A method performed by a node device in a wireless network comprising an access point

Abstract

A method performed by a node device in a wireless network comprising an access point is disclosed. The node device is communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The access point is configured to assign a wireless channel of a plurality of wireless channels to the node device, wherein over time the wireless channel assigned to the node device may change. The method is, essentially, a process for predicting which wireless channel of the plurality of wireless channels that will be assigned to a node device if the access point re-assigns a wireless channel of the plurality of wireless channels to the node device. The method is based on data relating to the wireless channels on whether the control device has connected to the node device using the respective wireless channels and usage of the wireless channels by the node device, which data has been collected during a selected period of time.

Description

[0001] A method performed by a node device in a wireless network comprising an access point

[0002] TECHNICAL FIELD

[0003] The present invention relates to relates to a method performed by a node device in a wireless network comprising an access point, the node device being communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The present invention further relates to the node device and the control device.

[0004] BACKGROUND

[0005] In lighting systems, a control device or controller may be configured to control operation of one or more lighting devices in the lighting system, wherein wireless local area network (WLAN) channels may be used for communication of control signaling from the controller to the lighting device(s). WLAN channels may be accessed using the IEEE (Institute of Electrical and Electronics Engineers) 802.11 protocols, for example. The IEEE 802.11 standard provides several distinct radio frequency bands for use in Wi-Fi communications, such as, for example, the 2.4 GHz range, with each range being divided into several channels. For example, in the 2.4 GHz range, fourteen channels are designated. The controller may be referred to as a remote control (e.g., for the user), and may operate on power from a battery in the controller.

[0006] US2022272746A1 is about managing uplink resource grants in wireless networks. A mobile terminal receives from a base station a first uplink resource grant schedule including a first uplink resource grant and a second uplink resource grant. The first uplink resource grant gives the mobile terminal an exclusive right to use a first set of resource blocks on a recurring basis and the second uplink resource grant gives the mobile terminal a non-exclusive right to use a second set of resource blocks on a recurring basis. The mobile terminal uses the second set of resource blocks to transmit data to the base station during at least a first time interval of the first period of time, said first period of time including multiple time intervals during which the mobile terminal has been granted the right to transmit data.

[0007] US2009040928A1 relates to methods and apparatus operative in a wireless communications system divide a communications resource available for performing information transmission and retransmission operations into a plurality of communication resource units. The units are ordered in a predetermined order. A first group of communication resource units are selected from the communication resource in ascending order and assigned to a first group of communications devices to perform information transmission operations in a first time period. A second group of communication resource units are selected from the communication resource in descending order and assigned to a second group of communications devices to perform information transmission operations in a second time period. At least a portion of the first group of communication resource units is assigned to the first group of communication resource units to perform retransmission operations. In operation often the first group of communication resource units will be available to perform retransmission operations in the second time period. In such a manner a non-adaptive HARQ retransmissions can be accommodated in a 3GPP LTE OFDM based wireless communications system.

[0008] US2020145506A1 relates to predictive use of resources across a dispersed Internet protocol capable network connecting devices electrically attached to the network. It is configured to determine a resource utilization profile associated with a first user; receive an indication from the first user to improve the resource utilization profile; initiate a first user interface, wherein the first user interface comprises one or more target resource utilization profiles associated with one or more users; receive a first user selection of a target resource utilization profile associated with the resource utilization profile that the first user wishes to change; determine one or more access paths associated with the at least one target resource utilization profile; and display on the first user computing device the one or more access paths to enable the first user to achieve the at least one target utilization profile.

[0009] US10361942B2 relates to allocation of resources based on resource utilization.

[0010] The system is configured to electronically receive information associated with a user, wherein the information comprises a primary user profile; determine one or more actions associated with the primary user profile, wherein the one or more actions are to be executed by the user; determine one or more resources required to execute the one or more actions based on at least the primary user profile; and assign the one or more resources to the user based on at least the primary user profile associated with the user, wherein the one or more resources enable the user to execute the one or more actions.

