Unattended sensor ad-hoc communication system and method

Abstract

The application discloses an unattended sensor self-organizing communication system, which comprises a management control center, the management control center is connected with at least one access gateway, and the management control center forms a first-level network; a single access gateway is connected with at least one relay node or sensor node, and the at least one access gateway forms a second-level network; a single relay node is connected with at least one sensor node, and the at least one relay node forms a third-level network; a sensor node is connected with a sensor node or a relay node, and the at least one sensor node forms a fourth-level network; the first-level network, the second-level network and the third-level network are tree structure networks with the management control center of the first-level network as a root node, and the sensor in the fourth-level network is independently used as a leaf node or a plurality of sensor nodes are connected with each other to form an independent and autonomous sensor node network as a leaf node; and the application realizes self-organizing and autonomous management of the communication system.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to an unattended sensor self-organizing communication system. Background Technology

[0002] In unattended sensor self-organizing communication systems, most devices operate outdoors, facing objective limitations such as high and low temperatures, low air pressure, high humidity, sunlight, corrosion, rain, and power supply difficulties. Communication methods primarily include satellite communication, UHF, wireless sensor networks, near-field NFC, Bluetooth, Wi-Fi, fiber optic communication, Ethernet, RS232, RS422, RS485, CAN bus, and 4G / 5G mobile communication. Most devices employ low-power, low-cost, and miniaturized designs, resulting in insufficient processing power and low reliability. Traditional outdoor networks use fixed gateways, lacking self-diagnosis and self-healing capabilities. They cannot select device operating modes based on unit bit communication cost and unit bit power consumption, and lack integrated working mechanisms such as automatic network discovery, autonomous registration, operating mode switching, node addition / removal, self-diagnosis and self-healing, and forwarding table self-learning, leading to insufficient self-organization and autonomous management capabilities. Summary of the Invention

[0003] To address the problems existing in the prior art, the purpose of this invention is to provide an unattended sensor self-organizing communication system, which realizes the self-organization and autonomous management of the communication system.

[0004] To achieve the above objectives, the technical solution adopted by this invention is as follows: an unattended sensor self-organizing communication system, comprising a management and control center, which is connected to at least one access gateway, forming a first-level network; a single access gateway is connected to at least one relay node or sensor node, forming a second-level network; a single relay node is connected to at least one sensor node, forming a third-level network; sensor nodes are connected to other sensor nodes or relay nodes, forming a fourth-level network; the first-level network, second-level network, and third-level network form a tree structure network with the management and control center of the first-level network as the root node; sensors in the fourth-level network are individually leaf nodes, or multiple sensor nodes are interconnected to form an independent and autonomous sensor node network as a whole, which is also a leaf node; the access gateway repeatedly switches between three working modes: access gateway, relay node, and sensor; the relay node repeatedly switches between two working modes: relay node and sensor.

[0005] This invention also provides an unattended sensor self-organizing communication method, which employs the unattended sensor self-organizing communication system described above, and includes the following steps:

[0006] Step 1: After the device with sensor node function is powered on, it automatically scans the public channels one by one according to the pre-configured public channel information list and receives data. Based on the data information, it selects a relay node or access gateway for communication and sends registration data information to the relay node or access gateway using an anti-collision mechanism. The relay node or access gateway allocates communication resources and sets the transmission rate based on the registration data information.

[0007] Step 2: After the device with relay node function is powered on, it automatically scans the public channels one by one according to the pre-configured public channel information list and receives data. It selects the access gateway to communicate based on the data information and sends registration data information to the access gateway using an anti-collision mechanism. The access gateway allocates communication resources and sets the transmission rate based on the registration data information. After the relay node successfully connects to the access gateway, it updates the relay node forwarding table, transparently transmits the received sensor node data to the access gateway, and transparently transmits the data sent by the access gateway to the sensor node to the sensor.

[0008] Step 3: After the device with access gateway function is powered on, it automatically initiates a link establishment request to the management and control center through the transmission network according to the pre-configured information, and sends registration data information to the management and control center using an anti-collision mechanism. The management and control center allocates communication resources and sets the transmission rate according to the registration information. After the access gateway connects to the management and control center, it updates the access gateway forwarding table, and transparently transmits the data received from the sensor nodes or relay nodes to the management and control center, and also transparently transmits the data sent by the management and control center to the sensor nodes or relay nodes to the sensor nodes or relay nodes.

[0009] Step 4: Automatically upgrade and downgrade by switching working modes of access gateway, relay node, and sensor node devices, and select the optimal working mode;

[0010] Step 5: The management and control center establishes a communication connection with the access gateway through the transmission network. It is responsible for the management, mapping, authentication and registration of the unique communication addresses of the access gateway, relay nodes and sensor nodes, the addition, deletion and modification management of the communication forwarding table of the management and control center, the reverse control of the access gateway, relay nodes and sensor nodes, the updating of the communication network topology map, the selection of downlink data forwarding table, and the visualization display of the status and geographical location of the access gateway, relay nodes and sensor nodes.

