Protocol for reliable, self-organizing, low-power wireless network for security and building automation systems

• US 7,483,403 B2
• Filed: 11/21/2002
• Issued: 01/27/2009
• Est. Priority Date: 01/10/2002
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Herrmann, Falk, Hill, Jason, Manjeshwar, Arati
• Primary Examiner(s): Nguyen; Duc
• Assistant Examiner(s): THIER, MICHAEL
• Application Number:
  US10/301,478
• Publication Number:
  US 20030152041A1
• Time in Patent Office: 2,259 Days
• Field of Search: 370/216, 370/217, 370/221, 370/254, 370/255, 370/256, 370/310, 370/328, 370/338, 370/350
• US Class Current: 370/310
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2827 Reporting to a device within the home network; wherein the reception of the information reported automatically triggers the execution of a home appliance functionality
• CPC Class Codes: H04Q 2209/883 where the sensing device enters an active or inactive mode
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method to wirelessly network a sensor/actuator node is described. The sensor/actuator node is installed in a sensor/actuator node network and arranged in a hierarchical manner with a plurality of node levels and a cluster head network. A unique node identifier is assigned to the sensor node and the sensor node network is initialized. The sensor node is woken-up to perform a task and then set to an active low power mode.

Claims

1. A method to wirelessly network a sensor node, comprising:

installing the sensor node in a sensor node network arranged in a hierarchical manner with a plurality of node levels and a cluster head network;

assigning a unique identifier to the sensor node;

initializing the sensor node network; and

the sensor node;

periodically entering an awake state;

activating a receiver component, the receiver component performing a receiver-signal strength measurement in a reserved channel;

determining if the strength measurement is greater than a threshold;

responsive to the determination of the strength measurement;

when the strength measurement is not greater than the threshold, entering an active low power mode; and

when the strength measurement is greater than the threshold, determining whether a wakeup sequence is included at a start of a message that has been received; and

responsive to the determination of the wakeup sequence;

when the wakeup sequence is included, maintaining the awake state to perform a task for performance of which the wakeup sequence was transmitted, the task including determining intended recipients of the message, and subsequently entering the active low power mode, prior to a propagation of the message to all node levels in the sensor node network, once the task is complete; and

when the wakeup sequence is not included, entering the active low power mode.

2. The method of claim 1, further comprising:

distributing an encryption key to the sensor node.

3. The method of claim 1, further comprising:

supervising the sensor node network with acknowledged supervision packets to update a clock of the sensor node.

4. The method of claim 1, wherein a clock of the sensor node is synchronized with respect to its node level.

5. The method of claim 1, further comprising:

assigning the sensor node to a single one of the plurality of node levels, wherein each of the nodes of the sensor node network is assigned to a single respective one of the plurality of node levels.

6. The method of claim 5, wherein the assignment of the nodes to the respective node levels is in accordance with respective power constraints of the nodes.

7. The method of claim 1, wherein each of the nodes of the sensor node network is assigned to a respective one of the plurality of node levels and each of the plurality of node levels is assigned a respective one of a plurality of communication time slots.

8. A method for operating a sensor node network arranged in a hierarchical manner with a plurality of node levels and a cluster head network, comprising:

a sensor node;

periodically entering an awake state;

activating a receiver component, the receiver component performing a receiver-signal strength measurement in a reserved channel;

determining if the strength measurement is greater than a threshold;

responsive to the determination of the strength measurement;

when the strength measurement is not greater than the threshold, entering an active low power mode; and

when the strength measurement is greater than the threshold, determining whether a wakeup sequence is included at a start of a message that has been received; and

responsive to the determination of the wakeup sequence;

when the wakeup sequence is included, maintaining the awake state to perform a task for performance of which the wake-up sequence was transmitted, the task including determining intended recipients of the message and transmitting the message to node levels in the sensor node network that are lower than that of the sensor node, and subsequently entering the active low power mode prior to a propagation of the message to all the node levels once the task is complete; and

when the wakeup sequence is not included entering the active low power mode.

9. The method of claim 8, wherein the sensor node is woken-up about one to four times per second.

10. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a plurality of high-priority control packets.

11. The method of claim 10, wherein the high-priority control packets are transmitted in multicast to nodes in several of the node levels.

12. The method of claim 10, wherein the high-priority control packets are transmitted in unicast to a single node.

13. The method of claim 10, further comprising:

piggy-backing only a low-priority message onto a supervision acknowledgement packet.

14. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a plurality of alarm packets.

15. The method of claim 14, wherein the alarm packets are transmitted via a directed flooding approach.

16. The method of claim 15, wherein:

the wakeup sequence is broadcast prior to transmitting the alarm packets; and

the wakeup sequence and alarm packets are forwarded to the cluster head network via an intermediate sensor node.

17. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting an alarm packet in unicast via a separately-defined topology.

18. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a plurality of supervision packets via one of a level-based time slot approach, a parent-children level-based time slot approach, and a parent-child level-based time slot approach.

19. The method of claim 18, wherein the supervision packets are sent about once per hour.

20. The method of claim 18, wherein the supervision packets are sent in a periodic manner.

21. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a plurality of link assessment packets.

22. The method of claim 21, wherein the link assessment packets are transmitted in an RF channel separate from at least one of alarm packets and control packets.

23. The method of claim 21, wherein the link assessment packets are transmitted once per day.

24. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a new node packet.

25. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a new node packet.

26. The method of claim 8, wherein the step of transmitting the message further includes:

transmitting a registration packet.