[0011] US2023155964A1 relates to network system queue management and dynamic real-time re-allocation of resources to prevent oversubscription and packet loss due to oversubscription. The techniques and systems enable monitoring of traffic and initial identification of queues at risk for oversubscription based on a rate of change of traffic load on the queue in advance of oversubscription occurring. After identifying a queue at risk for oversubscription, an Extended Berkeley Packet Filter or other similar component performs a likelihood determination using predictive algorithm techniques to identify a likelihood of oversubscription in the near future and re-allocates to parallel queues for efficient and loss- free use of the queues.

[0012] KR102433577B1 relates to a method and device for controlling resource reallocation in a vehicle network, comprising a step in which a device receives location information, allocated resource information, and a reward for a plurality of vehicles through a vehicle network; a step in which the device calculates a first probability for resource reallocation of the vehicle based on the location information and the reward, and inputs the resource information and the reward into a reinforcement learning model to calculate a second probability for the resource reallocation; and a step in which the device determines a policy of the vehicle network based on calculation results for the first probability and the second probability.

[0013] SUMMARY

[0014] In a ‘connected’ lighting system, in which a control device or controller may be wirelessly communicatively coupled or couplable to each lighting device in the lighting system and configured to control operation of each lighting device by means of communication of control signaling from the controller to the lighting device via at least one wireless channel of a plurality of wireless channels of a wireless network, there may be provided an access point in the wireless network with which the lighting device(s) is or are communicatively coupled. The access point may be configured to assign a wireless channel of the plurality of wireless channels to each lighting device, which wireless channel may be used by the lighting device for communicating with one or more other entities in the lighting system, such as with the controller. The access point may for example comprise a wireless router. Each lighting device may be, essentially, always coupled to the access point. For example because of this, the wireless channel of the plurality of wireless channels assigned to each lighting device may change over time, for example as a result of the access point being turned off and subsequently turned on. The access point may be configured to, upon having been turned off and subsequently turned on, initiate (e.g., automatically initiate) a process of assigning one wireless channel of the plurality of wireless channels to each lighting device. In general, the lighting system may include several lighting devices, and the said process of assigning wireless channel(s) may result in that for each of at least some lighting devices in the lighting system, a different wireless channel is assigned to the lighting device compared to before the access point was turned off and subsequently turned on. For each lighting device, the controller may use the wireless channel that is currently assigned to the lighting device for communication of, e.g., control signaling from the controller to the lighting device. However, after there has been a change in the access point’s assignment of wireless channels to the lighting devices, the controller may need to determine, for each lighting device, which wireless channel of the plurality of wireless channels that is now assigned to lighting device. The controller may be configured to determine this by means of a channel scanning process. The channel scanning process may involve the controller, for each lighting device, attempting communication with the lighting device using the plurality of wireless channels in sequence until the controller establishes a successful communication with the lighting device using one of the wireless channels, e.g., by the lighting device receiving an acknowledgement message from the lighting device on that wireless channel. The sequence in which the wireless channels are used for attempting communication with the lighting device may be arbitrary, as different access points may employ different algorithms or methods for assignment of wireless channels. Also, for each wireless channel, the controller may need to attempt communication with each of the lighting devices over an extended period of time, such as, for example 200 ms. If the number of wireless channels of the plurality of wireless channels is relatively large and the controller does not scan the ‘correct’ wireless channel early in the channel scanning process, the channel scanning process may be time-consuming. Further, in such cases, the power of the controller’s battery may be reduced relatively fast as a result of the channel scanning process.

[0015] Instead of or in addition to lighting devices, there may be provided other types of devices which the controller may be configured to control operation of by means of communication of control signaling from the controller to the device(s). Therefore, while reference may be made herein to a ‘connected’ lighting system and lighting devices, embodiments of the present invention are not limited to lighting systems but may relate to systems including devices of other type than lighting devices. Such a device, which may or may not be a lighting device, will be referred to herein as a node device.

[0016] In view of the above, a concern of the present invention is to provide an improved process for a control device - which is included in a wireless network comprising one or more node devices, whose operation may be controlled by the control device by transmission of at least one control message to the node device(s), and further an access point with which the one or more node devices may be communicatively coupled and which is configured to assign a wireless channel of a plurality of wireless channels to each node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the device may change - to determine which wireless channel of the plurality of wireless channels that is assigned to a node device.

[0017] A further concern of the present invention is to provide such an improved process which further entails only a relatively low power consumption of the control device.

