Communication between controller and node

Abstract

A method for communicating between a controller (1) having a controller ID and an intended node (2) of a wireless network, comprising determining a distance, D, between the controller (1) and the intended node (2), using non-UWB distance detection, broadcasting a message (22) including the distance, D, and the controller ID, completing a UWB ranging process (23a, 23b) with all nodes (2, 3) that received the message (22). Each node will compare the UWB ranging distance with the detected distance D, and respond to the message if it is established that a difference between the UWB ranging distance and the distance, D, is smaller than a given threshold. With the present invention, UWB distance ranging is combined with non- UWB distance detection used for identifying an intended network node among several potential network nodes.

Description

[0001] COMMUNICATION BETWEEN CONTROLLER AND NODE

[0002] FIELD OF THE INVENTION

[0003] The present invention generally relates to communication between a controller and a node. In particular, the invention relates to identifying an intended node among several nodes.

[0004] BACKGROUND OF THE INVENTION

[0005] It is becoming increasingly common that remote control of devices or appliances, such as a controllable illumination system, is based on a wireless network, such as a Zigbee network. Each controllable device is a node in the network, with a unique identification (ID). In order to function properly, the remote-control unit (controller) must know the ID of the node associated with the intended device, in order to establish a designated communication channel over the wireless network.

[0006] At the same time, it would be desirable to simply point the controller at any controllable device. Especially in an environment with several such controllable devices (e.g. multiple controllable lighting devices in an illumination system in an apartment), it becomes challenging to identify the intended device and establish a designated communication channel.

[0007] CN116935611 A discloses that a remote control equipment transmits an ultrasonic signal in a movement process; the at least one electronic device receives the ultrasonic signal and determines at least one first motion parameter of the remote control device according to the ultrasonic signal. And the remote control device or the at least one electronic device determines a target control device from the at least one electronic device according to the at least one first motion parameter. According to the technical scheme, the cost of the remote control equipment can be reduced, and popularization and use of the remote control equipment are facilitated.

[0008] CN112689242A discloses that an object searching device receives a first position relation sent by a transfer device, and the first position relation is the position relation of a target device to be searched relative to the transfer device; the object searching equipment determines a second position relationship between the transfer equipment and the object searching equipment; and the object searching equipment determines the position relationship of the target equipment relative to the object searching equipment according to the first position relationship and the second position relationship. All the position relationships are determined by UWB technology.

[0009] SUMMARY OF THE INVENTION

[0010] It is an object of the present invention to provide a wireless network-based control method that allows a user to simply point a controller at any a controllable device associated with a node in the wireless network (the intended node).

[0011] According to a first aspect of the present invention, this and other objects are achieved by a method for communicating between a controller having a controller UWB ID and an intended node of a wireless network, comprising determining a distance, D, between the controller and the intended node, using non-UWB distance detection, broadcasting a message including the distance, D, and the controller UWB ID, completing a UWB ranging process with all nodes that received the message, and receiving a response message from the intended node including a node ID.

[0012] According to a second aspect of the present invention, this and other objects are achieved by a method for communicating between a node having a node ID and a controller having a controller ID, comprising receiving a message including a distance, D, and the controller ID, completing a UWB ranging process with the controller identified by the controller ID, to determine a UWB ranging distance, establishing that a difference between the UWB ranging distance and the distance, D, is smaller than a given threshold, and responding to the message.

[0013] According to this approach, a first ranging method is used to establish a distance between the controller and the intended node, which is communicated to a set of nodes. Each node will then initiate an UWB ranging process, to establish a UWB ranging distance, and compare this UWB ranging distance with the detected distance D. A node will respond to the message only if it is established that a difference between the UWB ranging distance and the distance, D, is smaller than a given threshold.

[0014] With the present invention, UWB distance ranging is combined with non- UWB distance detection used for identifying an intended network node among several potential network nodes. This approach efficiently facilitates establishing a designate link between the controller and the intended node, only requiring a user to point the controller towards the intended node. The response by the node may involve returning the node ID to the controller, which can then proceed with dedicated communication using the node ID. Alternatively, in a more straight-forward implementation, the response involves performing an action indicated by the message.

[0015] In embodiments, the message is broadcasted using directional broadcasting, thereby limiting the potential number of receiving nodes. This significantly simplifies the process, as the number of UWB ranging processes is reduced. It also makes the method more robust, as nodes located at a same distance from the controller, but in completely different directions, will not be confused.

[0016] The non-UWB distance detection may be a reflection based ranging, such as IR reflection or ultrasound reflection.

[0017] The wireless network is preferably based on based on IEEE 802.15.4, in which case the network can be one of a Zigbee network, a wireless HART network and a MiWi network.

