Association Solutions for Wireless Communication Networks

Abstract

The present application relates to an association system for a wireless communication network. The system includes an association initiator device and an association target device. Each association target device transmits a beacon message including load data of the association target device, the load data including data indicating the number of router devices currently associated with the association target device. After receiving the beacon messages from the association target devices, each association initiator device determines whether to attempt association with the association target device based at least in part on the load data included in the beacon message received from the association target device, and transmits an association request message to each of the association target devices with which the association initiator device determines to attempt association.

Description

[Technical field]

[0001] The present invention relates generally to the technical field of wireless communication networks, and more particularly to an association process in wireless communication networks. [Background technology]

[0002] Typically, in a wireless communication system (e.g., 3G, LTE, 3GPP®, or IEEE 802.11), a wireless device, user equipment (UE) (e.g., in a 3GPP® system), or receiving station (STA) (e.g., in an IEEE 802.11 system), initiates a wireless connection to a base station (BS) or access point (AP) based on radio measurements, optimizes link performance, and transmits an association request (e.g., referred to as an RRC request in a 3GPP® system) to the selected BS / AP. The BS / AP is responsible for its load control by accepting or rejecting the received association request. Similar association techniques can also be applied to wireless multi-hop networks such as wireless sensor networks (WSNs), wireless mesh networks, and DECT-2020 (Digital European Cordless Telecommunication 2020)-based networks. However, in wireless multi-hop networks with multiple devices that typically have limited resources, e.g., battery or processing power, caused by relatively low-cost and simple components (e.g., radios, processors, etc.), it is intended to avoid unsuccessful association attempts. Sending association request and association reject messages is power and time consuming for both the device initiating the association and the device responding to the association message. For example, failed association attempts increase the time used for the association process.

[0003] Due to practical limitations of technology and environment, wireless communication networks typically comprise only devices that can generate data (non-router devices) and devices that can generate data (router devices) and participate in routing application data through the network. Router devices may have limitations on how many associated devices they can serve. Devices served by router devices may be router devices or non-router devices. Typically, router devices no longer have room for association and all associated devices may be non-router devices. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,830,838 [Patent Document 2] U.S. Pat. No. 10,499,264 Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide an association system, an association method, an association device, a computer program, and a computer readable medium for a wireless communication network. Another object of the present invention is to enable the association system, the association method, the device, the computer program, and the computer readable medium for a wireless communication network to at least reduce unnecessary association request messages and association response messages indicating a rejection of the association request.

[0006] The object of the invention is achieved by an association system, an association method, an association device, a computer program and a computer readable medium as defined by the respective independent claims. [Means for solving the problem]

[0007] The following presents a simplified summary in order to provide a basic understanding of some aspects of various invention embodiments. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of example embodiments of the invention.

[0008] According to a first aspect, there is provided an association system for a wireless communication network. The system includes at least one association initiator device and at least one association target device, wherein at least one of the association initiator devices and at least one of the association target devices belong to a plurality of communication devices, each communication device of the plurality of communication devices being a wireless node device configured to provide bidirectional wireless communication with at least one of the plurality of communication devices, each association target device being configured to transmit a beacon message including load data of the association target device, the load data including at least data indicating a number of router devices with which it is currently associated, and after receiving the beacon message from at least one association target device, each association initiator device decides whether to attempt to associate with at least one of the association target devices from which the beacon message is received based on the load data included at least in part in the beacon message received from at least one of the association target devices, and transmits an association request message to each of the at least one association target device with which the association initiator device attempts to associate.

[0009] Determining may depend on the operational role of the association initiator, which may be a router role or a non-router role.

[0010] The load data may further include data indicative of a maximum number of associated devices allowed and / or data indicative of the number of non-router devices currently associated.

[0011] The load data may further include one or more performance parameters including random access channel (RACH) load data, channel load data, traffic load data, and / or route cost data.

[0012] If the beacon messages are received from at least two association target devices, each association initiating device may be configured to select at least one most suitable association target device based on at least one selection criterion.

[0013] At least one of the selection criteria may comprise the load data of at least two of the associated devices, at least partially contained in the beacon messages received from at least two of the associated devices.

[0014] At least one of the selection criteria may further include link quality data, the ability to use higher order modulation, a minimum bit rate provided to one associated device, guaranteed end-to-end latency characteristics, and / or the availability of a route to a sink device.

[0015] The association request message may include data indicating an operational role of the association initiator.

[0016] The association request message may further include data indicating an energy saving mode of the association initiator device, data indicating the number of devices currently associated with the association initiator device, and / or data indicating the traffic load of the association initiator device.

[0017] In response to receiving the association request message from at least one association initiator device, each association target device may be configured to determine whether to accept the association request from at least one of the association initiator devices based on data indicative of a maximum number of association devices for the association target device, and if the maximum number of permitted association target devices has been reached, each association target device may be further configured to use data included in the association request message received from at least one of the association initiator devices to determine whether to accept the association request from at least one association initiator device.

[0018] When the maximum number of permitted association devices is reached and the association target device decides to accept an association request from at least one association initiator device acting in a router role, each association target device may be configured to disassociate at least one currently associated non-router device.

[0019] The wireless communication network may be a wireless sensor network (WSN), a Digital European Cordless Telecommunication 2020 (DECT-2020) based network, or a wireless mesh network.

