Abstract: A communication protocol that provides link-level and media access control (MAC) level functions for wireless (e.g., ad-hoc) networks and is robust to mobility or other dynamics, and for scaling to dense networks. In a mobile or otherwise dynamic network, any control-packet collisions will be only temporary and fair. In a dense network, the network performance degrades gracefully, ensuring that only a certain percentage of the common channel is consumed with control packets. The integrated protocol allows packets (e.g., data scheduling control packets) to be scheduled in a collision-free and predictable manner (known to all neighbors), multicast packets can be reliably scheduled, as well as streams of delay- or delay-jitter-sensitive traffic. Further, using an optional network code, the scheduling of control packets can appear to observers to be randomized.

Abstract: Routing table update messages that include both network-level and link-level addresses of nodes of a computer network are exchanged among the nodes of the computer network. Further, a routing table maintained by a first one of the nodes of the computer network may be updated in response to receiving one or more of the update messages. The routing table is preferably updated by selecting a next node to a destination node of the computer network only if every intermediate node in a path from the next node to the destination node satisfies a set of nodal conditions required by the first node for its path to the destination node and the next node offers the shortest distance to the destination node and to every intermediate node along the path from the next node to the destination node. The shortest distance to the destination node may be determined according to one or more link-state and/or node-state metrics regarding communication links and nodes along the path to the destination node.

Abstract: A communication protocol that provides link-level and media access control (MAC) level functions for wireless (e.g., ad-hoc) networks and is robust to mobility or other dynamics, and for scaling to dense networks. In a mobile or otherwise dynamic network, any control-packet collisions will be only temporary and fair. In a dense network, the network performance degrades gracefully, ensuring that only a certain percentage of the common channel is consumed with control packets. The integrated protocol allows packets (e.g., data scheduling control packets) to be scheduled in a collision-free and predictable manner (known to all neighbors), multicast packets can be reliably scheduled, as well as streams of delay- or delay-jitter-sensitive traffic. Further, using an optional network code, the scheduling of control packets can appear to observers to be randomized.

Abstract: One or more labeled routing trees (LRTS) are produced at a router of a computer network according to a shortest path determination made over a partial topology graph of the network, which graph is produced according to knowledge of adjacent links of the router and one or more LRTs of neighboring routers. The LRTs of the router may be updated in response to receipt of routing state update messages, and such messages may include local link identifiers assigned by a head of a link to which the identifiers pertain, and node parameters of a tail of the link to which the local link identifiers pertain.

Abstract: One or more labeled routing trees (LRTs) are produced at a router of a computer network according to a shortest path determination made over a partial topology graph of the network, which graph is produced according to knowledge of adjacent links of the router and one or more LRTs of neighboring routers. The LRTs of the router may be updated in response to receipt of routing state update messages, and such messages may include local link identifiers assigned by a head of a link to which the identifiers pertain, and node parameters of a tail of the link to which the local link identifiers pertain.

Abstract: Scheduling packets are exchanged among neighboring nodes of a computer network. These scheduling packets include descriptions of a transmitting node's 2-hop neighborhood within the computer network, and nodes are able to determine transmission schedules from information received via said scheduling packets. Preferably, the computer network is a synchronized network in which time is dived into a number of frames, each of which are made up of a plurality of slots. In such cases, the exchange of scheduling packets should occur within a first number of the slots of each frame, preferably in a common communication channel. Transmission schedules may be determined, at least in part, because nodes advertise their availability using the scheduling packets. The above-mentioned descriptions may include an identification of received communication times and/or channels, an identification of requested communication times and/or channels and an identification of available communication times and/or channels.

Abstract: A protocol for a computer network in which routing operation codes (ROCs) in headers of packets transmitted within the network specify to a receiving router which of a number of routing or switching methods to apply to forward associated packets. The packets may be forwarded in any of the following modes: (a) a broadcast mode, (b) a hop-by-hop mode based on receiving node address information, (c) a label swapping mode, (d) a source-switching mode, (e) a flow switching mode, or (f) a hop-by-hop mode based on sending mode address information. In the label swapping mode, packets are accepted by the receiving router if the packets include a media access control address of the receiving router, and packets are forwarded from the receiving router according to a switching table indexed by a media access control address of a transmitting router. In the source switching mode, the headers include source routes specified in terms of local link identifiers used by routers in the network.