[0018] According to a third aspect of the present invention, this and other objects are achieved by a controller comprising a non-UWB distance detector, a broadcasting unit, a UWB ranging unit, and controller processing circuitry configured to perform the method according to the first aspect.

[0019] According to a fourth aspect of the present invention, this and other objects are achieved by a wireless network node comprising a receiver, a UWB ranging unit; and node processing circuitry configured to perform the method according to the second aspect.

[0020] According to a fifth aspect of the present invention, this and other objects are achieved by a system including a controller according to the third aspect and at least one node according to the fourth aspect.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiments of the present invention.

[0023] Fig. 1 schematically shows UWB ranging.

[0024] Fig. 2 shows messages between a controller and two nodes of a wireless network according to an embodiment of the present invention.

[0025] Figs. 3a-b are block diagrams of a controller and a node according to embodiments of the present invention. Fig. 4 is a flow chart of a method according to an embodiment of the present invention, performed by the controller in Fig. 3a.

[0026] Fig. 5 is a flow chart of a method according to an embodiment of the present invention, performed by the node in Fig. 3b.

[0027] DETAILED DESCRIPTION

[0028] Ultra-Wideband (UWB) ranging is a short-range impulse radio technology that can calculate the relative position of other UWB-enabled devices at a distance of up to 100 meters with down to 10 cm of accuracy. UWB ranging uses a wide channel bandwidth (500 MHz) between 3.1 GHz and 10.6 GHz and very short (two nanosecond) pulses to accurately measure the Time-of-Flight (ToF) between two devices, such as smartphones, wearables, keys, tags, door locks, and anchor points. UWB can use two-way ranging (TWR) scheme to calculate the distance between two objects by determining the time of flight (TOF) of signals travelling between them. The basic principle of TWR is shown in Figure 1.

[0029] A first message 11 is sent from an initiator A to a responder B at time ti (note that the timeline points down in Figure 1). The time between transmission and reception is the time-of-flight (TOF). After certain delay, trepiy, the responder B returns a reply message 12 which is received by the initiator at time t2. Using the timestamps ti and t2, and knowing the delay trepiythe initiator A can now calculate the TOF as:

[0030] T OF=(t2-ti-treply) / 2

[0031] The distance between the objects may be calculated using the formula:

[0032] Distance = c TOF where it is assumed that the speed of radio waves through air is the speed of light c.

[0033] To improve the ranging due to device clock drift and frequency drift, more complex approaches include symmetric double sided TWR, and asymmetric double sided TWR.

[0034] Turning to Figure 2, the left hand side shows processing in a controller 1, having a unique UWB address (controller ID), while the right-hand side shows processing in two network nodes 2, 3, having unique network addresses (node lD). The network can be a local area network based on IEEE 802.11 (WiFi) or IEEE 802.15.4 (e.g. Zigbee, wireless HART, MiWi etc ).

[0035] The nodes 2, 3 may be associated with units in a domestic appliance system, e.g. lighting devices in a lamination system, or loudspeakers in a home entertainment system. The controller 1 (or the user thereof) intends to communicate with the first node 2 (the “intended node”). The controller 1 does not know the node ID of the nodes 2, 3.

[0036] Figure 3a-b shows very schematically some of the elements in the controller 1 and the nodes 2, 3.

[0037] The controller 1 includes controller processing circuitry 11 connected to an IR sensor 12, a broadcast unit 13, and a UWB ranging unit 14. The IR sensor is connected to an IR emission device, e.g. a suitable light emitting diode (LED) 15, and the broadcast unit 13 and UWB ranging unit 14 are connected to a UWB antenna 16. In practice, the broadcast unit 13 and UWB ranging unit 14 may be implemented as one single UWB communication unit.

[0038] The node 2, 3 includes node processing circuitry 17 connected to a UWB receiver 18 and a UWB ranging unit 20. The receiver and ranging units are both connected to a UWB antenna 19. In practice, the receiver 18 and the UWB ranging unit 19 may be implemented as one single UWB communication unit.

[0039] With reference to Figures 4 and 5, a method according to an embodiment of the present invention will be described. Figure 4 shows the steps occluding in the controller 1, while Figure 5 shows the steps occurring in the intended node 2.

[0040] First, in step SI, the user points the controller 1 towards the intended node 2, and the controller 1 performs a non-UWB type ranging process 21 to determine a distance D between the controller and the intended node 2. The non-UWB ranging method can be some type of reflective ranging like IR or ultrasound ranging, or any other type of appropriate directional ranging.

