	US 7,486,627 B2
	Time-aware strategy for message-initiated constraint-based routing
Ying Zhang, Cupertino, Calif. (US); Markus P. J. Fromherz, Palo Alto, Calif. (US); Sergei Vassilvitskii, Kensington, Md. (US); and Yi Shang, Columbia, Mo. (US)
Assigned to Palo Alto Research Center Incorporated, Palo Alto, Calif. (US)
Filed on Jun. 03, 2003, as Appl. No. 10/453,750.
Prior Publication US 2004/0246901 A1, Dec. 09, 2004
Int. Cl. H04L 12/28 (2006.01)

U.S. Cl. 370—255 [370/351; 370/400]

19 Claims

1. A method for a time-aware strategy utilized within message-initiated constraint based routing for digital message communication among nodes in multi-purpose communication networks, such as ad-hoc networks, to achieve message delivery within a specified maximum time delay, wherein each node includes a plurality of attributes having attribute values, comprising:

determining attributes for each of the nodes in the ad-hoc network;

providing access to the attributes of each neighboring node within the ad-hoc network, wherein said neighboring node is one hop away from a current node within the ad-hoc network;

estimating the minimum values of at least one attribute within the plurality of attributes;

defining a plurality of constraints on the plurality of attributes, wherein said plurality of constraints includes at least one route constraint and at least one destination constraint, wherein said destination constraint includes a time bound, wherein said time bound comprises a specified maximum time delay for delivery of a message, and is checked at each node at each hop receiving the message to identify the next node to receive the message in order to remain within the time bound for delivery of the message;

performing constraint checking for each message type, wherein said message type includes a destination specification, route specification, and objective specification;

performing cost estimation checking for each said message type at said current node, wherein cost is defined as the total value of at least one of the plurality of attributes along a message path to identify at least one said message path that satisfies said time bound; and

routing a message to at least one destination node within the ad-hoc network, said message including the address of a sending node, the address of the source node, route constraints, destination constraints specified with said time bound, the number of route constraints, the number of destination constraints, message identification number, sequence identification number, and routing objectives.