Abstract: A multi-drop digital telephone loop uses point-to-point digital communication between a series of Add/drop units and a central office terminal to route telephone traffic to customers. The loop automatically detects and signals subscriber channel conflicts and also function in an auto-assign mode for automatically assigning subscriber channels. The loop may also be deployed in conjunction with a remote terminal located at a subscriber's residence or business.

Abstract: A method and apparatus are provided for improved data transmissions on telephone links between service providers and remote clients. The method and apparatus perform the steps of receiving an analog encoded data signal and performing a high precision, synchronized analog to digital conversion while the signal is relatively close to a phone company central office switch assembly. The signal is transferred to output circuitry used to transmit signals on phone company subscriber lines. The signal is converted back to an analog signal prior to its final transmission to a subscriber client modem. In an embodiment of the invention, the high precision, synchronized analog to digital conversion is performed by a client-type modem and the output is transferred to a server-type modem which transmits the converted signal, in digital form, over a pair gain system.

Abstract: A method and apparatus are provided for efficient improved data transmissions on telephone links between service providers and remote clients. The method and apparatus perform the steps of receiving an analog encoded data signal, selectively routed by a switch which is communicatively connected to a set of central office switch assembly codecs, and performing a high precision, synchronized analog to digital conversion while the signal is relatively close to a phone company central office switch assembly. The signal is transferred to output circuitry used to transmit signals on phone company subscriber lines. The signal is converted back to an analog signal prior to its final transmission to a subscriber client modem. In an embodiment of the invention, the high precision, synchronized analog to digital conversion is performed by a client-type modem and the output is transferred to a server-type modem which transmits the converted signal, in digital form, over a pair gain system.

Abstract: A packet switching arrangement in which packet retransmission is provided by the network for packets found by the network to be unusable. A packet switch node is equipped with a packet path and a control signaling path cooperating with packet address route arbitration and gating circuitry for effecting the packet retransmission. As a packet from a network input unit is passed from switch node to switch node a control signaling path through the switch nodes back to the input unit originating the packet is established. When a switch node detects an unusable packet a retransmit control signal is returned via the control signaling path to the input unit originating the packet. The input unit responds to the retransmit signal by resending the original packet. An unusable packet is blocked from further transmission in one embodiment and marked for removal at the network output ports in another embodiment. Unusable packets result from packet corruption or from packet collision within a switch node.

Abstract: A switch node for the communication of circuit switched and packet information via parallel electrical and photonic connections within the node between input links and output links. The links each have electrical and optical sublinks. A node is responsive to an address received via the electrical sublink of an input link to establish both an electrical and photonic connection for the subsequent communication of both electrical and photonic data to an output link designated by the address. The switch node selects the designated output link from a set of similarly address designated output links all of which are equally capable of establishing the path. Based on this type of selection within the node, a switching network with a plurality of stages using the nodes has multipaths between any given input port to any output port.

Abstract: A communication method and packet switching network in which self-routing packets are communicated among stages of switching nodes via inter-stage links whereon data of the packets is transmitted in one direction and the packet clocking signals are transmitted in the other direction. Upon having the capability to accept a packet from one of the inter-stage links, a switch node transmits the packet clock signals to the upstream stage connect to that link indicating the present capacity to accept a packet. Furthermore, each switch node after receiving the end of a packet from an upstream stage times for a predefined amount of time before commencing the transmission of the packet clocking signals.

Abstract: A self-routing packet switching network in which packets are communicated through stages of the network in response to self-contained addresses and in which a packet is discarded if a packet cannot be transferred to a subsequent stage of the network within a predefined amount of time. In addition, upon a packet being discarded, a maintenance message is transmitted over a maintenance channel to the processor controlling the network. Each network comprises stages of switching nodes which are responsive to the physical address in a packet to communicate the packet to a designated subsequent node. The nodes provide for variable packet buffering, packet address rotation techniques, and inter-node and intra-node signaling protocols. Each node comprises a timer which commences timing for a predefined amount of time upon receipt of a packet. If the timer times out, the packet is discarded and a maintenance message is transmitted to the processor controlling the network.

Abstract: A communication method and packet switching network in which self-routing packets are communicated via multipaths through the network while maintaining the sequence of the packets. The switching network has a plurality of stages and the stages are interconnected by inter-node links. Each inter-node link comprises a pair of sublinks thus establishing multipaths through the switching network in response to the self-routing packets. Each stage has a plurality of switch nodes. A switch node is responsive to packets received on one inter-node like destined for a second inter-node link to maintain the sequence of packets as they are communicated out on the second inter-node link. Each node comprises a plurality of input circuits each individually connected to one of the incoming sublinks and a plurality of output circuits each connected to one of the outgoing inter-node links.