Abstract: A number of peripheral controllers are connected to a PCM highway used exclusively for switching through signalling and packet data. Each controller has a counter indicating the usage factor. If the usage of one controller is too high, the next controller is activated.

Abstract: Non-linear intersymbol interference and noise in a received data signal are corrected through use of a Viterbi detector which estimates the most likely sequence of transmitted data symbols by keeping track of candidate data sequence that are recursively updated, based on likelihood measures which are determined by a signal processor which includes circuits for estimating hypothesized channel outputs in the absence of noise. Non-linear input-output relations are stored in one or more look-up tables which, in a preferred embodiment, are registers that store hypothesized channel output symbols in the absence of noise. The contents of the look-up tables may be modified in response to an error signal representative of the difference of the channel output signal and the look-up table output signal.

Abstract: Method and device for managing access to the transmission medium of a multiservice distributed switching network adapted to switch traffic in synchronous circuit-switched mode and in synchronous or asynchronous packet-switched mode, the architecture of the network being based on a transmission medium time-shared between different stations characterized in that: (1) the transmission medium is synchronous and structured in frames in turn structured in time slots in turn structured in time cells, the latter being sized to contain a communication entity which can be either a circuit-switched cell or a segmented packet-switched cell, (2) an ideal time slot for access to the transmission medium in packet-switched mode is assigned to the respective stations communicating within the network, and (3) in each time cell and for all stations transmission medium access arbitration is applied to procure priority access to this medium for circuit-switched cells available at this time in any station.

Abstract: A method and apparatus for communicating a voice conversation over a single telephone channel using continuously variable level quadrature amplitude modulation establishes and maintains two totally independent communication paths, each near perfect in amplitude and phase with respect to frequency over a bandwidth suitable for communication of continuously variable amplitude pulses. These pulses may be representations of any suitable bandlimited analog signal. The method establishes almost flawless QAM channels (real, imaginary), then allows switching to continuously variable amplitude analog transmissions.

Abstract: A data communication system, including at least one base station and at least one portable module 120, wherein the portable module 120 transmits data on a high frequency, and the base station transmits data on a much lower frequency. Transmissions by the base station use a pulse-width modulation scheme where the most commonly used signals correspond to the shortest pulse. A "read" command is encoded as the same pulse width as one of the two write commands. Since the direction of data transmission is known in overhead, there will be no ambiguity.

Abstract: An improved digital phase-locked device and method for synchronizing incoming data (8) with a local clock (24) includes registers (12a,12b) which, when alternately triggered during each successive selection cycle, trap the states of waveforms supplied by a delay element string (11). A transition detector (13) detects transitions in these waveforms and provides to a selection means (17, 18, 19) a plurality of outputs, each corresponding directly to a respective clock position. Registers 19a, 19b of the selection register are alternately triggered by clock signals. Selection register 19 provides a window (SW) defining the maximum number of unique clock positions adjacent a then present clock position within which bit patterns are examined for determining whether any of the clock positions then within the window constitutes a valid local clock selection choice.

Abstract: In order to insure the accuracy of information transmitted over a network, the initiation of the message must be unambiguously identified. In the present invention, the intermessage spacing consists of a series of identical logic signals that exceeds a minimum value distinguishing this interval from a message character. The message character has predefined length, with a start bit position logic signal and a stop bit position logic signal bounding the character that has the same number of predetermined logic signals for every message character. The character has at least one additional non-data bit position that has a first logic signal for the initial character of a message and the complementary logic signal for the remaining characters in the message.