[0018] According to a first aspect of the present invention, a method is provided. The method is performed by a node device in a wireless network comprising an access point. The node device is communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The access point is configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change. The method comprises determining over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point. For each assigned wireless channel of the plurality of wireless channels, at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not is determined. Based on the determined indication(s), an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device is determined. The determined estimations are transmitted to the control device.

[0019] According to a second aspect of the present invention, a node device is provided. The node device is a node device in a wireless network comprising an access point, with the node device being communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The access point is configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change. The node device is configured to determine over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point. The node device is configured to, for each assigned wireless channel of the plurality of wireless channels, determine at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not. The node device is configured to, based on the determined indication(s), determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device. The node device is configured to transmit the determined estimations to the control device. The control device may be configured to control operation of the node device by transmission of at least one control message to the node device. The at least one control message may include a command to control the operation of the node device.

[0020] As indicated in the foregoing, the node device may for example comprise a lighting device. As such, the control device and the node device may be considered to be included in a lighting system. However, this is not required, and embodiments of the present invention are not limited to lighting systems but may relate to systems including node devices of other type than lighting devices.

[0021] By a method and a node device according to the first and second aspects, respectively, of the present invention, it is provided, essentially, a process for predicting which wireless channel of the plurality of wireless channels that will be assigned to a node device if the access point re-assigns a wireless channel of the plurality of wireless channels to the node device. The process for predicting can be considered to utilize statistical analysis of data, and the method for predicting is based on data relating to the wireless channels on whether the control device has connected to the node device using the respective wireless channels and usage of the wireless channels by the node device, which data has been collected during the selected period of time. The selected period of time may for example correspond to a plurality of days, e.g., at least seven days. The process for predicting in accordance with the method and the node device according to the first and second aspects, respectively, of the present invention may reduce the time needed for the control device to perform a channel scanning process as described in the foregoing.

[0022] In accordance with the method and the node device according to the first and second aspects, respectively, of the present invention, such data is used, by the node device, to determine the above-mentioned determined indication(s). Then, based on the determined indication(s), an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels, in case of the access point reassigning a wireless channel of the plurality of wireless channels to the node device, is determined. The determined estimations are transmitted by the node device to the control device. The control device may then use the determined estimations in any subsequent channel scanning process such as described in the foregoing. As mentioned, the channel scanning process may involve the control device, for each node device, attempting communication with the node device using the plurality of wireless channels in sequence until the control device establishes a successful communication with the node device using one of the wireless channels, e.g., by the control device receiving an acknowledgement message from the node device on that wireless channel. The control device may use the determined estimations to determine the sequence of the plurality of wireless channels it shall use to attempt communication with the node device, so that communication is first attempted using the most likely wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels. Should that attempt be unsuccessful, communication can then be attempted using the wireless channel that is next most likely to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels, and so on, in order of descending likelihood. Thus, a goal for the process for predicting in accordance with the method and the node device according to the first and second aspects, respectively, of the present invention is for the control device to be able to scan or determine the ‘correct’ wireless channel early in the channel scanning process, to thereby permit keeping the amount of time needed for the control device to perform the channel scanning process relatively small.

[0023] The wireless network may for example comprise a wireless local area network (WLAN). WLAN channels may be accessed using the IEEE 802.11 protocols, with the IEEE 802.11 standard providing several distinct radio frequency bands for use in Wi-Fi communications, such as, for example, the 2.4 GHz range, with each range being divided into several channels. For example, in the 2.4 GHz range, fourteen channels are designated. As mentioned, the access point may for example comprise a wireless router, e.g., a WLAN router such as, for example, a Wi-Fi router. Such routers may employ algorithms for automatic channel selection or assignment among, e.g., the fourteen channels in the 2.4 GHz range. These channels may be enumerated from 0 to 13, or from 1 to 14, for example. The inventors have observed that while such algorithms can vary between different types of such routers (e.g., between such routers manufactured by different manufacturers), particular types of such routers can exhibit certain channel selection or assignment tendencies when they are placed in certain environments. For example, using an enumeration from 1 to 14 of the fourteen channels in the 2.4 GHz range, the inventors have observed that some routers from certain manufacturers may tend to select or assign one of channels 1, 6 and 11, while routers from other manufacturers may tend to only select or assign channel 3.

