Route discovery in networks with combined nodes

Abstract

Route discovery in a network with combined nodes. The present invention relates to the field of wireless mesh communication networks, and particularly to a method, network, and node (101) for use in such a wireless mesh network (100) for establishing routes in the wireless mesh network (100) by actively and regularly sending many-to-one route requests at randomized intervals by a wireless network node (101), which can operate as a proxy node for a mobile wireless device (104) communicating using a first wireless communication protocol and other nodes (102, 103) in the wireless mesh network (100) communicating using a second wireless communication protocol.

Description

Technical Field

[0001] This invention relates to the field of wireless communication networks, and more particularly to a wireless network, wireless network node, and method for establishing routes in a wireless mesh network using many-to-one routing requests. Background Technology

[0002] An ongoing trend in the professional lighting market is the increasing shift towards connected lighting systems, which enable all sorts of new features, such as (remote) dispatching, energy monitoring, sensor-based lighting control, and asset management.

[0003] European patent application EP3154237 A1 discloses a network system having a client configured to transmit response requests at specific intervals, and a server configured to send a response to the client based on response requests received from the client, the network system being connected via a network. The server calculates a communication interval indicating the interval at which the client transmits response requests based on factors affecting the server's processing load, and sends communication interval information indicating the calculated communication interval to the client. The client transmits response requests at intervals corresponding to the intervals indicated by the communication interval information received from the server.

[0004] In many cases, these systems are installed in existing buildings, where wireless networks are preferred to avoid the need to deploy new cabling through the ceiling (for lighting control). Examples of such wireless network protocols widely used in current practice are open standard protocols like Zigbee, Thread, Bluetooth Low Energy (BLE), BLE Mesh, Wi-Fi, Wi-Fi Direct, and various proprietary network implementations built on top of the IEEE 802.15.4, IEEE 802.15.1, or IEEE 802.11 standards.

[0005] Recently, we have seen an increase in the use of so-called chip-on-chip (BOC) technology in lighting networks. BOC is essentially a cost-effective way to allow nodes in a lighting network to communicate using different communication protocols. Alternatively, two chips placed back-to-back can be used to bridge two different wireless networks.

[0006] International patent application WO2018 / 228883A1 discloses a system and method for relaying single-hop services (such as BLE) over multi-hop wireless networks (such as Zigbee). The basic idea is to extend the coverage and availability of BLE or other types of single-hop wireless networks by relaying single-hop messages over multi-hop wireless networks, leveraging the combined single-hop / multi-hop capabilities of wireless combining devices that can seamlessly bridge between two networks.

[0007] This invention aims to solve the problem of materialization in the context of Zigbee / BLE nodes. Summary of the Invention

[0008] In a typical Zigbee network, applications on a smartphone connect to the network via an internet-connected gateway (e.g., using a Wi-Fi connection). The gateway ensures that routes to every Zigbee node in the network are pre-established. This allows applications on the smartphone to communicate quickly with every node in the network because routes from the gateway to other nodes in the network have already been discovered—because the gateway remains connected to the network even if the smartphone disconnects. If no route to a node has been established and the smartphone (or gateway) intends to communicate with that node via unicast, that route must first be discovered.

[0009] Route discovery takes time and increases application latency. Furthermore, it creates broadcast bursts, which can temporarily negatively impact network performance. In Zigbee networks, route discovery can take up to 1 to 2 seconds. Additionally, the route discovery tables of nodes in a Zigbee network (i.e., tables that temporarily store the results of ongoing route discovery to keep track of the cost of retransmissions and changes to route request frames over a 10-second time period) are limited resources (Zigbee r22 PICS requires only a minimum of 4 route discovery tables). For both of these reasons, sending multiple AODV routes simultaneously should be avoided.

[0010] As another perspective, the inventors noted that there is no fixed gateway in a standalone Zigbee network. As a result, there is no fixed / single entry point into the Zigbee network from which a smartphone can reach all other nodes. Instead, the inventors envision a standalone Zigbee network comprising multiple Zigbee / BLE agents, through which a phone can randomly connect, while still retaining the intent to communicate with other nodes on the Zigbee network through the agents it connects to.

[0011] Communicating with multiple nodes on such a Zigbee network through a chosen proxy has several advantages: it allows users to avoid the tedious identification of individual nodes before establishing a 1:1 BLE connection; it eliminates the aforementioned redundant connection time (which can range from 1 to 2 seconds per node per connection, depending on the discovery and security methods used); and it allows for further time savings by parallelizing operations on the network instead of reading node states one by one. To this end, smartphones can request state updates by broadcasting to all nodes or by unicasting to multiple nodes and collecting responses as they are received.

[0012] However, the inventors envisioned a typical Zigbee standalone network system comprising several agent nodes supporting BLE / Zigbee, and optionally, the network may also include one or more network nodes that support only Zigbee. Establishing routes to all other nodes in the network when a phone connects to an agent would result in long route discovery times, leading to a poor user experience.

[0013] This invention aims to reduce overall network latency when sending messages from any proxy node to other Zigbee nodes in the network. This objective is achieved through wireless mesh networks, wireless network nodes, and route discovery methods in wireless mesh networks as described in this application.

