Methods for extending the battery life of wireless ad hoc networks

Abstract

The invention relates to a method for extending the battery life of a wireless ad hoc network, and belongs to the technical field of wireless ad hoc networks. The method comprises the following steps: S1: each node reports power information, and a central node collects and statistics; S2: a multi-standard decision-making analysis is performed on a lower-layer proxy node with the fastest energy consumption, and the proxy node is used as a target proxy node; S3: an initial threshold is set; S4: it is judged whether the power of the target proxy node is greater than the initial threshold, if so, the next step is performed, otherwise the judgment is continued; S5: a suitable candidate proxy node is selected; S6: a proxy change is triggered; S7: it is judged whether the power of the proxy node is less than a minimum threshold, if so, the proxy change is stopped, otherwise the threshold is changed and the step S2 is returned.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless ad hoc networks and relates to a method for extending the battery life of a wireless ad hoc network. Background Art

[0002] Wireless self-organizing network (MANET) is a self-organizing network without a center. The network does not rely on a fixed backbone network (but can cooperate with it) or a base station, and can be quickly deployed in place to establish a complete, powerful, and highly resistant network communication system, and provide effective data and multimedia communication services. It was first proposed to be used in individual communication in the military field, and countries around the world began to vigorously study this technology after 2000. This network has the characteristics of high mobility, high convenience, and easy construction. It has great development prospects in scenarios such as the Internet of Things, wireless cities, smart furniture, robot communications, and rapid construction of communication networks during emergency rescue. Wireless self-organizing networks mainly have two structures, a plane structure and a hierarchical structure. The former is suitable for small-scale networks with fewer nodes, while the latter is a large-scale network with many nodes. The method of the present invention is mainly used for hierarchical multi-hop wireless self-organizing networks, and the network nodes can be roughly divided into three categories: central nodes, proxy nodes, and ordinary nodes. The central node is the root node of the 0th layer of the network, and the proxy node is located after the 0th layer. Each layer has one or more proxy nodes, and the two ordinary nodes of the next layer are connected to the node below, which have the function of data storage and forwarding. Ordinary nodes in this network do not have the function of data forwarding, and all nodes in the network except the central node are powered by batteries. However, when the terminal nodes are powered by batteries, the proxy nodes in the same layer may be affected by factors such as load and business volume, resulting in excessive power consumption in some proxy nodes, which will affect the energy balance of the entire network and further affect the network's endurance.

[0003] There are two main methods to improve network endurance. The first is to re-network when the proxy node runs out of power. The second method is to set a low power alarm threshold for each proxy node. When the proxy node reaches the threshold, it will report to the central node to trigger the proxy change and find a new proxy node. Both methods have corresponding disadvantages. The former will cause some network services to be interrupted due to the proxy node during a certain period of time and cannot continue. The latter may cause a centralized power alarm during a certain period of time, which will lead to a sharp increase in the complexity of network proxy changes. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method for extending the battery life of a wireless ad hoc network based on battery power detection.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for extending the battery life of a wireless ad hoc network comprises the following steps:

[0007] S1: Each node reports power information, and the central node collects statistics;

[0008] S2: The proxy node with the fastest energy consumption in the lower layer of the multi-criteria decision analysis is taken as the target proxy node;

[0009] S3: Set the initial threshold;

[0010] S4: Determine whether the power of the target proxy node is greater than an initial threshold, if so, proceed to the next step, otherwise continue to determine;

[0011] S5: Select a suitable candidate proxy node;

[0012] S6: trigger proxy change;

[0013] S7: Determine whether the power of the proxy node is less than the minimum threshold. If so, stop the proxy change. Otherwise, change the threshold and return to step S2.

[0014] Further, step S1 specifically includes the following steps:

[0015] S11: Detecting power information using the power detection module inside the system;

[0016] S12: storing the power information in the existing data frame;

[0017] S13: Send the data frame to the proxy node through the existing signaling data channel;

[0018] S14: The proxy node sends the power information data in a heartbeat detection message to the central node;

[0019] S15: The central node stores the collected power information of each node into the node information form for statistics.

[0020] Further, step S2 specifically includes the following steps:

[0021] S21: The central node retrieves the node information of the lower-level proxy node;

[0022] S22: Read the load number and business volume of each proxy node, and substitute them into formula (1) to calculate the weight of each point;

[0023] W i =β n ·N i +β m ·M i (1)

[0024] In the formula, β n , β mis the load number N under the i-th proxy node i and the number of transactions M i The weight, W i is the weight of the i-th proxy node;

[0025] S23: Arrange the proxy nodes in descending order according to their weight values;

[0026] S24: Select the proxy node with the largest weight value as the target proxy node.

[0027] Furthermore, the initial threshold in step S3 is set to 60% of the total power, the threshold adjustment interval is set to 10%, and the threshold is lowered by 10% after each step S7.

