A method and apparatus for managing a network node

Abstract

The application provides a management method and device of a network node, the method comprising: each node in the network calculating an initial weight value according to its own function parameter, and sending its initial weight value and the maximum weight value among the received other weight values to other nodes in the form of broadcast, so that each node in the network can determine the node with the maximum initial weight value as a master node. Through the method, the master node in the network can be determined in time even if the broadcast message of some nodes cannot be received by all the other nodes in the network, so that the efficiency of the collaborative work among the nodes in the network is improved.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly to a method and apparatus for managing network nodes. Background Technology

[0002] With the development of IoT technology, the types of IoT devices are increasing, and the need for mutual discovery, connection, and control among these devices is also growing. One or more IoT devices can form a network, such as a wireless mesh network, using methods like Bluetooth or Wi-Fi. The IoT devices in the network can be called nodes, and for ease of network management and data transmission, the master node manages the slave nodes.

[0003] Currently, each node in the network can determine its master node by the functional parameters of the devices carried in the broadcast messages received from other nodes in the network. However, in some cases, due to changes in network topology, link failures between some nodes, or other reasons, the broadcast messages of some nodes may not be received by all the other nodes in the network. In this case, the network master node may not be determined in a timely manner, which is detrimental to the collaborative work between nodes.

[0004] Therefore, how to promptly identify the master node in the network is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a method and apparatus for managing network nodes, which aims to promptly identify the master node in the network when the network environment is unstable, thereby improving the efficiency of collaborative work among nodes in the network.

[0006] In a first aspect, this application provides a method for managing network nodes. This method can be executed by a first node, or by a component (such as a chip, chip system, etc.) configured in the first node, or by a logic module or software capable of implementing all or part of the functions of the first node. This application does not limit the method in this regard.

[0007] For example, the method includes: a first node receiving one or more broadcast messages from other nodes in a network, each of the one or more broadcast messages carrying a weight value, the network containing multiple nodes, each of the multiple nodes having an initial weight value, the initial weight value of each node being calculated based on the functional parameters of the corresponding node, and the weight value carried in each broadcast message being the largest weight value among the initial weight value of the node sending the broadcast message and the other received weight values; the first node determining a master node among the multiple nodes based on the first node's initial weight value and the weight values ​​in the one or more broadcast messages, the master node being the node with the largest initial weight value among the multiple nodes.

[0008] Based on the above technical solution, the first node, based on its own initial weight value and one or more broadcast messages carrying weight values ​​received, can determine the node with the largest initial weight value, and thus identify it as the master node in the network. This weight value could be the initial weight value of the node sending the broadcast message, or it could be the initial weight value of another node; whichever value is larger is carried. Therefore, even if some nodes' broadcast messages cannot be received by all the other nodes in the network, other nodes can relay the initial weight values ​​of these nodes (if they are relatively large). In other words, even if a node cannot receive all the broadcast messages from other nodes, it can still obtain the initial weight value of the node with the largest initial weight value among all other nodes, and thus determine the node with the largest initial weight value, which is the master node. Through this method, even if some nodes in the network are not connected, the master node in the network can be determined in a timely manner, thereby improving the efficiency of collaborative work among nodes in the network.

[0009] In conjunction with the first aspect, in some possible implementations of the first aspect, the above functional parameters include one or more of the following three items: whether there is a screen, the supported network protocol, and whether there is a source.

[0010] In conjunction with the first aspect, in some possible implementations of the first aspect, the initial weight value of each node is calculated based on the functional parameters of the corresponding node, including: the initial weight value of each node is calculated based on the functional parameters of the corresponding node and the device identifier.

[0011] The initial weight value of each node can be further calculated based on the device identifier. For example, when some nodes have the same functional parameters, the device identifier of the node can be used as a seed to generate a random number corresponding to that node. This random number can then be used as the increment of the initial weight value determined based on the functional parameters to determine the final initial weight value corresponding to that node. This effectively reduces the probability that different nodes in the network have the same initial weight value, thus facilitating the identification of the master node in the network.

[0012] In conjunction with the first aspect, in some possible implementations of the first aspect, before the first node determines the master node of multiple nodes in the network based on the first node's initial weight value and the weight values ​​in one or more broadcast messages, the above method further includes: the first node comparing the first node's initial weight value with the weight values ​​in the received broadcast messages of the second node to determine the largest weight value, wherein the second node is the node that sent the broadcast message before the first node sent its broadcast message; the first node sends a broadcast message carrying the largest weight value, which is used by one or more other nodes to determine the master node.

[0013] In this context, the second node refers to one or more nodes in the network that send a broadcast message before the first node sends its broadcast message. Before determining the master node, the first node can compare its own initial weight value with the weight value in the received broadcast message, and then send a broadcast message carrying the larger weight value. This way, even if a node that receives the first node's broadcast message cannot receive the second node's broadcast message, it can still know the largest initial weight value corresponding to the second node and the first node, which is beneficial for timely determination of the master node.

[0014] In conjunction with the first aspect, in some possible implementations of the first aspect, the above method further includes: the first node sending a broadcast message carrying the initial weight value of the master node in the next transmission cycle.

[0015] After the first node determines the master node, it sends a broadcast message carrying the initial weight value of the master node in the next transmission cycle. In other words, after the master node is determined, the first node takes over the initial weight value of the master node, which helps each node to determine in a timely manner whether the master node in the network has changed.

[0016] In conjunction with the first aspect, in some possible implementations of the first aspect, the first node is not the master node, and before the first node sends a broadcast message carrying the initial weight value of the master node in the next transmission cycle, the above method further includes: the first node receiving a broadcast message from the master node, which includes the initial weight value of the master node.