Abstract: One or more labeled routing trees (LRTS) are produced at a router of a computer network according to a shortest path determination made over a partial topology graph of the network, which graph is produced according to knowledge of adjacent links of the router and one or more LRTs of neighboring routers. The LRTs of the router may be updated in response to receipt of routing state update messages, and such messages may include local link identifiers assigned by a head of a link to which the identifiers pertain, and node parameters of a tail of the link to which the local link identifiers pertain.

Abstract: Routing table update messages that include both network-level and link-level addresses of nodes of a computer network are exchanged among the nodes of the computer network. Further, a routing table maintained by a first one of the nodes of the computer network may be updated in response to receiving one or more of the update messages. The routing table is preferably updated by selecting a next node to a destination node of the computer network only if every intermediate node in a path from the next node to the destination node satisfies a set of nodal conditions required by the first node for its path to the destination node and the next node offers the shortest distance to the destination node and to every intermediate node along the path from the next node to the destination node. The shortest distance to the destination node may be determined according to one or more link-state and/or node-state metrics regarding communication links and nodes along the path to the destination node.

Abstract: Routing table update messages that include both network-level and link-level addresses of nodes of a computer network are exchanged among the nodes of the computer network. Further, a routing table maintained by a first one of the nodes of the computer network may be updated in response to receiving one or more of the update messages. The routing table is preferably updated by selecting a next node to a destination node of the computer network only if every intermediate node in a path from the next node to the destination node satisfies a set of nodal conditions required by the first node for its path to the destination node and the next node offers the shortest distance to the destination node and to every intermediate node along the path from the next node to the destination node. The shortest distance to the destination node may be determined according to one or more link-state and/or node-state metrics regarding communication links and nodes along the path to the destination node.

Abstract: The invention provides a method and apparatus for determining cost metrics for routing in a computer network. The cost metrics may include a measure of the quality of a wireless communication link within the computer network. Such a metric may be used in determining which links of the network to utilize. For example, one may examine local routing information maintained by a first node of a computer network to determine whether alternate paths exist to a neighbor node of the first node, using a sequence of one or more links other than a candidate link through the computer network and compute a link quality of the candidate link. Then, if no alternate path exists to the neighbor node, or the link quality of the candidate link exceeds a defined threshold value, the candidate link may be accepted.

Abstract: The Invention provides methods and apparatus for determining various cost metrics for routing in a computer network. The cost metrics may include measures of interference over time to neighbor nodes of a first node of the computer network per data bit transmitted on a communication link used by the first node. Such a metric may be estimated using the RF transmit power used by the first node for the communication link, the link data rate and the RF-path loss on the communication link, which is determined by a neighbor node comparison of the RF transmit power to a received signal strength at the neighbor node. The cost metric may also include measure of node energy consumed per data bit for transmissions over a communication link within the computer network. Node energy may be computed so as to account for all power not used by a node in a non-transmitting state.

Abstract: A system for maintaining routing tables at each router in a computer network. The system is based on (a) a feasibility condition that provides multiple loop-free paths through a computer network and that minimizes the amount of synchronization among routers necessary for the correct operation of a routing algorithm, and (b) a method that manages the set of successors during the time it synchronizes its routing-table update activity with other routers, in order to efficiently compute multiple loop-free paths, including the shortest path, through a computer network.

Abstract: A vehicle creep control system which has: a speed transducer arrangement coupled to the vehicle's speedometer cable or the like, which provides an active output whenever the vehicle stops; an accelerator switch connected to the accelerator pedal, which has an active output whenever the driver's foot depresses the accelerator pedal; a latching circuit with a set input connected to the speed transducer arrangement and a clear input connected to the accelerator switch; a first delay circuit connected to the output of the latching circuit, such that when the latching circuit is set due to the vehicle slowing down to the given low speed value, a first set signal is connected to the delay circuit, which in turn produces a delayed output, after a given first delay time, so that the brakes are actuated and hold the vehicle.