Abstract: Multi-path routing techniques using intra-flow splitting are disclosed. For example, a technique for processing traffic flows at a node in a network comprises the following steps/operations. At least one traffic flow is obtained. The at least one traffic flow comprises multiple packets or bytes. The at least one flow is split into at least two sub-flows, wherein each of the at least two sub-flows comprises a portion of the multiple packets or bytes. The packets or bytes of the at least two sub-flows are respectively routed on at least two paths in the network.

Abstract: Method and apparatus for provisioning a protection pathway of a link joining a first point in a network and a second point in the network. The method includes the step of determining a shortest path between the first point and the second point in a protection graph, computing a length of said shortest path, determining if said link should be added to the protection graph according to said computed length and setting the shortest path in the protection graph as protection path for said link. The second step of determining includes evaluating the protection graph to determine if there no existing path or an existing path that is longer than a hop limit. Based on this evaluation, the method either adds the link or makes no change to the protection graph.

Abstract: Network design techniques and techniques for routing virtually-concatenated data traffic in a network in a manner which distributes delay to intermediate nodes of the network are disclosed. For example, in one aspect of the invention, a technique for routing virtually-concatenated data traffic in a network comprising a plurality of nodes comprises, for a given traffic demand to be routed from a source node to a destination node in the network, the following steps/operations. Two or more paths are determined to route the given traffic demand. Each of the two or more paths correspond to a member of a virtually-concatenated group. At least one path of the two or more paths comprises the source node, the destination node and at least one other node coupled between the source node and the destination node. Further, at least a subset of the source node, the destination node and the one other node buffer at least a portion of the given traffic demand such that a delay is distributed over the at least one path.

Abstract: Techniques for single-failure protection in load-balanced network architectures are disclosed. For example, in one aspect of the invention, a technique for processing a traffic flow in a communication network comprising a plurality of nodes, the traffic flow being deliverable from a source node to at least one destination node via one or more intermediate nodes, comprises the following steps/operations. The traffic flow is split at the source node into a plurality of parts. The parts are distributed to respective ones of the intermediate nodes such that the parts are routed from the source node to the at least one destination node in a disjoint manner.

Abstract: Techniques are disclosed for designing optical transmission systems that efficiently compute cost-optimal configurations under one or more constraints. For example, in one aspect of the present invention, a technique for designing an optical transmission system comprises the following steps/operations. A set of one or more demands and a set of optical transmission system elements are obtained. Elements may be consecutively coupled via a span. At least one constraint on the design of the optical transmission system is obtained.

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: Improved network design techniques are provided. More particularly, the invention provides network design techniques that support fast restoration. In one aspect of the invention, a technique for designing a protection capacity to be reserved in a network comprises the following steps/operations. Link capacities associated with a network topology and existing working traffic in the network are obtained. Capacity partitions are determined for links in the network topology. Each of at least a portion of the capacity partitions comprise a protection capacity portion and a working capacity portion that equals or exceeds the existing working traffic on a corresponding link, such that upon a failure on the link, the working traffic on the link is rerouted over a pre-provisioned detour path using the protection capacity portion on one or more links on the detour path. Further, the capacity partition determination step/operation substantially guarantees protection for existing working traffic in the network.

Abstract: Improved network design techniques are provided. More particularly, the invention provides network design techniques for pre-provisioning networks to support fast restoration with minimum overbuild. In one aspect of the invention, a technique for designing a protection capacity to be reserved in a network comprises the following steps/operations. One or more link capacities associated with a network topology are obtained, wherein the network is assumed to have no pre-existing working traffic. A capacity partition is determined for at least one link in the network topology, the capacity partition comprising a working capacity portion and a protection capacity portion, the protection capacity portion being reserved for rerouting working traffic upon a failure. The capacity partition determination step/operation enables control over the number of backup tunnels, associated with the at least one link, on which working traffic can be rerouted.

Abstract: A method for location tracking on a distributed basis using multiple locations. which utilizes a pairwise application of distance constraints and vicinities for determining locations. The location of a particular node is represented by a group of points (as opposed to a single point) defined by the vicinity.

Abstract: A method and apparatus for determining the current location of a mobile device. More particularly, Bluetooth® enabled mobile devices can be located precisely in an independent fashion, i.e., independent from any communications network associated with the particular mobile device or independent from a GPS or other dedicated system used for location identification purposes.

Abstract: Techniques for network routing and design are provided. A technique for determining a route for a demand in a network, wherein the network comprises primary paths and secondary paths, and at least two secondary paths may share a given link, comprises the following steps/operations. First, a graph representing the network is transformed. Edges of the graph represent channels associated with paths and nodes of the graph represent nodes of the network. The transformation is performed such that costs associated with the edges reflect costs of using channels in secondary paths. Then, the shortest path between nodes corresponding to the demand is found in the transformed graph. The shortest path represents the least-cost path in the network over which the demand may be routed. When the above route determination steps/operations result in a path with at least one loop, an alternative routing process may be executed so as to determine a loopless path for the demand.