[0020] According to a second aspect, there is provided an association method for a wireless communication network, the method comprising: presenting at least one association initiating device and at least one association target device belonging to a plurality of communication devices operating as wireless node devices, each communication device of the plurality of communication devices providing bidirectional wireless communication with at least one of the plurality of communication devices, each association target device transmitting a beacon message including load data of the association target device including at least data indicating a number of router devices with which it is currently associated, after receiving the beacon message from at least one association target device, each association initiating device deciding based on the load data included at least in part in the received beacon message from at least one of the association target devices whether to attempt to associate with at least one of the association target devices with which the beacon message is received, and each association initiating device transmitting an association request message to each of the at least one association target device with which the association initiating device has decided to attempt to associate.

[0021] According to a third aspect, there is provided an association initiation device for participating in an association process in a wireless communication network, the association initiation device comprising a control means and a wireless communication means (536) for operating as a wireless node device, the wireless communication means being configured to provide bidirectional wireless communication with at least one of a plurality of communication devices, and after the wireless communication means receives a beacon message from at least one association target device, the control means determines whether to attempt to associate with at least one of the association target devices for which the beacon message is received based on load data at least partially included in the received beacon message from at least one association target device, the beacon message including load data of the association target device including at least data indicating a number of currently associated router devices, and the wireless communication means transmits an association request message to each of the at least one association target device with which the association initiation device has determined to attempt to associate.

[0022] According to a fourth aspect, there is provided an association method for an association process in a wireless communication network, the method comprising: a wireless communication means of an association initiating device operating as a wireless node device providing bidirectional wireless communication with at least one of a plurality of communication devices, after receiving a beacon message from at least one association target device, a control means of the association initiating device determining whether to attempt association with at least one of the association target devices based on load data at least partially contained in the received beacon message from at least one of the association target devices, the beacon message including the load data of the association target device including at least data indicative of a number of currently associated router devices, and the wireless communication means of the association initiating device transmitting an association request message to each of the at least one association target device with which the association initiating device has determined to attempt association.

[0023] According to a fifth aspect, there is provided an association target device for participating in an association process in a wireless communication network, the association target device comprising control means and wireless communication means for operating as a wireless node device, the association target device being configured for the wireless communication means to provide bidirectional wireless communication with at least one of a plurality of communication devices, the association target device being configured for the wireless communication means to transmit a beacon message including load data of the association target device including at least data indicative of a number of router devices with which it is currently associated.

[0024] According to a sixth aspect, there is provided an association method for an association process in a wireless communication network, wherein a wireless communication means of an association target apparatus operating as a wireless node apparatus provides bidirectional wireless communication with at least one of a plurality of communication devices, and the wireless communication means of the association target apparatus transmits a beacon message including load data of the association target apparatus including at least data indicative of a number of router devices with which it is currently associated.

[0025] According to a seventh aspect, there is provided a computer program comprising instructions which, when executed by a computer, cause the computer to carry out at least the association method according to claim 15 or 17.

[0026] According to an eighth aspect, there is provided a tangible, non-volatile computer readable medium, the tangible, non-volatile computer readable medium comprising the computer program of claim 18.

[0027] Various exemplary and non-limiting embodiments of the present invention, both as to structure and method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplary and non-limiting embodiments when read in connection with the accompanying drawings.

[0028] Verbs such as "comprise" and "comprise" are used herein as open limitations that do not exclude or require the presence of unrecited features. Features recited in dependent claims may be freely combined with each other unless otherwise stated. Furthermore, it is to be understood that throughout this specification the use of "a", "an", etc., i.e. the singular, does not exclude the plural. [Brief description of the drawings]

[0029] [Figure 1] 1 illustrates a schematic diagram of an association system in a wireless communication environment. [Diagram 2]1 illustrates a schematic flow chart of an association method. [Diagram 3] 4 illustrates generally an exemplary format of load data included in a beacon message. [Figure 4] 13A and 13B show schematic diagrams of an example of a determination process performed by an association target device. [Diagram 5] 1 illustrates operational portions of a wireless communication device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying figures.

[0031] 1 illustrates an association system 100 operating in a wireless communication environment. The environment comprises a wireless wireless communication network (system) 102 comprising a plurality of wireless wireless communication devices (nodes) 104. The devices 104 operate on the same spectrum, comprising one or more frequency bands, for example, in the same geographic area within the presented environment. The use of the same spectrum enables two-way wireless communication between the devices 104 in the network 102, such that a wireless transmission transmitted by one device 104 can be received by another device 104, and vice versa.

[0032] The system 100 may be applied to any wireless radio communication network 102 that uses packet transmission in communication, i.e., in data exchange. Preferably, the system 100 may be applied to any wireless radio communication network that may be used for multi-hop communication between devices 104, i.e., packets may be delivered over at least two consecutive radio links. The system 100 may be applied to a radio communication network 102 that complies with the DECT-2020 (Digital European Cordless Telecommunication 2020) standard. Some non-limiting examples to which the system 100 may be applied may include, but are not limited to, wireless multi-hop networks, wireless mesh networks, such as wireless sensor networks (WSNs), Bluetooth Low Energy (BLE) mesh networks, Zigbee networks, Thread networks, public land mobile networks (PLMNs), wireless local area networks (WLANs), low power wide area networks (LPWANs), cellular-based local area networks, cellular networks, and / or any other wireless networks. An example of a WSN is described in U.S. Pat. No. 7,830,838.

[0033] The devices 104 may be capable of receiving transmissions with one wireless technology, e.g., a BLE transmission or a WLAN transmission, all transmissions from the same network 102. However, at least one of the devices 104, e.g., one, two, three, four, or more devices, may be capable of receiving transmissions with at least two wireless technologies, e.g., a BLE transmission and a WLAN transmission, all transmissions from the same network 102.

