Abstract: A plurality of NIUs are interconnected by a multiple channel communications medium, and each NIU includes a sequence of inputs and outputs. Each channel is connected to a separate input, and exits the NIU at a separate output. The output that each channel exits is connected to the next input in the sequence of inputs on the next connector in the chordal ring. Further, channels which enter at a predetermined input of the NIU are cut and connected to a user equipment before exiting the NIU. Thus, if a predetermined channel is cut and connected to a particular user equipment, it will not be cut again at the next NIU since it will enter the next NIU at a different input in the input sequence. Indeed, the channel will not be cut again until N NIU's are traversed, where N is the length of the sequence. Thus, by choosing N to be the chordal length, an NIU is constructed which may be connected in an identical fasion to each user equipment in order to automatically establish chords in the network.

Abstract: This invention is an inventive N input by L output interconnect fabric. In operation, packets comprising an information field and an address are received at the N inputs to the interconnect fabric, and the address in each packet is mapped to a group of outputs, rather than to any particular output. Each packet is then routed to any available one of the interconnect fabric outputs associated with the group to which the packet is mapped. If a number of packets destined for the same group simultaneously arrive at the interconnect fabric inputs and the group to which they are all destined does not comprise enough outputs to accept them, then all packets in excess of the number that the destined group can accept are simply discarded. The probability of lost jackets due to such discarded packets is acceptably small. In one exemplary embodiment, the invention can be utilized to build arbitrarily large packet switches.

Abstract: This invention is large N.times.N packet switch, formed using a plurality of smaller packet switches. The invention comprises an N input, L output interconnect fabric (L>N), and a plurality of J.times.K smaller packet switches (J>K). Each of the J inputs to each packet switch is connected to a separate one of the L outputs of the interconnect fabric, and each of the K outputs from each packet switch is connected to a destination equipment. In operation, packets are received at the N inputs to the interconnect fabric, and each packet is routed to one of the inputs of the packet switch associated with the destination user equipment for the packet. Simultaneous packets, up to J in number, are routed to separate inputs of a particular packet switch for distribution to their respective destinations, while all other simultaneous packets destined for user equipments associated with the same packet switch are lost, the probability of such a loss being acceptably small.

Abstract: The present invention relates to a high speed, multihop, Local Area Network (LAN) comprising a communications medium for supporting a plurality of channels therealong and a plurality of Network Interface Units (NIUs) disposed along the medium in a predetermined sequence. Each channel of the communications medium comprises one or more point-to-point communication links, and each NIU is arranged to transmit to, or receive from, at least two other NIUs using point-to-point links from a separate subset of the multiple channels. Several of the NIUs are also arranged to transmit to, or receive from, additional NIUs on the network using (i) point-to-point links from a separate subset of the channels and, (ii) a non-linear connection pattern. Each channel can be used to establish point-to-point links between several pairs of NIUs in nonoverlapping sections of the sequence of NIUs.

Abstract: The present invention relates to a multichannel multihop lightwave communication network which allows packet concurrency in the network while avoiding the need for agile optical devices. The network comprises a lightwave communication medium (10) for supporting a plurality of independent user nodes; and a plurality of N network interface units (NIUs) (11). Each NIU is connected to the lightwave medium and one or more separate user nodes and comprises a trnasmitter section (28-35) and a receiver section (20-27) which are each fixedly assigned to transmit and receive, respectively, over a single channel or a plurality of separate channels to or from other NIUs of the network. In a connectivity pattern for one embodiment of the network, the NIUs are divided into k groups of p.sup.k NIUs such that each NIU of a first group of p.sup.