[0017] If the first node is not the master node, then the master node's broadcast message is relayed. That is, each node's broadcast message carries the master node's initial weight value. By relaying the master node's initial weight value, nodes that cannot receive the master node's broadcast message can promptly determine whether the master node in the network has changed based on the broadcast messages of the nodes they are connected to. Furthermore, if a new node joins the network, as long as it receives a broadcast message carrying the master node's initial weight value, it can determine the master node in the network, facilitating rapid updates of the master node in the network.

[0018] In conjunction with the first aspect, in some possible implementations of the first aspect, the above method further includes: when the first node is not the master node, the first node adjusts the sending time of the first node's broadcast message according to the master node's sending cycle.

[0019] When the first node is not the master node, it synchronizes its broadcast message sending time with that of the master node, thereby ensuring that all nodes in the network send broadcast messages at the same time. This means that the rhythm of broadcast message sending by all nodes is consistent, reducing broadcast interference and improving the cooperation efficiency of all nodes.

[0020] In conjunction with the first aspect, in some possible implementations of the first aspect, the broadcast message also carries a sequence number, which is used to indicate the transmission period in which the broadcast message is sent.

[0021] The sequence number carried in the broadcast message serves two purposes: firstly, it helps to identify the master node in the network when the initial weight values ​​of the nodes are the same; secondly, it effectively reduces the situation where the first node repeatedly relays the broadcast message of a certain node within the same transmission cycle.

[0022] In conjunction with the first aspect, in some possible implementations of the first aspect, within a transmission period after the master node is determined, the total number of broadcast messages sent by the plurality of nodes in the network within a transmission period is the same as the number of the plurality of nodes.

[0023] After the master node in the network is determined, each node can send a broadcast message only once during the transmission period. This broadcast message carries the initial weight value of the master node, which reduces the number of times each node sends a broadcast message, thus reducing interference with the broadcast signal and the power consumption of each node.

[0024] Secondly, this application provides a network node management apparatus, including units for implementing the methods of the first aspect and any possible implementation thereof. It should be understood that each unit can implement its respective function by executing a computer program.

[0025] Thirdly, this application provides a network node management device, including a processor, the processor being configured to execute the network node management method described in the first aspect and any possible implementation thereof.

[0026] The device may further include a memory for storing computer-readable instructions, which the processor reads to enable the management device to implement the methods described in the foregoing aspects. The device may also include a communication interface for communicating with other devices; exemplarily, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0027] Fourthly, this application provides a chip system including at least one processor for supporting the implementation of the functions involved in the first aspect and any possible implementation of the first aspect, such as receiving or processing data and / or information involved in the above methods.

[0028] In one possible design, the chip system also includes a memory for storing program instructions and data, which may be located within or outside the processor.

[0029] The chip system can consist of chips or include chips and other discrete components.

[0030] Fifthly, this application provides a computer-readable storage medium storing computer-readable instructions that, when executed by a computer, cause the computer to implement the method of the first aspect and any possible implementation thereof.

[0031] In a sixth aspect, this application provides a computer program product comprising: computer-readable instructions that, when executed by a computer, cause the computer to implement the method of the first aspect and any possible implementation thereof.

[0032] It should be understood that the second to sixth aspects of this application correspond to the technical solutions of the first aspect of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be repeated here. Attached Figure Description

[0033] Figures 1 to 4 This is a schematic diagram illustrating an application scenario applicable to the method provided in the embodiments of this application;

[0034] Figure 5 This is a flowchart illustrating the network node management method provided in an embodiment of this application;

[0035] Figure 6This is another flowchart illustrating the network node management method provided in the embodiments of this application;

[0036] Figure 7 This is a schematic diagram illustrating the number of heartbeat packets sent according to an embodiment of this application;

[0037] Figure 8 This is a schematic block diagram of a network node management device provided in an embodiment of this application;

[0038] Figure 9 This is another schematic block diagram of the network node management device provided in the embodiments of this application. Detailed Implementation

[0039] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0040] To facilitate understanding of the embodiments of this application, the following description is provided first:

[0041] First, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and role. For example, "first node" and "second node" are used to distinguish different nodes, but do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" do not necessarily imply that they are different.

[0042] Second, the terms “comprising” and “having” and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0043] Third, in the embodiments of this application, "multiple" refers to two or more.

[0044] Fourth, in the embodiments of this application, "when," "if," and "if" all refer to the device making corresponding processing under certain objective circumstances, and are not limited to a time, nor do they require the device to make a judgment action when it is implemented, nor do they mean that there are other limitations.

[0045] To better understand the network node management method provided in the embodiments of this application, the terms involved in this application will be briefly explained first.

[0046] 1. Internet of Things (IoT) and IoT Devices: The Internet of Things (IoT) is an important component of future information technology development. Its main technical characteristic is connecting objects to networks through communication technologies, thereby realizing an intelligent network that enables human-machine interaction and machine-to-machine interaction. IoT technology can achieve massive connectivity, deep coverage, and low power consumption at the terminal through technologies such as narrowband (NB).

[0047] Internet of Things (IoT) devices include, but are not limited to: mobile phones, tablets, computers with wireless transceiver capabilities (such as laptops and PDAs), mobile internet devices (MIDs), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving vehicles, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in 5G networks, or future evolution of public land mobile communication networks. Terminal devices in a network (PLMN), etc.