[0034] The DECT-2020 standard is a radio access technology developed by ETSI. DECT-2020 supports massive machine type communications (mMTC) and ultra-reliable low latency communications (URLLC). On the physical (PHY) layer, the key technical components of DECT-2020 are orthogonal frequency division multiplexing (OFDM), adaptive modulation and coding schemes (MCS), modern channel coding methods (turbo, LDPC, convolutional coding), hybrid automatic repeat request (HARQ) for both scheduled and contention-based transmissions, and support for multi-antenna transmissions with different multiple-input multiple-output (MIMO) streams. On the medium access (MAC) layer, and from a system perspective, the key technical components of DECT-2020 are support for a large number of Internet of Things (IoT) sensors, actuators, and other industrial applications, support for mesh network topologies, support for URLLC communications with very low latency (a typical application could be wireless microphones), operation on license-exempt frequencies, and support for multiple overlapping non-cooperative networks with cognitive radio capabilities to share spectrum resources among multiple networks.

[0035] The system 100 is used to establish associations between devices 104 to enable data routing through the network 102. The system 100 is primarily described by using three devices 104a, 104b, 104c forming a group of devices 104a, 104b, 104c belonging to the system 100 and operating within the network 102. However, these devices 104a, 104b, 104c correspond to the device 104. The network 102 may also comprise a number of other devices 104 that also participate in forming said group, in which case the group comprises the devices 104, 104a, 104b, 104c.

[0036] As explained above, each device 104 can provide, by means of its radio 436, two-way wireless communication with at least one other device 104. This means that each device 104 can operate as a transmitter, as a receiver, or as a transmitter-receiver, where each device 104 can transmit at least one message to other devices 104 and receive at least one message from other devices 104 in the network 102.

[0037] The system 100 may also include at least one gateway device 105, e.g., one, two, three, four, or more gateway devices. Each gateway device 105 acts as a gateway between the network 102 and other external networks 106 (e.g., the Internet) and distributes data to and from the network 102. Each gateway device 105 communicates with at least one sink device (node) 104a, e.g., one, two, three, four, or five or more sink devices, and each sink device 104a acts as a wireless interface for the gateway device 105 in the network 102. Each sink device 104a may be physically located in connection with the gateway device 105 or may be located separately in different parts of the network 102. If the gateway 105 includes several sink devices 104a, they may be located separately relative to the gateway device 105 and others in different parts of the network 102.

[0038] The sink device 104a is a fixed router device (router), while the other node devices 104 can operate in different fixed or non-fixed roles in the network 102. The other devices 104 in the system 100 are router devices, i.e. devices operating in a router role, and non-router devices (non-routers), i.e. devices operating in a non-router role depending on whether the device 104 needs to participate in data forwarding. One method for selecting the roles of router and non-router can follow, for example, the method described in Patent Document 2 (U.S. Pat. No. 10,499,264).

[0039] Each router device 104 maintains connectivity for the system 100 and routes (forwards) data for other devices 104 when necessary. Each non-router device 104, like the sink and router devices 104, can provide two-way communication to transmit its own data and receive data directed to it, but the non-router devices 104 do not route data for other devices 104. Each of the devices 104 is capable of operating at least as a router or a non-router device.

[0040] The system 100 includes devices 104 because not all devices 104 can directly communicate with the sink device 104 (gateway device) 105 due to the wide distance between the devices 104 and the limited wireless range, in which case multi-link (multi-hop) communication between each device 104 and the sink device 104 must be used.

[0041] FIG. 2 illustrates an association process, i.e., an association method for an association procedure, according to the above-mentioned association system 100 in a wireless communication network 102. The purpose of the association process is to initiate bidirectional communication, i.e., data exchange, between two devices 104. One device 104 can have active associations to multiple other devices 104 simultaneously. Once an association is established, it may be maintained until explicitly released by either party. Here, one association initiator 104b and one association target device 104c are used for the description. The system 100 may further include at least one other association initiator device, e.g., one, two, three, four, or five or more other association initiator devices, including the association initiator 104b. The system 100 may further include at least one other associated device, e.g., one, two, three, four, or five or more other associated devices including the associated device 104c. The association initiator 104b, i.e., the device that at least attempts to initiate bidirectional communication, may be a router device or a non-router device. In other words, each router device and each non-router device of the network 102 may act as an association initiator 104b of the system 100. The associated device 104c, i.e., the device that at least attempts to establish an association, may be a sink device 104a or a router device. In other words, each sink device 104a and each router device of the network 102 may act as an associated device 104c of the system 100.

[0042] In step 202, the associated target device 104c periodically transmits, by its wireless communication means 536, a beacon message including the load data of said associated target device 104c. In other words, in step 202, each associated target device 104c is configured to periodically transmit a beacon message including the load data to distribute the load data in the network 102. The beacon message can be, for example, a network beacon message or a cluster beacon message. The load data includes at least data indicative of the number of currently associated router devices of said associated target device 104c. The data indicative of the number of currently associated router devices can include, for example, the number of currently associated router devices expressed as an exact numerical value and / or a percentage value. "Currently associated device of a target device" means throughout this application that the device has an association to the associated target device 104c substantially at that moment. However, the number of currently associated devices may be considered a subjective view by the associated device 104c since there may be some delay in realizing that one or more associated devices have released their association with the associated device 104c.