[0024] As mentioned, the access point is configured to assign a wireless channel of the plurality of wireless channels to the node device. Further, the access point may be configured to indicate, to the node device, which wireless channel of the plurality of wireless channels is currently assigned to the node device. By the access point indicating, to the node device, which wireless channel of the plurality of wireless channels is currently assigned to the node device, the node device can be informed of the (e.g., result of the) channel assignment made by the access point.

[0025] As mentioned, based on the determined indications, there is determined an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device. That is, an absolute probability or likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device is not necessarily determined or estimated, but it may rather be a probability or likelihood of a particular channel to be assigned to the node device relatively to the probability or likelihood of other channels to be assigned to the node device, e.g., in the form of a ranked list (with respect to likelihood) indicating which wireless channels are more likely to be assigned to the node device compared to other wireless channels.

[0026] The selected period of time may be defined by a plurality of consecutive subperiods of time. As mentioned, the selected period of time may for example correspond to a plurality of days, e.g., at least seven days. Each sub-period of time may correspond to one day of the plurality of days.

[0027] The method may comprise, or the node device may be configured for, determining when during the selected period of time the wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point.

[0028] The determining, for each assigned wireless channel of the plurality of wireless channels, of at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not may comprise determining, for each assigned wireless channel of the plurality of wireless channels, for each sub-period of time, indications of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not, and of how long time, if any, during the sub-period of time the wireless channel has been assigned to the node device.

[0029] The determination, for each assigned wireless channel of the plurality of wireless channels, and for each sub-period of time, of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not, may comprise determining whether or not the node device has received any command message from the control device using the wireless channel during the sub-period of time.

[0030] For each wireless channel of the plurality of wireless channels, and for each sub-period of time, the indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not may be represented as a parameter having a first value or a second value, respectively. The indication of how long time, if any, during the sub-period of time the wireless channel has been assigned to the node device may be represented as a ratio between the time the wireless channel has been assigned to the node device during the sub-period of time and the duration of the sub-period of time. The determination of an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels may comprise determining, for each wireless channel of the plurality of wireless channels, a weight factor based on the determined indications, wherein the weight factor is determined based on summation of the value of said parameter and the value of said ratio. The determination, for each wireless channel of the plurality of wireless channels, of the weight factor may comprise determining the weight factor based on summation of the value of said parameter and the value of said ratio and a decaying function of time taken over the selected period of time.

[0031] The parameter having a first value or a second value may for example be implemented as a parameter having a value of 0 or a value of 1, for example such as described in the following in relation to the parameter Sk. However, values for the first value and the second value other than 0 and 1 are possible.

[0032] The decaying function of time may be implemented in different ways. According to one implementation example and in accordance with one or more embodiments of the present invention, for each wireless channel of the plurality of wireless channels, and for each sub-period of time, the indication of whether the control device has been communicatively coupled with the node device using the wireless channel during the sub-period of time or not may be represented as a parameter Sk, which may have a value 1 or 0, respectively, for example. The indication of how long time, if any, during the sub-period of time the wireless channel has been assigned to the node device may be represented as a ratio Tk between the time during the sub-period of time the wireless channel has been assigned to the node device and the duration of the sub-period of time. The determination of an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels may comprise determining, for each wireless channel k of the plurality of wireless channels, wherein k is an integer between 1 and the number of wireless channels of the plurality of wireless channels, of a weight factor Wk based on the determined indications, wherein the weight factor Wk may be determined as:

[0033] In the expression for the weight factor Wk above, N may be the number of sub-periods of time, c is a constant for which c > 0. Sk(n) is the indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time n. Tk(n) is the ratio between the time the wireless channel has been assigned to the node device during the sub-period of time n and the duration of the sub-period of time n. c may for example be a value in a range 0 < c < 1. According to an example, c = 0.5.

[0034] In the above-described implementation example, the decaying function of time t is implemented by a function of the type ect. However, it is to be understood that this is according to an example, and that other implementations of the decaying function of time are possible, as will be recognized by a skilled person in the light of the disclosure herein.