[0011] As a further improvement of the present invention, in step 1, the sensor node calculates the communication performance value E with the relay node or access gateway, and selects the node with the largest communication performance E as the communication node of the sensor node, relay node, or access gateway; the method for calculating the communication performance value E is as follows:

[0012]

[0013] Where i is the index number of the communication performance evaluation index, P i W represents the score of the i-th communication performance evaluation indicator. i , where is the weighting coefficient of the i-th communication performance evaluation index; the communication performance evaluation index includes communication cost per bit, power consumption per bit, transmission delay, bandwidth utilization, received signal strength, received power, transmission rate, transmission bandwidth, and bit error rate; wherein, communication cost per bit = cost / actual communication rate, and power consumption per bit = device power consumption / actual communication rate.

[0014] As a further improvement of the present invention, in step 2, when the relay node detects that the connection with the current access gateway is broken, the relay node attempts to establish a connection with other access gateways. If all attempts fail, the relay node switches its working mode to the sensor node mode, and at the same time triggers the sensor nodes under the relay node to search for and discover new relay nodes or access gateways.

[0015] The relay node forwarding table includes a sequence number, a unique communication address for each sensor node, and link information between the relay node and the sensor nodes. The relay node forwarding table stores records all sensor node entries under that relay node, with each sensor node corresponding to a unique sensor node entry. The relay node forwarding table update and maintenance process is as follows:

[0016] A. After a sensor node is successfully registered, a relay node forwarding table entry for that sensor is generated, and the newly generated entry is inserted into the relay node forwarding table.

[0017] B. If a relay node detects a link failure or disconnection of a sensor node, it deletes the corresponding entry for that sensor in the relay node's forwarding table.

[0018] C. Upon receiving a re-registration or parameter change instruction from a sensor node, update the corresponding entry in the relay node's forwarding table.

[0019] D. The relay node reports the data information of inserting, deleting, and updating the relay node forwarding table to the access gateway.

[0020] As a further improvement of the present invention, in step 3, when the access gateway detects that the connection with the management and control center is disconnected, the access gateway switches its working mode to the relay node working mode, and at the same time triggers the sensor nodes or relay nodes under the access gateway to search for and discover a new access gateway.

[0021] The access gateway forwarding table includes a serial number, a unique communication address for the sensor node, a unique communication address for the relay node, and link information between the access gateway and the relay node. The access gateway forwarding table stores entries for all relay nodes and sensor nodes under that access gateway, with each sensor node corresponding to a unique entry. The access gateway forwarding table update and maintenance process is as follows:

[0022] a. After a sensor node or relay node is successfully registered, an access gateway forwarding table entry for that sensor node or relay node is generated and inserted into the access gateway forwarding table.

[0023] b. If the access gateway detects a link failure or disconnection of a relay node or sensor node, it deletes the entry for the sensor node or relay node itself and all sensor nodes under the relay node from the access gateway's forwarding table.

[0024] c. Upon receiving a re-registration or parameter change instruction from a sensor node or relay node, update the corresponding entry in the access gateway forwarding table.

[0025] d. The access gateway reports the data information of insertion, deletion and update of the access gateway forwarding table to the management and control center.

[0026] As a further improvement of the present invention, the data information in the public channel information list includes device node type, received signal strength, received power, transmission rate, transmission bandwidth, bit error rate, transmission delay, and bandwidth utilization.

[0027] As a further improvement of the present invention, the processing flow of the anti-collision mechanism is as follows:

[0028] Step (1): The node listens to the pre-configured public channel to determine whether the channel is idle;

[0029] Step (2): If the channel is idle, send a data transmission request command through the public channel, and wait for the sensor node, relay node or access gateway to reply with a data transmission permission command before sending the data.

[0030] Step (3): If the channel is occupied or data from other nodes is received during data transmission, resulting in a data collision at the same time, the node immediately stops transmitting data and waits for a delay of T, where T is the time interval between the current node and the next node. i =e i ×Δt, where i is the i-th wait, T is the Δt, and T is the Δt. i Let Δt be the waiting time for the i-th time and Δt be the waiting time interval. After the waiting time ends, if there is still data that has not been sent, continue to execute steps (1) and (2).

[0031] As a further improvement of the present invention, in step 4, the access gateway's automatic downgrade process for switching working modes is as follows:

[0032] The access gateway determines whether the automatic downgrade handover conditions are met. If the handover conditions are met, the access gateway switches its operating mode to the relay node's operating mode.

[0033] 1) When the access gateway detects that the link with the management and control center is broken or the continuous measurement of the communication error rate with the management and control center within a certain period of time is greater than the preset threshold, the access gateway will start switching working modes and automatically downgrade to the relay node working mode.

[0034] 2) When the bandwidth utilization rate of the access gateway is lower than the preset threshold or the number of access devices is lower than the preset threshold for a certain period of time, it indicates that the bandwidth utilization rate of the access gateway is low, the communication cost per bit is high, the power consumption per bit is high, and the network traffic load is unbalanced. The access gateway will start switching working modes and automatically degrade to the relay node working mode.

