Abstract: A system for implementing multiple communication channels on a single twisted pair transmission line is disclosed. The system derives additional communication channels by way of a separate transceiver unit for each derived line. Each transceiver unit communicates in a separate predetermined frequency band. Each transceiver unit, upon connection to the transmission line, automatically utilizes the lowest unoccupied frequency band by monitoring each frequency band for the presence of signal power. Thus, as many derived lines as will be supported by the customer transmission loop can be readily added.

Abstract: A method and apparatus for qualifying a telephone transmission line for XDSL communication services is disclosed. The system includes a modem, located at the customer premises to be connected. The modem analyzes actual signals to determine the electrical characteristics of the communication channel associated with the customer premises. The modem includes a transmitter, receiver and controller to generate test signals and receive responses. The modem then analyzes the data to generate an output value indicative of the electrical characteristics of the communication channel being tested. This output value is then displayed to a user or transmitted over the communication channel to a network. The system thereby eliminates the necessity of dispatching a technician to test the telephone line, and provides more accurate test results than those achievable at the network-side of the connection alone.

Abstract: A method and system for optimizing coding gain that alters the backsearch buffer length and/or the input buffer length of a decoder in response to one or more transmission performance characteristics of the system. The performance characteristics are monitored to determine the performance of the system. The measured transmission performance characteristics are used to control the lengths of the backsearch buffer and the input buffer. The measured transmission performance characteristics along with the backsearch length and/or the input buffer length are analyzed and compared with simulated decoding results. In accordance with the simulated results, the system determines the optimal size of the backsearch buffer and the input buffer needed to achieve a desired performance target. The system adjusts the size of the backsearch buffer length and/or the input buffer length to equal the determined optimal lengths.

Abstract: A method a system for automatically controlling an adaptive interleaver involves monitoring performance parameters of a transmission system and controlling the adaptive interleaver in response to the performance parameters. The SNR and the data rate of the transmission system are preferably determined. The data rate is analyzed and the adaptive interleaver is adjusted in response to the data rate and the SNR. Alternatively, the BER and the data rate of the transmission system are determined. The data rate is analyzed and the adaptive interleaver is adjusted in response to the data rate and the BER. Alternatively, any one of the SNR, BER or data rate can alone be monitored and used to the adaptive interleaver. The system provides a effective system for adjusting an adaptive interleaver in response to performance parameters of a transmission system.

Abstract: A method a system for automatically controlling an adaptive interleaver involves monitoring performance parameters of a transmission system and controlling the adaptive interleaver in response to the performance parameters. The SNR and the data rate of the transmission system are preferably determined. The data rate is analyzed and the adaptive interleaver is adjusted in response to the data rate and the SNR. Alternatively, the BER and the data rate of the transmission system are determined. The data rate is analyzed and the adaptive interleaver is adjusted in response to the data rate and the BER. Alternatively, any one of the SNR, BER or data rate can alone be monitored and used to the adaptive interleaver. The system provides a effective system for adjusting an adaptive interleaver in response to performance parameters of a transmission system.

Abstract: A switching system including a number of switching modules each having a plurality of access ports. Incoming and outgoing packet channels are extended between each switching module and an inter-module packet switch. Each switching module includes a packet switching unit that transmits user information packets, received from the access ports, via the incoming packet channel to the inter-module packet switch, and switches user information packets, received via the outgoing packet channel from the inter-module packet switch, to the access ports for inter-module packet-switched communication. The intermodule packet switch concurrently packet switches user information packets, received on a number of the incoming packet channels, via multiple independent paths to a number of the outgoing packet channels.

Abstract: A method and apparatus for bus contention resolution for use in a digital communications system wherein a plurality of communications controllers are connected to a shared bus for transmitting information in frames. A priority field is included in each transmitted frame. The bus is monitored such that any time the bus is conveying a frame, the priority field of that frame is known at each of the communications controllers. A given communications controller makes a determination based on the priority fields of a new frame and a present frame being actively conveyed by the shared bus that the new frame is of higher priority than the present frame. Upon such a determination, the given communications controller transmits the new frame.

Abstract: A method and apparatus for graceful preemption on a digital communications link used for selective communication from a plurality of user devices. Link controllers are used to implement the enforcement of a protocol on the link. When a first user device is actively communicating over the link, a second user device can gracefully preempt the first user device by having a link controller transmit a preempt character. The link controllers at either end of the link each save values of a set of status variables collectively defining the status of the link controller. When the second user device relinquishes link access, the saved values are used to return the link controllers to their status at the time of preemption such that the first user device can resume communication from the point of interruption without requiring data retransmission.

Abstract: A bus fault location arrangement for locating the source of a fault condition on a bus connecting a plurality of devices energized by a power supply. When such a fault condition is detected, a bus diagnostic unit included in the arrangement transmits a signal to place a given one of the plurality of devices in a high impedance state. The bus diagnostic unit then transmits a given signal level on the bus. To determine whether the given device is the source of the fault condition, current flow between the device and the power supply is sensed and an error signal is stored when the sensed current exceeds a predetermined magnitude.

Abstract: An arrangement for indicating when different types of electrical components, such as circuit boards and the like, are concurrently joined with connector assemblies. Common to the connector assemblies is a plurality of output conductors which is connected to corresponding plurality of output terminals positioned on each of the connector assemblies, respectively. On each component is a plurality of identification conductors arranged to identify the component through the application of a distinct pattern of potentials on the output conductors when one of the components is joined with one of the connector assemblies. When different types of components are concurrently joined with associated connectors, the identification conductors interconnect all the output conductors, such that only a predetermined pattern of potentials other than the distinct patterns may be applied to the output conductors.