[0014] According to a first aspect, a wireless mesh network including a first plurality of wireless network nodes is provided, wherein each of the first plurality of wireless network nodes is arranged to operate as a proxy and includes a first transceiver that communicates using a first wireless communication protocol and a second wireless communication protocol for the wireless mesh network. Each of the first plurality of wireless network nodes is arranged to: communicate with a mobile wireless device using the first communication protocol; communicate with wireless nodes in the wireless network using the second wireless communication protocol; and, in response to receiving a many-to-one routing request using the wireless mesh network, store an entry in the routing table of the receiving wireless network node, the entry indicating that the node issuing the many-to-one routing request is a concentrator node. The wireless mesh network is characterized in that: each of the first plurality of wireless network nodes is arranged to operate both as a proxy and as a concentrator; and, in preparation for communicating as a concentrator using the second wireless communication protocol, regularly sends out many-to-one routing requests at randomized intervals in the wireless mesh network with an average delay higher than a predetermined value, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

[0015] According to a second aspect, a wireless mesh network including a first plurality of wireless network nodes is provided, wherein each of the first plurality of wireless network nodes is arranged to operate as both a proxy and a concentrator, and includes: a first transceiver communicating using a first wireless communication protocol, and a second transceiver communicating using a second wireless communication protocol for the wireless mesh network, wherein each of the first plurality of wireless network nodes is arranged to: communicate with a mobile wireless device using the first communication protocol; communicate with wireless nodes in the wireless network using the second wireless communication protocol, and in response to receiving a many-to-one routing request using the wireless mesh network, store an entry in the routing table of the receiving wireless network node indicating that the node issuing the many-to-one routing request is a concentrator node; the wireless mesh network is characterized in that: each of the first plurality of wireless network nodes is arranged to: operate as both a proxy and a concentrator, and; in preparation for communicating as a concentrator using the second wireless communication protocol, regularly sends out many-to-one routing requests at randomized intervals on the wireless mesh network with an average delay higher than a predetermined value, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

[0016] Preferably, the first plurality of network nodes of the first and second aspects continuously track routes in the network in preparation for communication using the second wireless communication protocol.

[0017] The advantage of the wireless network according to the first and / or second aspects lies in the fact that the wireless network nodes are arranged in a way that performs route discovery, preparing for communication using mobile devices capable of “self-organizing” connection to the wireless network. This is accomplished by using wireless nodes capable of communicating using both the first and second communication protocols, so-called combined wireless nodes, or simply combined nodes. In this way, it is possible to provide selected combined nodes that “open” the wireless mesh network for (e.g., control) communication. Thus, even when only a limited number of combined nodes are provided in a room, these combined nodes can enable access to the wireless mesh network. In the case where the first communication protocol is the BLE protocol, discovery can be achieved through BLE advertising, which allows mobile devices to control both combined and non-combined nodes in the room after connection, as the route has been discovered.

[0018] The inventors noted that in a network where the second communication protocol is Zigbee, messages can take as long as one second to pulsate through the mesh. Consistent with this, many-to-one routing requests in the network should be sufficiently spaced in time so that the network topology updates in line with application requirements, but the network load caused by MTORRs remains constrained. Based on the rule of thumb for office applications, it is preferable to limit the number of MTORRs in the network to a level where there is no more than one MTORR on average every 5 seconds. It is worth noting that this still incurs considerable MTORR overhead, and the average number of MTORR occurrences can be reduced to once every 10 seconds, which already reduces the overhead. An option with an average of one MTORR every 15 seconds appears to be a preferred parameter for office lighting networks.

[0019] It will be clear to those skilled in the art that different applications may require different parameters. If the number of topology changes is high, it may be desirable to increase the number to an average of once every 10 seconds at the cost of greater MTORR overhead. Conversely, if the number of topology changes is low, a larger average time between MTORRs may be acceptable, and the randomization interval may be one MTORR on average every 30 seconds or one MTORR per minute.

[0020] In exemplary implementations of the first and second aspects described above, each of the first plurality of wireless network nodes is a BLE / Zigbee proxy node in a Zigbee mesh network, wherein the proxy acts as a concentrator and regularly sends out many-to-one routing requests (MTORRs) at randomized intervals. For example, randomization can be achieved using a random backoff period, which can be set within a predetermined value (maximum backoff period).

[0021] Preferably, the randomization interval (e.g., a predetermined value) is selected based on the size of the network and the number of agents in the network. Since MTORRs generate load in the network, consecutively issuing MTORRs causes significant message overhead. If a MTORR typically takes less than one second to complete, then having a message every 10 seconds causes substantial network load. Therefore, an average of 15 seconds between MTORRs in the network is preferred, but as a rule of thumb, an average of 10-30 seconds between MTORRs in the network should be feasible. Having a longer average time between consecutive MTORRs would be effective, but would result in a longer time before all routes are established / updated.

[0022] For example, in a network with 250 router nodes, having an average of one MTORR every 15 seconds means that all routes can then be mapped in approximately 250 × 15 seconds.

[0023] When a node receives a MTORR, it stores an entry in its routing table indicating that the other node that sent the MTORR is a concentrator node. When all agent nodes have sent MTORRs, each node has a complete routing table with known routes to any other agent node in the network.

[0024] Once the routing table is full, when a smartphone connects to any proxy node, it can use the information already present in the proxy node's routing table to reach any Zigbee node.

[0025] Furthermore, note that a Zigbee router acting as a router within a Zigbee wireless mesh can also act as a concentrator, issuing many-to-one routing requests in a manner similar to that described above for agents. As will be clear to those skilled in the art, this can be combined with the two aspects mentioned above.

[0026] The randomization interval of the wireless mesh network in the first and / or second aspects is preferably based on a predetermined value on the network size, or more preferably on the number of agents in the wireless mesh network, and is randomized. The basic idea is that networks with a larger number of nodes or a larger number of agents / concentrators will result in more MTORR message overhead. Therefore, propagating this information at a lower frequency will reduce the impact. In addition, randomization will help reduce the possibility of peak congestion.

[0027] Preferably, the wireless mesh network comprises a first plurality of wireless network nodes and a second plurality of wireless network nodes, and each of the second plurality of wireless network nodes includes a second transceiver for communicating using a second wireless communication protocol, and each of the second plurality of network nodes is arranged to communicate with nodes in the wireless mesh network using the second wireless communication protocol, wherein the number of wireless router nodes in the first plurality is greater than 30% of the total number of wireless router nodes in the wireless mesh network. Optionally, the number of wireless router nodes in the first plurality is greater than 40% or even greater than 50% of the total number of wireless router nodes in the wireless mesh network.