[0035] 3) After the access gateway initiates the automatic downgrade to relay node mode, it attempts to probe for other access gateways within its communication range. If any other available access gateway nodes are found, the access gateway automatically downgrades to relay node mode, while the original relay node and sensor node topology remains unchanged. After downgrading to relay node mode, the access gateway selects the access gateway with the highest communication efficiency (E) for communication.

[0036] As a further improvement of the present invention, in step 4, the relay node's autonomous automatic upgrade and downgrade process for switching working modes is as follows:

[0037] (1) The relay node determines whether the automatic degradation switching conditions are met. If the switching conditions are met, the relay node switches its working mode to the sensor node's working mode:

[0038] 1) When a relay node detects that the link with the relay node or access gateway has been lost, or when the continuous measurement of the communication bit error rate with the relay node or access gateway within a certain period of time exceeds a preset threshold, the relay node will initiate a switch to automatically downgrade to the sensor node working mode.

[0039] 2) If the bandwidth utilization rate of a relay node is lower than the preset threshold or the number of connected sensors or relay nodes is lower than the preset threshold within a certain period of time, it indicates that the bandwidth utilization rate of the relay node is low, the communication cost per bit is high, the power consumption per bit is high, and the network traffic load is unbalanced. The relay node will then switch its working mode and automatically downgrade to the sensor node working mode.

[0040] 3) After a relay node initiates a switchover and automatically downgrades to sensor node mode, it attempts to detect other relay nodes within its communication range. If any available relay nodes are found, the relay node automatically downgrades to sensor node mode, triggering all sensor nodes and relay nodes under that node to search for and discover new relay nodes. The topology of the original relay nodes and sensor nodes connected to that relay node changes. After downgrading to sensor node mode, the relay node selects the relay node with the highest communication efficiency (E) for communication.

[0041] (2) The relay node determines whether the automatic upgrade and switching conditions are met. If the switching conditions are met, the relay node switches its working mode to the access gateway working mode:

[0042] 1) When the downgraded relay node detects that the link with the management and control center has been restored and the continuous measurement of the communication error rate with the management and control center within a certain period of time is less than the preset threshold, the relay node starts to switch working modes and automatically upgrades to the access gateway working mode.

[0043] 2) If the bandwidth utilization rate of a relay node is higher than the preset threshold or the number of connected sensors or relay nodes is greater than the preset threshold within a certain period of time, it indicates that the subsequent scalability of the relay node is insufficient, the communication congestion and packet loss rate are increased, and the network traffic load is unbalanced. The relay node will then start switching working modes and automatically upgrade to the access gateway working mode.

[0044] 3) After a relay node initiates an automatic upgrade to the access gateway working mode, the topology of the original relay nodes and sensor nodes connected to that relay node remains unchanged. After the relay node is upgraded to an access gateway, it maintains its communication connection with the management and control center.

[0045] As a further improvement of the present invention, in step 4, the autonomous and automatic upgrade process for the downgraded sensor node to switch working modes is as follows:

[0046] After being downgraded, the sensor node determines whether the automatic upgrade switching conditions are met. If the switching conditions are met, the sensor node switches its operating mode to the relay node operating mode.

[0047] 1) When the downgraded sensor node detects that the connection with the relay node and access gateway has been restored, and the continuous measurement of the communication error rate with the relay node and access gateway within a certain period of time is less than the preset threshold, the sensor node starts to switch working modes and automatically upgrades to the relay node working mode.

[0048] 2) When a sensor node receives a message that the bandwidth utilization rate of a relay node is higher than a preset threshold or a message that the number of relay nodes connected to a sensor is greater than a preset threshold, it indicates that the traffic load of the relay node is close to saturation and the network traffic load is unbalanced. The sensor node will start switching working modes and automatically upgrade to the relay node working mode, which is beneficial to divert the original relay node traffic, balance the network load, and improve network reliability.

[0049] 3) After the sensor node starts switching working mode and automatically upgrades to the relay node working mode, it supports connecting relay nodes and sensor nodes, and the entire network topology changes; after the sensor node is upgraded to a relay node, it selects the relay node with the highest communication efficiency E and connects to the gateway for communication.

[0050] This invention's communication system comprises a management and control center, access gateways, relay nodes, sensor nodes, and a transmission network, forming a four-level self-organizing network for unattended sensors. Based on the characteristics of unattended sensor networks, such as asymmetrical uplink and downlink bandwidth, short-term operation, low transmission rates, and heterogeneous networks, the management and control center uniformly allocates and manages system resources. Access gateways, relay nodes, and sensor nodes dynamically switch operating modes based on unit bit communication cost, unit bit power consumption, transmission latency, bandwidth utilization, received signal strength, received power, transmission rate, transmission bandwidth, and bit error rate, ensuring high reliability and communication connectivity and data reachability among the management and control center, access gateways, relay nodes, and sensor nodes. Switching operating modes is achieved through the autonomous automatic upgrade and downgrade of access gateways and relay nodes, realizing network traffic load balancing, high reliability in heterogeneous networks, low transmission latency, and reducing unit bit communication cost and unit bit power consumption. The system supports automatic network discovery, autonomous registration, operating mode switching, node addition / removal, self-diagnosis and self-healing, and forwarding table self-learning, thereby achieving self-organization and autonomous management of the communication system.