[0043] The load data may further include data indicative of a maximum number of allowed association devices of the associated target device 104c and / or data indicative of a number of currently associated non-router devices of the associated target device 104c. The data indicative of the number of currently associated non-router devices may include, for example, the number of currently associated non-router devices expressed as an exact number and / or as a percentage value. The data indicative of the maximum number of allowed association devices may include, for example, the maximum number of allowed association devices expressed as an exact number and / or as a percentage value. The maximum number of allowed association devices defines the maximum allowed number of association devices of the associated target device 104c for both router and non-router devices. The maximum number of allowed association devices may depend, for example, on the underlying radio technology, the spectrum resources, the time and frequency allocation of the network 102, the memory limitations of the implementation, and / or the type and amount of application data desired in the network 102. Thus, the maximum number of allowed association devices may be defined per implementation and / or there may be different maximum numbers of allowed association devices used by different associated devices 104c in the same network 102. In other words, all associated devices 104c of the system 100 in the network 102 may have the same maximum number of allowed association devices. Alternatively, at least one associated device 104c of the system 100 in the network 102 may have a device-specific, i.e., its own maximum number of allowed association devices. If the maximum number of allowed association devices is the same for all devices 104 in the network 102, i.e., the maximum number of allowed association devices is constant for all devices 104 in the network 102, the data indicating the maximum number of allowed association devices may be defined as a network configuration parameter.Data indicative of the maximum number of allowed association devices defined as a network configuration parameter may be pre-provisioned for each device 104 of the network 102. If the data indicative of the maximum number of allowed association devices is defined as a network configuration parameter, the data indicative of the maximum number of allowed association devices may be included in the beacon message, but may not necessarily be included in the beacon message. In particular, if the maximum number of allowed association devices is not device-specific, i.e., is not the same for all devices 104 in the network 102, each associated target device 104c preferably includes data indicative of the maximum number of allowed association devices of said associated target device 104c in the load data included in the beacon message. Each associated target device 104c may keep a count of the number of router devices and non-router devices with which it is currently associated.

[0044] The load data may further comprise one or more performance parameters of the associated target device 104c. These one or more performance parameters of the associated target device 104c may comprise, for example, random access channel (RACH) load data, channel load data, traffic load data, and / or route cost data. Each associated target device 104c may define the one or more performance parameters, for example, by observing transmissions by its associated device and / or by at least one other associated target device.

[0045] 3 illustrates a non-limiting exemplary format of load data 300 that may be included in a beacon message in a DECT 2020 based wireless communication network 102. While possible exemplary parameters included in the load data 300 are illustrated in the example of FIG. 3, as noted above, the load data 300 included in the beacon message may include at least data indicative of the number of associated router devices, and other parameters of the load data 300 included in the beacon message may be optional. A definition of the load data 300 shown in FIG. 3 is provided in Table 1.

[0046] Table 1: Definition of an example load data 300 format for FIG.

[0047] [Table 1]

[0048] As step 204, the association initiator device 104b receives, by its wireless communication means 536, a beacon message from at least one association target device, for example the association target device 104c. The received beacon message comprises load data of said association target device 104c, as explained above.

[0049] In step 208, after receiving a beacon message from at least one associated target device 104c in step 204, the association initiator device 104b decides by its control means 530 whether to attempt to associate with at least one associated target device 104c from which a beacon message is received, based on load data at least partially included in the received beacon message from said at least one associated target device 104c. As mentioned above, the load data may include at least data indicative of the maximum number of allowed associated devices in addition to data indicative of the number of currently associated router devices. If the maximum number of allowed associated devices is device specific, the data indicative of the maximum number of allowed associated devices is included in the load data included in the beacon message. Alternatively or additionally, if the maximum number of allowed associated devices is the same for all devices in the network 102, the data indicative of the maximum number of allowed associated devices may be defined as a network configuration parameter and not necessarily included in the beacon message. Thus, the load data of the at least one associated device 104c may be at least partially, ie, either partially or entirely, included in the received beacon message from the at least one associated device 104c.

[0050] According to one example, the decision in step 208 may depend on the operational role of the association initiator 104b, i.e., the decision process in step 208 differs depending on whether the association initiator 104b is a router device or a non-router device.

[0051] Next, some examples of the decision process in step 208 are disclosed. In these examples, it is assumed that the association initiator device 104b receives a beacon message from one associated target device 104c. However, if the association initiator device 104b receives a beacon message from two or more associated target devices 104c, a similar decision process in step 208 can be applied to each associated target device 104c.

[0052] According to one example, if the association initiator device 104b is a router device, it may decide to attempt association with the association target device 104c if the number of currently associated router devices of the association target device 104c, expressed as a percentage value, is less than 100%.

[0053] According to another example, if the association initiator device 104b is a router device, it may decide to attempt association with the association target device 104c if the number of currently associated router devices of the association target device 104c is smaller than the maximum number of allowed association devices of the selected association target device 104c. The maximum number of allowed association devices of the association target device 104c may be included in the load data included in the received beacon message as described above. Alternatively, the maximum number of allowed association devices of the association target device 104c may be defined as a network configuration parameter as described above.

[0054] Alternatively, according to one example, if the association initiator device 104b is a non-router device, it may decide to attempt to associate with the associated target device 104c if, for example, the number of currently associated router devices of the associated target device 104c expressed as a percentage value is less than 100%. Alternatively, a stricter restriction may be implemented to decide to attempt to associate with the associated target device 104c if, for example, the number of currently associated router devices of the associated target device 104c expressed as a percentage value is less than 75%.

[0055] According to another example, if the association initiating device 104b is a non-router device and the load data further comprises data indicating the number of currently associated non-router devices of the associated target device 104c, it may be determined to attempt association with the associated target device if the sum of the number of currently associated router devices of the associated target device 104c expressed as a percentage value and the number of currently associated non-router devices of the associated target device 104c expressed as a percentage value is less than 100%.

