Abstract: Techniques are provided for determining mobility of a first node in an ad hoc network. A particular node generates a fixed neighbor node table comprising second nodes in the area of the particular node which are not mobile. The particular node can monitor changes between the first node and the second nodes, and then determine if the first node is mobile based on the changes.

Abstract: A system and method which enables access points in a wireless ad-hoc communications network to effectively and efficiently determine the approximate location of a mobile node without performing a broadcast flood. The system and method enables a message to be efficiently communicated from an access point of the network, which provides access to a portion of the network or access to another network, to a wireless mobile node in the network. The system and method employ the operations of determining the access point with which the wireless mobile node is affiliated, storing information in a routing table at the affiliated access point pertaining to a routing path from the affiliated access point to the wireless mobile node, and updating the routing path when the wireless mobile node moves by a certain amount. The wireless mobile node can provide this routing path information to the affiliated access point in data packets sent to the affiliated access point.

Abstract: A method and system for measuring the time-of-flight (TOF) of a radio signal is described herein. According to various implementations, the system uses multiple antennas, each of which receives direct path radio signals and reflected radio signals. In various implementations, the system sends a sequence of bursts that are detected using a cross correlation detector. The receiver steers antenna nulls to a different angles for each burst and measures the TOF at each angle. The system then calculates the minimum correlation peak from all measurements, and treats that correlation peak as the true, direct path TOF measurement.

Abstract: A system and method for locating optimal routes between source and destination nodes in a communications network, in particular, a wireless ad-hoc communications network by employing a link reliability algorithm that estimates the reliability of links between nodes using a prediction mechanism and a variable-weight filter. The prediction can be based on signal strength, signal-to-noise ratio or any statistic collected at the physical layer that is deemed representative of the quality of a link, and the weighting filter adjusts the predicted value based on the traffic conditions (e.g., idle, light traffic, moderate traffic or heavy traffic) being experienced by the nodes whose link quality is being estimated.

Abstract: The present invention relates to a system and method for deploying devices, such as routers (107) and mobile nodes (102) or tags, that communicate in a wireless multihopping ad-hoc communication network (100), that enables a monitoring system such as a dispatcher (212) to create a reference system to identify the location of each device. The system and method thus allows for prompt identification of the locations of persons or items, particularly firefighters and other persons operating in hazardous environments, to expedite rescue efforts.

Abstract: A system and method for decreasing the route convergence time in a wireless communication network, such as a wireless ad-hoc peer-to-peer network, by finding an alternate route if the nodes anticipate weakening or breakage of a route currently in use. The system and method which enables reactive routing protocols to find optimal routes between nodes in these types of networks when those routes cannot otherwise be found in certain conditions. The system and method thus decrease the route convergence time, provide an effective and efficient way to find optimal routes, and improve overall performance of the network with regard to throughput, delay, packet completion rate and other factors.

Abstract: A system and method for supporting multicast in highly dynamic wireless multi-hop networks, such as ad-hoc networks, with good scalability. The system and method provide a multicast routing algorithm to work in wireless ad-hoc networks without any fixed infrastructure nodes present. In doing so, the system and method provide a technique to build a multicast source specific tree on demand, while using a core source node to limit routing overhead. The system and method further provide a repair process to reduce the latency of discovery of topology change, employ a node sequence number mechanism to differentiate between upstream nodes and downstream nodes on the multicast tree in the repair process, and provide an active joining process to reduce the latency of discovery of membership change.

Abstract: The present invention provides a bandwidth efficient system and method of measuring the range between nodes (102, 106, 107) in a wireless communications network (100) with one-way data transfer, where each node (102, 106, 107) periodically transmits a message that contains information regarding neighboring nodes (102, 106, 107) from which any prior messages have been received by the transmitting node (102, 106, 107). A node (102, 106, 107) receives the messages transmitted from neighboring nodes (102, 106, 107) in the network (100), and records the times of arrival of the received messages. The node (102, 106, 107) receiving those messages can thus determine the respective distances between itself and the neighboring nodes (102, 106, 107) based on the respective time of arrivals of the received messages and the respective information included in the respective messages.

Abstract: A method and system for routing data in a wireless network (400) that enables all nodes (106, 402, 404, 406, 408) to find routes to each other even if the nodes (106, 402, 404, 406, 408) are non-meshed which are incapable of operating as a router to route packets received from other nodes (106, 402, 404, 406, 408), and for associating and reassociating the non-meshed and meshed nodes with other meshed nodes (106, 402, 404, 406, 408). The non-meshed nodes (STA 13-STA 15) request association with one of the meshed nodes (AP5) which are capable of performing packet routing, to request that the meshed node (AP5) with which the non-meshed node (STA 13) is associating operate as a proxy node to route packets between the associated non-meshed node (STA 13) and other meshed or non-meshed nodes (106, 402, 404, 406, 408).

Abstract: A system and method for enabling an ad-hoc communication network to maintain connectivity with the mobile nodes in the network in an effective and efficient manner with minimal overhead. The system and method enables an ad-hoc communication network to maintain connectivity between intelligent access points of the network and mobile nodes in the network while performing an on-demand protocol. The system and method further uses an improved distance vector routing algorithm and unicast messages, to thus avoid an increase routing advertisement frequency in the network while keeping network overhead at a minimum. The system and method also modifies the Ad Hoc On-Demand Distance Vector Routing (AODV) protocol to facilitate smooth handoff of subscriber devices in an ad-hoc communication network while also eliminating unidirectional links between nodes in the network.

