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 fast shared path allocation technique is disclosed. Network nodes are pre-configured such that data from multiple data sources or multiple primary data paths may be sent via a shared secondary data path. Merge nodes merge input from a plurality of input ports onto an output port. The merge nodes implement a blocking function such that upon receipt of a signal from one of the input ports, the signals from the other input ports are blocked from reaching the output port. Upon a triggering event indicating a need to allocate the shared path, the data is first sent to the merge node where it is appropriately merged onto the output link and transmitted towards its destination. Only after the data has been sent does the merge node block the remaining input ports from reaching the output port. This blocking may be performed automatically by the merge node or by conventional network signaling.

Abstract: A methodology for making joint channel and routing assignments in multi-radio wireless mesh networks that takes into account interference constraints, the number of channels in a network and the number of radio available at each mesh router, and maximizes bandwidth allocation subject to fairness constraints. In particular, the methodology provides for routing, channel assignment and link scheduling in multi-radio mesh wireless networks utilizing a constant factor approximation technique that models the interference and fairness constraints and is able to account for the number of radios at each of the wireless nodes of a wireless mesh network.

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: Disclosed is a two tier packet labeling technique for use in connection with network traceback in a network having multiple autonomous systems, with routers and other network resources within each autonomous system. Tier 1 labels are assigned at the autonomous system level, and tier 2 labels are assigned at the router level. In order to reduce the number of labels that are required, a technique called logical partitioned coloring may be used, in which certain autonomous systems and border routers may be logically partitioned into a plurality of mesh connected nodes, and the labels are assigned to these mesh-connected nodes. During network operation the network routers store either tier 1 or tier 2 labels in data packets. The determination of whether to store a label in any particular packet, and the determination of which label to store, may be determined probabilistically by the network router.

Abstract: Improved network design techniques are provided. For example, 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. The network is assumed to have no pre-existing working traffic. A capacity partition including a working capacity portion and a protection capacity portion is determined for at least one link in the network topology. The protection capacity portion is reserved for rerouting working traffic upon a failure and enabling control over the number of backup tunnels, associated with the at least one link, on which working traffic can be rerouted. Determining the capacity partition substantially guarantees at least one of a minimal failure restoration time and a minimal overbuild. A minimal overbuild may include an overbuild equivalent to no more than two times an overbuild required for an optimal solution.

Abstract: Techniques and systems for designing a network providing communication and location identification services are described. A solution point comprising parameters for each of a plurality of base stations is generated. A coverage and locatability performance value for the solution point is computed, as well as derivatives of the performance value. The coverage and locatability performance value and its derivatives are used to indicate favorable directions for searching for subsequent solution points, and subsequent solution points are generated and compared against previous solution points until an optimum solution point is found. The coverage and locatability performance value is a weighted sum of coverage and locatability values for each point in the service area of the network, with coverage values representing forward and reverse link quality and locatability values representing the probability that a point will experience an acceptable power level from at least four base stations.

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: 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.

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: Disclosed is a method and system for multi-character multi-pattern pattern matching. In the multi-character multi-pattern pattern matching method, patterns in an input stream are detected by transitioning between states of a “compressed deterministic finite state automaton (DFA)”, with each transition based on multiple characters of the input stream. The compressed DFA is created by compressing an original DFA, such as an Aho-Corasick DFA, such that each state of the compressed DFA represents multiple consecutive states of the original DFA and each transition between the states of the compressed DFA is a combination of all of the transitions between the multiple consecutive states of the original DFA. This method can be implemented using a Ternary Content-Addressable Memory (TCAM) to store the transitions of the compressed DFA and compares the transitions with multiple characters of an input stream at a time to detect patterns in the input stream.

Abstract: Disclosed is a two tier packet labeling technique for use in connection with network traceback in a network having multiple autonomous systems, with routers and other network resources within each autonomous system. Tier 1 labels are assigned at the autonomous system level, and tier 2 labels are assigned at the router level. In order to reduce the number of labels that are required, a technique called logical partitioned coloring may be used, in which certain autonomous systems and border routers may be logically partitioned into a plurality of mesh connected nodes, and the labels are assigned to these mesh-connected nodes. During network operation the network routers store either tier 1 or tier 2 labels in data packets. The determination of whether to store a label in any particular packet, and the determination of which label to store, may be determined probabilistically by the network router.