[0056] According to yet another example, if the association initiator device 104b is a non-router device and the load data further includes data indicating the number of currently associated non-router devices of the association target device 104c, it may decide to attempt to associate with the association target device 104c if the sum of the number of currently associated router devices of the association target device 104c and the number of currently associated non-router devices of the association target device 104c is smaller than the maximum number of allowed associated devices of the selected association target device 104c. The maximum number of allowed association devices of the selected association target device 104c may be included in the load data included in the received beacon message as described above. Alternatively, the maximum number of allowed association devices of the association target device 104c may be defined as a network configuration parameter as described above.

[0057] In both cases, i.e. when the association initiator device 104b is a router device or a non-router device, the association initiator device 104b may further use one or more performance parameters of the association target device 104c included in the load data in the decision in step 208 of whether to attempt to associate with the association target device 104c. These one or more performance parameters included in the load data may comprise RACH load data, channel load data, traffic load data, and / or route cost data, as explained above. Alternatively or in addition, the association initiator device 104b may further use at least one additional performance parameter, e.g. link quality data, in the decision of whether to attempt to associate with the association target device 104c. The association initiator device 104b may define the link quality data, for example, based on the signal strength of the beacon message received from the association target device 104c.

[0058] The decision of whether to attempt to associate with the association target device 104c in step 208 makes it possible to at least reduce or even avoid unnecessary association request messages and rejection signaling.

[0059] If the association initiator device 104b receives beacon messages from at least two association target devices 104c in step 204, the association initiator device 104b may select at least one most suitable association target device 104c in step 206 by its control means 530 based on at least one selection criterion, e.g. at least one selection parameter. The selection may be performed before the decision in step 208, as shown in Fig. 2 as an optional step. After the selection of the at least one most suitable association target device 104c, the association initiator device 104b may decide in step 208 whether to attempt to associate with the at least one selected (i.e. most suitable) association target device 104c based at least in part on load data contained in the received beacon messages from the at least one selected association target device 104c. In other words, the association initiator device 104b may first select at least one most suitable association target device 104 in step 206, and after the selection, perform a decision process of at least one selected (most suitable) association target device 104c in step 208 as described above. Alternatively, the selection may be performed after the decision performed in step 208. In that case, the association initiator device 104b may first determine in step 208 whether to attempt association with at least two association target devices 104c from which beacon messages are received as described above. After the decision in step 208, the association initiator device 104b may further select at least one most suitable association target device 104c in step 206 based on at least one selection criterion. In other words, the association initiator device 104b can first perform the determination process of at least two association target devices 104c in the above-mentioned step 208, and after the determination in step 206, select at least one most suitable association target device 104 in step 206.

[0060] At least one selection criterion may comprise load data of the at least two associated devices 104c included at least partially in the received beacon message from the at least two associated devices 104c. As described above, the load data may include at least data indicative of the maximum number of allowed associated devices in addition to data indicative of the number of currently associated router devices. If the maximum number of allowed associated devices is device specific, the data indicative of the maximum number of allowed associated devices is included in the load data included in the beacon message. Alternatively or additionally, if the maximum number of allowed associated devices is the same for all devices in the network 102, the data indicative of the maximum number of allowed associated devices may be defined as a network configuration parameter and not necessarily included in the beacon message. Thus, the load data of the at least two associated devices 104c may be included at least partially, i.e. partially or entirely, in the received beacon message from the at least two associated devices 104c as described above. By using the load data of at least two associated target devices 104c as at least one selection criterion in step 206 in selecting at least one most suitable associated target device 104c, it becomes possible to balance the system load among different router devices 104.

[0061] At least one selection criterion may further comprise one or more additional parameters of at least two association target devices 104c. The one or more additional parameters of each association target device 104c may comprise, for example, link quality data, the ability of the association target device to use higher order modulation, a minimum bit rate provided to one of the association target devices, a guaranteed end-to-end latency characteristic of a link, the availability of a route of the association target device to a sink device, and / or any other additional parameters. For example, the association initiator device 104b may first select one or more candidates for the at least one most suitable association target device by using the load data of the at least two association target devices as described above, and then select at least one most suitable association target device from among the one or more candidate target devices by using one or more additional parameters of the at least two association target devices as described above. Each association initiator device 104b may, for example, define one or more additional parameters based on the received beacon message from the association target device 104c.

[0062] The selection of the at least one most suitable associated target device 104c in step 206 may for example comprise a comparison between at least one selection criterion of each of the at least two associated target devices 104c and a selection of at least one most suitable associated target device from among the at least two associated target devices 104c based on the result of the comparison. For example, the association initiating device 104b may compare the selection criteria of each of the at least two associated target devices 104c, such as their respective load data or their respective one or more additional parameters, with each other and select the at least one most suitable associated target device 104c, for example, but not limited to, based on the result of the comparison between the at least one associated target device with the highest selection parameter, the lowest selection parameter value, the selection parameter exceeding a predefined limit or, depending on the at least one selection parameter used, the selection parameter being below a predefined limit. For example, if at least one selection criterion used is the number of currently associated router devices, the association initiating device 104b may compare the numbers of currently associated router devices of at least two associated target devices 104c with each other and select, for example, at least one associated target device 104c with the highest number of currently associated router devices or with a number of currently associated router devices exceeding a predefined limit.

[0063] According to an example, at least one selection criterion may be prioritized, e.g., at least one selection criterion may be prioritized over at least one other selection criterion when defining at least one selection criterion to be used in the selection at step 206. Alternatively, e.g., when using more than one selection criterion, the order of the selection criteria used in the selection at step 206 may be prioritized.

[0064] Next, some examples of the selection process in step 206 are disclosed. In these examples, it is assumed that the association initiator device 104b receives beacon messages from two association target devices 104c, namely, association target device A and association target device B. However, if the association initiator device 104b receives beacon messages from two or more association target devices 104c, a similar selection process in step 206 can also be applied. Although the selection process in these examples is disclosed by using a single selection criterion, the association initiator device 104b can also use two or more selection criteria in the selection process. The selection process may also be performed by using any at least one selection criterion other than the selection criteria used in these examples.

