Energy aware network management

• US 20030063585A1
• Filed: 07/30/2002
• Published: 04/03/2003
• Est. Priority Date: 08/03/2001
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Youssef, Moustafa A., Younis, Mohamed F., Arisha, Khaled A.
• Granted Patent: US 7,277,414 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: G01D 9/005 Solid-state data loggers
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/46 Cluster building
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/08 based on transmission power
• CPC Class Codes: H04W 40/10 based on available power or energy
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 40/28 for reactive routing
• CPC Class Codes: H04W 40/32 for defining a routing cluster membership
• CPC Class Codes: H04W 40/34 Modification of an existing route
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of managing a network of sensors in an energy aware manner includes the steps of clustering the sensors to minimize energy consumption, routing the network (step 44), modeling the energy available at each sensor (step 45), and rerouting the network (step 47) when the sensor battery level drops to a predetermined value, or when the energy model is adjusted because it deviates from a sensor'"'"'s actual energy state.

Claims

1. A method of building and managing a network including nodes of wireless sensors (100), wherein each sensor is capable of detecting environmental parameters, receiving digital data, transmitting digital data and relaying digital data received from another sensor, said method comprising the steps of:

(a) deploying (step 41) the sensors over a predetermined geographical area;

(b) determining (step 42) the geographic location of each sensor;

(c) clustering (step 43) the sensors into a plurality of groups, wherein each group further includes a gateway that is responsible for relaying data from each sensor in the group to a control node (11);

(d) setting (step 44) network data routes to minimize energy consumption using a cluster-wide routing table at each gateway and smaller local forwarding tables at the sensors, said routing and forwarding tables determining

(i) whether each sensor will transmit and receive data, either directly from a specific one of said gateways or indirectly with one of said gateways via relaying from a specific plurality of other of said sensors, and

(ii) when each sensor will transmit and receive data;

(e) modeling (step 45) the energy available at each sensor by using a mathematical equation, where said equation considers the amount of time that the sensor is performing various functions and the amount of energy each function consumes, said various functions comprising,

(i) the detection of environmental parameters,

(ii) the reception of digital data, and

(iii) the transmission of digital data;

(f) detecting (step 46) environmental parameters and relaying data to the control node; and

(g) re-setting (step 47) the network data routes to compensate for changes in the amount of energy available at each sensor.

2. The method recited in claim 1, wherein the step of routing the network (step 44) minimizes a total cost function for the network, wherein the total cost function further comprises the following cost factors:

(a) a communication cost factor (CF1);

(b) a remaining energy available cost factor (CF2) that favors network nodes with more energy or those with less energy;

(c) an energy consumption rate cost factor (CF3) a sensing enabled cost factor (CF3) that disfavors using sensing-enabled nodes as relay nodes;

(d) an enabling cost factor (CF4) that favors using presently enabled versus presently inactive nodes and disfavors using sensing-enabled nodes as relay nodes; and

(e) a routing cost factor (CF5) that avoids adding communication paths that exceed a predetermined maximum.

3. The method recited in claim 1, wherein the step of rerouting the network (step 47) is based on the following three criteria:

(a) a sensor reorganization, when an event occurs that requires the reselection of active sensors;

(b) a change in sensor battery level; and

(c) an adjustment to said mathematical equation that models the energy at a sensor.

4. A method of managing a network including nodes of wireless sensors (100), wherein each sensor is capable of detecting environmental parameters, receiving digital data, transmitting digital data and relaying digital data received from another sensor, said method comprising the steps of:

(a) setting (step 44) network data routes to minimize energy consumption by creating a table that details the interconnectivity of the network where said interconnectivity defines for each of the various sensors,

(i) whether that sensor will transmit and receive data whether directly from a specific one of said gateway nodes or indirectly with one of said gateway nodes via relaying from a specific plurality of other of said sensors and

(ii) when that sensor will transmit and receive data;

(b) modeling (step 45) the energy available at each sensor by using a mathematical equation, where said equation considers the amount of time that the sensor is performing various functions and the amount of energy each function consumes, said various functions comprising,

(i) the detection of environmental parameters,

(ii) the reception of digital data, and

(iii) the transmission of digital data;

(c) detecting (step 46) environmental parameters and relaying data to the control node; and

(d) re-setting (step 47) the network data routes to compensate for changes in the amount of energy available at each sensor.

5. A system for managing a network of sensors, said system comprising:

(a) a plurality of sensors, each sensor capable of detecting environmental parameters, said sensors being arranged in a plurality of clusters;

(b) a gateway associated with each of said clusters and receiving sensor data from the sensors in its cluster, said gateway including a table that details the interconnectivity of the sensors in its cluster, models the energy available at each of its sensors, and transmits control signals to its sensors to change the connections of its sensors accordance with changes in the amount of energy available at said sensors; and

(c) a control processor for receiving sensor data from each gateway.