Improvements to body area networks

• US 8,704,656 B2
• Filed: 02/01/2010
• Issued: 04/22/2014
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Abedi, Saied
• Primary Examiner(s): La, Anh V
• Application Number:
  US13/254,090
• Publication Number:
  US 20120092155A1
• Time in Patent Office: 1,541 Days
• Field of Search: 340/539.12, 340/539.11, 340/539.1, 340/573.1, 340/3.1, 340/5.61, 340/286.07, 340/286.01, 340/286.02, 370/310, 370/339, 370/347, 455/67.11
• 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 the 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); and establishing a high-priority link with the devices (11E) in the emergency state, the high-priority link having higher priority for network resources than the low-priority link. 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, each network device including a sensor, 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, the network device comprises:

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

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

wherein the network device 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 the network device.

2. The network device according to claim 1, wherein the recognising means are further operable to recognise whether each the other network device is also in the emergency state.

3. The network device according to claim 2 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 the peer-to-peer communications in dependence upon at least whether each the other network device is in the emergency state.

4. The network device according to claim 3 wherein the responding means are arranged to maintain, modify or drop the 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 the network device.

5. The network device according to claim 3 wherein the responding means are arranged to modify peer-to-peer communications over a low-priority link with another the network device which is not in the emergency state by reducing a rate thereof.

6. The network device according to claim 3 wherein the responding means are arranged to drop peer-to-peer communications over a low-priority link with another the network device which is not in the emergency state.

7. The network device according to claim 3 wherein the responding means are arranged to maintain peer-to-peer communications over a high-priority link with another the network device in the emergency state.

8. The network device according to claim 1 further comprising counting means for maintaining a count of a number of the other network devices for which the network device itself is acting as a relay, and wherein the 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.

9. A wireless sensor network comprising:

a plurality of network devices, each network device including a sensor, 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 the coordinator is arranged for communication over a low-priority link with at least a subset of the 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 the one or more of the devices, the high-priority link having higher priority for network resources than the low-priority link, and

wherein at least one of the network devices is 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 the network device.

10. The wireless sensor network according to claim 9 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.

11. The wireless sensor network according to claim 10 applied to monitoring medical parameters of a living body.

12. The wireless sensor network according to claim 9 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 the high-priority link.

13. The wireless sensor network according to claim 12 wherein the network resources are further structured to define a contention access period per unit period for use by at least the low-priority link.