[0028] When a large number of wireless nodes are combined / dual-protocol nodes, the impact of route discovery on network traffic can increase, and therefore the benefits of propagating MTORR messages also increase over time. In fact, the inventors foresaw that this invention would be particularly beneficial if one wanted to implement a network that primarily uses combined / dual-protocol nodes.

[0029] When a large number of wireless nodes will be combinatorial / dual-protocol nodes, especially in dense networks, it may be advantageous to consider switching some combinatorial / dual-protocol nodes to operate only on the second mesh protocol, or even to a non-router role. The advantage of doing so is that in dense networks, switching nodes to non-router roles, such as Zigbee end devices or ZED roles, is possible without significantly impacting network / routing reliability. As a result, the number of nodes requiring path discovery can be reduced, further contributing to reducing the MTORR message load in the network.

[0030] Switching a wireless network node to the ZED role (second mesh protocol operation only) can be done prior to installation, for example, based on an installation plan, and via software configuration (e.g., using NFC) or hardware configuration (e.g., using a DIP switch). Alternatively, such a switch can be performed during network initialization based on an installation plan and / or field radio measurements, and via hardware configuration or software configuration utilizing network initialization tools. Finally, such a switch can be performed during the operation phase, in which case software-based configuration using the second wireless communication protocol is preferred.

[0031] Because wireless networks can have varying characteristics that can affect routing within the network, the randomization interval may need to be adjusted accordingly. For example, if the only variation in network routing / topology is a device defect or incidental RF interference from a non-network source, the randomization interval can be set to a value that causes the mapping router to take an average of more than one or more hours. Alternatively, if the network contains wireless nodes that can regularly enter power-saving mode, or if low latency is required, the randomization interval can be chosen to complete route mapping within the network within a range of 15 minutes to one hour. In these scenarios, the temporal characteristics or attributes of the network topology / routing are used to configure the randomization interval.

[0032] Advantageously, according to the first or second aspect, the wireless mesh network is a network without a fixed gateway (such as a Zigbee network without a fixed gateway).

[0033] According to a third aspect, a wireless network node for use in a wireless mesh network is provided, the wireless network node being arranged to operate as an agent in the wireless mesh network, the wireless network node including a first transceiver communicating using a first wireless communication protocol and communicating using a second wireless communication protocol for use in the wireless mesh network, wherein the wireless network node is arranged to: communicate with a mobile wireless device using the first communication protocol; communicate with wireless nodes in the wireless network using the second wireless communication protocol, and, in response to receiving a many-to-one routing request using the wireless mesh network, store an entry in the routing table of the receiving wireless network node, the entry indicating that the node issuing the many-to-one routing request is a concentrator node; the wireless mesh node is characterized in that: in preparation for communicating as a concentrator using the second wireless communication protocol, the wireless network node regularly sends out many-to-one routing requests at randomized intervals in the wireless mesh network with an average delay higher than a predetermined value, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

[0034] According to a fourth aspect, a wireless network node for use in a wireless mesh network is provided, the wireless network node being arranged to operate as an agent in the wireless mesh network, the wireless network node comprising: a first transceiver communicating using a first wireless communication protocol, and a second transceiver communicating using a second wireless communication protocol for the wireless mesh network, wherein the wireless network node is arranged to: communicate with a mobile wireless device using the first communication protocol; communicate with wireless nodes in the wireless network using the second wireless communication protocol, and, in response to receiving a many-to-one routing request using the wireless mesh network, store an entry in the routing table of the receiving wireless network node, the entry indicating that the node issuing the many-to-one routing request is a concentrator node; the wireless mesh node is characterized in that: in preparation for communicating as a concentrator using the second wireless communication protocol, the wireless network node regularly sends out many-to-one routing requests (MTORR) at randomized intervals in the wireless mesh network with an average delay higher than a predetermined value, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

[0035] Preferably, the wireless network node continuously tracks routes in the network according to the third and fourth aspects, in preparation for communication using the second wireless communication protocol.

[0036] The randomization interval can be chosen in accordance with those discussed above for the first and second aspects.

[0037] According to the third / fourth aspect, the wireless network nodes are arranged to communicate with mobile wireless devices using the first communication protocol. The wireless network nodes can be further arranged to prepare for such communication, such as the concentrator regularly transmitting MTORR at randomized intervals using a second wireless communication protocol, for example using a random backoff period that can be set within a predetermined value, which is preferably selected based on the size of the network / the number of agents in the network.

[0038] Preferably, the network node is a lighting network node, which is one of an presence sensor, a light sensor, a lighting switch, a modified lamp, a luminaire, and / or a wireless network controller.

[0039] Preferably, the first wireless protocol is the BLE protocol.

[0040] Preferably, the second wireless protocol is the Zigbee protocol.

[0041] According to a fifth aspect, a route discovery method in a wireless mesh network is provided. The method includes a first plurality of wireless network nodes, each of which is configured to operate as a proxy in the wireless mesh network, and includes: a first transceiver that communicates using a first wireless communication protocol and a second wireless communication protocol for the wireless mesh network; or alternatively, a first transceiver communicating using the first wireless communication protocol and a second transceiver communicating using the second wireless communication protocol for the wireless mesh network, in response to receiving a many-to-one routing request using the wireless mesh network, storing an entry indicating that the node issuing the many-to-one routing request is a concentrator node in the routing table of the receiving wireless network node. The method is characterized in that each of the first plurality of wireless network nodes operates as both a proxy and a concentrator, and in preparation for communicating as a concentrator using the second wireless communication protocol, the corresponding wireless mesh node regularly sends out many-to-one routing requests at randomized intervals in the wireless mesh network with an average delay higher than a predetermined value, to propagate the many-to-one routing requests in the wireless mesh network over time.

[0042] A computer program including a code means is also disclosed, which, when executed by a wireless combination node including a processing means, causes the processing means to perform any of the methods of the present invention. Attached Figure Description

[0043] In the accompanying drawings, similar reference numerals are used throughout the different views to refer to the same parts. Furthermore, the drawings are not necessarily to scale; instead, the focus is generally on illustrating the principles of the invention.