[0048] Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices; they achieve powerful functions through software support, data interaction, and cloud interaction. Broadly defined, wearable smart devices include those with comprehensive functions, large sizes, and the ability to perform complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses. They also include devices focused on a specific application function that require the use of other devices, such as smart bracelets and smart jewelry for vital sign monitoring.

[0049] In addition, IoT devices can also include sensors such as smart printers, train detectors, and gas stations. Their main functions include collecting data (for some terminal devices), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0050] The network node management method provided in this application can be applied to mesh networks, for example. A mesh network is a self-organizing network of IoT devices. The IoT devices in a mesh network can be called nodes, and each node has an equal status; there are no opposing roles like access point and terminal. However, for ease of network management and data transmission, the master node in the mesh network can be considered an access point, responsible for managing the slave nodes. It can be understood that when there is only one node in a mesh network, that node can be considered the master node of the network.

[0051] It should be understood that the methods provided in this application embodiment can also be applied to other networks that support technologies such as Bluetooth, Wi-Fi, and Zigbee, and this application embodiment does not limit them.

[0052] To facilitate understanding of the network node management method provided in the embodiments of this application, the following will be combined with... Figures 1 to 4 The application scenarios applicable to the network node management method provided in the embodiments of this application are described. It is understood that the application scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided in the embodiments of this application.

[0053] One possible scenario is, such as Figure 1As shown, in scenario 100, network 110 includes IoT devices 111, 112, and 113. The master node of this network is IoT device 113, and the slave nodes are IoT devices 111 and 112. When IoT device 114 joins network 110, IoT devices 111 to 114 form a new network 120. In other words, the network topology of network 110 changes. It is then necessary to promptly determine the new master node of network 120 so that the master node can manage the slave nodes.

[0054] Another possible scenario is, such as Figure 2 As shown, in scenario 200, network 210 includes IoT devices 211, 212, 213, and 214. The master node in network 210 is IoT device 213, and the slave nodes are IoT devices 211, 212, and 214. Due to changes in the network environment or the movement of IoT devices, IoT device 213 may leave network 210. In this case, IoT devices 211, 212, and 214 form a new network 220. Therefore, the new network 220 needs to promptly determine its master node for network management.

[0055] Another possible scenario is the merging of two networks. For example... Figure 3 As shown, in scenario 300, network 310 includes IoT devices 311 to 314. The master node in this network is IoT device 313, and the slave nodes are IoT devices 311, 312, and 314. Network 320 includes IoT devices 321 to 323. The master node is IoT device 321, and the slave nodes are IoT devices 322 and 323. Perhaps due to proximity or other reasons, IoT device 313 and IoT device 322 establish a connection, and the two networks merge into a new network 330. At this point, network 330 needs to promptly determine its master node.

[0056] Another possible scenario is, such as Figure 4 As shown, in scenario 400, network 410 includes IoT devices 411 to 413. The master node is IoT device 411, and the slave nodes are IoT devices 412 and 413. IoT devices 412 and 411 are directly connected, while IoT devices 413 and 411 are connected through IoT device 412. When IoT device 412 leaves the network, IoT devices 411 and 413 become unaware of each other and degenerate into isolated nodes.

[0057] It should be understood that Figures 1 to 4Multiple networks and communication links between various IoT devices are illustrated exemplarily. Optionally, the networks may include other numbers or types of IoT devices; for example, the networks may include more or fewer IoT devices. As another example, the networks may include other types of IoT devices. This application does not limit this.

[0058] With the development of IoT technology, the types of IoT devices are increasing, and the need for mutual discovery, connection, and control among these devices is also growing. The master node in the network is responsible for managing the slave nodes. Therefore, timely identification of the master node in the network is beneficial for the collaborative work among all nodes.

[0059] Currently, each node in the network can determine the master node by the functional parameters of the devices carried in the broadcast messages received from other nodes. However, in some cases, due to changes in network topology, link failures between some nodes, or other reasons, the broadcast messages of some nodes may not be received by all the other nodes in the network. In this case, the network master node may not be determined in a timely manner, which is detrimental to the collaborative work between nodes. For example, Figure 1 In the scenario shown, when a new node joins the network, each node needs to receive broadcast messages from all other nodes. If, due to link failures or other reasons, a node's broadcast message cannot be received by all other nodes, some nodes will be unable to determine the master node in a timely manner. For example, Figure 3 In the scenario shown, when two networks merge into a new network, IoT device 321 cannot communicate with IoT device 313. Therefore, neither can receive broadcast messages sent by the other. In this case, IoT device 321 and IoT device 313 cannot determine the master node in the network based on known technologies.

[0060] Therefore, this application provides a method for managing network nodes. Any node in the network can determine the master node in the network based on its own initial weight value and the weight values ​​in one or more broadcast messages it receives. The weight values ​​in the broadcast messages may be the initial weight value of the node that sent the broadcast message or the initial weight values ​​of other nodes. In other words, any node in the network can take over the weight values ​​of other nodes. Therefore, for any node in the network, even if it may not be able to receive broadcast messages from some of the other nodes, it can still determine the maximum value of the initial weight values ​​of all nodes in the network through the broadcast messages sent by the nodes it is connected to, and thus determine the master node in the network, thereby improving the efficiency of collaborative work between nodes.

[0061] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0062] Figure 5 This is a flowchart illustrating the network node management method 500 provided in an embodiment of this application. Figure 5 The method 500 shown may include steps S510 to S520, and the steps in method 500 will be described in detail below.