[0065] According to an example, if the traffic load of association target device A is, for example, 90% and the traffic load of association target device B is, for example, 20%, the association initiator device 104b may select association target device B as the optimal association target device 104c.

[0066] According to another example, if the link quality data of association target device A indicates a better link quality than the link quality data of association target device B, association initiator device 104b may select association target device A as the optimal association target device 104c.

[0067] According to yet another example, if association target device A has, for example, five currently associated router devices and association target device B has, for example, eight currently associated router devices, association initiator device 104b may select association target device A as the most suitable association target device 104c.

[0068] The selection of at least one most suitable association target device in step 206 makes it possible to at least reduce or even avoid unnecessary association request messages and rejection signaling, i.e. association response messages indicating the rejection of the association request, which would consume energy and spectrum resources.

[0069] In step 210, the association initiator 104b transmits, by its wireless communication means 536, an association request message to each of the at least one association target device 104c with which the association initiator 104b decides to attempt association in step 208. The association request message includes at least data indicative of the operational role of the association initiator 104b. Each association initiator 104b knows its operational role, i.e. whether it is operating in a router role or in a non-router role. The content of the association request message may be divided into one or more radio link messages, e.g. packets or protocol data units (PDUs).

[0070] 2 / 27 In step 212, the association target device 104c receives, by its wireless communication means 536, an association request message from at least one association initiator device, for example from the association initiator device 104b. Each received association request message comprises at least data indicative of the operational role of the association initiator device 104b from which the association request message is received, as described above.

[0071] In step 214, in response to receiving an association request message from at least one association initiator device, for example from the association initiator device 104b in step 212, the respective association target device, for example the association target device 104c, by its control means 530 decides whether to accept the association request received from the at least one association initiator device 104b based on data indicative of the maximum number of permitted associated devices of said association target device 104c. If the maximum number of permitted associated devices is not reached, the association target device 104c may decide in step 214 to accept all received association requests, regardless of the operational role of the association initiator device 104b. If the maximum number of permitted associated devices has been reached, the association target device 104c may further use the data contained in the association request message received from the at least one association initiator device 104b in step 214 to determine whether to accept the association request from the at least one association initiator device 104b.

[0072] In response to the decision in step 214 whether to accept the association request from the at least one association initiator device 104b, the association target device 104c transmits by its wireless communication means 536 in step 216 or, depending on the decision made, in step 218, an association response message to the at least one association initiator device 104b indicating either the acceptance of the association request or the rejection of the association request. If in step 214 the association target device 104c decides to accept the association request from the at least one association initiator device 104b, the association target device 104c transmits in step 216 an association response message to said at least one association initiator device 104b including an indication of the acceptance of the association request. Alternatively, if in step 214 the association target device 104c decides to reject the association request from the at least one association initiator device 104b, the association target device 104c sends an association response message including an indication of the rejection of the association request to said at least one association initiator device 104b in step 216. The contents of the association response message may be split into one or more radio link messages, e.g., packets or protocol data units (PDUs).

[0073] The association target device 104c may prioritize router devices over non-router devices when deciding whether to accept an association request from at least one association initiator device 104b in step 214. For example, the association target device 104c may disassociate at least one currently associated non-router device and the maximum number of allowed association devices is reached, and said association target device 104c decides to accept an association request from at least one association initiator device 104b operating in a router role. According to another example, the association target device 104c may decide not to accept an association request from at least one association initiator device 104b operating in a non-router role if the maximum number of allowed association devices is reached. Prioritizing router devices over non-router devices when determining whether to admit an association request from at least one association initiator 104b improves the routing performance of the network 102.

[0074] The association request message may further include data indicating the energy saving mode of the association initiating device 104b (e.g., low energy (LE) / low latency (LL) mode), data indicating the number of currently associated devices of the association initiating device 104b, and / or data indicating the traffic load of the association initiating device 104b. In LL mode, the association initiating device 104b is always active, i.e., not in sleep state, so that it can receive low latency data to be routed. Association initiating devices 104b operating in LL mode try to optimize the use of their wireless communication means 536 to enable the routing of low latency data. Association initiating devices 104b operating in LL mode do not try to save power. Each association initiating device 104b is aware of its energy saving mode, defines its traffic load, and maintains a count of the number of its currently associated devices. The association target device 104c may further use this further data included in the association request message to decide whether to accept the association request from at least one association initiator 104b. For example, an association initiator 104b operating in a router role that is mains powered (i.e., operating in LL mode) may be prioritized over other association initiators 104b operating in a router role that is mains powered. According to another example, with less battery resources, an association initiator 104b operating in a router role (i.e., operating in LE mode) may be prioritized over more capable association initiators operating in a router role, so that it needs to spend less energy to search for alternative connections.

