Abstract: A method for scheduling data bursts from origin to destination nodes of a communication system involves selecting a yet-unscheduled, feasible node pair for scheduling of a burst therebetween; selecting a timeslot from a finite timeslot sequence; scheduling the burst for the selected timeslot; and repeating the preceding steps to exhaustion of unscheduled demand or of feasible node pairs. The feasibility of a node pair is conditioned on the avoidance of collisions with already-scheduled bursts, taking the various origin-to-destination propagation delays into account.

Abstract: In a system and method of optical communication, optical signals are generated in multiple wavelength channels. Each optical signal is passively transported from an origination node of a network to a destination node. The destination node is determined by the signal wavelength. For at least some signals, the passive transport includes transport through a branch point of the network, such that the signal wavelength determines the output branch through which the signal is routed. In certain embodiments, signals are generated according to a schedule devised to substantially prevent the concurrent arrival, at the same destination node, of signals having the same wavelength but coming from different origination nodes.

Abstract: Broadly, techniques for solving network routing within a predetermined error are disclosed. These techniques may be applied to networks supporting dedicated reserve capacity, where reserved capacity on links in the network is dedicated for a particular commodity (generally, a source and sink pair of computers), and shared recovery, where reserved capacity on links is shared amongst two or more commodities. These techniques use an iterative process to determine flows on each of the links in a network. Costs are set for each commodity, and primary and secondary (i.e., backup) flows are initialized. A commodity is selected and demand for the commodity is routed through the shortest path. Costs are updated for each potential failure mode. For each commodity, the flows and costs are updated. Once all flows and costs are updated, then it is determined if a function is less than a predetermined value.

Abstract: A method of operating a packet network includes the step of selecting one of a plurality of candidate gateways to connect a multimedia communication session between the packet network and a TDM network. The packet network has a source node of the multimedia communication session, and the TDM network has a destination of the multimedia communication session. The candidate gateways interconnect the packet network and the TDM network. The selecting step includes comparing end-to-end congestions for bearer traffic between the source node and different candidate gateways of the plurality.

Abstract: A wireless mobile device is configured to set up communications via wireless links with wireless base stations of a cellular communication system and to obtain information indicative of shadow prices of said wireless base stations via wireless transmissions. Each of the wireless base stations has a corresponding shadow price. The wireless mobile device is configured to make a select one of the wireless base stations for a wireless link with the wireless mobile device based on the information indicative of the shadow prices.

Abstract: Flow control techniques are disclosed for use in data communications networks such as those implementing a time-domain wavelength interleaved network (TWIN) architecture or other suitable architectures. Such techniques may provide for congestion management and scheduling for asynchronous traffic. For example, in one aspect, a technique comprises collecting information at a node of an optical-based communications network, wherein at least a portion of the collected information pertains to congestion in the optical-based communications network, and adjusting a transmission rate of the node in response to at least a portion of the collected information such that the node operates under a substantially stable transmission schedule with respect to asynchronous data bursts. The transmission rate adjusting step/operation may further comprise adjusting the transmission rate such that the node operates under a substantially fair transmission schedule. The node may operate under a random transmission schedule.

Abstract: A procedure for designing WDM optical networks provides both working circuits and protection circuits for carrying traffic demands between node pairs. The protection circuits are activated for the purpose of network recovery in case of a fault on a working circuit. Each protection circuit is link-disjoint, and preferably node-disjoint, from its corresponding working circuit. The network is subdivided into logically defined rings, such that each working and protection circuit lies on one or more of the rings. In particular embodiments of the invention, the joint routing of circuits is carried out so as to minimize the total length of the working and protection circuits according to a length that includes a weight for each link. The weight is selected to promote the efficient packing of optical fibers with wavelength channels.

Abstract: A procedure for designing WDM optical networks provides both working circuits and protection circuits for carrying traffic demands between node pairs. The protection circuits are activated for the purpose of network recovery in case of a fault on a working circuit. Each protection circuit is link-disjoint, and preferably node-disjoint, from its corresponding working circuit. The network is subdivided into logically defined rings, such that each working and protection circuit lies on one or more of the rings. In particular embodiments of the invention, the joint routing of circuits is carried out so as to minimize the total length of the working and protection circuits according to a length that includes a weight for each link. The weight is selected to promote the efficient packing of optical fibers with wavelength channels.

Abstract: A procedure for designing WDM optical networks provides both working circuits and protection circuits for carrying traffic demands between node pairs. The protection circuits are activated for the purpose of network recovery in case of a fault on a working circuit. Each protection circuit is link-disjoint, and preferably node-disjoint, from its corresponding working circuit. The network is subdivided into logically defined rings, such that each working and protection circuit lies on one or more of the rings. In particular embodiments of the invention, the joint routing of circuits is carried out so as to minimize the total length of the working and protection circuits according to a length that includes a weight for each link. The weight is selected to promote the efficient packing of optical fibers with wavelength channels.