[0051] The beneficial effects of this invention are:

[0052] This invention employs a dynamic switching working mode, achieving network traffic load balancing, high reliability in heterogeneous networks, and low transmission latency through the autonomous and automatic upgrade and downgrade of access gateways and relay nodes, thereby reducing the communication cost and power consumption per unit bit. It utilizes a combined working mechanism including automatic network discovery, autonomous registration, working mode switching, node addition / removal, self-diagnosis and self-healing, and forwarding table self-learning to achieve network self-organization and autonomous management. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the four-level network structure in an embodiment of the present invention;

[0054] Figure 2This is a flowchart illustrating the network forwarding table update process in an embodiment of the present invention.

[0055] Figure 3 This is a flowchart of downlink data processing in an embodiment of the present invention. Detailed Implementation

[0056] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0057] Example

[0058] like Figure 1 As shown, an unattended sensor self-organizing communication system comprises a management and control center, an access gateway, relay nodes, sensor nodes, and a transmission network. The access gateway can upgrade and downgrade between three operating modes: access gateway, relay node, and sensor. Relay nodes can upgrade and downgrade between two operating modes: relay node and sensor. Sensors can only operate in sensor mode. The transmission network includes communication methods such as satellite communication, UHF, wireless sensor network, near-field NFC, Bluetooth, WIFI, fiber optic communication, Ethernet, RS232, RS422, RS485, CAN bus, and 4G / 5G mobile communication. The management and control center, access gateway, relay nodes, and sensor nodes form a four-level unattended sensor self-organizing network, as shown in the four-level network diagram.

[0059] The entire network has only one management and control center, connected to one or more access gateways, forming the first-level network. A single access gateway supports connections to one or more relay nodes and sensor nodes, forming the second-level network. A single relay node supports connections to one or more sensor nodes, forming the third-level network. Sensor nodes support connections to other sensor nodes or relay nodes, forming the fourth-level network. This fourth-level network is a hybrid network combining tree and mesh structures. The first, second, and third-level networks form a tree structure with the first-level network management and control center as the root node. In the fourth-level network, sensor nodes can act as individual leaf nodes, or multiple sensor nodes can connect to form an independent, autonomous sensor node network as a whole, also acting as leaf nodes.

[0060] like Figure 2 and Figure 3 As shown, the process by which this communication network self-organizes and self-discovers to form a stable autonomous network is as follows:

[0061] 1. After power-on, devices equipped with sensor node functionality automatically scan public channels one by one according to a pre-configured list of public channel information and receive data. Based on received signal strength, received power, transmission rate, transmission bandwidth, bit error rate, transmission delay, and bandwidth utilization, they select a relay node or access gateway for communication. An anti-collision mechanism is employed to send registration data information to the relay node or access gateway. The relay node or access gateway allocates communication resources and sets the transmission rate based on the registration information.

[0062] The public channel information list is periodically sent by relay nodes or access gateways through pre-configured public channels. This data includes device node type, transmission rate, transmission bandwidth, transmission delay, and bandwidth utilization. Sensor nodes calculate their communication performance value E with relay nodes or access gateways, and select the node with the highest communication performance E as the communication node for the sensor node, relay node, or access gateway. In the formula, E represents communication performance, i represents the communication performance evaluation index number, and P represents the communication performance evaluation index number. i Let W be the score of the i-th communication performance evaluation indicator. i The weighting coefficient of the i-th communication performance evaluation index, which includes communication cost per bit, power consumption per bit, transmission delay, bandwidth utilization, received signal strength, received power, transmission rate, transmission bandwidth, and bit error rate. Wherein, communication cost per bit = cost / actual communication rate, and power consumption per bit = device power consumption / actual communication rate.

[0063] The anti-collision mechanism's processing flow is as follows: Step 1: The node listens to the pre-configured public channel to determine if the channel is idle. Step 2: If the channel is idle, the node sends a data transmission request command through the public channel and waits for a data transmission permission command from the sensor node, relay node, or access gateway before transmitting the data. Step 3: If the channel is occupied or data information from other nodes is received during data transmission, resulting in a data collision at the same time, the node immediately stops transmitting data and waits for a delay of T, where T... i =e i ×Δt, where i is the i-th wait, T is the Δt, and T is the Δt. i Let Δt be the waiting time for the i-th iteration, and Δt be the waiting time interval. After the waiting time expires, if there is still data that has not been sent, continue executing steps 1 and 2.

[0064] 2. After power-on, devices equipped with relay node functionality automatically scan public channels item by item according to a pre-configured list of public channel information and receive data. They select an access gateway for communication based on received signal strength, received power, transmission rate, bit error rate, and transmission delay. An anti-collision mechanism is employed to send registration data to the access gateway, which allocates communication resources and sets the transmission rate based on the registration information. Once a relay node successfully connects to the access gateway, it updates its forwarding table, transparently transmitting received sensor node data to the access gateway and transmitting data sent from the access gateway to the sensor nodes back to the sensors. If a relay node detects a disconnection from the current access gateway, it attempts to establish a connection with other access gateways. If all attempts fail, the relay node switches its operating mode to sensor node mode, simultaneously triggering the sensor nodes under that relay node to search for and discover new relay nodes or access gateways.