[0044] Figure 1The system provides an overview, in which mobile devices interact with the wireless network through a combination of nodes;

[0045] Figure 2-5 This shows an example of how the routing table is established in a node after power-on;

[0046] Figure 6A and Figure 6B A schematic block diagram of a wireless network node is shown;

[0047] Figure 7 A flowchart illustrating a route discovery method in a wireless mesh network is shown.

[0048] Figure 8 A graph showing the transmission of multiple MTORRs over time is shown; and

[0049] Figure 9 A wireless network including lighting network nodes is shown. Detailed Implementation

[0050] Throughout this patent application, examples utilizing Zigbee networks have been used, and in fact, the invention is particularly advantageous for Zigbee networks. However, the concept of the invention is not limited to Zigbee and can be used in conjunction with other networks such as Thread, BT Mesh, Wi-Fi Mesh, JupiterMesh, or other mesh topologies.

[0051] When considering wireless networks, the concept of a "standalone" wireless network is one that eliminates the need for a gateway. Such a Zigbee network and the setup and configuration of devices within it can be done via mobile devices (such as...). Figure 1 The application on the smartphone (shown in the diagram) uses a BLE connection from the smartphone to the Zigbee / BLE combo node 101 (here, a modified lamp). The Zigbee / BLE combo node 101, to which the smartphone is connected via BLE, is used as a proxy for the Zigbee network: by connecting to a single Zigbee / BLE combo node on BLE, the smartphone can connect to and control any node in the Zigbee mesh network.

[0052] In this way, mobile device 104 can be used to communicate directly with wireless mesh nodes 101 and 103 that support the Zigbee / BLE protocol. However, route discovery is required to communicate with network nodes outside of the agent.

[0053] In this embodiment, the combined node is a Zigbee / BLE combined device that can use a combined chip, wherein the chip is arranged to operate simultaneously according to one of the two protocols. In such a device, some processing resources can be reused, and a more cost-effective solution is possible. Figure 6A An example wireless network node WN1 is depicted, which includes a first transceiver XCV1 for communicating using a first wireless communication protocol and a second wireless communication protocol for wireless mesh networks. This works best when the first and second wireless communication protocols operate in similar frequency bands, as portions of the antenna infrastructure can then be reused. Thus, the wireless network node WN1 can be arranged to communicate with a mobile wireless device 104 using the first communication protocol (e.g., BLE) and with a mobile wireless device 104 using the second wireless communication protocol (e.g., Zigbee). Figure 1 Wireless nodes 102 and 103 communicate in the wireless network 100 shown. Wireless network node WN1 may optionally include a memory MEM and / or a controller CTRL for storing its(one or more) routing tables. Those skilled in the art will understand that such a MEM and CTRL may be separate physical entities within the wireless network node WN1, or may represent logical entities, for example, where the functionality is implemented in an application-specific integrated circuit (ASIC).

[0054] Alternatively, a Zigbee / BLE combo chip can be equipped with one or more chips or transceivers, enabling the device to operate in parallel on both networks. Figure 6B The corresponding example wireless network WN2 is depicted. Wireless network node WN2 includes a first transceiver XCV1 communicating using a first wireless communication protocol, and a second transceiver XCV2 communicating using a second wireless communication protocol for wireless mesh networks. The wireless network node can be arranged in such a way that it communicates with mobile wireless devices using the first communication protocol and with wireless nodes (102, 103) in the wireless network using the second wireless communication protocol. This allows for parallel operation of the two radios, which may be relevant when the protocols use different portions of the RF spectrum.

[0055] The wireless network node WN2 may also optionally include a memory MEM and / or a controller CTRL for storing its(one or more) routing tables. Those skilled in the art will understand that such a MEM and CTRL can be separate physical entities within the wireless network node WN2, or can represent logical entities, for example, in cases where functionality is implemented in a single physical entity by means of an application-specific integrated circuit (ASIC).

[0056] Zigbee supports the concept of "Many-to-One Route Request" (MTORR), in which a concentrator (usually a gateway) periodically broadcasts an MTORR. When a node receives the MTORR, it stores an entry in its routing table indicating that the initiating node is the concentrator node and from which other node it received the lowest-cost MTORR frame. This establishes a route from that node to the concentrator—and the MTORR is relayed from each router node on the network to the concentrator.

[0057] Reverse routes from the concentrator to the Zigbee nodes still need to be established. There are several ways to do this. Zigbee has two other routing methods: source routing and AODV routing. Typically, MTORR is used in combination with source routing, but it can also be used in combination with AODV routing. Typically, a Zigbee network has only one concentrator node, which is the gateway / bridge. Similar considerations apply to other mesh networking protocols.

[0058] In a typical Zigbee network, each Zigbee router node sends a link-state message approximately every 15 seconds. With this link-state message, neighboring nodes are able to update their neighbor tables with the correct link costs (outgoing link costs) of their neighbors, as measured by those neighbors themselves. Link-state messages are single-hop broadcast messages.

[0059] Consider a standalone Zigbee network without a fixed gateway. The result is that there is no fixed / single entry point into the Zigbee network; a smartphone can reach all other nodes from that entry point. Consider a standalone Zigbee network consisting of multiple Zigbee / BLE agents, where a phone can connect randomly to the network—still having the intention to communicate with other nodes on the network through the agent it connects to.

[0060] Communicating with multiple nodes on a Zigbee network through a chosen proxy has several advantages: it allows users to avoid the tedious identification of individual nodes before establishing a 1:1 BLE connection, eliminates redundant connection time (each connection per node can take between 1 and 2 seconds, depending on the discovery and security methods used), and allows for further time savings due to parallelized operations on the network: smartphones can request state updates from all nodes via broadcast or from multiple nodes via unicast and collect responses as they are received, rather than reading node state one by one.