[0028] Further, step S5 specifically includes the following steps:

[0029] S51: Determine whether there is a proxy node with higher power than the target proxy node in the layer where the target proxy node is located. If so, proceed to the next step. Otherwise, stop the proxy change.

[0030] S52: Determine whether the number of proxy nodes that meet the conditions is greater than 1, if so, proceed to the next step, otherwise, directly change the proxy;

[0031] S53: Select the proxy node closest to the target proxy node as the candidate proxy node.

[0032] The beneficial effects of the present invention are:

[0033] In this method, each node stores its own power information in the blank part of the original data frame by making reasonable use of it, and then reports the power information to the central node with the help of the existing signaling channel. The central node will open up a blank column in the node information list to store the power information of each node, and then analyze the lower-level proxy nodes by load number and business volume to determine the target proxy node, set a dynamic power threshold to frequently change the proxy, and thus maintain the power consumption of the entire network in a stable state. This can not only avoid business interruption caused by re-entering the network during a certain period of time, but also avoid the phenomenon of a sharp increase in the complexity of network proxy changes caused by centralized power alarms. At the same time, unlike the traditional power detection in which the battery power percentage is reported as power information, this method will use the mAh of each battery as power information statistics, so that the errors caused by different battery losses of each node can be effectively avoided.

[0034] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0036] Figure 1 is a flow chart of the present invention;

[0037] Figure 2 A network topology diagram of an embodiment of the present invention;

[0038] Figure 3 The figure is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0040] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0041] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0042] Broadband micro-power network is a ubiquitous power Internet of Things, and also belongs to a type of wireless ad hoc network. With the advancement of the construction of the Internet of Things, this technology will gradually emerge in smart industry and smart agriculture. Because the characteristics of this network are very similar to the network described in the present invention, the application of the present invention in this network is used as an embodiment. The communication nodes of the broadband micro-power network can be divided into three categories: Central Coordinator (CCO), Proxy Coordinator (PCO) and Station (STA). The CCO module is placed in the concentrator, and the PCO and STA are placed in the smart meter and type II collector, forming a 15-layer tree network through the communication protocol. In the network, CCO is the root node of the 0th level, and PCO is between 1 and 14 layers. Each layer has one or more PCOs, and the PCO is connected to the STA of the next level, which has the function of data storage and forwarding. STA is a leaf node in the network and does not have the function of data forwarding. The terminal nodes (PCO and STA) support both battery and 220V DC power supply. With the large-scale increase in the number of terminal nodes, the requirements for data transmission rate and real-time performance are greatly improved. When the terminal node is powered by a battery, the PCO at the same layer will consume too much energy due to the load number and business volume, thus affecting the energy balance of the entire network.

[0043] Heartbeat detection is a common mechanism in wireless communication networks. It can determine in real time whether each node in the network is working normally. In broadband micro-power wireless communication networks, CCO needs to perceive the status of network sites in a timely manner in order to manage the network. Whether the site is online depends on the regular discovery list message sent by each site. Each site needs to send a discovery list message at a fixed period for the proxy site to determine whether the site is active online. The proxy site sends the site activity information in the locally maintained discovery list to the CCO through a fixed period heartbeat detection message so that the CCO can summarize the information on whether the sites in the entire network are online. The heartbeat detection message is sent at least once within the cycle. During the sending of the heartbeat detection message, the bottom-level proxy site can generate a heartbeat detection message through the heartbeat detection message of the high-level proxy site. The bottom-level proxy site is triggered by the high-level proxy site, and the generated heartbeat detection message can summarize the content of the heartbeat detection message of the proxy site of the machine, and summarize all the perceived active site information in one message, thereby saving the overhead of network maintenance messages.

[0044] Table 1 shows the heartbeat detection message format of the broadband micro-power wireless communication network. Each station can store the corresponding power information in the reserved position in the heartbeat detection message, and then periodically send it to the PCO and then to the CCO. The CCO stores the power information of each station in the node information list. Figure 2 This is part of the topology of the network. It can be seen that the structure is clear and the responsibilities are clear.

[0045] Table 1

[0046]

[0047] like Figure 1-3 As shown, when the network is successfully established, the system will perform the following embodiments to extend the network life:

[0048] 1. Each STA reports power information, and CCO collects and counts it;

[0049] There are many mechanisms in wireless ad hoc networks to help central nodes interact with each other. The heartbeat detection mechanism is a mechanism that allows the central node to periodically collect real-time information from each node through the proxy node to determine whether the nodes in the network are working properly. In order to develop subsequent functions, the data frames in these interaction mechanisms will have certain blank spaces. Therefore, we can reasonably use the blank spaces of these data frames to store the power information of each node in them. Without affecting the quality of network communication, the central node can collect the power information of each node faster. Taking the heartbeat detection mechanism as an example, the specific steps for power information collection are as follows:

[0050] Each STA uses the power detection module inside the system to detect the power information, stores the power information in the existing data frame, and sends the data frame to the proxy node through the existing signaling data channel. Here, the heartbeat detection mechanism of the broadband micro-power network is taken as an example. The proxy node sends the power information data in the heartbeat detection message to the central node, and the central node stores the collected power information of each node in the node information form for statistics.

