Ad hoc network formation and management based on aggregation of ad hoc nodes according to an aggregation hierarchy

Abstract

Each mobile ad hoc node has an assigned hierarchy position within an identified tree-based aggregation group. Each ad hoc node is configured for selectively attaching to one of a plurality of available ad hoc nodes based on identifying a best match, for the assigned hierarchy position within the identified aggregation group, from among identifiable hierarchy positions of identifiable aggregation groups. Each ad hoc node also is configured for selectively attaching to any available ad hoc node based on a determined absence of any available ad hoc node advertising the identified aggregation group of the ad hoc node, or an aggregation group containing the identified aggregation group. Hence, a root node of an aggregation group can filter group-specific routing information from packets destined toward a network clusterhead, resulting in a scalable routing protocol that is not adversely affected by added nodes.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to protocols for creation of an ad hoc mobile network by multiple ad hoc mobile routers. The present invention also relates to management of the ad hoc mobile network by the multiple ad hoc mobile routers by distributing routing information and network traffic in an efficient manner. [0003] 2. Description of the Related Art [0004] Mobile computing has evolved to an extent that it is no longer limited to a mobile computing model (e.g., “Mobile IP”) that relies a fixed wide area network infrastructure such as the Internet to provide connectivity between a mobile node and a correspondent node; rather, an ad hoc networking model has been pursued that enables an isolated group of mobile nodes to independently establish communications among each other (e.g., a “mesh”) and establish optimized routing paths among each other. [0005] In particular, the aforementioned Mobile IP model has been deve...

AI Technical Summary

Benefits of technology

[0017] There is a need for an arrangement that enables formation of large ad hoc networks without adversely affecting network convergence ability or communications efficiency. In particular, there is a need for an arrangement that minimizes the need for distributing unnecessary routing information throughout the network.

[0018] There also is a need for an arrangement that enables ad hoc network nodes to selectively filter routing information to prevent unnecessary routing information from being needlessly distributed throughout the ad hoc network.

[0021] There also is a need for an arrangement that enables ad hoc network nodes to organize according to a prescribed hierarchy, enabling the use of aggregation techniques to selectively distribute routing information and compress routing headers in transmitted packets, without limiting any ad hoc network node from moving about the ad hoc network.

[0026] The selective attachment of the mobile ad hoc router based on available best match for the assigned hierarchy position within the identified aggregation group enables the mobile ad hoc router to independently organize with other mobile ad hoc routers, enabling the independent formation of a structured hierarchy within a tree-based ad hoc mobile network. In addition, the mobile ad hoc router is not precluded from attaching to other mobile ad hoc routers in the absence of any attachments within its identifiable aggregation groups; hence, the mobile ad hoc router still can attach to mobile ad hoc routers of other distinct aggregation groups, as needed.

Problems solved by technology

The routers and hosts are free to move randomly and organize themselves arbitrarily; thus, the network's wireless topology may change rapidly and unpredictably.

The MANET system is particularly suited to low-power radio networks that may exhibit an unstable topology, where wireless propagation characteristics and signal quality between a wireless transmission source and a receiver can be difficult to model and quantify.

As described above, a fundamental problem with the ad hoc networking model is that movement of a mobile router in the ad hoc network requires recalculation of routes for the new topology.

However, the formation of a larger ad hoc network creates a greater probability that an individual mobile router will move, requiring route recalculation for each movement by a mobile router.

Further, the formation of the larger ad hoc network requires recalculation of routes among a larger number of mobile routers, resulting in a longer convergence time.

Consequently, the size of the ad hoc network is limited by the frequency of route recalculation relative to the convergence time, because if the frequency of route recalculation exceeds the convergence time, the ad hoc network will lose connectivity between the ad hoc mobile nodes due to their failure to converge before another ad hoc mobile node moves.

Even if a large ad hoc network manages to converge before another ad hoc mobile node moves, communications efficiency within the ad hoc network suffers dramatically due to substantially increased overhead in packets utilizing routing headers, since a separate routing header is required for each hop in the path from a source node to a destination node.

Consequently, a fundamental problem with a large ad hoc network is the associated increase in routing information that must be distributed to maintain network integrity (i.e., convergence of network routes) and to permit routing of packets.

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