[0065] Relay nodes forward data according to their forwarding tables. Each relay node forwarding table entry must contain at least a sequence number, the sensor node's unique communication address, and the link information between the relay node and the sensor node. The relay node forwarding table stores records all sensor node entries under that relay node, with each sensor node corresponding to a unique sensor node entry. The relay node forwarding table update and maintenance process is as follows: Step 1: After a sensor node successfully registers, a relay node forwarding table entry for that sensor is generated and inserted into the relay node forwarding table. Step 2: If a relay node detects a sensor node link failure or disconnection, it deletes the corresponding entry in the relay node forwarding table. Step 3: Upon receiving a re-registration or parameter change instruction from a sensor node, the relay node updates the corresponding entry in the relay node forwarding table. Step 4: The relay node reports the inserted, deleted, and updated data information in its relay node forwarding table to the access gateway.

[0066] 3. After powering on, devices equipped with access gateway functionality automatically initiate a link establishment request to the management and control center via the transmission network according to pre-configured information. An anti-collision mechanism is employed to send registration data to the management and control center, which allocates communication resources and sets the transmission rate based on the registration information. After the access gateway connects to the management and control center, it updates its forwarding table, transparently transmitting received data from sensor nodes or relay nodes to the management and control center, and also transparently transmitting data sent from the management and control center to the sensor nodes or relay nodes. When the access gateway detects a disconnection from the management and control center, it switches its operating mode to relay node mode, simultaneously triggering the sensor nodes or relay nodes under that access gateway to search for and discover a new access gateway.

[0067] The access gateway forwards data according to its forwarding table. Each entry in the access gateway forwarding table must contain at least a sequence number, a unique communication address for the sensor node, a unique communication address for the relay node, and link information between the access gateway and the relay node. The access gateway forwarding table stores records entries for all relay nodes and sensor nodes under that access gateway. Each sensor node corresponds to a unique entry. The access gateway forwarding table update and maintenance process is as follows: Step 1: After a sensor node or relay node successfully registers, an access gateway forwarding table entry for that sensor node or relay node is generated and inserted into the access gateway forwarding table. Step 2: If the access gateway detects a link failure or disconnection of a relay node or sensor node, it deletes the entry for that sensor node or relay node itself and all sensor nodes under that relay node from the access gateway forwarding table. Step 3: Upon receiving a re-registration or parameter change instruction from a sensor node or relay node, the access gateway forwarding table updates the corresponding entry for that sensor. Step 4: The access gateway reports the inserted, deleted, and updated data information from the access gateway forwarding table to the management and control center.

[0068] 4. In unattended sensor self-organizing communication systems, most devices operate outdoors, facing objective limitations such as high and low temperatures, low air pressure, high humidity, sunlight, corrosion, rain, and power supply difficulties. Most devices adopt low-power, low-cost, and miniaturized designs. Through the switching of operating modes between access gateways, relay nodes, and sensor nodes, they autonomously and automatically upgrade and downgrade, selecting the optimal operating mode. This effectively improves overall network reliability, networking flexibility, and reduces the cost per bit of communication and power consumption per bit.

[0069] The cost and power consumption per bit of communication vary significantly depending on the operating mode of the device. Typically, the cost per bit of communication for an access gateway is higher than that for a relay node, which in turn is higher than that for a sensor node. Conversely, the power consumption per bit for an access gateway is typically higher than that for a relay node, which in turn is higher than that for a sensor node.

[0070] The main process for the access gateway to switch working modes and automatically downgrade is as follows:

[0071] (1) The access gateway determines whether the automatic downgrade switching conditions are met. If the switching conditions are met, the access gateway switches its working mode to the relay node working mode.

[0072] 1) When the access gateway detects that the link with the management and control center is broken or the continuous measurement of the communication error rate with the management and control center within a certain period of time is greater than the preset threshold, the access gateway will start switching working modes and automatically downgrade to the relay node working mode.

[0073] 2) If the bandwidth utilization rate of the access gateway is lower than the preset threshold or the number of access devices is lower than the preset threshold for a certain period of time, it indicates that the bandwidth utilization rate of the access gateway is low, the communication cost per bit is high, the power consumption per bit is high, and the network traffic load is unbalanced. The access gateway will then switch its working mode and automatically degrade to the relay node working mode.

[0074] 3) After the access gateway initiates the automatic downgrade to relay node mode, it attempts to probe for other access gateways within its communication range. If any other available access gateway nodes are found, the access gateway automatically downgrades to relay node mode, while the original relay node and sensor node topology remains unchanged. After downgrading to relay node mode, the access gateway selects the access gateway with the highest communication efficiency (E) for communication.

[0075] The main process for relay nodes to automatically upgrade or downgrade their operating modes is as follows:

[0076] (1) The relay node determines whether the automatic downgrade switching conditions are met. If the switching conditions are met, the relay node switches its working mode to the sensor node working mode.