[0035] Once the weight factor Wk for each wireless channel k of the plurality of wireless channels has been determined, the determined weight factors may be arranged in a succession in descending order according to the values of the weight factors, i.e., with the largest weight factor being first in the succession. The wireless channel corresponding to the weight factor that is first in the succession may then be considered to represent the most likely wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device. The wireless channel corresponding to the weight factor that is next in the succession, after the first weight factor, may then represent the next most likely wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels, and so on, in order of descending likelihood.

[0036] According to an example use case, relevant for the above-described implementation example, the case where the wireless communications network comprises a WLAN and where the plurality of wireless channels include or are constituted by the designated channels in the 2.4 GHz range, which may be enumerated from 0 to 13, or from 1 to 14, for example, may again be considered. According to the example use case, the selected period of time may for example correspond to a plurality of days, and each sub-period of time may correspond to one day of the plurality of days. According to the example use case, for the node device, from midnight to 6 pm (or 18:00) on one of the days - which day is represented by n = 0 - the channel 4 is assigned to the node device. Therefore, T4(0) may be set to T4(0) = 18 / 24. However, according to the example use case, during this time the control device has not been communicatively coupled with the node device using the channel 4. Therefore, 84(0) may be set to 84(0) = 0. Thereby, for that day, W4 = 84(0) + T4(0) = 0 + 18 / 24. Further according to the example use case, from 6 pm (or 18:00) to midnight going into the following day, the channel 5 is assigned to the node device. Therefore, Ts(0) may be set to Ts(0) = 6 / 24. Further, according to the example use case, during this time the control device has been communicatively coupled with the node device using the channel 5. Therefore, Ss(O) may be set to Ss(O) = 1. Thereby, for that day, W5 = Ss(O) + Ts(0) = 1 + 6 / 24. Thus, W5 > W4. The same or similar principle may be used for determining weights for each channel and for each day (or more generally, for each subperiod of time).

[0037] According to a third aspect of the present invention, a control device is provided. The control device is communicatively couplable with a node device via at least one wireless channel of a plurality of wireless channels of a wireless network comprising an access point. The access point is configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change. The node device is configured to determine over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point. The node device is configured to, for each assigned wireless channel of the plurality of wireless channels, determine at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not. The node device is configured to, based on the determined indication(s), determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device. The control device is configured to receive the estimations determined by the node device.

[0038] In case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device, the control device may be configured to attempt communication with the node device using a wireless channel of the plurality of wireless channels for which the estimated likelihood is the highest.

[0039] According to a fourth aspect of the present invention, a system is provided.

[0040] The system comprises a control device, and a node device in a wireless network comprising an access point. The node device is communicatively couplable with the control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The access point is configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change. The node device is configured to determine over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point. The node device is configured to, for each assigned wireless channel of the plurality of wireless channels, determine at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not. The node device is configured to, based on the determined indications, determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device. The above-mentioned operations carried out by the node device may for example be carried out by a processor of the node device, which processor may be configured to carry out the above-mentioned operations. The node device is configured to transmit the estimations determined by the node device to the control device.

[0041] The node device may be communicatively couplable with the control device, and the control device may be communicatively couplable with the node device via a wireless communications network and using at least one wireless channel of a plurality of wireless channels. Further, the access point may be communicatively coupled with the node device. To that end, the node device, the access point and / or the control device may comprise one more transmit and / or receive elements such as one or more radio frequency antennas in order to provide the node device, the access point and / or the control device, respectively, with a capability to communicate with an entity in the wireless network. Further, the node device, the access point and / or the control device may comprise one or more processors configured to cooperate with the one more transmit and / or receive elements to perform transmission and / or reception as described herein as well as to carry out any other operation as described herein. The one or more processors of the node device, the access point and / or the control device may for example comprise a central processing unit (CPU), a digital signal processor (DSP), one or more microprocessors, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, or the like.

[0042] According to another aspect of the present invention, a computer-readable storage medium is provided, on which computer-readable storage medium a computer program product is stored. The computer program product is configured to, when executed in one or more processors of a node device (e.g., a node device according to the second aspect of the present invention or a node device included in a system according to the fourth aspect of the present invention), perform at least the determining steps of a method according to the first aspect of the present invention.

