Publish/subscribe model in a wireless sensor network

• US 7,590,098 B2
• Filed: 10/27/2004
• Issued: 09/15/2009
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Ganesh, Arul
• Primary Examiner(s): Pérez-Gutiérrez; Rafael
• Assistant Examiner(s): Patel; Nimesh
• Application Number:
  US10/974,362
• Publication Number:
  US 20060088014A1
• Time in Patent Office: 1,784 Days
• Field of Search: 455/404.1, 455/418, 455/422.1, 455/456.1, 455/41.2, 455/574, 455/11.1, 370/310, 370/321
• US Class Current: 370/338
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. A subscription for an event of interest occurring in the wireless sensor network is installed in the wireless sensor network. A publisher node included in the plurality of nodes determines when the event of interest occurs and, when the event of interest occurs, publishes data related to the event of interest for a subscriber node included in the plurality of nodes.

Claims

1. A wireless sensor network comprising:

a plurality of nodes that communicate over wireless communication links, wherein at least one of the plurality of nodes receives sensor data from a sensor;

wherein a first node in the plurality of nodes is operable to generate at least one subscription for an event of interest occurring in the wireless sensor network from a query received at the wireless sensor network, the at least one subscription being generated in an executable form;

wherein the executable form of the subscription is communicated from the first node to a publisher node included in the plurality of nodes, wherein the publisher node is connected to the sensor; and

wherein a virtual machine executing on the publisher node executes the executable form of the subscription to determine when the event of interest occurs based on sensor data output from the sensor and to publish data related to the event of interest for a subscriber node included in the plurality of nodes when the event of interest occurs and in response to the event occurring.

2. The wireless sensor network of claim 1, wherein each event included in the set of events has an associated event filter for that event that is used by the producer node to identify when that event occurs.

3. The wireless sensor network of claim 1, wherein for at least one event included in the set of events, when that event occurs, the producer node for that event generates the event data related to that event by performing an aggregation operation.

4. The wireless sensor network of claim 3, wherein the aggregation operation comprises calculating at least one of a sum, an average, a minimum, a maximum, and a median.

5. The wireless sensor network of claim 1, wherein the query is expressed in a human-readable language and the executable form of the subscription comprises a binary form.

6. The wireless sensor network of claim 5, wherein the query is expressed in a Backus-Naur Form.

7. The wireless sensor network of claim 6, wherein the query is expressed in a formal and verifiable query language and the first node verifies the query before generating the executable form of the subscription.

8. A wireless sensor node, comprising:

a wireless transceiver to communicate over a wireless communication link;

a sensor interface to receive sensor data from a sensor;

wherein when the wireless sensor node receives, via the wireless communication link, an executable form of a subscription that comprises an event filter associated with an event of interest and that was generated from a query; and

wherein the wireless sensor node executes the executable form of the subscription in order to;

filter the sensor data to determine when the event of interest occurs; and

transmit event data related to the event of interest to a subscribing node over the wireless communication link when the event of interest occurs and in response to the event occuring; and

wherein the wireless sensor node further comprising a programmable processor that executes a virtual machine that executes the executable form the subscription.

9. The wireless sensor node of claim 8, wherein the sensor is included in the wireless sensor node.

10. The wireless sensor node of claim 8, further comprising a power source.

11. The wireless sensor node of claim 10, wherein the power source comprises a battery.

12. The wireless sensor node of claim 8, wherein the wireless transceiver comprises at least one of a radio frequency transceiver and an infrared transceiver.

13. The wireless sensor node of claim 8, wherein when the event of interest occurs, the wireless sensor node generates the event data related to the event by aggregating at least one of sensor data and data received from another node.

14. The wireless sensor node of claim 8, further comprising a hardware timer.

15. A method of processing a query for data from a wireless sensor network comprising a plurality of nodes that communicate over wireless communication links, at least one of which receives sensor data from a sensor, wherein the query specifies a set of events of interest, at least one of which is related to sensor data sensed by the sensor, the method comprising, for each event included in the set of events of interest:

at a first node included in the plurality of nodes, generating from the query at least one subscription for that event, wherein the subscription is generated in a form that is executable by a producer node included in the plurality of nodes; and

causing the subscription for that event to be executed by a virtual machine executing on the producer node for that event in order to cause that producer node to;

identify when that event occurs based on sensor data output from the sensor; and

when that event occurs and in response to the event occurring, communicate event data related to that event from the producer node to a consumer node included in the plurality of nodes over a wireless communication link.

16. The method of claim 15, wherein each event included in the set of events of interest has an associated event filter and wherein, for each event included in the set of events of interest, identifying when that event occurs at the producer node for that event comprises filtering at least one of sensor data received by that producer node and event data received from another producer node included in the plurality of nodes.

17. The method of claim 15, further comprising, for each event included in the set of events, at the first node, selecting the producer node for that event from the plurality of nodes.

18. The method of claim 17, wherein, for each event included in the set of events, selecting the producer node for that event from the plurality of nodes is a function of at least one of power available at least one of the plurality of nodes, computational resources available at least one of the plurality of nodes, bandwidth available for communicating between the consumer node and at least one of the plurality of nodes, and geographic location of at least one of the plurality of nodes.

19. The method of claim 15, wherein execution by the producer node of the subscription is operable to cause the producer node to, when that event occurs, generate, at the producer node for that event, at least a portion of the event data for that event by aggregating at least one of sensor data received by that producer node and event data received from another producer node included in the plurality of nodes.