[0075] FIG. 4 shows an example of the determination process performed by the association target device 104c in step 214. In the example of FIG. 4, router devices are prioritized over non-router devices in each step. FIG. 4 also shows optional prioritization (optional steps 410-414, shown by dashed lines in FIG. 4), in which among multiple router devices, router devices operating in a non-energy saving mode are prioritized over router devices that do not operate in a non-energy saving mode, i.e., router devices operating in an energy saving mode. In step 402, in response to receiving an association request message from the association initiating device 104b in step 212, the association target device 104c checks whether the maximum number of allowed association devices has been reached. If the maximum number of permitted association devices has not been reached, the association target device 104c decides to approve the association request and sends an association response message to the association initiator device 104b including an indication of the approval of the association request (216). If the maximum number of permitted association devices has been reached in step 402, then the association target device 104c defines in step 404 whether the association initiator device 104b that received the association request message is a router device or a non-router device. If the association initiator device 104b is a non-router device, the association target device 104c decides to reject the association request and sends an association response message to the association initiator device 104b including an indication of the rejection of the association request (218). If the association initiator is a router device, the association target device 104c checks in step 406 whether the number of currently associated router devices is full, ie, whether the maximum number of currently associated router devices has been reached.If the number of currently associated router devices is not full in step 406, the association target device 104c decides to accept the association request, disassociates at least one currently associated non-router device in step 408, and sends (216) an association response message to the association initiator device 104b that includes an indication of the acceptance of the association request. If the number of currently associated router devices is full in step 406, the association target device 104c may send (218) an association response message to the association initiator device 104b that includes an indication of the rejection of the association request. Alternatively, the number of currently associated router devices is arrived at in step 406, and the association target device 104c may further use further data contained in the association request message to decide whether to accept the association request from the association initiator device 104b, for example by checking in step 410 whether the association initiator device 104b from which the association request message is received is operating in a non-energy saving mode, for example LL mode. If the association initiator device 104b is operating in an energy saving mode, i.e. not in a non-energy saving mode, in step 410 the association target device 104c may decide to reject the association request and send (218) an association response message to the association initiator device 104b including an indication of the rejection of the association request. If, in step 410, the association initiating device 104b is operating in a non-energy saving mode, the association target device 104c may further check in step 412 whether the number of currently associated devices operating in a non-energy saving mode is full, i.e., whether the maximum number of currently associated devices operating in a non-energy saving mode has been reached.If the number of currently associated devices operating in a non-energy saving mode is reached in step 412, the association target device 104c may decide to reject the association request and send (218) an association response message including an indication of the rejection of the association request to the association initiator device 104. If the number of currently associated devices operating in a non-energy saving mode is not reached in step 412, the association target device 104c may decide to accept the association request and disassociate (216) at least one currently associated router device operating in an energy saving mode in step 414 and send an association response message including an indication of the acceptance of the association request to the association initiator device 104b.

[0076] 5 illustrates devices 104 (104a, 104b, 104c) capable of communicating within network 102 and performing the relevant features (steps) of the association method as described above. In other words, a device 104 has been described that can act as an association initiator device 104b and perform the features of the association method associated with association initiator device 104b as described above, or a device 104 has been described that can act as an association target device 104c and perform the features of the association method associated with association target device 104c as described above.

[0077] The device 104 comprises a control means (controller) 530 for controlling the operation of its parts 532, 534, 536, 538, 540 so that the device 104 operates as described above.

[0078] The control means 530 comprises a processor 532 for executing operator-initiated instructions and / or computer program-initiated instructions and for processing data to execute applications. The processor 532 may comprise at least one processor, for example, one, two, three, four, five or more processors.

[0079] The control means 530 also includes a memory (memory section) 534 for storing and maintaining data. The data may be instructions, computer programs, and data files. The memory 534 includes at least one memory, for example, one, two, three, four, five or more memories.

[0080] The device 104 also comprises a wireless communication means (wireless communication unit, data transfer unit) 536 and an antenna (antenna unit) 538 that the control means 530 uses to transmit commands, requests, messages, and data to at least one entity in the system 100, e.g., the device 104, via the antenna 538. The wireless communication means 536 also receives commands, requests, and data from at least one entity in the system 100, e.g., the device 104, via the antenna 538. Communication between the wireless communication means 536 of the device 104 and other entities in the system 100 is provided wirelessly via the antenna 538.

[0081] The device 104 may further include a power supply 540. The power supply 540 includes components for providing power to the device 104, such as a battery and a regulator.

[0082] The memory 534 stores at least a wireless communication application 542 for operating (controlling) the wireless communication means 536 and a power supply application 544 for operating the power supply 540.

[0083] The memory 534 also stores a computer program (computer software, computer application) 546 which, when executed (run) by the control means 530, e.g. in a computer within the device 104, uses at least one of the portions 536, 538, 540 to perform at least the operations of the device 104 described above in relation to the previous figures.

[0084] The computer program 546 may be stored on a tangible, non-volatile computer readable storage medium, for example a compact disc (CD) or a universal serial bus (USB) type storage device.

[0085] The specific examples provided in the above description should not be construed as limiting the applicability and / or interpretation of the appended claims. The lists and groups of examples provided in the above description are not exhaustive unless expressly stated.

Claims

1. An association system (100) for a wireless communication network (102), comprising: at least one association initiator (104b); at least one associated device (104c); Including, at least one association initiator (104b) and at least one association target (104c) belong to a plurality of communication devices (104, 104a, 104b, 104c); each communication device (104, 104a, 104b, 104c) of the plurality of communication devices (104, 104a, 104b, 104c) is a wireless node device configured to provide bidirectional wireless communication with at least one of the plurality of communication devices (104, 104a, 104b, 104c); each associated target device (104c) is configured to transmit a beacon message including load data of said associated target device (104c), including at least data indicating the number of router devices with which it is currently associated; After receiving the beacon message from at least one association target device (104c), each association initiator device (104b) determining whether to attempt to associate with at least one of the association target devices (104c) from which the beacon message is received based on the load data included at least in part in the beacon message received from at least one of the association target devices (104c); sending an association request message to each of the at least one association target device (104c) with which the association initiator device (104b) attempts to associate; Association System (100).

2. determining is dependent on the operational role of said association initiator (104b); the operating role of the association initiator (104b) is a router role or a non-router role; The association system (100) of claim 1.