[0063] It should be noted that, Figure 5 The provided network node management method can be applied to networks comprising multiple nodes. Each node in the aforementioned network has an initial weight value, which is calculated based on the functional parameters of the corresponding node. Each node in the network can determine the master node based on the network node management method provided in this application. For ease of understanding and explanation, the network node management method provided in this application will be described below using a first node as an example without loss of generality. It can be understood that the first node can be any one of the multiple nodes in the network.

[0064] S510, The first node receives one or more broadcast messages from other nodes in the network. The weight value carried in each broadcast message is the largest weight value among the initial weight value of the node that sent the broadcast message and other weight values ​​received by the node.

[0065] In other words, for any node in the network, the weight value carried in its broadcast message is either its own initial weight value or the initial weight value of another node in the relay network. Relay refers to a situation where a node receives a broadcast message from another node with a weight value greater than its own initial weight value, and then sends a broadcast message with the larger initial weight value.

[0066] One possibility is that the weight values ​​carried in the broadcast messages received by the first node are all the initial weight values ​​of the node that sent the broadcast messages. For example, in a network including node 1, node 2, and node 3, node 1 receives broadcast messages from node 2 and node 3. The broadcast messages from node 2 and node 3 both carry their own initial weight values, meaning that at this time, node 2 and node 3 have not yet inherited each other's initial weight values.

[0067] Another possibility is that the weight value carried in the broadcast message received by the first node includes the initial weight value of the node that sent the broadcast message and the initial weight values ​​of the other nodes that the node that sent the broadcast message has passed on to. For example, in a network including node 1, node 2, node 3, and node 4, node 1 receives broadcast messages from nodes 2 and 3. Node 2's broadcast message carries its own initial weight value, and node 3's broadcast message carries node 4's initial weight value, meaning that node 3 has already passed on node 4's initial weight value.

[0068] Another possible scenario is that the weight values ​​carried in the broadcast messages received by the first node are the initial weight values ​​of the other nodes relayed by the node that sent the broadcast message. For example, in a network including nodes 1 to 5, node 1 receives broadcast messages from nodes 2 and 3. Node 2's broadcast message carries the initial weight value of node 4, and node 3's broadcast message carries the initial weight value of node 5.

[0069] It should be noted that each of the multiple nodes in the above network has an initial weight value, which is calculated based on the functional parameters of the corresponding node.

[0070] Optionally, the above functional parameters include one or more of the following three items: whether there is a screen, supported network protocols, and whether there is a source.

[0071] Supported network protocols include, but are not limited to, Bluetooth, Wi-Fi, and Zigbee. "Active" refers to whether the device is plugged into a power source.

[0072] One possible design is that nodes with stronger functionalities have larger initial weight values. For example, the functional parameters of a mobile phone include having a screen, supporting Bluetooth protocol, and being active, while the functional parameters of a smart headset include not having a screen, supporting Bluetooth protocol, and being passive. Therefore, the initial weight value of a mobile phone is greater than that of a smart headset. For example, the initial weight value for a mobile phone is 200, and the initial weight value for a smart headset is 150. This application does not limit the value of the initial weight. Exemplarily, multiple nodes in the network can jointly maintain the correspondence between functional parameters and initial weight values, so each node can calculate its own initial weight value by combining its own functional parameters with the above correspondence.

[0073] It should be understood that the above functional parameters are merely examples and should not constitute any limitation on the embodiments of this application. For example, functional parameters may also include the device's memory, supported operating systems, etc.

[0074] For example, each of one or more nodes in the network calculates its own initial weight value locally based on its own functional parameters, which is used by one or more nodes to determine the master node in the network.

[0075] Optionally, the initial weight value of each node is calculated based on the functional parameters of the corresponding node, including: the initial weight value of each node is calculated based on the functional parameters of the corresponding node and the device identifier.

[0076] The device identifier is, for example, a unique device identifier (UDID) for a device. It should be noted that some nodes in the network may have the same device type; in other words, some nodes in the network may have the same functional parameters, resulting in the same initial weight value for different nodes. Therefore, the initial weight value of each node in the network can also be calculated based on the corresponding node's functional parameters and device identifier.

[0077] One possible design is that the UDID corresponding to each node can be used as a seed for generating a random number for each node. The sum of this random number and the initial weight value determined based on the functional parameters is used as the final initial weight value of the node. This avoids the situation where different nodes have the same functional parameters, which would result in the same initial weight value. In other words, it ensures that different nodes have different initial weight values, which is beneficial for one or more nodes to determine the master node in the network.

[0078] For example, consider two IoT devices, mobile phone 1 and mobile phone 2, that correspond to two nodes in the network. Mobile phone 1 and mobile phone 2 have the same functional parameters, and their initial weight values, determined based on these parameters, are both 100. Mobile phone 1 generates a random number of 20 based on its own UDID, while mobile phone 2 generates a random number of 30 based on its own UDID. Therefore, the final initial weight value for mobile phone 1 is 120, and the initial weight value for mobile phone 2 is 130. It can be seen that, based on the above method, devices of the same type can have different initial weight values; that is, nodes with the same functional parameters can have different initial weight values.

[0079] S520. The first node determines the master node of multiple nodes in the network based on the initial weight value of the first node and the weight values ​​in the one or more broadcast messages.

[0080] The master node is the node with the largest initial weight value among multiple nodes in the network. The first node can determine the largest initial weight value from its own initial weight value and the weight values ​​carried by each broadcast message in one or more broadcast messages, and then determine the node corresponding to the largest initial weight value as the master node.

[0081] One possible scenario is that the first node is the node with the largest initial weight value among the multiple nodes in the network, i.e., the master node. In this case, after receiving one or more broadcast messages, the first node determines that its own initial weight value is the largest among the multiple nodes, identifies itself as the master node in the network, and sends a broadcast message carrying its own initial weight value.