[0061] The aforementioned Zigbee standalone network system can consist of all BLE / Zigbee-enabled proxy nodes. Establishing routes to all other nodes in the network only when a phone connects to a proxy results in long route discovery times and thus a poor user experience. This invention significantly reduces overall network latency when messages are sent from any proxy node to one or more other Zigbee nodes in the network.

[0062] While particularly advantageous in standalone Zigbee networks, the same principle can be applied to other mesh networks with multiple concentrators. In networks with a large number of concentrator / agent nodes, keeping track of available routes within the network is relevant. When this is done, mobile devices will be able to self-organize their connection to the network and communicate not only with agents but also with other nodes in the mesh network, without having to wait for route discovery to complete.

[0063] The proposed method can also be used in wireless mesh networks where, in addition to the Zigbee / BLE nodes described earlier, there are other nodes that only support the second protocol. Such nodes can be "traditional" Zigbee-only nodes, or Zigbee / BLE-enabled nodes that can be configured (before installation, during network initialization, or during operation) to operate as Zigbee-only nodes. For example, in networks with many closely spaced Zigbee / BLE nodes, it is advisable to configure some Zigbee / BLE router nodes as Zigbee End Devices (ZEDs) to simplify the network topology and reduce the need for route discovery.

[0064] In a hybrid network with both Zigbee-only nodes and Zigbee / BLE nodes, the combined device can act as a concentrator and / or proxy. The Zigbee / BLE-enabled device will then proactively perform route discovery, similar to the example above where the network only includes Zigbee / BLE-enabled nodes. The basic idea is that Zigbee / BLE-enabled devices in a hybrid configuration can also provide mobile nodes with access to the Zigbee network.

[0065] Preferably, the behavior of the described proxy node and router node represents the preferred default behavior.

[0066] In another embodiment, this behavior can be triggered when a node operates in a network where the number or density of routers / agent nodes exceeds a certain threshold, or when a node joins a specific type of network in a specific ecosystem (e.g., with distributed or centralized security modes), or when a specific cluster of clients / servers exists in the network.

[0067] In addition, it can be automatically triggered when an agent / router on a network with a gateway node loses connection to that gateway node, or if a program used to replace the gateway node is triggered (e.g., via the Zigbee Trust Center exchange method).

[0068] Alternatively, it can be triggered in specific action or configuration modes.

[0069] Furthermore, in methods related to agent nodes, the following behavior can be triggered if the agent is initialized for network access via the BLE interface, if the agent node's BLE interface remains / becomes open to BLE connections from smartphones, etc. This can be activated via configuration parameters / commands.

[0070] Similarly, the following behaviors can be deactivated when any of the above triggers are detected to be missing or altered.

[0071] After power-on, the Zigbee node broadcasts MTORR. It sends MTORR with a random delay to prevent broadcast storms that can occur when multiple nodes are powered on simultaneously, a common problem in lighting systems.

[0072] Network address conflicts cause the routing table of the conflicting address to be removed. Therefore, when recovering from an address conflict, a node with a new address should also proactively send a MTORR to re-establish a route to itself.

[0073] Similarly, any change to network parameters—namely, a change to the channel, PANID, or network key—can cause a node to miss updates and temporarily lose connectivity, resulting in a change in network topology. Likewise, a node rejoining with the new parameter set may need to resend MTORR to re-establish routing using the new link. Doing so after a defined delay from the parameter update command can be beneficial, giving other nodes time to find the new network rather than being forced to repeat MTORR multiple times.

[0074] Because nodes involved in routing may disappear (power outage) or propagation conditions may change, making the links along the route less reliable (e.g., due to moving metal objects, such as metal doors), it is important that each node not only sends a MTORR upon power-up but also periodically repeats the MTORR. This method is similar to Zigbee router nodes periodically sending link-state messages, except that link-state messages are single-hop broadcasts while MTORRs are multi-hop broadcasts. Due to this difference, it is important to send MTORRs at a lower frequency than link-state messages to avoid network congestion. Link-state messages are used to populate the neighbor tables of nodes within reach. MTORR messages are used to populate the routing tables of router nodes in the network.

[0075] Upon power-up, a Zigbee node broadcasts a device advertisement to announce its presence on the network. Other nodes can use this device advertisement as a trigger to send the next MTORR to populate the empty routing table of the newly advertised node (as quickly as possible). Nodes can intelligently send their MTORRs when a new node joins: nodes within the direct scope of the new joiner node do not need to send their MTORRs when the node joins, as they will be able to establish communication based on single-hop link-state broadcasts. Furthermore, nodes can analyze the device type flag in the capability field of the received Device_annce: if the joining device is a Reduced Function Device (RFD), no route needs to be established, as the parent of the joiner RFD will route on its behalf, and that route should already be in place. Similarly, Device_annce commands sent on behalf of Green Power Devices (GPDs) added to the network should not trigger any additional MTORRs; Device_annces on behalf of GPDs are identified by an IEEE address set to 0xffffffffffffffffff.

[0076] Broadcast storms can be reduced by regularly sending MTORRs spaced apart by randomization intervals. Here, randomization is understood to refer to variations based on physically random phenomena, but also includes more common pseudo-random variations, such as those implemented using LFSRs or other pseudo-random generators. The basic idea behind the randomization interval is that the MTORR will propagate with an average delay higher than a predetermined value. In this way, the randomization interval can be selected in a way that distributes the network load of the proxied MTORR over time, thereby reducing the likelihood of broadcast storms.

[0077] Figure 8 The diagram illustrates the transmission of multiple MTORRs from a single concentrator / agent node over time, with each MTORR labeled as a triangle. As can be seen, the concentrator / agent node transmits MTORRs regularly, but the MTORRs are not spaced at fixed intervals. MTORRs are separated by corresponding time periods T1, T2, T3, etc. On average, MTORRs are spaced by Tavg; by controlling Tavg, the likelihood of multiple concentrators / agents simultaneously publishing MTORRs is reduced.