[0043] According to yet another aspect of the present invention, a computer program product is provided. The computer program product is configured to, when executed in one or more processors of a node device (e.g., a node device according to the second aspect of the present invention or a node device included in a system according to the fourth aspect of the present invention), perform at least the determining steps of a method according to the first aspect of the present invention.

[0044] Further objects and advantages of the present invention are described in the following by means of exemplifying embodiments. It is noted that the present invention relates to all possible combinations of features recited in the claims. Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the description herein. Those skilled in the art realize that different features of the present invention can be combined to create embodiments other than those described herein.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Exemplifying embodiments of the invention will be described below with reference to the accompanying drawings.

[0047] Fig. l is a schematic view of a system according to an embodiment of the present invention.

[0048] Fig. 2 is a schematic flowchart of a method according to an embodiment of the present invention.

[0049] All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate embodiments of the present invention, wherein other parts may be omitted or merely suggested.

[0050] DESCRIPTION WITH REFERENCE TO THE DRAWINGS

[0051] The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplifying embodiments of the present invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments of the present invention set forth herein; rather, these embodiments of the present invention are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art. In the drawings, identical reference numerals denote the same or similar components having a same or similar function, unless specifically stated otherwise.

[0052] Figure 1 is a schematic view of a system 10 according to an embodiment of the present invention. The system 10 comprises a control device 1, and a node device 2 in a wireless network comprising an access point 4. The node device 2 is communicatively couplable with the control device 1 via at least one wireless channel of a plurality of wireless channels of the wireless network, which plurality of wireless channels are schematically indicated in Figure 1 at 3 by the double-headed arrows. The control device 1 may be configured to control operation of the node device 2 by transmission of at least one control message to the device. The at least one control message may include a command to control the operation of the node device 2. In accordance with the embodiment of the present invention illustrated in Figure 1, the system 10 comprises one such device 2. However, it is to be understood that the system 10 may comprise in principle any number of such devices 2, e.g., two, three, four, five, or ten or more such devices.

[0053] The node device 2 may for example comprise a lighting device. As mentioned, the control device 1 may be configured to control operation of the node device 2 by transmission of at least one control message to the node device 2, with the at least one control message possibly including a command to control the operation of the node device 2. The command included in the command message may be a command to control emission of light from the node device 2.

[0054] The wireless network may for example comprise a wireless local area network (WLAN). WLAN channels may be accessed using the IEEE 802.11 protocols, with the IEEE 802.11 standard providing several distinct radio frequency bands for use in Wi-Fi communications, such as, for example, the 2.4 GHz range, with each range being divided into several channels. For example, in the 2.4 GHz range, fourteen channels are designated. The plurality of wireless channels 3 could for example comprise the fourteen channels in 2.4 GHz range, and / or the channels of any other radio frequency band as per the IEEE 802.11 standard. It is to be understood that the number of wireless channels of the plurality of wireless channels as indicated by the number of double-headed arrows in Figure 1 (i.e., four) is according to an example, and that the number of wireless channels of the plurality of wireless channels could be more or less than what is indicated by the number of doubleheaded arrows in Figure 1 (i.e., more or less than four).

[0055] The access point 4 is configured to assign a wireless channel of the plurality of wireless channels 3 to the node device 2, wherein over time the wireless channel of the plurality of wireless channels 3 assigned to the node device 2 may change. The node device 2 may be, essentially, always coupled to the access point 4. For example because of this, the wireless channel of the plurality of wireless channels 3 assigned to the node device 2 may change over time, for example as a result of the access point 4 being turned off and subsequently turned on, upon which the access point 4 may be configured to initiate (e.g., automatically initiate) a process of assigning one wireless channel of the plurality of wireless channels 3 to the node device 2.

[0056] The access point 4 may be configured to indicate, to the node device 2, which wireless channel of the plurality of wireless channels 3 is currently assigned to the node device 2. The access point 4 may be configured to indicate, to the node device 2, which wireless channel of the plurality of wireless channels 3 is currently assigned to the node device 2 by the access point 4 transmitting a message to the node device 2 indicating or from which it is derivable which wireless channel of the plurality of wireless channels 3 is currently assigned to the node device 2.

[0057] The access point 4 may for example comprise a wireless router, e.g., a WLAN router such as, for example, a Wi-Fi router.

