BODY AREA NETWORKS

• US 20120092155A1
• Filed: 02/01/2010
• Published: 04/19/2012
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Abedi, Saied
• Granted Patent: US 8,704,656 B2
• Time in Patent Office: Days
• US Class Current: 340/539.12
• CPC Class Codes: H04W 74/0875 with assigned priorities based access
• CPC Class Codes: H04W 76/50 for emergency connections
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method of operating a wireless sensor network having a plurality of network devices including sensors (11E, 13) for monitoring a plurality of parameters, and a coordinator (10) for communicating with the network devices either directly in a star protocol or indirectly in a peer-to-peer protocol, the method comprising:

arranging the coordinator (10) for communication over a low-priority link with at least a subset of said network devices;

gathering sensor data by sensors of the network devices and transferring the data to the coordinator;

detecting existence of an emergency state with respect to at least one of the network devices (11E);

establishing a high-priority link with said at least one of the devices (11E) in the emergency state, said high-priority link having higher priority for network resources than said low-priority link; and

• • where said one device is acting as a relay for low-priority links with other devices (13), maintaining, modifying or dropping those low-priority links in dependence upon whether or not the other devices are in emergency, a level of congestion or QoS of the high-priority link, and/or the electrical power available to said one (11E) of the devices. 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 network device for use in a wireless sensor network having a plurality of network devices including sensors for monitoring one or more parameters, and a coordinator capable of conducting communications with the network devices over a low-priority link or a high-priority link, wherein the network device comprises:

recognising means for recognising whether the network device is in an emergency state;

responding means responsive to recognition of the emergency state to establish a high-priority link with the coordinator.

2. The network device according to claim 1 arranged to act as a relay for peer-to-peer communications over a high-priority link or a low-priority link of at least one other said network device.

3. The network device according to claim 2 wherein the recognising means are further operable to recognise whether each said other network device is also in the emergency state.

4. The network device according to claim 3 wherein the responding means are further responsive to recognition of the emergency state with respect to the network device itself to maintain, modify or drop said peer-to-peer communications in dependence upon at least whether each said other network device is in the emergency state.

5. The network device according to claim 4 wherein the responding means are arranged to maintain, modify or drop said peer-to-peer communications in further dependence upon at least one of a QoS or congestion level of the high-priority link and availability of power to said network device.

6. The network device according to claim 4 wherein the responding means are arranged to modify peer-to-peer communications over a low-priority link with another said network device which is not in the emergency state by reducing a rate thereof.

7. The network device according to claim 4 wherein the responding means are arranged to drop peer-to-peer communications over a low-priority link with another said network device which is not in the emergency state.

8. The network device according to claim 4 wherein the responding means are arranged to maintain peer-to-peer communications over a high-priority link with another said network device in the emergency state.

9. The network device according to claim 2 further comprising counting means for maintaining a count of a number of said other network devices for which the network device itself is acting as a relay, and wherein said responding means is further responsive to recognition of the emergency state to refuse a request to act as relay for a further network device in dependence upon the current value of the count.

12. The network device, coordinator or network according to claim 2 wherein the emergency state with respect to a network device is recognised when a parameter being sensed by a sensor of the network device reaches a critical value.

13. The network device, coordinator or network according to claim 12 applied to monitoring medical parameters of a living body.

14. The network device, coordinator or network according to claim 2 wherein the network resources are structured in a time-division manner to define one or more time slots per unit period, and wherein one or more of the time slots are reserved for use in said high-priority link

15. The network device, coordinator or network according to claim 14 wherein the network resources are further structured to define a contention access period per unit period for use by at least said low-priority link.

10. A coordinator in a wireless sensor network having a plurality of network devices, wherein said coordinator is arranged for communication with each of said network devices over a high-priority link or a low-priority link, the high-priority link having higher priority for resources in the network than the low-priority link, and said coordinator comprising means responsive to declaration of an emergency state with respect to any of the network devices to establish a high-priority link with that network device.

11. A wireless sensor network having a plurality of network devices including sensors for monitoring a plurality of parameters, and a coordinator for communicating with the network devices either directly in a star protocol or indirectly in a peer-to-peer protocol, wherein said coordinator is arranged for communication over a low-priority link with at least a subset of said network devices and is responsive to a determination of the existence of an emergency state of one or more of the network devices to establish a high-priority link with said one or more of the devices, said high-priority link having higher priority for network resources than said low-priority link