[0078] It will be apparent to those skilled in the art that this is particularly relevant in wireless networks with a large number of concentrator / agent nodes. In such networks, the route discovery network load can become very high if not properly managed. The claimed invention proposes a proactive route discovery method that allows concentrator / agent nodes to provide fast network access to mobile nodes in the network. To avoid many nodes simultaneously broadcasting their MTORRs, the frequency of MTORR transmission can be adapted to the size of the network, or more preferably to the number of agents and / or routers on the network (a lower frequency is used for large networks to avoid congestion).

[0079] In a simple, unrestricted example, it is possible that the concentrator / agent node will T n The duration (duration of subsequent randomization interval) is determined as follows:

[0080] T n = Proportion·((Number of network nodes or proxy nodes)·RAND(seed)+Offset).

[0081] Here, RAND (seed) is a seed pseudorandom function that uses the "seed" as its seed, returning pseudorandom values ​​in the range [0, 1], and preferably has a uniform probability density function. The scaling factor allows for a slight adjustment of the average interval duration to create sufficient MTORR propagation for all concentrators. Optionally, an offset can be added to guarantee a minimum interval length. Using the above, concentrator / router nodes can generate randomized intervals between MTORRs. The aforementioned duration can be used to implement "random backoff" periods between the corresponding MTORRs.

[0082] like Figure 9 As illustrated in the diagram, preferably, the Zigbee / BLE combined node is a wireless node in the lighting network. Figure 9 A room with a subset of lighting network nodes 600 is shown. The lighting network may include, for example, lighting network nodes in the form of sensors, such as presence sensors SNS1 or light sensors SNS2. Wireless light switches SW, luminaires / lighting fixtures LUM1 with wireless functionality and light sources, and modified light bulbs LUM2 with wireless functionality and light sources are also provided in the network. Furthermore, two independent lighting controllers are provided, each with wireless functionality: one is a remote control device REM, and the second is a lighting controller LC, for example, in the form of a hub or building controller.

[0083] It is worth noting that the wireless mobile device 104 shown by the dashed line is not part of the lighting network, but instead can communicate with one of the combined nodes in the wireless lighting network using a first wireless communication protocol (such as BLE).

[0084] Optionally, the network can be a home automation network, which is not limited to lighting applications but may include other nodes, such as nodes for HVAC and / or asset tracking. However, it will be apparent to those skilled in the art, particularly for lighting control, that utilizing combined nodes as end-user devices, such as mobile phones and tablets that can be used for lighting control, typically do not support Zigbee but may support BLE, for example.

[0085] Nodes can determine network size using the number of (MTORR) routing table entries in their own routing tables. They can further use Device_annces or a local nwkAddressMap. This might be another configuration parameter, set during network initialization or once the network is up and running. For example: a link-state interval of 15 seconds. If the intended MTORR interval is 30 seconds, and there are 200 agent / router nodes on the network, then each of those agent / router nodes should send an MTORR every 6000 seconds.

[0086] In addition, nodes can track the interval between each connected MTORR and adapt their own MTORR interval accordingly.

[0087] Another approach to optimizing the number of MTORRs is to analyze MTORR routing errors and / or the resulting out-of-order route requests, the number of MTORRs, or AODVs. This could be an indication of instability in certain parts of the network (e.g., due to changing propagation conditions) and may require a temporary increase in the MTORR frequency.

[0088] In yet another extension, the frequency at which a particular node sends its MTORR is individual to that node and depends, for example, on its location in the network, the number of RFD child nodes it may have, the history of proxy connections, etc.

[0089] Next, a node-based short address scheduling scheme can be used for MTORR transmission: knowing other nodes in the network via routing table entries and / or nwkAddressMap, the sorted list of short addresses can be used to determine a node's own position in the list and deduce when to send the next MTORR, ensuring it won't conflict with any other node's MTORR. This also helps to evenly distribute the network overhead of this periodic MTORR mechanism over a period of time.

[0090] Furthermore, this method can be used in combination with other routing methods, such as AODV routing and source routing, but is not limited to only these two methods.

[0091] Figure 2-5This illustrates an example of how routing tables are established in nodes after power-on. The lines in these diagrams represent links between nodes; for example, node B has direct links to nodes A and C, but not to node D.

[0092] Initially, the routing table T of all nodes... A T B T C T D They are all empty.

[0093] Figure 2 This illustrates the scenario after node A sends its MTORR, where nodes B, C, and D receive the MTORR and add the route to node A to their respective routing tables (T). B T C T D ).

[0094] Figure 3 This illustrates the scenario after node B sends its MTORR, where nodes A, C, and D receive the MTORR and add the route to node B to their respective routing tables (T). A T C T D ).

[0095] Figure 4 This illustrates the scenario after node C sends its MTORR, where nodes A, B, and D receive the MTORR and add the route to node C to their respective routing tables (T). A T B T D ).

[0096] Figure 5 This illustrates the scenario after node D sends its MTORR, where nodes A, B, and C receive the MTORR and add the route to node D to their respective routing tables (T). A T B T C ).

[0097] Figure 7 A flowchart illustrating a route discovery method in a wireless mesh network is shown. The wireless mesh network includes a first plurality of wireless network nodes, each of which is configured to operate as both a proxy and a concentrator. Each wireless network node includes a first transceiver that communicates using a first wireless communication protocol and also using a second wireless communication protocol for wireless mesh networks, or alternatively, a first transceiver that communicates using the first wireless communication protocol and a second transceiver that communicates using the second wireless communication protocol for wireless mesh networks.

[0098] The method includes each of the first plurality of wireless network nodes preparing to communicate using a second wireless communication protocol as a concentrator, while the corresponding wireless mesh node regularly sends out S2 many-to-one routing requests at randomized intervals in the wireless mesh network to prevent broadcast storms. Preferably, the randomization interval averages more than 1 minute.

[0099] The method according to the invention can be implemented on a computer as a computer-implemented method, or in dedicated hardware, or in a combination of both.

