Abstract: 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.

Abstract: A frame aligner and a method and system for control thereof, in which the frame alignment is executed while assuring TSSI (Time Slot Sequence Integrity). In a system for transmitting a plurality of low-speed signals having a frame structure in a high-speed frame, a plurality of candidates for a write start phase for a frame aligner memory are set, and by accessing a common phase memory storing a write start phase shared by low-speed signals requiring phase matching therebetween of all the low-speed signals stored in the high-speed frame, a write start phase is selected from among the candidates for the write start phase for the frame aligner memory.

Abstract: 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.

Abstract: An ATM switch has a plurality of concentration space-division switches each constituted with an S-stage connection of switch modules. Each of the switch modules includes M buffers and a selector for selecting an arbitrary one of outputs from the M buffers. Each stage includes switch modules of which the number is obtained by multiplying by at most M a number of switch modules disposed in a stage succeeding thereto. The S stages include a final stage constituted with a switch module.

Abstract: Disclosed is a method and apparatus of phase-converting a frame, each frame containing a plurality of data, a frame synchronous signal arranged in a predetermined first relative phase position in the frame, and a pointer arranged in a predetermined second relative phase position and storing a value indicating a phase difference between the second relative phase position and the front position of the data in the frame, in which the following operations are carried out: consecutively receiving the frames; sequentially arranging a predetermined number of data among the plurality of data in the received frame in a transmission frame in accordance with a received order, and arranging the frame synchronous signal and the pointer in the received frame in the first relative phase position and the second relative phase position, the first relative phase position being independent to the second relative phase position, to form the tansmission frame; detecting a fourth relative phase position in the transmission frame,

Abstract: 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.