Polytechnic University

Mario Joa-Ng

I-Tai Lu

Synchronizing the clocks of nodes or stations in a communications network in a way that is independent of computation and switching time. This may be done by synchronizing pseudo-random noise clocks (found in the nodes of a spread spectrum communication system) or by synchronizing chip sequence clocks (found in the nodes of a CDMA communication system). In this way, the accuracy of synchronization should only be affected by the resolution of a matched filter (i.e., a facility to match or correlate bit sequences) in the node. Once synchronized, these nodes may be used to locate another node or station based on transmission propagation delays determined by the synchronization method.

Methods and apparatus for synchronizing and/or determining the location of nodes

A 'peer-to-peer' hierarchical routing protocol&#x2014;also referred to as Zone-based Hierarchical Link State Routing protocol (or 'ZHLS')&#x2014;which incorporates location information into a novel &#x201c;peer-to-peer&#x201d; hierarchical routing approach. The network may be divided into non-overlapping zones. Aggregating nodes into zones conceals the detail of the network topology. Initially, each node knows its own position and therefore zone ID through a position determination unit, such as a Global Positioning System (GPS). After the network is established, each node knows the low level (node level) topology about node connectivity within its zone and the high level (zone level) topology about zone connectivity of the whole network. A packet may be forwarded by specifying the hierarchical address&#x2014;zone ID and node ID&#x2014;of a destination node in the packet header.

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Iselin, NJ, United States of America

Mario Joa-Ng