[0100] The executable code of the method according to the invention can be stored on a computer / machine-readable storage device. Examples of computer / machine-readable storage devices include non-volatile memory devices, optical storage media / devices, solid-state media, integrated circuits, servers, etc. Preferably, the computer program product includes non-transitory program code means stored on a computer-readable medium for executing the method according to the invention, as disclosed in the above embodiments, when the program product is executed on a computer or a processing device included in a node or network or network access initialization device.

[0101] Methods, systems, and computer-readable media (temporary and non-temporary) may also be provided to implement selected aspects of the above embodiments.

[0102] The term "controller" is generally used herein to describe various means relating to the operation and other functions of one or more network devices or coordinators. A controller can be implemented in a variety of ways (e.g., such as with dedicated hardware) to perform the various functions discussed herein. A "processor" is an example of a controller employing one or more microprocessors, which can be programmed using software (e.g., microcode) to perform the various functions discussed herein. A controller may be implemented with or without a processor, and may also be implemented as a combination of dedicated hardware performing some functions and processors (e.g., one or more programmed microprocessors and associated circuitry) performing other functions. Examples of controller components that may be employed in various embodiments of this disclosure include, but are not limited to, conventional microprocessors, application-specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0103] In various implementations, the processor or controller may be associated with one or more storage media (generally referred to herein as "memory"), such as volatile and non-volatile computer memories (e.g., RAM, PROM, EPROM, and EEPROM, high-density disks, optical disks, etc.). In some implementations, the storage medium may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within the processor or controller, or may be removable, such that one or more programs stored thereon can be loaded into the processor or controller to implement various aspects of the invention discussed herein. The terms "program" or "computer program" are used herein in a general sense to refer to any type of computer code (e.g., software or microcode) that can be used to program one or more processors or controllers.

[0104] As used herein, the term "network" refers to any interconnection of two or more devices (including controllers or processors) that facilitates the transfer of information (e.g., for device control, data storage, data exchange, etc.) between any two or more devices and / or between multiple devices coupled to the network.

[0105] As used in the specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" should be interpreted as inclusive, that is, including multiple elements or at least one of the elements in the list, but also including multiple elements or more than one of the elements in the list, and optionally, additional unlisted items.

Claims

1. A wireless network node for use in a wireless mesh network, the wireless network node being configured to operate as a proxy in the wireless mesh network, the wireless network node including a first transceiver communicating using a first wireless communication protocol and communicating using a second wireless communication protocol for wireless mesh networks. And the wireless network node further includes: Controller; The memory associated with the controller is configured to store computer programs that can be executed by the controller; The controller is configured to: - Communicate with mobile wireless devices using the first communication protocol; - Communicate with wireless nodes in the wireless network using a second wireless communication protocol, and - In response to receiving a many-to-one routing request using a wireless mesh network, an entry indicating that the node issuing the many-to-one routing request is a concentrator node is stored in the routing table of the receiving wireless network node. The wireless network node is characterized by: The controller is also configured to: - In preparation for the wireless network node to communicate using the second wireless communication protocol as a concentrator, many-to-one routing requests are regularly sent in the wireless mesh network at randomized intervals with an average delay higher than a predetermined value, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

2. The wireless network node according to claim 1, wherein, The first wireless communication protocol is one of Bluetooth Low Energy (BLE); Bluetooth Mesh; Thread; Z-wave; WirelessHART; and IEEE 802.

11.

3. The wireless network node according to claim 1 or 2, wherein, The second wireless communication protocol is the Zigbee protocol.

4. The wireless network node according to claim 1 or 2, wherein, The randomization is performed by means of a randomization backoff period before the transmission of the corresponding many-to-one routing request MTORR.

5. The wireless network node according to claim 1 or 2, wherein, The wireless network node is a lighting network node, and is at least one of the following: presence sensor, light sensor, lighting switch, modified lamp, illuminator, and wireless lighting controller.

6. A wireless network node for use in a wireless mesh network, the wireless network node being configured to operate as a proxy in the wireless mesh network, the wireless network node comprising: - A first transceiver that communicates using a first wireless communication protocol, and - A second transceiver that communicates using a second wireless communication protocol for wireless mesh networks. And the wireless network node further includes: Controller; The memory associated with the controller is configured to store computer programs that can be executed by the controller; The controller is configured to: - Communicate with mobile wireless devices using the first communication protocol; - Communicate with wireless nodes in the wireless network using a second wireless communication protocol, and - In response to receiving a many-to-one routing request using a wireless mesh network, an entry indicating that the node issuing the many-to-one routing request is a concentrator node is stored in the routing table of the receiving wireless network node. The wireless network node is characterized by: The controller is also configured to: - In preparation for the wireless network node to communicate using the second wireless communication protocol as a concentrator, a many-to-one routing request (MTORR) is regularly sent in the wireless mesh network at randomized intervals with an average delay higher than a predetermined value, so as to propagate the many-to-one routing request in the wireless mesh network over time.

7. The wireless network node according to claim 6, wherein, The first wireless communication protocol is one of Bluetooth Low Energy (BLE); Bluetooth Mesh; Thread; Z-wave; WirelessHART; and IEEE 802.

11.

8. The wireless network node according to claim 6 or 7, wherein, The second wireless communication protocol is the Zigbee protocol.

9. The wireless network node according to claim 6 or 7, wherein, The randomization is performed by means of a randomization backoff period before the transmission of the corresponding many-to-one routing request MTORR.

10. The wireless network node according to claim 6 or 7, wherein, The wireless network node is a lighting network node, and is at least one of the following: presence sensor, light sensor, lighting switch, modified lamp, illuminator, and wireless lighting controller.

