WIRELESS SENSOR NETWORKS

• US 20120082036A1
• Filed: 02/04/2010
• Published: 04/05/2012
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Abedi, Saied, Chebbo, Hind
• Granted Patent: US 9,681,492 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method of allocating resources in a wireless sensor network, the network having functions including medical monitoring of a patient using multiple network devices having sensors, the method including steps of: sensing, by a network device in the network, a life parameter of the patient; recognising the existence of an emergency condition with respect to the parameter; the network device sending a request for streaming towards a coordinator of the network; the coordinator receiving (S12) the request along with any other requests from other devices in the network; and the coordinator granting (S14, S16) each the request by scheduling one of: a streaming allocation with highest priority for a network device which is in an emergency condition; a streaming allocation of medium priority for a network device sensing a life parameter which is not in an emergency condition; and a streaming allocation of lowest priority for a network device which is not sensing any life parameter of the patient and which is not in an emergency condition. The emergency condition may be defined with respect to one or more medical parameters of the patient. The method may be applied, for example, to monitoring of patients in a hospital using MBANs operating in accordance with IEEE 802.15.6.

Claims

1. A coordinator for use together with other network devices in a wireless sensor network, including:

transceiver means arranged to receive a request for streaming originated by at least one of the network devices; and

scheduling means arranged to grant the request by allocation of network resources to an extent determined by conditions in the network, said conditions including whether the network device which originated the request is in an emergency condition.

2. The coordinator according to claim 1 wherein the scheduling means is responsive to a declaration of the emergency condition received in said request or received independently by other means.

3. The coordinator according to claim 1 for use in a wireless sensor network involved in medical monitoring of a living body wherein said conditions further include whether or not network devices requesting network resources are medical devices.

4. The coordinator according to claim 3 wherein the emergency condition involves a medical emergency in respect of a life parameter being sensed by a sensor of the network device from which the request originated.

5. The coordinator according to claim 3 wherein the scheduling means is arranged to grant the request by scheduling any of the following types:

a streaming allocation with highest priority for a device in an emergency condition;

a streaming allocation of medium priority for a medical device not in an emergency condition; and

a streaming allocation of lowest priority for a non-medical device not in an emergency condition.

6. The coordinator according to claim 5 wherein priority of streaming allocation determines at least one of a delay time for transmission to or from the network device, the size of a data pipe to or from the network device, and precedence over requests from other network devices.

7. The coordinator according to claim 5, arranged for wireless communication with said network devices in units of frames, wherein upon receipt of a frame containing a said request by the transceiver means, the scheduling means is responsive to a streaming request included in a frame header.

8. The coordinator according to claim 7 wherein the scheduling means is arranged to set a stream index indicating the type of streaming allocation being requested and the transceiver means is arranged to transmit a frame containing the stream index in its frame header.

9. The coordinator according to claim 1 wherein the scheduling means is further arranged for taking away network resources allocated to an existing stream in the network if necessary to grant the request originated from a network device in an emergency condition.

10. The coordinator according to claim 1 wherein the scheduling means is further arranged, in response to a said network device lifting its emergency condition, to re-allocate, to other network devices, resources which had been allocated to a stream requested by that network device.

14. A wireless sensor network including at least one coordinator according to claim 1 and a plurality of network devices each according to claim 11.

11. A network device for use in a wireless sensor network, comprising:

a sensor for sensing a parameter of an entity monitored by the network;

emergency recognising means for recognising an emergency condition with respect to said parameter; and

requesting means responsive to the recognising means recognising an emergency condition to transmit a request for streaming towards a coordinator in the network.

12. The network device according to claim 11 wherein the emergency recognising means itself detects the existence of said emergency condition from data sensed by said sensor, and said request for modification of streaming includes an indication of said emergency condition.

13. The network device according to claim 12 wherein the requesting means is arranged to transmit said request by transmission of a frame with a frame header containing a stream index set to a pre-arranged value denoting an unassigned stream, and/or by transmission of a MAC command frame in which a command frame identifier signifies a channel time request.

15. A method of allocating resources in a wireless sensor network, the network having functions including medical monitoring of a patient using multiple network devices having sensors, the method including steps of:

sensing, by a network device in the network, a life parameter of the patient;

recognising the existence of an emergency condition with respect to said parameter;

said network device sending a request for streaming towards a coordinator of the network;

said coordinator receiving said request along with any other requests from other devices in the network; and

said coordinator granting each said request by scheduling one of;

a streaming allocation with highest priority for a network device which is in an emergency condition;

a streaming allocation of medium priority for a network device sensing a life parameter which is not in an emergency condition; and

a streaming allocation of lowest priority for a network device which is not sensing any life parameter of the patient and which is not in an emergency condition.