[0082] For example, a network may have two nodes, namely a first node and a second node. If the initial weight value of the first node is greater than that of the second node, then the first node will determine that there is no larger weight value than its own initial weight value in the broadcast message it receives, and will further determine itself as the master node in the network.

[0083] Another possibility is that the first node is not the master node in the network. After receiving one or more broadcast messages, the first node determines the maximum weight value carried in one or more broadcast messages and identifies the node corresponding to that value as the master node in the network.

[0084] For example, a network includes three nodes: node 1, node 2, and node 3. Assume the initial weight values ​​of these three nodes are in the order of: node 1 < node 2 < node 3. Taking node 1 as an example, the process of node 1 determining the master node in the network is described in detail. One possible scenario is that node 1 receives one or more broadcast messages, including a broadcast message from node 2, which carries the initial weight value of node 3. This means node 2 has already received the broadcast message from node 3. In this case, node 1 determines that its own initial weight value is less than the weight value in the broadcast message and determines the node with the larger value, i.e., node 3, as the master node. Another possible scenario is that node 1 receives one or more broadcast messages, including broadcast messages from node 2 and node 3. After receiving the broadcast messages, node 1 determines that the maximum initial weight value in the broadcast messages corresponds to the initial weight value of node 3 and determines the node with the maximum value, i.e., node 3, as the master node.

[0085] It should be understood that after the first node determines the maximum value of the initial weight, it can determine the node corresponding to the maximum value of the initial weight based on a predefined correspondence in the network, such as a predefined correspondence between device identifiers and initial weight values. The first node can also reverse-calculate the node corresponding to the maximum value of the initial weight based on the calculation method for the initial weight. This application does not limit this aspect.

[0086] Optionally, before the first node determines the master node of multiple nodes in the network based on the first node's initial weight value and one or more broadcast messages, the above method further includes: the first node comparing the first node's initial weight value with the weight value in the broadcast message received from the second node to determine the largest weight value; the first node sending a broadcast message carrying the largest weight value for one or more other nodes to determine the master node.

[0087] In this context, the second node is one or more nodes that send a broadcast message before the first node sends its broadcast message. Before determining the master node of the network, the first node compares its initial weight value with the weight value in the broadcast message each time it receives a broadcast message from another node, determines the largest weight value, and sends a broadcast message carrying the largest weight value so that other nodes can determine the master node.

[0088] In one example, the second node includes node 2. The first node receives the broadcast message from node 2, compares its own initial weight value with the weight value in the broadcast message of node 2, determines the largest weight value, and sends a broadcast message carrying the largest weight value.

[0089] In another example, the second node includes node 1 and node 2. The first node receives a broadcast message from node 1, compares its own initial weight value with the weight value in node 1's broadcast message, and determines the larger weight value. The first node also receives a broadcast message from node 2, compares the larger weight value with the weight value in node 2's broadcast message, determines the largest weight value, and sends a broadcast message carrying the largest weight value.

[0090] Optionally, the above method further includes: the first node sending a broadcast message carrying the initial weight value of the master node in the next transmission cycle.

[0091] After the first node determines the master node, it sends a broadcast message carrying the master node's initial weight value in the next transmission cycle. In other words, the first node takes over the master node's initial weight value, which can be called the first node's relay weight value.

[0092] One possible scenario is that the first node is the master node. In this case, after the first node determines the master node, it will send a broadcast message carrying its own initial weight value in the next transmission cycle.

[0093] Another possibility is that the first node is not the master node. In this case, after receiving the master node's initial weight value, the first node sends a broadcast message carrying the master node's initial weight value. It should be noted that the first node may receive the master node's initial weight value by receiving a broadcast message from the master node that includes the master node's initial weight value, or it may receive broadcast messages from other nodes that carry the master node's initial weight value. This application embodiment does not limit this approach.

[0094] Optionally, if the first node is not the master node, the first node adjusts the sending time of the first node's broadcast message according to the master node's sending cycle.

[0095] When the first node is not the master node, the first node can adjust the time when it sends broadcast messages to match the time when it sends broadcast messages. This helps to unify the rhythm of broadcast message sending by multiple nodes in the network, thereby reducing interference between broadcast messages sent by different nodes.

[0096] One possible implementation is that each node in the network maintains a periodic alarm clock to indicate its transmission cycle. The transmission cycle is consistent across all nodes, meaning the interval between broadcast messages is uniform, but the specific times at which each node sends the broadcast message differ. When the weight value in the broadcast message received by the first node exceeds its own initial weight value, it resets its own periodic alarm clock, adjusting its transmission time to the time the broadcast message was received.

[0097] For example, a network includes two nodes, node 1 and node 2. Assume that node 1's initial weight value is less than node 2's initial weight value. When node 1 receives a broadcast message from node 2, it determines that its own initial weight value is less than the weight value carried in the broadcast message and adjusts its broadcast message sending time to match the time it received the broadcast message. This ensures that in the next transmission cycle, node 1 and node 2 send broadcast messages at the same time. Node 1 can also further determine that node 2 is the master node in the network based on the correspondence between initial weight values ​​and device identifiers.

[0098] Optionally, the broadcast message also carries a sequence number, which indicates the transmission period in which the broadcast message is sent.

[0099] Each node in the network can also carry a sequence number in its broadcast messages. This sequence number indicates the period in which the broadcast message is broadcast. It is easy to understand that the longer a node has been in the network, the larger the sequence number will be.