[0058] The node device 2 may comprise a processor 5, which may be configured to, possibly based on the indication(s) from the access point 4, determine, over a selected period of time which wireless channel(s) of the plurality of wireless channels 3 has or have been assigned to the node device 2 by the access point 4, and possibly also when during the selected period of time.

[0059] The processor 5 the node device 2 may be configured to, for each assigned wireless channel of the plurality of wireless channels 3, determine at least an indication of whether the control device 1 has been communicatively coupled with the node device 2 using the wireless channel during the selected period of time or not.

[0060] The processor 5 of the node device 2 may be configured to, based on the above-referenced determined indication(s), determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels 3 to be assigned to the node device 2 by the access point 4 relatively to the other wireless channel(s) of the plurality of wireless channels 3 in case of the access point 4 re-assigning a wireless channel of the plurality of wireless channels 3 to the node device 2.

[0061] The node device 2 is configured to transmit the estimations determined by the node device 2 to the control device 1. The control device 1 may then use the determined estimations in any subsequent channel scanning process such as described in the foregoing. As has been described elsewhere herein, by using the determined estimations in such a subsequent channel scanning process, the amount of time needed for the control device 1 to perform the channel scanning process may be relatively small.

[0062] Figure 2 is a schematic flowchart of a method 20 according to an embodiment of the present invention. The method 20 is performed by a node device in a wireless network comprising an access point. The node device is communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The access point is configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change. The method 20 comprises, at 21, determining over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point.

[0063] At 22, it is determined for each wireless channel of the plurality of wireless channels at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not.

[0064] At 23, it is determined, based on the determined indication(s), an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device.

[0065] At, 24, the determined estimations are transmitted to the control device.

[0066] The method 20 may then end.

[0067] In conclusion, a method performed by a node device in a wireless network comprising an access point is disclosed. The node device is communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network. The access point is configured to assign a wireless channel of a plurality of wireless channels to the node device, wherein over time the wireless channel assigned to the node device may change. The method is, essentially, a process for predicting which wireless channel of the plurality of wireless channels that will be assigned to a node device if the access point re-assigns a wireless channel of the plurality of wireless channels to the node device. The method is based on data relating to the wireless channels on whether the control device has connected to the node device using the respective wireless channels and usage of the wireless channels by the node device, which data has been collected during a selected period of time.

[0068] While the present invention has been illustrated in the appended drawings and the foregoing description, such illustration is to be considered illustrative or exemplifying and not restrictive; the present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the appended claims, the word “comprising” does not exclude other elements or steps, and the indefinite article ”a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A method (20) performed by a node device in a wireless network comprising an access point, the node device being communicatively couplable with a control device via at least one wireless channel of a plurality of wireless channels of the wireless network, the control device being configured to control operation of the node device by means of communication of control signaling from the control device to the node device over the at least one wireless channel, the access point being configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change, the method comprising: determining (21) over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point; for each assigned wireless channel of the plurality of wireless channels, determining (22) at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not; based on the determined indication(s), determining (23) an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device; and transmitting (24) the determined estimations to the control device.

2. A method according to claim 1, wherein the selected period of time is defined by a plurality of consecutive sub-periods of time, and wherein the method further comprises determining when during the selected period of time the wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point; and wherein the determining for each assigned wireless channel of the plurality of wireless channels of at least an indication of whether the control device has beencommunicatively coupled with the node device using the assigned wireless channel during the selected period of time or not comprises: determining, for each assigned wireless channel of the plurality of wireless channels, for each sub-period of time, indications of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not, and of how long time, if any, during the sub-period of time the wireless channel has been assigned to the node device.

3. A method according to claim 2, wherein the determination, for each assigned wireless channel of the plurality of wireless channels, and for each sub-period of time, of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not comprises determining whether or not the node device has received any command message from the control device using the wireless channel during the sub-period of time.

4. A method according to claim 2 or 3, wherein for each wireless channel of the plurality of wireless channels, and for each sub-period of time, the indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not is represented as a parameter having a first value or a second value, respectively, and wherein the indication of how long time, if any, during the sub-period of time the wireless channel has been assigned to the node device is represented as a ratio between the time the wireless channel has been assigned to the node device during the sub-period of time and the duration of the sub-period of time; wherein the determination of an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels comprises determining, for each wireless channel of the plurality of wireless channels, a weight factor based on the determined indications, wherein the weight factor is determined based on summation of the value of said parameter and the value of said ratio.