[0077] 1) When a relay node detects that the link with the relay node or access gateway has been lost, or when the continuous measurement of the communication error rate with the relay node or access gateway within a certain period of time exceeds a preset threshold, the relay node will initiate a switch to automatically downgrade to the sensor node working mode.

[0078] 2) If the bandwidth utilization rate of a relay node is lower than the preset threshold or the number of connected sensors or relay nodes is lower than the preset threshold within a certain period of time, it indicates that the bandwidth utilization rate of the relay node is low, the communication cost per bit is high, the power consumption per bit is high, and the network traffic load is unbalanced. The relay node will then switch its working mode and automatically downgrade to the sensor node working mode.

[0079] 3) After a relay node initiates its automatic downgrade to sensor node mode, it attempts to detect other relay nodes within its communication range. If any available relay nodes are found, the relay node automatically downgrades to sensor node mode, triggering all sensor nodes and relay nodes under that node to search for and discover new relay nodes. The topology of the original relay nodes and sensor nodes attached to that relay node changes. After downgrading to sensor node mode, the relay node selects the relay node with the highest communication efficiency (E) for communication.

[0080] (2) The relay node determines whether the automatic upgrade switching conditions are met. If the switching conditions are met, the relay node switches its working mode to the access gateway working mode.

[0081] 1) When the downgraded relay node detects that the link with the management and control center has been restored, and the continuous measurement of the communication error rate with the management and control center within a certain period of time is less than the preset threshold, the relay node starts to switch working modes and automatically upgrades to the access gateway working mode.

[0082] 2) If the bandwidth utilization rate of a relay node is higher than the preset threshold for a certain period of time, or if the number of connected sensors or relay nodes is greater than the preset threshold, it indicates that the subsequent scalability of the relay node is insufficient, the communication congestion and packet loss rate are increasing, and the network traffic load is unbalanced. The relay node will then start switching working modes and automatically upgrade to the access gateway working mode.

[0083] 3) After a relay node initiates an automatic upgrade to the access gateway working mode, the topology of the original relay nodes and sensor nodes connected to that relay node remains unchanged. After the relay node is upgraded to an access gateway, it maintains its communication connection with the management and control center.

[0084] The main process for the autonomous and automatic upgrade of sensor nodes after downgrading is as follows:

[0085] (1) After the sensor node is downgraded, it determines whether the automatic upgrade switching conditions are met. If the switching conditions are met, the sensor node switches its working mode to the relay node working mode.

[0086] 1) When the downgraded sensor node detects that the connection with the relay node and access gateway has been restored, and the continuous measurement of the communication error rate with the relay node and access gateway within a certain period of time is less than the preset threshold, the sensor node starts to switch working modes and automatically upgrades to the relay node working mode.

[0087] 2) When a sensor node receives a message that the bandwidth utilization of a relay node is higher than a preset threshold or that the number of relay nodes connected to a sensor is greater than a preset threshold, it indicates that the traffic load of the relay node is close to saturation and the network traffic load is unbalanced. The sensor node will then switch its working mode and automatically upgrade to the relay node working mode, which is beneficial for diverting the original relay node traffic, balancing the network load, and improving network reliability.

[0088] 3) After a sensor node automatically upgrades to relay node mode upon startup, it supports connections to both relay nodes and sensor nodes, resulting in a change in the overall network topology. When a sensor node is upgraded to a relay node, it selects the relay node with the highest communication performance (E) and connects to the gateway for communication.

[0089] 5. The management and control center establishes a communication connection with the access gateway through the transmission network. It is responsible for the management, mapping, authentication, and registration of the unique communication addresses of network nodes such as access gateways, relay nodes, and sensors. It also manages the addition, deletion, and modification of the communication forwarding table, performs reverse control of network nodes such as access gateways, relay nodes, and sensors, updates the communication network topology, selects downlink data forwarding tables, and provides a visual display of the status and geographical location of access gateways, relay nodes, and sensor nodes.

[0090] The attributes of network nodes such as access gateways, relay nodes, and sensors must include at least {unique communication address, device type, operating mode, operating status, location information, and preset encryption string}. Access gateways, relay nodes, and sensors employ both pre-configured and dynamically configured authentication and registration mechanisms to effectively address the authentication, registration, and communication of legitimate devices, and to effectively identify, verify, and authorize legitimate and illegitimate devices.

[0091] Preset node authentication and registration process: After configuring the attributes of the network node, the management and control center stores them in the management and control center's storage system. The network node registration data contains a unique communication address. The management and control center uses the unique communication address in the registration node data to query the corresponding preset encryption string in the storage system. If the corresponding preset encryption string in the storage system is the same as the encryption string in the registration node data, then authentication and registration are successful.

[0092] Dynamic Node Authentication and Registration Process: For network nodes such as access gateways, relay nodes, and sensors that are not pre-registered with the management control center, when a network node registers for the first time, the management control center uses a global key to decrypt the registration node data, verifies the compliance of the unique communication address generation rules in the registration node data, and uses the unique communication address in the registration node data to query the corresponding preset encryption string in the storage system. If the corresponding preset encryption string in the storage system is the same as the encryption string in the registration node data, authentication and registration are successful. If no corresponding unique communication address is found in the storage system, the management control center dynamically generates a unique communication address in real time according to the unique communication address generation rules and sends it to the registration node. Upon receiving the newly assigned unique communication address, the registration node restarts the dynamic authentication and registration process.

