Abstract: A communication system employing a multi-conjunction architecture has a supervising circuit for supervising whether or not a returning signal is received from a destination terminal device in response to a sending signal. When no returning signal is detected within a specific time after the sending signal is transmitted, a communication path used for transmitting the sending signal is isolated from rest of the communication system, or a pseudo returning signal is outputted from the supervising circuit to fix a communication path used for transmitting the sending signal and the pseudo returning signal. As a result, communication paths other than that used for transmitting the sending signal may be used for other communications when the returning signal is not detected for the specific time.

Abstract: A fast sequencing method and apparatus for use in a radio navigation system of the GPS type. Satellite-coded signals are simultaneously received from a plurality of sources. The signals are decoded in a single channel by multiple samplings of each signal per each signal modulating period. By taking multiple signal samplings per data period, broadband receiver operation is realized, enhancing the suitability of such apparatus for navigation of medium and high g performance vehicles and the like.

Abstract: A node apparatus is used in a communication network having a multi-conjunction architecture. The communication network has a plurality of transmission paths each coupling one node apparatus to another node apparatus or a terminal device. The node apparatus generally comprises an input port, an output port, and a control part for controlling the coupling of input channels of the input port to output channels of the output port. The control part disconnects and releases a fixed communication path when a certain logic state of a signal continues for a predetermined time period after the communication path is fixed. This predetermined time period is variable and is determined depending on a characteristic of the signal to suit a protocol of the communication.

Abstract: A node apparatus is used in a communication network having a multi-conjunction architecture. The communication network has a plurality of transmission paths each coupling one node apparatus to another node apparatus or a terminal device. The node apparatus generally comprises an input port, an output port, and a control part for controlling the coupling of input channels of the input port to output channels of the output port. The control part couples a first receiving input channel which receives a signal first out of the input channels to all of the output channels excluding an output channel having a channel number corresponding to that of the first receiving input channel, so as to broadcast the signal.

Abstract: This invention relates to a modular contiguous channel multiplexer having one or more modules that produce an asymmetric filter function that is combined with responses from other modules to produce an overall symmetrical response. The multiplexer can have channels arranged in any order of relative frequencies and one or more channels can be added or removed from the multiplexer without disturbing the operation of the existing or remaining channels. A method of constructing a multiplexer involves choosing the most downstream channel first, then choosing sequentially the channel immediately upstream from the channel last chosen and choosing filters of each channel to meet certain criteria. The filters of each channel are identical to one another but are not necessarily identical to filters in adjacent channels.

Abstract: A node apparatus is used in a communication network having a multi-conjunction architecture. The communication network has a plurality of transmission paths each coupling one node apparatus to another node apparatus or a terminal device. The node apparatus generally comprises an input port, an output port, and a control part for controlling the coupling of input channels of the input port to output channels of the output port. The control part disconnects and releases a fixed communication path when no signal is present at the input and output channels of the input and output ports for a first time period after the communication path is fixed, and initializes the node apparatus when no signal is present at the input and output channels of the input and output ports for a second time period before the communication path is fixed.

Abstract: An automatic telephone exchange, such as a PABX, includes a number of group control units (GCU1 to GCU4) each of which is a simplified version of the system of U.S. Pat. No. 4581733. These are connected via respective PCM highways to a central switch, which is an electronic time space switch, and a central controller. The central controller does the major part of the call setting and control, all calls being set up via the central switch.