11. A wireless mesh network, comprising a first plurality of wireless network nodes, Each of the first plurality of wireless network nodes configured to operate as agents includes a first transceiver that communicates using a first wireless communication protocol and a second wireless communication protocol for wireless mesh networks. Each of the first plurality of wireless network nodes also includes: Controller; The memory associated with the controller is configured to store computer programs that can be executed by the controller; The controller is configured to: - Communicate with mobile wireless devices using the first communication protocol; - Communicating with wireless nodes in a wireless network using a second wireless communication protocol; and - In response to receiving a many-to-one routing request using a wireless mesh network, an entry indicating that the node issuing the many-to-one routing request is a concentrator node is stored in the routing table of the receiving wireless network node. The wireless mesh network is characterized by: Each of the first plurality of wireless network nodes is configured to operate as both a proxy and a concentrator; and The controller of each wireless network node is also configured to: in preparation for the wireless network node to communicate using a second wireless communication protocol as a concentrator, regularly send many-to-one routing requests at randomized intervals with an average delay higher than a predetermined value in the wireless mesh network, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

12. The wireless mesh network according to claim 11, wherein, The predetermined value is based on the size of the network or the number of agents in the network, and is randomized.

13. The wireless mesh network according to claim 11 or 12, wherein the wireless mesh network comprises a first plurality of wireless network nodes and a second plurality of wireless network nodes, and Each of the second plurality of wireless network nodes includes a second transceiver for: - Communicate using a second wireless communication protocol. And each of the second or more network nodes is arranged as follows: - Communicate with nodes in a wireless mesh network using a second wireless communication protocol, and in which The number of wireless router nodes in the first multiple wireless mesh network is greater than 30% of the total number of wireless router nodes in the wireless mesh network.

14. The wireless mesh network of claim 13, wherein some or all of the second plurality of wireless network nodes are configurable and have the same communication capabilities as the first plurality of wireless network nodes, but wherein some or all of the second plurality of wireless network nodes have been configured to disable communication using the first wireless communication protocol.

15. The wireless mesh network according to claim 11 or 12, wherein the randomization interval is more than 15 minutes.

16. The wireless mesh network of claim 11 or 12, wherein the first plurality of wireless network nodes are arranged as follows: - Operates as a proxy node for a mobile device that wants to communicate with another wireless network node in a wireless mesh network; - Connect to the mobile device using the first communication protocol; and -At least one of the following: - Use a second communication protocol to forward information from the mobile device to the other wireless network node, and - Use the first communication protocol to forward information from the other wireless network node to the mobile device.

17. The wireless mesh network according to claim 11 or 12, wherein, The wireless mesh network nodes are networks without fixed gateways.

18. A wireless mesh network, comprising a first plurality of wireless network nodes, Each of the first plurality of wireless network nodes arranged to operate as a proxy includes: - A first transceiver that communicates using a first wireless communication protocol, and - A second transceiver that communicates using a second wireless communication protocol for wireless mesh networks. Each of the first plurality of wireless network nodes also includes: Controller; The memory associated with the controller is configured to store computer programs that can be executed by the controller; The controller is configured to: - Communicate with mobile wireless devices using the first communication protocol; - Communicating with wireless nodes in a wireless network using a second wireless communication protocol; and - In response to receiving a many-to-one routing request using a wireless mesh network, an entry indicating that the node issuing the many-to-one routing request is a concentrator node is stored in the routing table of the receiving wireless network node. The wireless mesh network is characterized by: Each of the first plurality of wireless network nodes is configured to operate as both a proxy and a concentrator; and The controller of each wireless network node is also configured to: in preparation for the wireless network node to communicate using a second wireless communication protocol as a concentrator, regularly send many-to-one routing requests at randomized intervals with an average delay higher than a predetermined value in the wireless mesh network, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

19. The wireless mesh network according to claim 18, wherein, The predetermined value is based on the size of the network or the number of agents in the network, and is randomized.

20. The wireless mesh network according to claim 18 or 19, wherein the wireless mesh network comprises a first plurality of wireless network nodes and a second plurality of wireless network nodes, and Each of the second plurality of wireless network nodes includes a second transceiver for: - Communicate using a second wireless communication protocol. And each of the second or more network nodes is arranged as follows: - Communicate with nodes in a wireless mesh network using a second wireless communication protocol, and in which The number of wireless router nodes in the first multiple wireless mesh network is greater than 30% of the total number of wireless router nodes in the wireless mesh network.

21. The wireless mesh network of claim 20, wherein some or all of the second plurality of wireless network nodes are configurable and have the same communication capabilities as the first plurality of wireless network nodes, but wherein some or all of the second plurality of wireless network nodes have been configured to disable communication using the first wireless communication protocol.

22. The wireless mesh network according to claim 18 or 19, wherein the randomization interval is more than 15 minutes.

23. The wireless mesh network according to claim 18 or 19, wherein the first plurality of wireless network nodes are arranged as follows: - Operates as a proxy node for a mobile device that wants to communicate with another wireless network node in a wireless mesh network; - Connect to the mobile device using the first communication protocol; and -At least one of the following: - Use a second communication protocol to forward information from the mobile device to the other wireless network node, and - Use the first communication protocol to forward information from the other wireless network node to the mobile device.

24. The wireless mesh network according to claim 18 or 19, wherein, The wireless mesh network nodes are networks without fixed gateways.

25. A route discovery method in a wireless mesh network, the wireless mesh network including a first plurality of wireless network nodes, each of the first plurality of wireless network nodes being arranged to operate as an agent in the wireless mesh network, and including a first transceiver, the first transceiver communicating using a first wireless communication protocol and communicating using a second wireless communication protocol for the wireless mesh network, and in response to receiving a many-to-one routing request using the wireless mesh network, storing an entry indicating that the node issuing the many-to-one routing request is a concentrator node in the routing table of the receiving wireless network node; The method is characterized by: - Each of the multiple wireless network nodes operates as both a proxy and a concentrator; and - In preparation for communication using a second wireless communication protocol as a concentrator, the corresponding wireless network node regularly sends out many-to-one routing requests at random intervals in the wireless mesh network with an average delay higher than a predetermined value, so as to propagate the many-to-one routing requests in the wireless mesh network over time.

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