Network utilities in wireless mesh communications networks

• US 8,189,577 B2
• Filed: 07/03/2008
• Issued: 05/29/2012
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Itron Networked Solutions, Inc. (Itron, Inc.)
• Original Assignee: Silver Spring Networks, Inc. (Itron, Inc.)
• Inventors: Vaswani, Raj, Hughes, Sterling, van Greunen, Jana, San Filippo, William E. III, Flammer, George III
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Mansoury, Nourali
• Application Number:
  US12/167,592
• Publication Number:
  US 20090003243A1
• Time in Patent Office: 1,426 Days
• Field of Search: 370/401, 370/389, 370/390, 370/315
• US Class Current: 370/389
• CPC Class Codes: H04L 41/0806 for initial configuration or provisioning, e.g. plug-and-play
• CPC Class Codes: H04L 41/082 the condition being updates or upgrades of network functionality
• CPC Class Codes: H04L 41/0856 by backing up or archiving configuration information
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and systems for providing a network and routing protocol for utility services are disclosed. A method includes discovering a utility network. Neighboring nodes are discovered and the node listens for advertised routes for networks from the neighbors. The node is then registered with one or more utility networks, receiving a unique address for each network registration. Each upstream node can independently make forwarding decisions on both upstream and downstream packets, i.e., choose the next hop according to the best information available to it. The node can sense transient link problems, outage problems and traffic characteristics. Information is used to find the best route out of and within each network. Each network node maintains multi-egress, multi-ingress network routing options both for itself and the node(s) associated with it. The node is capable of several route maintenance functions utilizing the basic routing protocol and algorithms.

Claims

1. A method of time synchronization in a network, comprising:

requesting, by a requesting node, a current time value from a gateway as maintained by the gateway by sending a request from the requesting node to the gateway inserted in a data-link interface TLV (type-length-value);

responding, by the gateway to the node, with a response packet comprising a value corresponding to the current time value maintained by the gateway;

at each hop from the gateway to the node, adding a value corresponding to a transmission delay to the response packet at that hop;

receiving, by the requesting node, the response packet; and

based on the current time value and the added values in the response packet received by the requesting node, determining, by the requesting node, a current time value to be maintained by the requesting node and corresponding to the current time value maintained by the gateway.

2. The method of claim 1, wherein the requesting node determines the current time value to be maintained by the requesting node by adding the value corresponding to the current time value as maintained by the gateway in the response packet and the value corresponding to the transmission delay for the each hop.

3. The method of claim 1, wherein each response packet including the current time value as maintained by the gateway is flagged to indicate that each such response packet should be examined at each hop.

4. The method of claim 1, wherein the requesting of time by the requesting node from the gateway is carried out by sending a request from the requesting node to the gateway as a standalone IP packet.

5. The method of claim 1, wherein the requesting of the current time by the requesting node from the gateway is carried out by sending a request from the requesting node to the gateway included in a network registration packet registering the requesting node with the gateway.

6. The method of claim 1, wherein the requested time information sent by the gateway to the requesting node is included in the response packet in TLV format.

7. The method of claim 1, wherein the requesting node and the gateway are part of a frequency-hopping spread-spectrum based wireless utility network.

8. A method of power management in a network, comprising:

determining whether a source node is in a high-density area of other nodes;

and automatically reducing transmit power of the source node in the event the determination is that the source node is in the high-density area,

wherein the high-density area is determined to exist if a total number of nodes culled by the source node as identified in transmit messages of the source node, and a total number of nodes culled by another node based on messages received by the source node, amounting to a combined total of culled messages, exceeds a predetermined value, wherein culling by the source node and the other nodes is based on a determination by the source node and the other nodes that use of memory by the source node and the other nodes to maintain neighbor relationships is excessive.

9. The method of claim 8, wherein the predetermined value is 100.

10. The method of claim 8, wherein the node'"'"'s power is reduced to a new randomly selected power level.

11. The method of claim 10, wherein the randomly selected power level is in a range from about a minimum of 1 to a maximum of 35 units on a scale of 0 to 65 units, wherein the 0 to 65 unit scale corresponds to a range of 7 db.

12. The method of claim 10, wherein the randomly selected power level is in a range from about 1 to 10 units on a scale of 0 to 65 units, wherein the 0 to 65 unit scale corresponds to a range of 7 db, when the combined total of culled messages is greater than 200.

13. The method of claim 8, wherein the source node may increase power by about 5 units on a scale of 0 to 65 units, wherein the 0 to 65 unit scale corresponds to a range of 7 db, when the source node determines that there are fewer than 50 nodes in a neighbor list of the source node.

14. A method of power management in a network, comprising:

determining whether a source node is in a high-density area of other nodes; and

automatically reducing transmit power of the source node in the event the determination is that the source node is in the high-density area,

wherein the high-density area is determined to exist if a total number of nodes culled by the source node as identified in transmit messages of the source node, and a total number of nodes culled by another node based on messages received by the source node, amounting to a combined total of culled messages, exceeds a predetermined value, wherein culling by the source node and the other nodes is based on a determination by the source node and the other nodes that use of memory by the source node and the other nodes to maintain neighbor relationships is excessive,

wherein the node'"'"'s power is reduced to a new randomly selected power level, and

wherein in an event of additional power reductions, the power reduction is terminated when there are no more than 2 nodes operating at maximum power out of 100 nodes.