between a plurality of input lines and a plurality of output lines, destinations of a plurality of cells incoming from the plurality of input lines are monitored to detect an output line in a congestion state. Upon detection of the output line in an congestion state, congestion information indicating the output line in the congestion state is generated and added to the output cells. An input buffer control circuit derives the congestion information from the received cell, and performs buffering of a cell or cells in an input buffer, which cells are distributed to the output line in the congested state, among cells input from the input line.

Abstract: A self-healing ring switch transmission system uses space division switches disposed upstream and downstream of an add drop switch in order to determine a correspondence with a plurality of ring-switch modes by merely changing the software. This is accomplished by having one output highway of the add drop switch and one output highway of a space division switch connected with an input stage of a selector for selecting one time slot of the two output highways.

Abstract: 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-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.

Abstract: 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.

Abstract: A method of switching a route path of a ring network having a plurality of route paths for signal transmission, in which a transmission station on a transmission side transmits information of a same content to said plurality of route paths, a transmission station on a reception side selects one of the plurality of route paths, and a failure on the selected route path is automatically retrieved. The method includes the steps of: monitoring whether a signal received on each route path is normal or not; loading failure information as a path status identifier in a predetermined field of the signal received on each route path, the failure information indicating whether the monitoring step has detected a failure; and selecting one of the plurality of route paths in accordance with the failure information and predetermined logic.

Abstract: 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-to-electric 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.

Abstract: In order that the various ring-switching modes of 2-Fiber BLSR, 4-Fiber BLSR and UPSR may be switched merely by changing a software, space division switches are disposed across an add drop switch, and one output drop switch and one output of the second space division switch are connected with the input stage of a selector which can be selected at the unit of a time slot. As a result, the various ring-switching modes can be switched merely by changing the software while suppressing the scale of the switch. Moreover, the change from the ring switch to the linear switch and vice versa can be effected.

Abstract: A method of processing inclusively STM signals and ATM signals is provided in which an address in a data memory, in which an output signal is temporarily stored for switching of the STM signals, is made different from that in the data memory, in which an input signal is temporarily stored for switching of the ATM signals, and the address which is to be given to the STM signal is registrated in a memory (an address control memory) to be given to the STM signal periodically, while with respect to the address which is to be given to the ATM signal, the unused address is stored in a memory (an idle address FIFO memory), and when storing the ATM signal in the data memory, the unused address is read out from the idle address FIFO memory to be used successively.

Abstract: 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.

Abstract: A method for constructing a network capable of self-healing from failure in a mesh network and a restoration algorithm are provided. A logical ring is set for each closed loop in the network, and when a failure occurs, the affected traffic is re-routed in the each logical ring toward the opposite direction away from the failure to restore the failed network. The network is divided into a plurality of logical rings to establish the restoration route so that time required for the restoration is shortened.

Abstract: An amplifying circuit for dynamic focus of the invention applies, in a DC feedback loop of amplifying circuit for horizontal dynamic focus, a parabolic waveform signal for correction of vertical dynamic focus to a non-inverting input terminal or inverting input terminal of a detection amplifier for DC feedback, or to an input terminal of a DC control circuit, and superposes on a parabolic waveform signal for correction of horizontal dynamic focus in an amplifying circuit for horizontal dynamic focus through the DC control circuit, thereby stabilizing the DC action point in the amplifying circuit for horizontal dynamic focus, and also obtaining the parabolic waveform signal for correction of horizontal dynamic focus superposing the parabolic waveform signal for correction of vertical dynamic focus from the output terminal of the amplifying circuit for horizontal dynamic focus.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and an apparatus for converting a frame phase of a signal having a frame structure specified in the CCITT recommendations which contains N (N: an integer 2 or above) pieces of frames applied with time-division/multiplex, in which the N pieces of frames are given to N pieces of memories, respectively, a write address is given independently to each memory so that the N pieces of frames are written in the respective memories in a same phase as the phase in the signal, a read address is given independently to each memory so that the N pieces of frames are read out of the respective memories in a same phase as the write phase, a difference between a write address and a read address in each memory is set identical under an initial state, and justification is executed for a frame which is read out of the memory in accordance with a difference between existing write address and read address in each memory, whereby to perform frame phase conversion while maintaining relative phase among respective frames.