Energy aware network management

• US 7,277,414 B2
• Filed: 07/30/2002
• Issued: 10/02/2007
• Est. Priority Date: 08/03/2001
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Youssef, Moustafa A., Younis, Mohamed F., Arisha, Khaled A.
• Primary Examiner(s): Chan; Wing F.
• Assistant Examiner(s): MOORE JR, MICHAEL J
• Application Number:
  US10/208,666
• Publication Number:
  US 20030063585A1
• Time in Patent Office: 1,890 Days
• Field of Search: None
• US Class Current: 370/338
• 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 configured to detect environmental parameters, receive digital data, transmit digital data and relay 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) grouping (step 43) the sensors into one or more clusters, wherein each of the one or more clusters further includes a gateway that is responsible for relaying data from each sensor in the respective cluster to a control node (11);

(d) in each of the one or more clusters, setting (step 44) network data routes from among a plurality of topologically-possible routes between each sensor of the cluster and the gateway in the cluster so as to minimize energy consumption using a cluster-wide routing table at the gateway in the cluster and smaller local forwarding tables at the sensors of the cluster, said routing and forwarding tables determining

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

(ii) whether each sensor will relay data between the gateway in the cluster and any other sensor of the cluster;

(iii) whether each sensor will relay data between any two other sensors of the cluster; and

(iv) when each sensor of the cluster will transmit and receive data;

(e) modeling (step 45) energy available at each sensor by using a mathematical equation, where said equation considers an amount of time that the sensor is performing various functions and an 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 setting (step 44) network data routes 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) 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 re-setting (step 47) the network data routes 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 configured to detect environmental parameters, receive digital data, transmit digital data and relay of 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 interconnectivity of the network where said interconnectivity defines for each of the various sensors

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

(ii) whether that sensor will relay data between a specific gateway node and any other of said sensors;

(iii) whether that sensor will relay data between any two other of said sensors; and

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

(b) modeling (step 45) energy available at each sensor by using a mathematical equation, where said equation considers an amount of time that the sensor is performing various functions and an 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 a 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 configured to detect environmental parameters, and each respective sensor including a table that determines if the respective sensor will relay data between any two of the other sensors, said sensors being arranged in one or more 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 interconnectivity of the sensors in its cluster, models energy available at each of its sensors using a mathematical equation, where said equation considers an amount of time the sensor is performing various functions and an amount of energy each function consumes, and transmits control signals to its sensors to change the connections of its sensors in accordance with changes in the amount of energy available at said sensors; and

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

6. The system of claim 5, said various functions comprising:

the detection of environmental parameters;

the reception of digital data; and

the transmission of digital data.