WO2012063187A1 - A method of pairing communicating devices using a linking device - Google Patents

Abstract

There is described a method of associating at least two communicating devices, using a linking device, in order to establish a communication link between them.

Description

A METHOD OF PAIRING COMMUNICATING DEVICES USING A LINKING

DEVICE

TECHNICAL FIELD

The present invention generally relates to the management of a set of communicating devices having the capacity of communicating one with the other. More particularly, the invention relates to the establishment of communication links between them. The invention may have applications in the medical field for creating communication links between sensors and receivers at the disposal of a healthcare professional.

BACKGROUND OF THE INVENTION

The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. Furthermore, all embodiments of the invention need not solve all (or even any) of the problems brought forward in this section.

The ZigBee Healthcare Profile describes an 802.15.4 and ZigBee mesh network based mechanism for carrying medical data according to the IEEE 1 1073 standard, as adopted by the Continua Alliance.

The profile describes various aspects of network and device operation, including configuration of application pairings (or bindings) between nodes.

Pairing (or binding) is a ZigBee mechanism for configuring an embedded device to send relevant messages to a second device.

Mechanisms for pairing may be button pairing, commissioning tools, management devices with or without a user interface, etc.

In professional healthcare applications, for example in a hospital, one may try to establish a pairing between a sensor attached to a patient, e.g. a heart rate or blood pressure monitor, and a receiver capable of displaying and/or recording the sensor's data. According to the "Button Pairing" approach, the user would push a 'binding' button on one device (or node), then on the other. Then, both nodes would send a message to a coordinator device that would match up clusters (effectively services) they both support and would configure the appropriate binding on the output device for each cluster matched.

However, within the hospital many such interactions may be occurring at the same time, meaning that the central coordinator device may mismatch the pairing between the sensors and receivers. Alternatively, the coordinator may be offline for some reason, e.g. maintenance, thereby preventing any pairing from taking place. Both result in a 'failed' pairing and perhaps also in a frustrated healthcare professional through lack of information and the inability to pair the sensor and receiver.

Alternatively, a "Commissioning Tool" which preconfigures bindings may be used.

However, a commissioning tool is unlikely to be used in this scenario because the pairings are not typically long term and are reasonably likely to change frequently, i.e. if a new patient arrives they will likely be fitted with a clean, sterile sensor rather than the one the previous patient had. Also, if a patient is moved to another ward or goes for surgery, the receiver equipment is likely to change. A commissioning tool approach may suitable for long term fixed bindings but troublesome for frequently changing pairings.

Alternatively, one may use a "Management Device" with a user interface (Ul) which presents a list of nearby devices and asks one of them to bind to it.

If the receiver device has a Ul ('Management Device with Ul'), then it may present a list of (possibly nearby) devices to the healthcare professional and ask him which sensor should bind to it. However, it may be difficult for the healthcare professional to know which of several sensors the correct one is. Alternatively, but also suffering from the same problem, a separate Management device with a Ul could be used to present a list of sensors and receivers to pair to the healthcare professional.

If the "Management Device" does not have a Ul, it may select a communicating device with the highest RSSI (Received Signal Strength Indicator) to bind to it. However, the highest RSSI devices may not be the ones the healthcare professional is trying to pair together.

Hence, there is a need for facilitating the pairing of communicating object in an environment wherein the pairing between communicating objects frequently changes.

SUMMARY OF THE INVENTION

Therefore, a first aspect of the invention relates to a method of associating at least two communicating devices, using a linking device, in order to establish a communication link between them as defined in claim 1 .

Embodiments of the invention may be implemented in the hospital domain for pairing sensors and receivers (multi-user environments such as hospitals, healthcare sensor and monitoring devices, hospital monitor devices for patient monitoring, etc.).

However, the invention may be applicable to other domains and other source and destination devices.

For example, embodiments are implemented in ZigBee based systems involving pairing between devices, for example where a large number of concurrent pairings can occur.