Abstract: A system and method for synchronizing a wireless network comprising a first node operable pursuant to a first time-division multiple access (TDMA) scheme and a second node operable pursuant to a second TDMA scheme, wherein the first TDMA scheme and the second TDMA scheme each comprise a plurality of ticks, and wherein the first node and the second node each comprise a tick counter for determining the time moment at which a transmission is made or at which a signal is received by the node.

Abstract: A system and method for providing a MAC protocol that optimizes communication within a wireless network. Specifically, the system and method operates with Mobile Terminals, Fixed References and at least one Main Control, wherein a method defines the sequence of messages exchanged between each Mobile Terminals, Fixed Reference and the Main Control for assuring the data is optimally communicated within the network.

Abstract: A communications network which is capable of effectively and efficiently handling mobility of wireless user terminals between access point nodes of a packet-switched network with minimal overhead and packet loss, and a method for using the same. The communications network employs a packet-switched core network and a plurality of access points coupled to the core network. Each access point is adapted to provide any user terminal with wireless communications access to the core network when that user terminal becomes affiliated with that access point. Each access point, as well as other nodes on the network such as a media server, DNS server and an IP gateway router, includes an address resolution cache which is adapted to store information representative of affiliation between the user terminals and the access points of the network.

Abstract: A system and method for controlling the dissemination of Routing packets, and decreasing the latency in finding routes between nodes. The system and method provides message exchanges between wireless devices to determine optimized communication routes with a minimum of overhead messages and buffered data. Exchanged messages are reduced to a specific series of exchanges indicating destination, destination node detection, and route, preferably using a series of IAP devices. Routes are discovered in an efficient manner and latency in finding routes between nodes is reduced, thereby reducing buffered information levels at individual devices.

Abstract: A first time division multiplex (TDM) time slot is provided which is defined as a bi-directional channel for use in a TDM network including a source node and a destination node. The source node can transmit data to the destination node in a first portion of a first TDM time slot. In one implementation, a second portion of the same first TDM time slot can be reserved for the destination node to transmit information to the source node. For example, the destination node can determine whether the data from the source node has arrived properly, and then transmit an indication message to the source node in the second portion of the same first TDM time slot to indicate whether the data from the source node has arrived properly at the destination node.

Abstract: A system and method for providing the ability to selectively share data in a network routing device with an associated host. The system and method employs a hardware firewall in the routing device which restricts the host such that it can only access areas in shared memory which contains data destined for the host. The routing device CPU notifies the host of pending data and the location of that data in the shared memory. The hardware firewall is also notified of the location in shared memory which the host may access. When the host attempts to read the data, the firewall ensures that only the stated memory area or areas are accessed by the host. Once the data has been read by the host, the firewall is notified to cancel the host's ability to access the shared memory until such time as a new packet destined for the host arrives in the routing device.

Abstract: A system and method for calculating an optimal route at a node by making use of routing metrics which if carefully chosen, can provide stability to the network and also provide features like Self Healing and Load Balancing. A Routing metric is calculated as a scalar number based upon a number of factors, such as number of hops, data rate, link quality and device type. Each factor can be determined by evaluation of Hello messages, or other routing messages as required.

Abstract: A system and method for achieving enhanced CSMA/CA which improves channel availability and quality of service (QoS) in a wireless communications network. The system and method establish channels to enable communication between nodes in a communication network, based on the relationship between the average time length of message data packets and the time lengths of the request to send and clear to send messages. A node of the communication network places a data packet at a location in a queue for retransmission based on a type of information contained in the data packet if the destination node for which the data packet is intended is unable to receive the data packet. The location in the queue is indicative of a duration of time that the node will delay before attempting to resend the data packet to the destination node.

Abstract: A system and method for enabling an ad-hoc communication network to maintain connectivity with the mobile nodes in the network in an effective and efficient manner with minimal overhead. The system and method enables an ad-hoc communication network to maintain connectivity between intelligent access points of the network and mobile nodes in the network while performing an on-demand protocol. The system and method further uses an improved distance vector routing algorithm and unicast messages, to thus avoid an increase routing advertisement frequency in the network while keeping network overhead at a minimum. The system and method also modifies the Ad Hoc On-Demand Distance Vector Routing (AODV) protocol to facilitate smooth handoff of subscriber devices in an ad-hoc communication network while also eliminating unidirectional links between nodes in the network.

Abstract: An ad-hoc, peer-to-peer radio system includes a series of radio terminals forming a service group, each radio terminal having a transceiver for communicating with terminals in the same service group, computer means, and memory for storing program software. Within the system, a method and protocol for communication among the terminals includes establishing a connection with one radio terminal based on time-division access; initiating an outgoing call from the radio terminal including registering with another radio terminal for serving as a node in the call connection by transmitting a registration request; and initially transmitting said registration request on a last time slot (TS) of a respective time frame (TF), said last time slot serving as a configuration channel.