摘要:
A maintenance information providing server (Web server) 20 that transmits maintenance information to a portable terminal carried by a vendor or a customer is appended to the network management system (NMS) 21 supervising the network 2, server 20 on receipt of malfunction information from the NMS 21, notifying the malfunction to one or more pre-registered portable terminals (23, 13, 33) of a communication service purveyor, vendor or the customer.
摘要:
A negative-phase output signal in an ECL circuit is extracted by an emitter-follower circuit, and the extracted signal is differentiated at its leading edge by a capacitor driven by the emitter-follower circuit so as to form a pulse wave, thus the differentiated signal drives a transistor connected in parallel with an emitter-follower resistor to which a positive-phase output signal is supplied. With this operation, a large amount of current flows only at the trailing edge of the output signal to shorten the fall time of the output from the logic circuit.
摘要:
A switching network is constituted by a plurality of time switches which are arranged in a matrix and at cross points between a plurality of input buses and a plurality of output buses, on which frame synchronization signals are multiplexed. Each time switch includes a data memory in which data on the input bus is written in synchronism with the frame synchronization signal included in the input bus, and from which data is read out under the address control of a control memory in synchronization with the frame synchronization signal included in the output bus.
摘要:
In a time division switching system, a reference pulse generator generates constant reference timing pulses for operating a switch. First and second variable phase pulse generators generate first and second trains of variable phase timing pulses. Data signals on a first group of input lines are multiplexed in response to the timing pulses of the first train to produce a first time division multiplexed (TDM) signal and data signals on a second group of the input lines are multiplexed in response to the timing pulses of the second train to produce a second TDM signal. The TDM signals are carried on first and second highways respectively to the space switch. The first and second variable phase pulse generators are controlled so that the timing of each of the first and second TDM signals coincides in the space switch with the reference timing pulse.