5. A method according to claim 4, wherein the determination, for each wireless channel of the plurality of wireless channels, of the weight factor comprises determining the weight factor based on summation of the value of said parameter and the value of said ratio and a decaying function of time taken over the selected period of time.

6. A method according to claim 2 or 3, wherein for each wireless channel of the plurality of wireless channels, and for each sub-period of time, the indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time or not is represented as a parameter Sk having a value 1 or 0, respectively, and wherein the indication of how long time, if any, during the sub-period of time the wireless channel has been assigned to the node device is represented as a ratio Tk between the time during the sub-period of time the wireless channel has been assigned to the node device and the duration of the sub-period of time, wherein the determination of an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels comprises determining, for each wireless channel k of the plurality of wireless channels, wherein k is an integer between 1 and the number of wireless channels of the plurality of wireless channels, of a weight factor Wk based on the determined indications, wherein the weight factor Wk is determined as:where N is the number of sub-periods of time, c is a constant for which c > 0, Sk(n) is the indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the sub-period of time n, and Tk(n) is the ratio between the time the wireless channel has been assigned to the node device during the sub-period of time n and the duration of the sub-period of time n.

7. A method according to any one of claims 2-6, wherein the selected period of time corresponds to a plurality of days, and each sub-period of time corresponds to one day of the plurality of days.

8. A method according to claim 7, wherein the selected period of time corresponds to at least seven days.

9. A node device in a wireless network comprising an access point, the node device being communicatively couplable with a control device via at least one wirelesschannel of a plurality of wireless channels of the wireless network, the control device being configured to control operation of the node device by means of communication of control signaling from the control device to the node device over the at least one wireless channel, the access point being configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change, wherein the node device is configured to: determine over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point; for each assigned wireless channel of the plurality of wireless channels, determine at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not; based on the determined indication(s), determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device; and transmit the determined estimations to the control device.

10. A control device (1) communicatively couplable with a node device (2) via at least one wireless channel of a plurality of wireless channels (3) of a wireless network comprising an access point (4), the control device being configured to control operation of the node device by means of communication of control signaling from the control device to the node device over the at least one wireless channel, the access point being configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change, wherein the node device is configured to determine over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point, for each assigned wireless channel of the plurality of wireless channels, determine at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not, and, based on the determined indication(s),determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device, wherein the control device is configured to receive the estimations determined by the node device.

11. A control device according to claim 10, wherein, in case of the access point reassigning a wireless channel of the plurality of wireless channels to the node device, the control device is configured to attempt communication with the node device using a wireless channel of the plurality of wireless channels for which the estimated likelihood is the highest.

12. A system (10) comprising: a control device (1); and a node device (2) in a wireless network comprising an access point (4), the node device being communicatively couplable with the control device via at least one wireless channel of a plurality of wireless channels (3) of the wireless network, the control device being configured to control operation of the node device by means of communication of control signaling from the control device to the node device over the at least one wireless channel, the access point being configured to assign a wireless channel of the plurality of wireless channels to the node device, wherein over time the wireless channel of the plurality of wireless channels assigned to the node device may change; the node device comprising a processor (5) configured to: determine over a selected period of time which wireless channel(s) of the plurality of wireless channels has or have been assigned to the node device by the access point; for each assigned wireless channel of the plurality of wireless channels, determine at least an indication of whether the control device has been communicatively coupled with the node device using the assigned wireless channel during the selected period of time or not; and based on the determined indications, determine an estimation of a likelihood for each wireless channel of the plurality of wireless channels to be assigned to the node device by the access point relatively to the other wireless channel(s) of the plurality of wireless channels in case of the access point re-assigning a wireless channel of the plurality of wireless channels to the node device;wherein the node device is configured to transmit the estimations determined by the node device to the control device.

13. A system according to claim 12, wherein the wireless network comprises a wireless local area network, WLAN.

14. A system according to claim 12 or 13, wherein the node device comprises one or more lighting devices.

15. A computer program product configured to, when executed in one or more processors of a node device according to claim 9, perform the determining steps of a method according to any one of claims 1-8.

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