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: Techniques and systems for designing a network providing communication and location identification services are described. A solution point comprising parameters for each of a plurality of base stations is generated. A coverage and locatability performance value for the solution point is computed, as well as derivatives of the performance value. The coverage and locatability performance value and its derivatives are used to indicate favorable directions for searching for subsequent solution points, and subsequent solution points are generated and compared against previous solution points until an optimum solution point is found. The coverage and locatability performance value is a weighted sum of coverage and locatability values for each point in the service area of the network, with coverage values representing forward and reverse link quality and locatability values representing the probability that a point will experience an acceptable power level from at least four base stations.

Abstract: Network design techniques are disclosed for optimally placing OXCs and OADMs in an optical mesh network to minimize network cost by using cheaper OADMs wherever possible and only using more expensive OXCs where required. In one aspect, the techniques are provided for determining the optimal configuration of each OXC in terms of each OXC's switch size and port configuration. In another aspect, the present invention provides network analysis transformation techniques which enable Dijkstra's shortest path algorithm to account for the degree of each network node and determine optimal placement of the OXCs and OADMs.

Abstract: Techniques and systems for designing a network providing communication and location identification services are described. A solution point comprising parameters for each of a plurality of base stations is generated. A coverage and locatability performance value for the solution point is computed, as well as derivatives of the performance value. The coverage and locatability performance value and its derivatives are used to indicate favorable directions for searching for subsequent solution points, and subsequent solution points are generated and compared against previous solution points until an optimum solution point is found. The coverage and locatability performance value is a weighted sum of coverage and locatability values for each point in the service area of the network, with coverage values representing forward and reverse link quality and locatability values representing the probability that a point will experience an acceptable power level from at least four base stations.

Abstract: Techniques for designing networks. The techniques integrate the planning and configuration steps of the design process so that an optimal network may be designed. An automated technique for designing a network may comprise the following steps. First, a set of nodes and a set of links with which network equipment may be deployed, and one or more traffic demands are obtained. Then, a network is computed by determining one or more routes for the one or more traffic demands while querying at least a portion of the network equipment to determine a cost for using said equipment to route the one or more traffic demands such that said cost is considered when determining the one or more routes. The network equipment may be queried via one or more application programming interfaces.

Abstract: Techniques for designing networks. The techniques utilize network management-based routing (NMS routing) in conjunction with the planning step (design-based routing) of the design process so that an optimal network may be designed. An automated technique for designing a network may comprise the following steps. First, one or more traffic demands are obtained. Then, a network is computed by determining one or more routes for the one or more traffic demands using a design-based routing methodology based on feedback from a network management-based routing methodology.

Abstract: Network design techniques are disclosed for optimally placing OXCs and OADMs in an optical mesh network to minimize network cost by using cheaper OADMs wherever possible and only using more expensive OXCs where required. In one aspect, the techniques are provided for determining the optimal configuration of each OXC in terms of each OXC's switch size and port configuration. In another aspect, the present invention provides network analysis transformation techniques which enable Dijkstra's shortest path algorithm to account for the degree of each network node and determine optimal placement of the OXCs and OADMs.

Abstract: A fast shared path allocation technique is disclosed. Network nodes are pre-configured such that data from multiple data sources or multiple primary data paths may be sent via a shared secondary data path. Merge nodes merge input from a plurality of input ports onto an output port. The merge nodes implement a blocking function such that upon receipt of a signal from one of the input ports, the signals from the other input ports are blocked from reaching the output port. Upon a triggering event indicating a need to allocate the shared path, the data is first sent to the merge node where it is appropriately merged onto the output link and transmitted towards its destination. Only after the data has been sent does the merge node block the remaining input ports from reaching the output port. This blocking may be performed automatically by the merge node or by conventional network signaling.