Embodiments of the invention are recited in the dependent claims attached hereto.

According to embodiments, the linking device or a mobile element which is associated to the linking device is pointed at the communicating devices. This provides a quick, simple, and low risk of error approach to "pairing" two devices.

A second aspect of the invention relates to a method of disassociating at least two communicating devices in order to break a communication link between them, using a separating device.

A third aspect of the present invention relates to computer program products comprising one or more stored sequences of instructions that are accessible to a processor and which, when executed by the processor, cause the processor to carry out the steps of the method of the first and/or the second aspect of the present invention.

A fourth aspect of the present invention relates to a linking/separating device for implementing a method according to the first and/or the second aspect of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements and in which:

- Figure 1 is a schematic illustration of context of use of a linking device according to embodiments;

- Figures 2-5 are schematic illustrations of steps of methods according to embodiments; and

- Figure 6 is a schematic illustration of a linking/separating device according to embodiments.

DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 illustrates a first communicating device 10 and a second communicating device 1 1 between which a user would like to crate a wireless communication link 12. For example, the device 10 is a receiver that collects data (for example for displaying it on a display unit (not represented)) and the device 1 1 is a sensor that can provide the device 10 with data.

The user uses a linking device 13 that can identify the devices 10 and 1 1 and create the communication link (i.e. create a pairing) between the identified devices.

In order to identify the devices 10 and 1 1 , the user can use a mobile acquisition element 14 (or "wand") of the linking device. The wand may be associated to the linking device through a connection means 15 that may be a cable or a wireless connection (Wifi for example). The mobile acquisition elements may be carried around with users, for example security ID badges. According to embodiments, the wand 14 and the linking device 13 form a single linking portable device.

In order to have the communicating devices identified by the linking device, the user holds the wand object close to one of them. Then, he/she presses a "select" button (not represented) on the wand object causing the linking device to acquire identification data of the device through the wand during a step S200 as illustrated in Figure 2.

For example, the wand performs some measurements useful for identifying the sensor, such as reading 802.15.4 RSSI values, or performing RFID communications, or reading a bar code imprinted on the second device. In terms of RSSI measurements, the highest value is likely to be the sensor the wand is held closest to.

An alternative ZigBee based approach would be for the communicating devices to fingerprint their environment (potentially on some periodic cycle), identifying what ZigBee nodes are visible to them and with what RSSI value. When the wand is held close to a device and its "select" button is pressed, the wand performs the same scan which is then compared to a database of stored fingerprints, perhaps on a central server. A wand held close to a device should produce a fingerprint which is similar to that which was previously generated by the communicating devices; therefore comparison with the stored fingerprints can be used to identify the sensor to pair.

Then, the wand transmits the identification data to the linking device during a step S201.

Once the identification data of the first communicating device is acquired, the identification data of the second communicating object is acquired during steps S202 and S203 respectively corresponding to steps S200 and S201 described above in view of the acquisition of the identification data of the first communicating object.

Each of the communicating devices may indicate its selection in terms of audio or visual feedback, for example by making a sound or lighting a LED (not represented).

Multiple devices could be selected by waving the wand over a selection of devices with the "select" button held down. Alternatively, the "select" button may be provided on the linking device.

According to embodiments, the devices to be linked are ZigBee sensors and receivers that are thus likely to be a battery powered ZigBee end devices. They will therefore have another ZigBee node as parent. As these end devices can only have one parent, communications between the wand and a device will occur via the parent. The device will sleep, typically waking every 7.5 seconds to ask its parent for any messages that the wand may have sent it.

Gathering RSSI readings from a sleeping device can require some special care. One approach would be for the wand to ask the device (via the parent) to perform an 'active scan'. This broadcasts a 'beacon request' and gathers results of nearby devices and their RSSI values. Being nearby, the wand's identification data and RSSI value will be part of this response.