[0100] On the one hand, when different nodes in the network have the same initial weight value, the master node in the network can be determined based on the sequence number carried in the broadcast message. For example, the network includes a first node and a second node, both with the same initial weight value. The first node sends a broadcast message with a sequence number of 20, while the second node sends a broadcast message with a sequence number of 30. When the first node receives the broadcast message from the second node, it finds that its initial weight value is the same as the weight value carried in the broadcast message. It then further compares its own sequence number with the sequence number carried in the broadcast message. Finding that its own sequence number is less than the sequence number carried in the broadcast message, the node with the larger sequence number is determined as the master node.

[0101] On the other hand, the sequence number carried in the broadcast message can prevent the first node from repeatedly inheriting the weight value of another node within the same transmission cycle. For example, the network includes a first node and a second node, with different initial weight values. After receiving a broadcast message from the second node, the first node designates the second node as the master node and updates its own sequence number to match the second node's. If, within the same transmission cycle, the first node receives another broadcast message from the second node, the sequence number carried in that broadcast message will be the same as the current sequence number of the first node. In this case, the first node will not inherit the weight value of the second node, i.e., it will not send a broadcast message carrying the second node's initial weight value and sequence number.

[0102] Figure 6 This is an example of a network node management method provided in this application. Taking a mesh network as an example, each node in the mesh network can perform three functions: maintaining an autonomous heartbeat, receiving broadcast messages, and sending broadcast messages. The autonomous heartbeat includes a weight value and a sequence number. The weight value may be its own initial weight value or the initial weight value of other nodes in the relay. The following will describe in detail how the first node determines the master node in the network, using examples of networks with one node, two nodes, and three or more nodes.

[0103] For clarity of description Figure 6 The method shown first explains the parameters involved.

[0104] w and s represent the weight value and sequence number of the autonomous heartbeat, respectively; wc and sc represent the weight value and sequence number carried in the received broadcast message, respectively; wr and sr represent the weight value and sequence number of the relay heartbeat, respectively; wb and sb represent the weight value and sequence number carried in the sent broadcast message, respectively; and m represents the initial weight value of the node.

[0105] It should be understood that each node has an initial weight value, calculated based on its own functional parameters and device identifier; therefore, the initial weight value remains unchanged. Each node needs to maintain an autonomous heartbeat. Before the master node is determined, the weight value carried in the broadcast message sent by each node based on its autonomous heartbeat may be its own initial weight value or the initial weight value of another node in the relay. After the master node is determined, the master node can send its autonomous heartbeat, but the slave nodes cannot. Since the master node has the largest initial weight value, the slave nodes take over the master node's initial weight value. Relay refers to a node receiving a broadcast message from another node, in which the weight value carried by the broadcast message is greater than its own initial weight value; in this case, the node sends a broadcast message carrying the larger initial weight value.

[0106] First, let's take a mesh network with a single node (such as the first node) as an example. The first node initiates an autonomous heartbeat. Specifically, the first node assigns its initial weight value to w, 0 to s, and 0 to sr. It can be understood that the first node can also maintain a periodic alarm, i.e., how often the first node updates its autonomous heartbeat parameters. Whenever the periodic alarm expires, it updates the autonomous heartbeat parameters by incrementing its sequence number by 1 and assigning its initial weight value to w. Then, it resets the periodic alarm, assigns w and s to wb and sb respectively, and sends a broadcast message carrying wb and sb.

[0107] Secondly, let's take a mesh network with two nodes (e.g., node 1 and node 2) as an example. Node 1 and node 2 each maintain their own heartbeat and send broadcast messages. Assume that node 1's initial weight value is less than node 2's initial weight value. After receiving node 2's broadcast message, node 1 determines whether node 2 is a network device. If not, it terminates directly. If so, node 1 compares w with wc in the received broadcast message. As assumed, w is less than wc, so node 1 determines node 2 as the master node in the network. Node 1 updates its heartbeat parameters, assigning wc and sc to w and s respectively, resets its periodic alarm, and sends a broadcast message carrying node 2's initial weight value and sequence number. Resetting the periodic alarm ensures that node 1 and node 2 send broadcast messages at the same time, reducing interference between broadcast signals sent by nodes. For example, if the second node sends broadcast messages at 5, 7, and 9 seconds, and the first node sends broadcast messages at 4, 6, and 8 seconds, then after receiving the broadcast message from the second node, the first node resets its periodic alarm, causing it to also send broadcast messages at 5, 7, and 9 seconds. In the next transmission cycle after the first node determines the master node, if the first node receives another broadcast message from the second node, its weight w is still the second node's initial weight value. Therefore, w is equal to wc. The comparison continues with s and sc-1. Since the second node has updated its sequence number, s and sc-1 are equal. The comparison then continues with wr and wc, and sr and sc. It can be seen that sr and sc are not equal. Therefore, the first node updates the relay heartbeat parameters, assigning wc and sc to wr and sr respectively, and further assigning wr and sr to wb and sb respectively, sending a broadcast message carrying wb and sb.

[0108] It should be understood that if the initial weight values ​​of the first node and the second node are the same, then s and sc-1 can be compared. If s is less than sc-1, it indicates that the second node has been in the network for a longer time. In this case, the first node updates its autonomous heartbeat parameters, assigns wc and sc to w and s respectively, resets the periodic alarm, and sends a broadcast message carrying the initial weight value and sequence number of the second node.