[0051] 2. Selecting the target PCO using multi-criteria decision making

[0052] The CCO retrieves the node information of the lower-level PCO, reads the load and traffic of the PCO, and substitutes them into formula (1) to calculate the weight of each point. The PCOs are arranged from large to small according to their weight values. The proxy node with the largest weight value is selected as the target PCO.

[0053] In the selection of the target proxy node, the comprehensive weight of multiple criteria is used as the selection judgment index, and the target proxy node is selected based on the load number and business volume. In the multi-criteria decision, the calculation formula of the comprehensive weight is as follows

[0054] W i =β n ·N i +β m ·M i (1)

[0055] In the formula, β n , β m is the load number N under the i-th proxy node i and the number of transactions M i The weight of i is the weight of the i-th proxy node. The larger the weight, the faster the proxy node consumes power. The weight ratio β is calculated based on the impact of load and business volume on power consumption. n :β m Set to 3:2.

[0056] 3. Set the initial threshold.

[0057] The battery used by each node in the broadband micropower network is 12V 8400mAh. Considering the different consumption of each battery, the initial threshold is set to 60% of the standard battery capacity, that is, 5880mAh.

[0058] 4. Whether the target PCO initially meets the requirements for agency change

[0059] CCO cyclically reads the power information of the target proxy node and compares it with the initial threshold. If it is greater than the initial threshold, the proxy change is preliminarily satisfied and the next step is carried out. Otherwise, the comparison continues.

[0060] 5. Select the right candidate PCO

[0061] Determine whether there is a PCO with higher power than the target PCO in its layer. If so, proceed to the next step, otherwise stop the proxy change; Determine whether the number of qualified proxy nodes is greater than 1. If so, proceed to the next step, otherwise directly change the proxy; Select the PCO closest to the target PCO as the candidate PCO;

[0062] 6. Triggering proxy changes

[0063] 7. Low battery alarm and threshold adjustment

[0064] When the agent change is completed, the target PCO is compared with the minimum power threshold of 840mAh (10% of the standard capacity). If it is less than the threshold, a low power alarm is triggered. Otherwise, it jumps back to the third step and lowers the initial threshold by 10%.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for extending the battery life of a wireless ad hoc network, characterized in that: The following steps are involved: S1: Each node reports power information, and the central node collects statistics; S2: Analyze the proxy node with the fastest energy consumption in the lower layer of the multi-criteria decision-making, and take it as the target proxy node; Step S2 specifically includes the following steps: S21: The central node retrieves the node information of the lower-level proxy node; S22: The comprehensive weight of multiple criteria is used as the judgment index for selection, and the target proxy node is selected using the load number and the business volume. In the multi-criteria decision, the calculation formula of the comprehensive weight is as follows: W i =b n ·N i +b m ·M i (1) In the formula, β n , β m is the load number N under the i-th proxy node i and the number of transactions M i The weight, W i is the weight of the i-th proxy node; the larger the weight, the faster the power consumption of the proxy node; Read the load and traffic volume of each proxy node and substitute them into formula (1) to calculate the weight of each point; S23: Arrange the proxy nodes in descending order according to their weight values; S24: Select the proxy node with the largest weight value as the target proxy node; S3: Set the initial threshold; S4: Determine whether the power of the target proxy node is greater than an initial threshold, if so, proceed to the next step, otherwise continue to determine; S5: Select a suitable candidate proxy node; Step S5 specifically includes the following steps: S51: Determine whether there is a proxy node with higher power than the target proxy node in the layer where the target proxy node is located. If so, proceed to the next step. Otherwise, stop the proxy change. S52: Determine whether the number of proxy nodes that meet the conditions is greater than 1, if so, proceed to the next step, otherwise, directly change the proxy; S53: Selecting a proxy node closest to the target proxy node as a candidate proxy node; S6: trigger proxy change; S7: Determine whether the power of the proxy node is less than the minimum threshold. If so, stop the proxy change. Otherwise, change the initial threshold and return to step S2.

2. The method for extending the battery life of a wireless ad hoc network according to claim 1, characterized in that: Step S1 specifically includes the following steps: S11: Detecting power information using the power detection module inside the system; S12: storing the power information in the existing data frame; S13: Send the data frame to the proxy node through the existing signaling data channel; S14: The proxy node sends the power information data in a heartbeat detection message to the central node; S15: The central node stores the collected power information of each node into the node information form for statistics.

3. The method for extending the battery life of a wireless ad hoc network according to claim 1, characterized in that: The initial threshold in step S3 is set to 60% of the total power, the threshold adjustment interval is set to 10%, and the threshold is lowered by 10% after each step S7.

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