A device waking every 7.5 seconds would not produce a very responsive pairing system. Ideally it would be better if this period could be reduced, or the device woken up entirely, when a pairing is likely to happen. A number of options are perceived:

- a "wake-up" button (not represented) could be pressed on the device to wake it (this could be used in conjunction with holding the wand close by, rather than pressing a button on the wand itself - an approach similar to the existing "button pairing" approach, but with improved reliability,

- a passive RFID element on the device could wake it up when the wand is brought nearby, or

- the device could be supervised by the system which would then know the device's wake up schedule. If a user is determined to be nearby (e.g. by RFID on choke points, WiFi fingerprinting, etc.) then the system could increase the device's wake up rate.

Once the identification data of the first and the second communicating objects are acquired, it may be:

- stored on the wand itself, or

- stored in the linking device acting as some central service, indexed by the wand's identification data.

The acquired device's identification data may be matched to devices recently identified by the linking device. Alternatively, an identification data of the wand object is communicated to the linking with the identification data of the two devices to be linked. The identification data of the wand object is used as a common key to map the devices the one with the other. The central service can now set up a pairing. According to this alternative, the linking device may be associated to a plurality of wand objects.

Then, the wand or the linking device itself sends a BIND request to the previously identified devices during a step S204, indicating that it (they) should bind to each other. For example, the request is sent by the linking device to the first.

In a case where a healthcare professional has "selected" a sensor to pair but has not selected a receiver, a timeout on the sensor selection may prevent erroneous pairings if the healthcare professional later selects another device.

In order to disassociate the communicating devices, for example in order to unpair a sensor and a receiver, a reverse procedure to the above method could be performed.

For example, "deselect" buttons could be present on the sensor/receiver, in addition to "select" ones.

An embodiment of a disassociation method is presented with reference to Figure 3.

Steps S301 , S302, S303 and S304 respectively correspond to steps S200, S201 , S202, S203 and S204 described above with reference to Figure 2. The identification data of the first and the second communicating devices 10 and 1 1 are acquired using the wand and transmitted to the linking device 13.

Then, during a step S304, the linking device issues a disconnection request to at least one of the communicating devices (for example the first communicating device 10) that indicates to the communicating devices that the communication link established with the other communicating object has to be broken.

On receipt, the communicating objects break the communication link during a step S305. The approaches described hereabove are schematically illustrated by Figures 4 and 5.

In the first approach, the wand and the linking device form a single element (the "wand" in this approach). As illustrated, during a step S400, a wand 40 is held close to a sensor device 41 . Then, the sensor identification data ("A") is acquired by the wand stored in a memory 42 of the wand during step S401. The wand is then held close to a receiver device 43 during a step S402. The receiver identification data ("B") is then stored in the memory on the wand during a step S403. Then, the wand sets up a pairing between sensor and receiver during a step S404.

In the second approach, the wand is a mobile element of the linking device. As illustrated in Figure 5, the wand 50 is held close to a sensor device 51 during a step S500. Then, the wand or the sensor device push a wand identification data ("W") and an acquired sensor identification data ("A") to a central linking device 52. The data are then stored in a memory 53 of the linking device during a step S501. The wand is then held close to a receiver device 54 during a step S502. The wand or the receiver device then pushes a wand identification data ("W") and an acquired receiver identification data ("B") to the linking device. The data are then stored in a memory 53 of the linking device during a step S503. Finally, the linking device sets up a pairing between the sensor and the receiver during a step S504.

According to embodiments, location information associated to the communicating devices, the linking device or the wand is used to aid pairing of the communicating devices. Several approaches may be envisaged, for example:

1 ) to use location information about the devices requesting the bindings

2) to use location information about the person/object performing the binding.

For example, considering the use of a "pairing" button on the communicating devices, many pairing attempts could occur at a same time. In the first approach listed above the location information about the devices (sensors and receivers) for which a binding is requested (by pushing the buttons) may be used to perform the binding irrespective of the ordering the actual binding requests occurred in. For example, if within a few seconds 2 bind requests are received from one location (for example a ward in a hospital), and 2 from another location, it is likely the bindings should be between the communicating objects in the first location and the communicating objects in the second location, irrespective of which order they actually arrived in.

