Nokia Corporation

Nokia Wireless Routers, Inc.

David A Beyer

J Joaquin Garcia-Luna-Aceves

Thane Frivold

Chane L Fullmer

Mika Kasslin

Jose Joaquin Garcia-Luna-Aceves

Jori Arrakoski

Marcelo Spohn

Joaquin Garcia-Luna-Aceves

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.

Adaptive communication protocol for wireless networks

Apparatus, and associated method, by which to synchronize nodes in a wireless mesh network, such as a fixed broadband network or a moving ad-hoc mesh network. Time stamps are added to data packets at a reference node defined pursuant to a pseudo hierarchy. The data packets are communicated by the reference node to a receiving node. The time stamp information is extracted therefrom, to provide an indication of a time reference value from which the time stamp information is formed. Registers are maintained at the nodes with updated values of the timing information, used in time synchronization between the nodes of the mesh network.

Apparatus, and an associated method, for facilitating synchronization in a wireless mesh network

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. Also, the nodal characteristics of the nodes of the computer system may be exchanged between neighbor nodes, prior to updating the routing table. Preferred paths to one or more destination nodes may be computed according to these nodal characteristics, for example using a Dijkstra shortest-path algorithm.

Unified routing scheme for ad-hoc internetworking

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. The routing state update messages may be transmitted within the network: (i) in response to a new destination node being detected by an existing node within the network, (ii) in response to a destination becoming unreachable by a collection of the existing nodes, (iii) in response to the change in the cost of a path to at least one destination exceeding a threshold and/or (iv) in situations where a routing loop may be encountered among two or more of the nodes of the network (e.g., at times when a path implied in the LRT of the router leads to a loop).

System for communicating labeled routing trees to establish preferred paths and source routes with local identifiers in wireless computer networks

System and method for collision-free transmission scheduling using neighborhood information and advertised transmission times

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. The requested communication times and/or channels should correspond to available times and/or channels advertised by one or more nodes of the computer network. In this scheme, the identification of reserved communication times and/or channels should be made after eliminating any conflicting scheduled transmissions for those communication times and/or channels.

Protocol for neighborhood-established transmission scheduling

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. Also, receiving routers are identified using local link identifiers associated with communication links between a transmitting router and an intended receiving router.

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Los Altos, CA, United States of America

David A Beyer