Abstract: Embodiments of a scalable optical network unit (ONU) architecture for multi-dwelling units (MDUs) that has a low initial cost (or first port cost) and a low maintenance cost are provided herein. The ONU architecture is scalable in that a growing number of end users can share a single drop fiber that couples the ONU to a passive optical network. The ONU architecture utilizes a multiplexer module to allow the ONU to be daisy chained with one or more additional ONUs.

Abstract: Embodiments of a scalable optical network unit (ONU) architecture for multi-dwelling units (MDUs) that has a low initial cost (or first port cost) and a low maintenance cost are provided herein. The ONU architecture is scalable in that a growing number of end users can share a single drop fiber that couples the ONU to a passive optical network. The ONU architecture utilizes a multiplexer module to allow the ONU to be daisy chained with one or more additional ONUs.

Abstract: Alternative routing schemes in high-speed networks ensure fault tolerance in the event of a link failure. An heuristic algorithm, based on maximal-flow algorithm, is first used to partition the network into parts: one part carries regular or primary traffic and another part is reserved to carry re-routed traffic in the event of a link failure. The result of applying the algorithm is used to find alternative routes for a given call at the time of call setup. The scheme can be modified to accommodate hop-court limitations and loop avoidance.

Abstract: A multimedia communications and computer platform that can serve as a network interface card combined with an internal distribution network for a full range of user terminal devices. It includes an interconnection network module that serves to route all incoming and outgoing information by way of high speed buses with value added features for communication protocol acceleration. In particular, attached to the different ports of the network are an ATM module, a communications processor, a media processor and a variety of terminal devices. By migrating processing intensive functions of network protocol termination, media stream distribution and media stream adaptation into the network interface card, there are avoided the bottlenecks of the traditional CPU centric approach to ATM systems.

Abstract: A robust tone detector is realized by applying a single taper, which provides a relatively narrow bandwidth filter, to a received signal and, then, performing a Discrete Fourier Transform of the tapered signal. The result of the Fourier transform is used to obtain an estimate of energy in the frequency domain of the expected tone. A prescribed selection algorithm based on the relationship of the received signal energy in the time domain and the energy estimate in the frequency domain is used to determine whether a valid tone has been received. Robustness of the tone detector is improved by performing a plurality of Discrete Fourier Transforms of the single tapered version of the received signal at a corresponding plurality of frequencies relative to the nominal frequency of an expected one or more tones. A further improvement in the tone detector is obtained by the dynamically adjusting tone acceptance thresholds based on a measure of channel impairments.

Abstract: Routing of packets in a packet cross-connect switch is determined based on the particular type of packet, i.e., statistical or periodic, grade of service assigned to the packet, e.g., minimum delay, the actual queuing delay at output assigned to the particular packet destination and the status of the assigned output ports. Additionally, for periodic type packets the routing decision is also based on whether an interval is reserved for transmission of periodic packets at the assigned output ports. The routing decision is also based under certain conditions on whether or not the packet has been previously scheduled over an alternate route. The actual queuing delay at the assigned output ports is compared to predetermined delay threshold values in determining the packet route and/or whether it should be discarded.

Abstract: Improved throughput is realized in a packet cross-connect switch by including an addressable memory unit in each of a plurality of input ports for storing packets and by allowing each of a plurality of output ports to address directly any one of the input ports to obtain a particular packet stored therein, which is destined for the output port. To this end, the input ports supply the packet destination and starting address of the packet stored in their memory to a scheduler. The scheduler controllably selects an output port assigned to the packet destination and supplies packet output information to the selected output port including the packet starting address and the identity of the input port storing the packet. When a particular output port is ready to obtain a particular packet, it addresses the memory unit in the particular input port to read the first packet word. The addressed packet word is supplied via a data bus to the requesting output port.

Abstract: A multiple queue packet bandwidth reservation arrangement is disclosed in which statistical type packets are scheduled for transmission and a prescribed interval is reserved for transmission of periodic type packets for each scheduled statistical packet. Each arriving statistical packet is assigned a scheduled time of service based on the amount of packet information already queued to be supplied as an output and the duration of any intervals reserved for transmission of periodic packets at an assigned output port. Operation of the bandwidth reservation arrangement is such that normally a statistical packet is not delayed from being transmitted at its scheduled time of service for more than an interval needed to transmit a maximum length periodic packet.