[0093] After a network node successfully registers, the management and control center updates the node's working status, location information, and visualization information, and draws the latest communication network topology diagram. The management and control center updates the downlink data forwarding table with the unique communication address of the access gateway, the unique communication address of the network node, and the link information between the management and control center and the access gateway from the registered node data. The downlink data forwarding table consists of forwarding route entries, each containing at least a sequence number, the unique communication address of the network node, the unique communication address of the access gateway, and the link information between the management and control center and the access gateway. When the management and control center sends downlink data to a network node, it iterates through the downlink data forwarding table item by item, using the unique communication address of the network node to query the corresponding access gateway and link information, and then sends the data to the access gateway. After receiving the data, the access gateway queries its forwarding table based on the unique communication address of the network node and sends the data to the relay node or sensor.

[0094] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An unattended sensor self-organizing communication system, characterized in that, The network includes a management and control center connected to at least one access gateway, forming a first-level network; a single access gateway connected to at least one relay node or sensor node, forming a second-level network; a single relay node connected to at least one sensor node, forming a third-level network; and sensor nodes connected to other sensor nodes or relay nodes, forming a fourth-level network. The first, second, and third-level networks form a tree-like structure with the management and control center of the first-level network as the root node. Sensor nodes in the fourth-level network function as individual leaf nodes, or multiple sensor nodes interconnected to form an independent and autonomous sensor node network as leaf nodes. The access gateways repeatedly switch between three operating modes: access gateway, relay node, and sensor node. Similarly, the relay nodes repeatedly switch between two operating modes: relay node and sensor node. The process for the access gateway to automatically downgrade its operating mode is as follows: The access gateway determines whether the automatic downgrade handover conditions are met. If the handover conditions are met, the access gateway switches its operating mode to the relay node's operating mode. 1) When the access gateway detects that the link with the management and control center is broken or the continuous measurement of the communication error rate with the management and control center within a certain period of time is greater than the preset threshold, the access gateway will start switching working modes and automatically downgrade to the relay node working mode. 2) When the bandwidth utilization rate of the access gateway is lower than the preset threshold or the number of access devices is lower than the preset threshold for a certain period of time, it indicates that the bandwidth utilization rate of the access gateway is low, the communication cost per unit bit is high, the power consumption per unit bit is high, or the network traffic load is unbalanced. The access gateway will start switching working modes and automatically degrade to the relay node working mode. 3) After the access gateway starts switching working mode and automatically downgrades to relay node working mode, the access gateway attempts to detect other access gateways within the communication range. If there are other available access gateways, the access gateway switches working mode and automatically downgrades to relay node working mode. The original relay node and sensor node topology relationship under the access gateway remains unchanged. After the access gateway is downgraded to a relay node, it selects the access gateway with the highest communication efficiency value E for communication. The automatic upgrade and downgrade process for relay nodes switching working modes is as follows: (1) The relay node determines whether the automatic degradation switching conditions are met. If the switching conditions are met, the relay node switches its working mode to the sensor node's working mode: 1) When a relay node detects that the link with the relay node or access gateway has been lost, or when the continuous measurement of the communication bit error rate with the relay node or access gateway within a certain period of time exceeds a preset threshold, the relay node will initiate a switch to automatically downgrade to the sensor node working mode. 2) If the bandwidth utilization rate of a relay node is lower than the preset threshold or the number of connected sensor nodes or relay nodes is lower than the preset threshold within a certain period of time, it indicates that the bandwidth utilization rate of the relay node is low, the communication cost per bit is high, the power consumption per bit is high, or the network traffic load is unbalanced. The relay node will then switch its working mode and automatically downgrade to the sensor node working mode. 3) After a relay node initiates a switchover and automatically downgrades to sensor node mode, it attempts to detect other relay nodes within its communication range. If any available relay nodes are found, the relay node automatically downgrades to sensor node mode, triggering all sensor nodes and relay nodes under that relay node to search for and discover new relay nodes. The topology of the original relay nodes and sensor nodes under that relay node changes. After downgrading to sensor node mode, the relay node selects the relay node with the highest communication efficiency value E for communication. (2) The relay node determines whether the automatic upgrade and switching conditions are met. If the switching conditions are met, the relay node switches its working mode to the access gateway working mode: 1) When the downgraded relay node detects that the link with the management and control center has been restored and the continuous measurement of the communication error rate with the management and control center within a certain period of time is less than the preset threshold, the relay node starts to switch working modes and automatically upgrades to the access gateway working mode. 2) If the bandwidth utilization rate of a relay node is higher than the preset threshold for a certain period of time, or if the number of connected sensor nodes or relay nodes is greater than the preset threshold, it indicates that the subsequent scalability of the relay node is insufficient, the communication congestion and packet loss rate are increased, or the network traffic load is unbalanced. The relay node will then start switching working modes and automatically upgrade to the access gateway working mode. 3) After a relay node starts switching its working mode and automatically upgrades to the access gateway working mode, the topology relationship between the original relay nodes and sensor nodes connected to that relay node remains unchanged; after the relay node is upgraded to an access gateway, it maintains its communication connection with the management and control center. The automatic upgrade process for sensor nodes switching operating modes after downgrading is as follows: After being downgraded, the sensor node determines whether the automatic upgrade switching conditions are met. If the switching conditions are met, the sensor node switches its operating mode to the relay node operating mode. 1) When the downgraded sensor node detects that the connection with the relay node and access gateway has been restored, and the continuous measurement of the communication error rate with the relay node and access gateway within a certain period of time is less than the preset threshold, the sensor node starts to switch working modes and automatically upgrades to the relay node working mode. 2) When a sensor node receives a message that the bandwidth utilization rate of a relay node is higher than a preset threshold or a message that the number of relay nodes connected to the sensor node is greater than a preset threshold, it indicates that the traffic load of the relay node is close to saturation and the network traffic load is unbalanced. The sensor node will start switching working modes and automatically upgrade to the relay node working mode, which is beneficial to divert the original relay node traffic, balance the network load, and improve network reliability. 3) After the sensor node starts switching working mode and automatically upgrades to the relay node working mode, it supports connecting relay nodes and sensor nodes, and the entire network topology changes; after the sensor node is upgraded to a relay node, it selects the relay node with the largest communication efficiency value E and connects to the gateway for communication.