3. The load data further includes data indicating a maximum number of allowed association devices and / or data indicating a number of currently associated non-router devices; An association system (100) according to claim 1 or claim 2.

4. the load data further includes one or more performance parameters including random access channel (RACH) load data, channel load data, traffic load data, and / or route cost data; The association system (100) of claim 3.

5. When the beacon messages are received from at least two association target devices (104c), each association initiator device (104b) is configured to select at least one most suitable association target device (104c) based on at least one selection criterion. An association system (100) according to claim 1 or claim 2.

6. at least one of the selection criteria includes the load data of at least two of the associated devices (104c), which is at least partially contained in the beacon messages received from at least two of the associated devices (104c); The association system (100) of claim 5.

7. At least one of the selection criteria further comprises link quality data, the ability to use higher order modulation, a minimum bit rate offered to one associating device, guaranteed end-to-end latency characteristics, and / or the availability of a route to a sink device; The association system (100) of claim 6.

8. the association request message includes data indicating the operational role of the association initiator (104b); An association system (100) according to claim 1 or claim 2.

9. the association request message further includes data indicating an energy saving mode of the association initiator (104b), data indicating the number of devices currently associated with the association initiator (104b), and / or data indicating a traffic load of the association initiator (104b); The association system (100) of claim 8.

10. In response to receiving said association request message from at least one association initiator (104b), each association target device (104c) is configured to determine whether to accept an association request from at least one of the association initiator devices (104b) based on data indicating the maximum number of association devices for the association target device (104c); When the maximum number of allowed associated devices is reached, Each association target device (104c) is further configured to use data included in the association request message received from at least one of the association initiator devices (104b) to determine whether to accept the association request from at least one association initiator device (104b). An association system (100) according to claim 1 or claim 2.

11. When the maximum number of allowed association devices is reached and the association target device (104c) decides to accept an association request from at least one association initiator device (104b) acting in a router role, each association target device (104c) is configured to disassociate at least one currently associated non-router device; The association system (100) of claim 10.

12. The association system (100) according to claim 1 or claim 2, wherein the wireless communication network (102) is a Wireless Sensor Network (WSN), a DECT-2020 (Digital European Cordless Telecommunication 2020) based network, or a wireless mesh network.

13. An association method for a wireless communication network (102), comprising: Present at least one association initiator (104b) and at least one association target (104c) belonging to a plurality of communication devices (104, 104a, 104b, 104c) operating as wireless node devices; a respective communication device (104, 104a, 104b, 104c) of the plurality of communication devices providing bidirectional wireless communication with at least one of the plurality of communication devices; Each associated target device (104c) transmits (202) a beacon message including its load data, including at least data indicating the number of router devices with which it is currently associated; After receiving (204) the beacon message from at least one association target device (104c), each association initiator device (104b) determines (208) whether to attempt to associate with at least one of the association target devices (104c) from which the beacon message is received, based on the load data included at least in part in the received beacon message from at least one of the association target devices (104c); each association initiator (104b) sending an association request message to each of the at least one association target device (104c) with which the association initiator (104b) has determined to attempt association; Association method.

14. An association initiator (104b) for participating in an association process in a wireless communication network (102), comprising: The association initiator (104b) Control means (530); wireless communication means (536) for operating as a wireless node device; Equipped with the association initiator (104b) is configured such that the wireless communication means (536) provides bidirectional wireless communication with at least one of a plurality of communication devices; After the wireless communication means (536) receives a beacon message from at least one association target device (104c), the association initiator device (104b) a control means (530) determining whether to attempt to associate with at least one associated target device (104c) from which the beacon message is received based on load data contained at least in part in the received beacon message from the at least one associated target device (104c); the beacon message includes load data of the associated device (104c), including at least data indicating the number of router devices currently associated with it; a wireless communication means (536) transmitting an association request message to each of the at least one association target device (104c) that the association initiator device (104b) has determined to attempt to associate with; Association initiator (104b).

15. An association method for an association process in a wireless communication network (102), comprising: a wireless communication means (536) of the association initiator device (104b) operating as a wireless node device provides bidirectional wireless communication with at least one of the plurality of communication devices; After receiving (204) a beacon message from at least one association target device (104c), a control means (530) of the association initiator device (104b) decides (208) whether to attempt association with at least one of the association target devices (104c) based at least in part on load data contained in the received beacon message from at least one of the association target devices (104c); the beacon message includes the load data of the associated device (104c), including at least data indicating the number of currently associated router devices; the wireless communication means (536) of the association initiator (104b) sending (210) an association request message to each of the at least one association target device (104c) with which the association initiator (104b) has determined to attempt association; Association method.

16. An association target device (104c) for participating in an association process in a wireless communication network (102), comprising: The association target device (104c) is: Control means (530); wireless communication means (536) for operating as a wireless node device; Equipped with the association target device (104c) is configured such that the wireless communication means (536) provides bidirectional wireless communication with at least one of a plurality of communication devices; the association target device (104c) is configured to cause the wireless communication means (536) to transmit a beacon message including load data of the association target device, the load data including at least data indicating the number of router devices currently associated with the association target device; An association target device (104c).

17. An association method for an association process in a wireless communication network (102), comprising: a wireless communication means (536) of the association target device (104c) operating as a wireless node device provides bidirectional wireless communication with at least one of the plurality of communication devices; a wireless communication means (536) of the association target device (104c) transmitting (202) a beacon message including load data of the association target device (104c), the load data including at least data indicating the number of router devices currently associated with the association target device; Association method.

18. comprising instructions which, when executed by a computer, cause the computer to carry out at least the association method of claim 15 or 17, Computer program.

19. 19. The computer program of claim 18, A tangible, non-volatile computer-readable medium.

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