Alternatively, in the second approach, when a user presses a communicating device's button to pair it, the information of which user is nearby to the communicating device could also be recorded. When a communicating device's button is pressed, again nearby users can be identified and this information used to lookup recent communicating devices in the vicinity of the same user whose pair button was pressed. The user's location could be determined through, but not limited to, WiFi fingerprinting, RFID choke points, visual location technologies (i.e. through security cameras). In the present second approach, if a binding needed to be made between a communicating devices across different locations (for example, if a Doctor wished to monitor some sensor from an office).

Referring to Figure 6, a linking (or separating) device 60 according to embodiments is described. The device comprises a processing unit 61 configured for implementing methods according to embodiments of the invention. The device also comprises a memory unit 62. The memory unit may comprise several types of memory. For example, the memory unit may comprise a memory for storing processing data. The memory unit may also comprise a memory for storing a computer program according to embodiments of the invention. The device also comprises an acquisition unit 67 for acquiring identification data of the communicating devices between which a communication link is to be created. The device also comprises a communication unit 63 for performing communications with the communicating objects in order to establish or break the communication link.

The linking device may be a portable device and constitute a wand as discussed above itself. Alternatively, it may have a mobile element 64 associated constituting the wand. The wand has an acquisition unit 65 for acquiring the identification data from communicating devices and a communication unit 66 for communicating with the linking device 60 and transmitting the acquired data. In this alternative, the communication unit may be further configured for receiving the acquired data from the wand. Embodiments of the present invention can be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which - when loaded in an information processing system - is able to carry out these methods. Computer program means or computer program in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after a conversion to another language. Such a computer program can be designed based on the flowcharts of Figure 2-5 and the present description. The computer program can be stored on a computer or machine readable medium allowing data, instructions, messages or message packets, and other machine readable information to be read from the medium. The computer or machine readable medium may include non-volatile memory, such as ROM, Flash memory, Disk drive memory, CD-ROM, and other permanent storage. Additionally, a computer or machine readable medium may include, for example, volatile storage such as RAM, buffers, cache memory, and network circuits. Furthermore, the computer or machine readable medium may comprise computer or machine readable information in a transitory state medium such as a network link and/or a network interface, including a wired network or a wireless network, that allow a device to read such computer or machine readable information.

Expressions such as "comprise", "include", "incorporate", "contain", "is" and "have" are to be construed in a non-exclusive manner when interpreting the description and its associated claims, namely construed to allow for other items or components which are not explicitly defined also to be present. Reference to the singular is also to be construed in be a reference to the plural and vice versa.

While there has been illustrated and described what are presently considered to be the preferred embodiments of the present invention, it will be understood by those skilled in the art that various other modifications may be made, and equivalents may be substituted, without departing from the true scope of the present invention. Additionally, many modifications may be made to adapt a particular situation to the teachings of the present invention without departing from the central inventive concept described herein. Furthermore, an embodiment of the present invention may not include all of the features described above. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed, but that the invention include all embodiments falling within the scope of the appended claims.

A person skilled in the art will readily appreciate that various parameters disclosed in the description may be modified and that various embodiments disclosed may be combined without departing from the scope of the invention.

Claims

1. A method of associating at least two communicating devices (10, 1 1 , 40, 50, 52) in order to establish a communication link (12) between them, using a linking device (13, 14), the method comprising the following steps performed by the linking device:

- acquiring (S200, S201 , S401 ) a first identification data identifying a first communicating device, from said first communicating device through a wireless acquisition means,

- acquiring (S202, S203, S403) a second information data identifying a second communicating device, from said second communicating device through a wireless acquisition means, and

- setting a communication link (S205, S404, S504) between the first and second devices based on the first and second identification data.