[0109] Secondly, let's take a mesh network with three nodes (node ​​1, node 2, and node 3) as an example. Assume the initial weights of the three nodes are in the following order: node 1 < node 2 < node 3. Also, assume node 1 can receive broadcast messages from node 2, and node 2 can receive broadcast messages from node 3. After receiving a broadcast message from node 3, node 2 sends its own broadcast message carrying node 3's initial weight value, coinciding with the timing of node 3's broadcast message. At the same time, node 1 receives the broadcast message from node 2, and the second node sends its own broadcast message carrying node 3's initial weight value. Therefore, node 1 determines node 3 as the master node in the network and sends its own broadcast message carrying node 3's initial weight value. For a more detailed explanation, please refer to the description of a network with two nodes; it will not be repeated here.

[0110] Figure 7 This is a schematic diagram illustrating the number of heartbeat packets sent according to an embodiment of this application. For example... Figure 7 As shown, the horizontal axis represents time in minutes (min), and the vertical axis represents the broadcast packets for each node. It can be seen that the network includes four nodes: node 1, node 2, node 3, and node 4. Each node has a transmission period of 5 minutes. Figure 7 As shown in a), black squares represent heartbeat packets actively sent, and white squares represent heartbeat packets replied to by other nodes. Without using the method provided in this embodiment, in each sending cycle, each of the four nodes sends a heartbeat packet once, and the remaining nodes reply with a heartbeat packet once. Therefore, the four nodes send heartbeat packets a total of 16 times in each cycle. Figure 7 As shown in b), after determining the master node in the network using the method provided in this application embodiment, each node only needs to send a heartbeat packet once per transmission cycle. Assuming node 1 is the master node, after the master node sends its heartbeat packet, the slave nodes simply relay the master node's heartbeat packet. This reduces the number of heartbeat packet transmissions, thereby reducing interference and power consumption from broadcasts between nodes.

[0111] Based on the above technical solution, each node in the network can determine the node with the largest initial weight value based on its own initial weight value and one or more broadcast messages carrying weight values, and then identify that node as the master node in the network. The weight value carried in each broadcast message is determined by comparing the largest weight value. That is to say, for a certain node, if its broadcast message cannot be received by all other nodes, it can still be relayed by a node that can receive its broadcast message when needed (if the node's initial weight value is relatively large, it will be relayed; if it is relatively small, there is no need to relay it), so that the other nodes can determine the master node in the network, which is beneficial to improving the efficiency of collaborative work among nodes in the network.

[0112] The following will combine Figure 8 and Figure 9 This application provides a detailed description of the network node management device provided in the embodiments.

[0113] Figure 8 This is a schematic block diagram of a network node management device 800 provided in an embodiment of this application. Figure 8 As shown, the device 800 may include a transceiver unit 810 and a processing unit 820. Each unit in the device 800 can be used to implement... Figure 5 or Figure 6 The corresponding process executed by the first node in the illustrated embodiment.

[0114] When the device 800 is used to execute the steps performed by the first node in the above method embodiment, the transceiver unit 810 can be used to receive one or more broadcast messages from other nodes in the network. Each of the one or more broadcast messages carries a weight value. The network contains multiple nodes, and each of the multiple nodes has an initial weight value. The initial weight value of each node is calculated based on the functional parameters of the corresponding node. The weight value carried in each broadcast message is the largest weight value among the initial weight value of the node that sent the broadcast message and the other received weight values. The processing unit 820 can be used to determine the master node of the multiple nodes in the network based on the initial weight value of the first node and the weight values ​​in the one or more broadcast messages. The master node is the node with the largest initial weight value among the multiple nodes. For details, please refer to the detailed description in the method embodiment, which will not be repeated here.

[0115] Optionally, the functional parameters include one or more of the following three items: whether there is a screen, supported network protocols, and active.

[0116] Optionally, the initial weight value of each node is calculated based on the functional parameters of the corresponding node, including: the initial weight value of each node is calculated based on the functional parameters of the corresponding node and the device identifier.

[0117] Optionally, the processing unit 820 is further configured to compare the initial weight value of the first node with the weight value in the broadcast message received from the second node to determine the maximum weight value; the transceiver unit 810 is further configured to send a broadcast message carrying the maximum weight value, which is used by one or more other nodes to determine the master node.

[0118] Optionally, the transceiver unit 810 is also configured to receive a broadcast message from the master node, which includes the master node's initial weight value, if the first node is not the master node.

[0119] Optionally, the processing unit 820 is also configured to adjust the sending time of the first node's broadcast message according to the sending cycle of the master node when the first node is not the master node.

[0120] Optionally, the broadcast message also carries a sequence number, which indicates the transmission period in which the broadcast message is sent.

[0121] Optionally, within a transmission period after the master node is determined, the total number of broadcast messages sent by the plurality of nodes in the network within a transmission period is the same as the number of the plurality of nodes.

[0122] It should be understood that the division of units in the embodiments of this application is illustrative and only represents a logical functional division. In actual implementation, there may be other division methods. Furthermore, the functional units in the various embodiments of this application can be integrated into a single processor, exist as separate physical units, or be integrated into one unit by two or more units. The integrated units described above can be implemented in hardware or as software functional units.

[0123] Figure 9 This is another schematic block diagram of the network node management device 900 provided in the embodiments of this application. The device 900 can be a chip system, or it can be a device configured with a chip system to implement the network node management functions in the above method embodiments. In the embodiments of this application, the chip system can be composed of chips, or it can include chips and other discrete components.

