Sri International

Sprint Communications Comapny L.p.

Richard G Ogier

Ambatipudi R Sastry

Bhargav R Bellur

Fred Lambert Templin

Nina Taft

William Lee Edwards

Karl Steadman

John Waterston

Barghav R Bellur

Michael Frandsen

Timothy Gene Kelley

D Scott Seaton

Carla Peccolo Woodworth

Nathan W Williams

Christian A Gellrich

James A Arnold

Mark G Lewis

Timothy Gene Kelly

Described are an apparatus and method for routing packets through a multiple-hop wireless communications network. Interference with packet switched communications carried by radio frequency (RF) over the multiple-hop wireless communications network is detected. In response to information related to the detected interference, a route is adaptively determined for transmitting packets through the multiple-hop wireless communications network that mitigates the effect of the interference on the packets.

Interference mitigation and adaptive routing in wireless ad-hoc packet-switched networks

Described is a link-state routing protocol used in a mobile ad hoc network or in an Internet for disseminating topology and link-state information throughout the network. Reverse-path forwarding is used to broadcast each update along the minimum-hop-path tree rooted at the source of the update. Each path tree has the source node as a root node, a parent node, and zero or more children nodes. Updates are received from the parent node in the path tree for the source node that originates the update. Each update includes information related to a link in the network. A determination is made whether to forward the update message to children nodes, if any, in the path tree maintained for the source node originating the update in response to information in the received update. This information itself can indicate whether the update is to be forwarded to other nodes.

System and method for disseminating topology and link-state information to routing nodes in a mobile ad hoc network

A proactive link-state routing protocol designed for mobile ad-hoc networks is disclosed, which provides hop-by-hop routing along shortest paths to each destination. Each node running the present protocol will compute a source tree (providing paths to all reachable nodes) based on partial topology information stored in its topology table. To minimize overhead, each node reports only 'part' of its source tree to neighbors. The present invention employs a combination of periodic and differential updates to keep all neighbors informed of the reportable part of its source tree. The present invention performs neighbor discovery using 'differential' HELLO messages that report only &#x201c;changes&#x201d; in the status of neighbors. This results in HELLO messages that are much smaller than those of other link-state routing protocols.

Method and apparatus for disseminating topology information and for discovering new neighboring nodes

Described are a system and method of providing quality of service assurances for transmitting packets over a channel capable of transmission at a nominal bandwidth. A plurality of classes is defined. Each class represents an aggregate behavior of packets and is allocated a nominal departure rate at which the packets of that class are transmitted when an available bandwidth of the channel is substantially at the nominal bandwidth. Each class is assured a minimum allocation of the available bandwidth for transmitting packets of that class if the available bandwidth of the channel is operating at less than the nominal bandwidth. The minimum allocations to each of the classes can be proportionally different than the nominal departure rates allocated to these classes.

Per hop behavior for differentiated services in mobile ad hoc wireless networks

A protocol for discovering a new neighbor node and detecting the loss of an existing neighbor node in a network is described. A node receives a neighbor discovery message from a neighbor node. The node receiving the neighbor discovery message periodically transmits a predetermined number of neighbor discovery messages in response to the received neighbor discovery message. Each neighbor discovery message includes an identity of the neighbor node. After transmitting the predetermined number of neighbor discovery messages, the node transmits neighbor discovery messages that omit the identity of the neighbor node until another neighbor discovery message is received from the neighbor node that indicates a change in a communications state associated with the neighbor node.

Reduced-overhead protocol for discovering new neighbor nodes and detecting the loss of existing neighbor nodes in a network

Scheduling mechanisms for attaining a per-hop behavior for a plurality of classes of packet traffic in a multi-hop network are described. The per-hop behavior allocates to each class a nominal departure rate and a minimum percentage of available bandwidth. The scheduling mechanisms define a first condition that affects packet forwarding in accordance with the nominal departure rates allocated to the classes and a second condition that affects packet forwarding in accordance with the minimum percentages of the available bandwidth allocated to the classes. Packet forwarding rates for each of the classes are compared with the first and second conditions to select one of the classes for forwarding packets of that class over the network.

Scheduling mechanisms for use in mobile ad hoc wireless networks for achieving a differentiated services per-hop behavior

Described is an internetworking system having various mobile ad hoc extensions to the Internet that are particularly suited to the dynamic environment of mobile ad hoc networks. The internetworking system includes any combination of a link-state routing protocol for disseminating topology and link-state information over a multi-hop network comprised of nodes, a neighbor discovery protocol that can detect the appearance and disappearance of new neighbor nodes, an address format that facilitates deployment of IPv6 nodes in a predominantly IPv4 network infrastructure, a queuing mechanism that can update information upon resuming interrupted communications between nodes, and dynamic network measurement techniques for adaptively using wireless bandwidth when establishing and maintaining connections between nodes and a server.

Mobile ad hoc extensions for the internet

Methods for determining at least two pre-computed paths to a destination in a communications network are provided. The two paths are maximally disjoint. Maximally disjoint paths are paths where the number of links or nodes common to the two paths is minimized. This minimization is given a priority over other path considerations, such as bandwidth or cost metrics. By pre-computing a maximally disjoint pair of paths, the probability that an inoperable link or node is in both paths is minimized. The probability that the inoperable link or node blocks a transfer of data is minimized. Additionally, a pair of maximally disjoint paths is determined even if absolutely disjoint paths are not possible. The communications network may include at least four nodes, and maximally disjoint pairs of paths are pre-computed from each node to each other node. A third path from each node to each other node may also be computed as a function of bandwidth or a cost metric. Therefore, the advantages of the maximally disjoint pair of paths are provided as discussed above and a path associated with a higher bandwidth or lower cost is provided to more likely satisfy the user requirements of a data transfer.

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Half Moon Bay, CA, United States of America

Richard G Ogier