2. The method of claim 1 , wherein the first and second identification data are obtained by a mobile acquisition element (14, 50) of the linking device, the acquisition means being comprised in the mobile acquisition element, and wherein the method further comprises the following steps of:

- receiving (S201 ) the first identification data from the mobile acquisition element, and

- receiving (S203) the second identification data from the mobile acquisition element.

3. The method of any one of the preceding claims, wherein the first data is acquired when the linking device or the mobile acquisition element is located in a first vicinity of the first communicating device, and the second data is acquired when the linking device or the mobile acquisition element is located in a second vicinity of the second communicating device.

4. The method of any one of the preceding claims, wherein the first data is acquired when the mobile acquisition element is pointed at the first communicating device and the second data is acquired when the mobile acquisition element is pointed at the second communicating device.

5. The method of any one of the preceding claims, wherein the first and second data are acquired when a communicating device selection function is activated on the linking device through a user interface of the linking device.

6. The method of any one of the preceding claims, wherein acquiring the first or the second or both first and second data comprises at least one of the following steps of:

- measuring an RSSI value broadcasted by the first or the second communicating object,

- reading an RFID value of the first or the second communicating object,

- reading a bar code on the first or the second communicating object, and

- comparing a wireless fingerprint of the first or the second communicating object to a set of wireless fingerprints comprising at least one stored wireless fingerprint.

7 The method of any one of the preceding claims, wherein the communication link between the first and the second communicating object is established when at least one of the following conditions is fulfilled:

- a time interval between the acquisition of the first data and the acquisition of the second data is less than a threshold, and

- the first communicating object and the second communicating object are located in a same area.

8. The method of any one of the preceding claims, wherein the communication link is established by sending a request to the first communicating device for connection to the second communicating device.

9. The method of any one of the preceding claims, further comprising setting the first communication device or the second communication from a sleep mode to an wake mode before acquiring the first identification data or the second identification data.

10. A method of disassociating at least two communicating devices (10, 1 1 , 43, 41 ) in order to break a communication link (12) between them, using a separating device (13, 14, 40, 50, 52), the method comprising the following steps performed by the separating device:

- acquiring (S300, S301 ) a first identification data identifying a first communicating device, from said first communicating device through a wireless acquisition means,

- acquiring (S302, S303) a second information data identifying a second communicating device, from said second communicating device through a wireless acquisition means, and

- breaking a communication link (S305) between the first and second devices based on the first and second identification data.

1 1 . A computer program product comprising a computer readable medium, having thereon a computer program comprising program instructions, the computer program being loadable into a data-processing unit and adapted to cause the data-processing unit to execute the steps of a method according to any one of claims 1 to 10 when the computer program is run by the data-processing unit.

12. A wireless linking device (60) for associating at least two communicating devices in order to establish a communication link between them, comprising:

- an acquisition unit (67, 64) for acquiring a first identification data identifying a first communicating device, from said first communicating device and acquiring a second information data identifying a second communicating device, from said second communicating device, and - a processing unit (61 ) for setting a communication link between the first and second devices based on the first and second identification data according to a method according to any one of claims 1 to 9.

13. The wireless linking device of claim 12, further comprising a mobile acquisition element (64) comprising the acquisition unit (64), and

- a communication unit (63, 66) for receiving the first and second identification data from the mobile acquisition element.

14. A wireless separating device (60) for disassociating at least two communicating devices in order to break a communication link between them, comprising:

- an acquisition unit (67, 64) for communication unit for acquiring a first identification data identifying a first communicating device, from said first communicating device and acquiring a second information data identifying a second communicating device, from said second communicating device, and

- a processing unit (61 ) for breaking a communication link between the first and second devices based on the first and second identification data according to a method according to claim 10.

15. The wireless separating device of claim 14, further comprising a mobile acquisition element (64) comprising the acquisition unit, and

- a communication unit (63, 66) for receiving the first and second identification data from the mobile acquisition element.