A method for configuring a wireless network comprised of a control node and a multiplicity of individual nodes includes the steps of logically organizing the network into a plurality of bands Bi, wherein each of the bands Bi includes a plurality of the individual nodes and is located a number i of hops away from the control node, where i=0 through N, and N.gtoreq.1, and then assigning a logical address to each of the individual nodes, and storing the assigned logical addresses in the respective individual nodes. The assigned logical address for each individual node includes a first address portion which indicates the band Bi in which that individual node is located, and a second address portion that identifies that node relative to all other individual nodes located in the same band. The network is preferably a packet-hopping wireless network in which data is communicated by transferring data packets from node-to-node over a common RF channel. Each of the individual nodes is preferably programmed to perform the step of comparing its own logical address to a routing logical address contained in each packet which it receives and to either discard, re-transmit, or process the packet based upon the results of the comparison. The routing logical address contained in a received packet contains the full routing information required to route the packet from a sending node to a destination node along a communication path prescribed by the routing logical address. The control node is programmed to control the routing of packets by inserting the routing logical address into each packet which it transmits detecting any unsuccessfully transmitted packets detecting a faulty node in the communication path prescribed by the routing logical address in response to detecting an unsuccessfully transmitted packet and changing the routing logical address of the unsuccessfully transmitted packet to a new routing logical address which prescribes a new communication path which does not include the detected faulty node. Also disclosed are a wireless network and a network node which are designed to implement the foregoing network configuration and/or routing methods.
A radio communication system includes a plurality of radio communication terminals, in which a first radio communication terminal stores, in a first field contained in a header of a radio communication packet, address information indicating at least one radio communication terminal to which the radio communication packet is directly transmitted, and a second terminal relays the radio communication packet with reference to the address information stored in the first field. The header of the radio communication packet includes a second field which stores address information indicating a final destination terminal and a third field which stores address information indicating the first terminal as a sending source.
A system and method is disclosed wherein a plurality of nodes within an ad hoc wireless network are able to wirelessly communicate with each other. Each node includes a first data array for storing a node identifier used in selecting a clusterhead and a second data array for storing information relating to the node providing the node identifier for selecting the clusterhead to the node. Control logic of each node is configured according to a heuristic wherein the node initially determines a largest and smallest node identifier for each node. The node selects a clusterhead for the node responsive to the largest node identifier and the smallest node identifier using a set of predefined rules. The nodes within the area are then linked with the selected clusterhead.
A "multicast code constructor" facilitates network based coding in a multicast environment by determining efficient codes for optimizing network flows, thereby increasing reliable network throughput. The network code constructor processes incoming data at each node on a byte-by-byte level to produce outgoing packets to each node in the network. Network coding is provided in which arithmetic operations can occur in any finite field with more than N-1 elements, where N represents the number of receivers in the network. Further, the complexity of arithmetic employed by the coder is independent of the network capacity, and dependent only on the number of receivers in the network. In addition, in one embodiment, multicast codes are restricted to the portion of the network obtained by a union of unicast flows from a sender node to each receiver node to produce codes which do not flood the network excessively, thereby producing a lower code design complexity.
In an ad-hoc mobile network, a geometry-based routing algorithm (GRA) is used to route traffic from a source node to a destination node. In the GRA, a source node maintains location information and routing information for all nodes in a local area and approximate location information for at least some nodes outside the local area. If the source node has to send a packet to a destination node outside their local area, then the source node uses the approximate location information of the destination node to identify which node in its local area is closer to the destination node than the source node. The source node then sends the packet to the identified local node for further routing.
Two network communication protocols, one for routing and one for mobility management, are presented that are particularly suited for use with ad-hoc networks. The routing protocol is a proactive-reactive hybrid routing protocol that limits the scope of the proactive procedure to the node's local neighborhood. Routing zones are defined for each node that include nodes whose distance from the subject node in hops is at most some predefined number, referred to as the zone radius. Each node is required to know the topology of the network within its routing zone only. The reactive procedure is limited during route discovery to queries of only those nodes located on the periphery of routing zones. In this manner, the queries hop across nodes in distances of zone radius, thus limiting the scope of the reactive procedure. The zone radius is preferably adjustable to accommodate different and differing network topologies and network operational conditions in the most efficient manner. The mobility management protocol relies on some network nodes assuming the mobility management function. In this scheme, each network node is "associated" with one or more mobility management nodes. The mobility management nodes form a virtual network which is embedded within the actual ad-hoc network. Each mobility management node knows the location of all nodes within its zone, and communicates this information to any other mobility management node that requests it.