Abstract: A number of techniques are described for routing methods that improve resistance to faults affecting groups of links subject to common risks. One of these techniques accounts for failure potentials in physical networks by considering shared risk link groups separately from performance and costs metrics in determining a primary routing path and a backup path. A shared risk link group (SRLG) is an attribute attached to a link to identify edges that have physical links in common and can therefore be simultaneously disrupted due to a single fault. Another technique considers node disjointness and provides a solution of two paths that are as node disjoint as possible and minimizes administrative costs. The techniques may further be combined in a priority order thereby providing a solution of at least two paths that are strictly SRLG disjoint, as node-disjoint as possible, and have minimum administrative costs.

Abstract: Delay-sensitive burst scheduling in a network is carried out through communications between source and destination nodes. A distributed scheduler at each destination node selects timeslots for burst arrivals from requesting source nodes, irrespective of timeslot selections made by distributed schedulers at other nodes.

Abstract: In a traffic engineering technique, a determination is made as to whether any path of a number of predetermined paths meets requirements corresponding to a request. The predetermined paths are determined by substantially maximizing carried demand using at least traffic demand estimates and network topology information and by performing routing for the substantially maximized carried demand. If a given path meeting the requirements is found, a connection on the given path is created, if possible. The predetermined paths are determined through offline TE techniques referred to herein as offline design-based routing (DBR). The requirements for the path may include a destination address and a bandwidth. The offline DBR techniques can include uncertain static demand information or dynamic connections.

Abstract: A system for, and method of, simulating traffic loads in a packetized communication network. In one embodiment, the system includes: (1) an initial arrival generator that generates an initial arrival for a simulated user session at an independent time from a previous user session arrival and (2) a subsequent arrival generator, associated with the initial arrival generator, that generates a number of connections to be associated with the simulated user session as an independent variable and, if the number of connections is greater than one, generates a mean connection interarrival time for the simulated user session and a plurality of timings of subsequent arrivals.

Abstract: In a system and method of optical communication, optical signals are generated in multiple wavelength channels. Each optical signal is passively transported from an origination node of a network to a destination node. The destination node is determined by the signal wavelength. For at least some signals, the passive transport includes transport through a branch point of the network, such that the signal wavelength determines the output branch through which the signal is routed. In certain embodiments, signals are generated according to a schedule devised to substantially prevent the concurrent arrival, at the same destination node, of signals having the same wavelength but coming from different origination nodes.

Abstract: A method for scheduling data bursts from origin to destination nodes of a communication system involves selecting a yet-unscheduled, feasible node pair for scheduling of a burst therebetween; selecting a timeslot from a finite timeslot sequence; scheduling the burst for the selected timeslot; and repeating the preceding steps to exhaustion of unscheduled demand or of feasible node pairs. The feasibility of a node pair is conditioned on the avoidance of collisions with already-scheduled bursts, taking the various origin-to-destination propagation delays into account.

Abstract: An optical WDM-TDM network includes a plurality of devices, each of the devices including at least one optical add/drop device adapted to drop optical signals of at least one channel of a plurality of received channels and pass through the remaining channels, at least one receiver, for receiving the at least one dropped channel from the at least one optical add/drop device, an aggregation device for assembling optical signals from the at least one receiver into original data formats, at least one transmitter for transmitting wavelength division multiplexed optical signals on the plurality of channels, a de-aggregation device for disassembling input data into blocks of data to be transmitted as optical signals by the at least one transmitter, and a controller for processing a global timing schedule.

Abstract: Broadly, techniques for solving network routing within a predetermined error are disclosed. These techniques may be applied to networks supporting dedicated reserve capacity, where reserved capacity on links in the network is dedicated for a particular commodity (generally, a source and sink pair of computers), and shared recovery, where reserved capacity on links is shared amongst two or more commodities. These techniques use an iterative process to determine flows on each of the links in a network. Costs are set for each commodity, and primary and secondary (i.e., backup) flows are initialized. A commodity is selected and demand for the commodity is routed through the shortest path. Costs are updated for each potential failure mode. For each commodity, the flows and costs are updated. Once all flows and costs are updated, then it is determined if a function is less than a predetermined value.

Abstract: A method for designing a ring communication network is presented. A candidate ring defined by a candidate subset of nodes and a candidate routing is identified. A direction of communication is determined for each of a set of anticipated demands. The cost of operating the ring is calculated based upon the anticipated demands. Finally, the calculated cost is compared to a selected cost threshold to determine if a candidate ring is feasible, wherein the ring communication network comprises the candidate ring.