[0124] like Figure 9 As shown, the device 900 may include a processor 910 and a communication interface 920. The communication interface 920 can be used to communicate with other devices via a transmission medium, thereby enabling the devices in the device 900 to communicate with other devices. The communication interface 920 may be, for example, a transceiver, an interface, a bus, a circuit, or a device capable of transmitting and receiving functions. The processor 910 can use the communication interface 920 to input and output data and to implement… Figure 5 or Figure 6 The corresponding embodiment describes a network node management method. Specifically, the device 900 can be used to implement the function of the first node in the above method embodiment.

[0125] For example, if the device 900 is used to implement the function of the first node in the method provided in this application embodiment, the processor 910 can be used to control the communication interface 920 to receive one or more broadcast messages from other nodes in the network. Each of the one or more broadcast messages carries a weight value. The network contains multiple nodes, and each of the multiple nodes has an initial weight value. The initial weight value of each node is calculated based on the functional parameters of the corresponding node. The weight value carried in each broadcast message is the largest weight value among the initial weight value of the node that sent the broadcast message and the other received weight values. The processor 910 can also be used to determine the master node of the multiple nodes in the network based on the initial weight value of the first node and the weight values ​​in one or more broadcast messages. The master node is the node with the largest initial weight value among the multiple nodes. For details, please refer to the detailed description in the method embodiment, which will not be repeated here.

[0126] Optionally, the device 900 further includes at least one memory 930 for storing computer-readable instructions. The memory 930 is coupled to the processor 910. The coupling in this embodiment is an indirect coupling or communication connection between devices, units, or modules, and can be electrical, mechanical, or other forms, for information exchange between devices, units, or modules. The processor 910 may operate in conjunction with the memory 930. The processor 910 may execute program instructions stored in the memory 930. At least one of the at least one memory may be included in the processor.

[0127] This application embodiment does not limit the specific connection medium between the processor 910, the communication interface 920, and the memory 930. This application embodiment... Figure 9 The processor 910, communication interface 920, and memory 930 are connected via bus 940. Bus 940 is... Figure 9 The connections between other components are shown in bold and are for illustrative purposes only, not as limiting information. The bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, Figure 9 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0128] This application also provides a computer program product, which includes computer-readable instructions that, when executed by a computer, implement... Figure 5 or Figure 6 The method described in any one of the embodiments shown.

[0129] This application also provides a computer-readable storage medium storing computer-readable instructions. When the computer-readable instructions are executed by a computer, they implement... Figure 5 or Figure 6 The method described in any one of the embodiments shown.

[0130] It should be understood that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate circuits, transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0131] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0132] The terms “unit”, “module”, etc., used in this specification may be used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution.

[0133] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application. In the several embodiments provided in this application, it should be understood that the disclosed apparatus, devices, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0134] The units described as discrete components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0135] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0136] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs, DVDs), or semiconductor media (e.g., solid-state disks, SSDs), etc.

[0137] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

Claims

1. A management method of a network node, characterized by, The method comprises: A first node receives one or more broadcast messages from other nodes in a network, each of the one or more broadcast messages carrying a weight value, the network comprising a plurality of nodes, each of the plurality of nodes having an initial weight value, the initial weight value of each node being calculated based on a first weight value of the corresponding node and a random number corresponding to the node, the first weight value being determined based on a functional parameter of the node, the random number being determined based on a device identifier of the node, different device identifiers corresponding to different random numbers, the weight value carried in each broadcast message being the maximum of the initial weight value of the node sending the broadcast message and other received weight values; the functional parameter comprising one or more of the following three: whether there is a screen, supported network protocol, and whether there is a source; The first node determines a master node of the plurality of nodes based on the initial weight value of the first node and the weight values in the one or more broadcast messages, the master node being the node in the plurality of nodes with the largest initial weight value; The method further comprises: In the case that the first node is not the master node, the first node adjusts the sending time of the first node for sending a broadcast message to be consistent with the sending time of the master node according to the sending period of the master node; the broadcast message further carries a serial number, the serial number being used to indicate the sending period in which the broadcast message is located; In a sending period after the master node is determined, the total number of broadcast messages sent by the plurality of nodes in the network in one sending period is the same as the number of the plurality of nodes.

2. The method of claim 1, wherein, Before the first node determines the master node of the plurality of nodes in the network based on the initial weight value of the first node and the weight values in the one or more broadcast messages, the method further comprises: The first node compares the initial weight value of the first node with the weight value in the broadcast message of a second node received by the first node to determine the largest weight value, the second node being a node in the plurality of nodes that sends a broadcast message to the first node before the first node sends a broadcast message; The first node sends a broadcast message carrying the largest weight value, the broadcast message being used by one or more other nodes to determine the master node.

3. The method of claim 1 or 2, wherein, The method further comprises: The first node sends a broadcast message carrying the initial weight value of the master node in the next sending period.

4. The method of claim 3, wherein, In the case that the first node is not the master node, before the first node sends a broadcast message carrying the initial weight value of the master node in the next sending period, the method further comprises: The first node receives a broadcast message from the master node, the broadcast message including the initial weight value of the master node.

5. A management apparatus of a network node, characterized by, The apparatus comprises units for performing the method of any one of claims 1 to 4.

6. A management apparatus of a network node, characterized by, The apparatus comprises a processor and a memory, the memory being used to store computer readable instructions, the processor being used to read the computer readable instructions to enable the management device to implement the method of any one of claims 1 to 4.

7. A computer readable storage medium characterized in that, The storage medium has stored therein computer readable instructions which, when executed by a computer, implement the method of any one of claims 1 to 4.

8. A computer program product, characterised in that, The computer program product comprises computer readable instructions which, when executed by a computer, implement the method of any one of claims 1 to 4.

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