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 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:
An optical receiving method utilizing polarization diversity is disclosed in which first and second reference lightwaves having different frequencies and having polarization planes substantially perpendicular to each other, are combined with a signal lightwave to form a combined lightwave. The combined lightwave is subjected to heterodyne detection to obtain a detection signal and the detection signal is separated into first and second intermediate-frequency signals having different carrier frequencies. The first and second intermediate-frequency signals are converted into first and second baseband signals, respectively, and the first and second baseband signals are added to obtain an output signal.
摘要:
The invention provides a communication method and system for use in a network for digital data exchange/transfer through a circuit switched network. According to the method and system, a call is given the attribute of an intermittent transfer mode, and a device for identifying attributes is provided on network controls in connection paths so that the network control establishes a path only in response to a data transfer request from identified call and releases the path when the call is held on standby for data transfer.
摘要:
A high speed digital signal multiplexing method and apparatus are provided wherein a plurality of first higher bit rate transmission frames are provided, each first higher bit rate transmission frame being multiplexed therein with lower bit rate signals in an n-byte (n is an integer) interleave manner, and the lower bit rate signals are selectively derived from the plurality of first higher bit rate transmission frames and multiplexed into a second higher bit rate transmission frame. When a phase conflict is detected among the derived lower bit rate signals, all the data columns of at least one of the derived lower bit rate signals are given a predetermined delay by means of a shift register, and the derived signals are multiplexed into the second higher bit rate transmission frame. When a first higher bit rate transmission frame asynchronous with the system frame is detected, a pointer is derived which pointer represents a predetermined information unit within the derived lower bit rate signal. The derived pointer is inserted into a time slot corresponding to the frame pattern position of the second higher bit rate transmission frame for the lower bit rate signal. Thereafter, the derived signals are multiplexed.
摘要:
A digital signal multiplexing apparatus comprising variable multiplexers each of which can alter a multiplexed channel format every call in compliance with a subscriber's request, a fixed multiplexer which has a multiplexing capacity integral times as large as the total multiplexing capacity of the variable multiplexers and the multiplexed channel format of which is fixed, and fixed multiplexed signal demultiplexers each of which fixedly demultiplexes signals in a capacity integral times as large as that of each of the variable multiplexers into signals in a capacity equal to the total capacity of the variable multiplexers, wherein the outputs of the fixed multiplexed signal demultiplexers are distributed to the variable multiplexers through a distributing switch network, and the outputs of the variable multiplexers are multiplexed by the fixed multiplexer.
摘要:
A router apparatus 5 is provided with an ATM switch, an IP controller for performing routing control as a controller for layer 3, plural kinds of interfaces which are individually provided to plural transmission paths in which various communications are performed, and a cell multiplexing/demultiplexing unit, and manages the cell communications between respective parts on the basis of identification information. The input packet is subjected to IP processing in an interface to be converted to a cell in a common format, and the cell is serially multiplexed with a cell from another interface on a cell basis, and transmitted to the ATM switch at the cell multiplexing/demultiplexing unit. Each interface and each cell multiplexing/demultiplexing unit sets and switches the identification information for the header portion of the packet and the cell to be communicated by using a table in which the corresponding relationship of the identification information is registered.
摘要:
A router apparatus 5 is provided with an ATM switch, an IP controller for performing routing control as a controller for layer 3, plural kinds of interfaces which are individually provided to plural transmission paths in which various communications are performed, and a cell multiplexing/demultiplexing unit, and manages the cell communications between respective parts on the basis of identification information. The input packet is subjected to IP processing in an interface to be converted to a cell in a common format, and the cell is serially multiplexed with a cell from another interface on a cell basis, and transmitted to the ATM switch at the cell multiplexing/demultiplexing unit. Each interface and each cell multiplexing/demultiplexing unit sets and switches the identification information for the header portion of the packet and the cell to be communicated by using a table in which the corresponding relationship of the identification information is registered.
摘要:
A router apparatus 5 is provided with an ATM switch, an IP controller for performing routing control as a controller for layer 3, plural kinds of interfaces which are individually provided to plural transmission paths in which various communications are performed, and a cell multiplexing/demultiplexing unit, and manages the cell communications between respective parts on the basis of identification information. The input packet is subjected to IP processing in an interface to be converted to a cell in a common format, and the cell is serially multiplexed with a cell from another interface on a cell basis, and transmitted to the ATM switch at the cell multiplexing/demultiplexing unit. Each interface and each cell multiplexing/demultiplexing unit sets and switches the identification information for the header portion of the packet and the cell to be communicated by using a table in which the corresponding relationship of the identification information is registered.
摘要:
For reducing the scale of a multiplexer, a lower speed ATM interface block, an interface block for SDT mode circuit emulation, and an interface block for UDT mode circuit emulation perform processing for terminating services provided by lower speed transmission lines accommodated therein, and part of AAL processing, which is pre-processing depending on a service, for generating ATM cells from signals received by a terminated service, and send the processed signal to a higher speed line interface using a previously assigned time slot on a time-division bus. The higher speed line interface once stores the signals received from the time-division bus in a buffer, and subsequently performs certain processing including a common portion for respective signals for generating therefrom ATM cells in which the signals are stored in payloads. The generated ATM cells are multiplexed and transmitted onto a higher speed transmission line.