[0041] Then, in step S2, the controller 1 broadcasts a message 22 including the controller ID and the distance D. In step SI 1, the message 22 is received by a set of nodes in the vicinity of the controller 1, in this case nodes 2 and 3. The broadcast may be directional, i.e. restricted to an angular range around the direction in which the controller 10 is pointed, thereby reducing the potential number of receiving nodes.

[0042] In steps S3 and S12, UWB ranging is performed between the controller 1 and each node 2, 3 that received the message 22. The UWB ranging is initiated by the respective node 2, 3, acting as the initiator A, while the controller 1 acts as the responder B. The UWB ranging can be performed as illustrated in Figure 1, or in any suitable manner. The ranging process 23a, between node 2 and the controller 1, results in a distance D2. The ranging process 23b, between node 3 and the controller 1, results in a distance D3.

[0043] In step SI 3, performed in each node 2, 3, the UWB ranging distance D2 / D3 is compared to the distance D received in the message 22. If the node establishes that the two different distance measures are sufficiently similar, i.e. if |D-D2| is less than a given threshold TH, then the node will determine that it is the intended node. In step S14, the intended node 2 responds to the message 22.

[0044] In one embodiment, the message 22 already contains a command intended to be performed by the intended node 2, for example a command to increase light intensity of a lighting device. In such a case, as soon as a node has established that it is the intended node, it may perform the command. In other embodiments, the intended node 2 may respond by transmitting a response message 24, including the node ID, to the controller 1. The controller 1 receives the response message 24 in optional step S24 and can then continue with dedicated network communication with the intended node 2.

[0045] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the communication between the controller and the node(s) may involve additional steps not mentioned herein. Further, the details of the UWB ranging may differ from those shown in Figure 1. Also, other non-UWB based distance detection techniques may be employed.

Claims

CLAIMS:

1. A method for communicating between a controller (1) having a controller ID and an intended node (2) of a wireless network comprising a plurality of nodes, comprising: determining (step SI) by the controller (1), a distance, D, between the controller (1) and the intended node (2), using non-UWB (Ultra Wide Band) distance detection, broadcasting (step S2) by the controller, a message (22) including the distance, D, and the controller ID, completing (step S3) by the controller (1), a UWB ranging process (23a, 23b) with all nodes (2, 3) that received the message (22), and receiving (step S4) by the controller (1), a response message from each node which establishes that a difference between the UWB ranging distance and the distance, D, is smaller than a given threshold, wherein each respective response message includes the node ID of the respective node..

2. The method according to claim 1, wherein the message (22) is broadcasted using directional broadcasting.

3. The method according to claim 1 or 2, wherein the non-UWB distance detection is a reflection based ranging, such as IR reflection.

4. The method according to claim lor 2, wherein the controller is pointed at the intended node which is a controllable device when performing the step of determining the distance D.

5. A method for communicating between a node (2) having a node ID and a controller (1), comprising: receiving (step SI 1) by the node(2), a message (22) including a non-UWB measured distance, D, and a controller ID, completing (SI 2) by the node (2), a UWB ranging process (23a) with thecontroller (1) identified by the controller ID, to determine a UWB ranging distance, comparing (SI 3) by the node (2), the UWB ranging distance with the distance D received in the message, sending (S14) by the node (2), a response message including the node ID to the controller if the difference between the UWB ranging distance and the distance, D, is smaller than a given threshold.

6. The method according to claim 5, further comprising includes performing by the node (2), an action indicated by the message (22).

7. The method according to any one of the preceding claims, wherein the wireless network is based on IEEE 802.15.4.

8. A wireless controller (1) comprising: a non-UWB distance detector (12); a broadcasting unit (13); a UWB ranging unit (14); and controller processing circuitry (11) configured to perform the method according to one of claims 1-3.

9. The wireless controller (1) according to claim 8, wherein the non-UWB distance detector (12) is configured to employ reflection based ranging, such as IR ranging.

10. The wireless controller (1) according to claim 8 or 9, wherein the UWB ranging unit is configured to communicate using IEEE 802.15.4.

11. A wireless network node (2) comprising: a receiver (18); a UWB ranging unit (20); and node processing circuitry (17) configured to perform the method according to claim 4.

12. The wireless network node (2) according to claim 11, wherein the UWB ranging unit (20) is configured to communicate using IEEE 802.15.4.

13. A system including a controller (1) according to any of claims 8-10 and at least one wireless network node (2) according to any of claims 11-12.

14. A computer program product configured to, when executed in one or more processors of a controller (1) according to any one of claim 8-10, cause the controller to perform a method according to any one of claims 1-4.

15. A computer program product configured to, when executed in one or more processors, cause the one or more processors to perform a method according to any one of claims 5-7.

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