2. A self-organizing communication method for unattended sensors, employing the self-organizing communication system for unattended sensors as described in claim 1, characterized in that, Includes the following steps: Step 1: After the device with sensor node function is powered on, it automatically scans the public channels one by one according to the pre-configured public channel information list and receives data. Based on the data information, it selects a relay node or access gateway for communication and sends registration data information to the relay node or access gateway using an anti-collision mechanism. The relay node or access gateway allocates communication resources and sets the transmission rate based on the registration data information. Step 2: After the device with relay node function is powered on, it automatically scans the public channels one by one according to the pre-configured public channel information list and receives data. It selects the access gateway to communicate based on the data information and sends registration data information to the access gateway using an anti-collision mechanism. The access gateway allocates communication resources and sets the transmission rate based on the registration data information. After the relay node successfully connects to the access gateway, it updates the relay node forwarding table, transparently transmits the received sensor node data to the access gateway, and transparently transmits the data sent by the access gateway to the sensor node to the sensor node. Step 3: After the device with access gateway function is powered on, it automatically initiates a link establishment request to the management and control center through the transmission network according to the pre-configured information, and sends registration data information to the management and control center through an anti-collision mechanism. The management and control center allocates communication resources and sets the transmission rate according to the registration information. After the access gateway connects to the management and control center, it updates the access gateway forwarding table, and forwards the received data from the sensor nodes or relay nodes to the management and control center, and forwards the data sent by the management and control center to the sensor nodes or relay nodes to the sensor nodes or relay nodes. Step 4: Achieve autonomous and automatic upgrades and downgrades by switching the working modes of access gateways, relay nodes, and sensor node devices, and select the optimal working mode; Step 5: The management and control center establishes a communication connection with the access gateway through the transmission network. It is responsible for the management, mapping, authentication and registration of the unique communication addresses of the access gateway, relay nodes and sensor nodes, the addition, deletion and modification management of the communication forwarding table of the management and control center, the reverse control of the access gateway, relay nodes and sensor nodes, the updating of the communication network topology map, the selection of downlink data forwarding table, and the visualization display of the status and geographical location of the access gateway, relay nodes and sensor nodes.

3. The unattended sensor self-organizing communication method according to claim 2, characterized in that, In step 1, the sensor node calculates the communication performance value E with the relay node or access gateway, and selects the node with the largest communication performance value E as the sensor node, relay node, or access gateway; the method for calculating the communication performance value E is as follows: Where i is the index number of the communication performance evaluation index, P i W represents the score of the i-th communication performance evaluation indicator. i , where is the weighting coefficient of the i-th communication performance evaluation index; the communication performance evaluation index includes communication cost per bit, power consumption per bit, transmission delay, bandwidth utilization, received signal strength, received power, transmission rate, transmission bandwidth, and bit error rate; wherein, communication cost per bit = cost / actual communication rate, and power consumption per bit = device power consumption / actual communication rate.

4. The unattended sensor self-organizing communication method according to claim 2, characterized in that, In step 2, when a relay node detects that the connection with the current access gateway has been lost, the relay node attempts to establish a connection with other access gateways. If all attempts fail, the relay node switches its working mode to sensor node mode and triggers the sensor nodes under that relay node to search for and discover new relay nodes or access gateways. The relay node forwarding table includes a sequence number, a unique communication address for each sensor node, and link information between the relay node and the sensor nodes. The relay node forwarding table stores records all sensor node entries under that relay node, with each sensor node corresponding to a unique sensor node entry. The relay node forwarding table update and maintenance process is as follows: A. After a sensor node is successfully registered, a relay node forwarding table entry for that sensor node is generated, and the newly generated entry is inserted into the relay node forwarding table. B. If a relay node detects a link failure or disconnection of a sensor node, it deletes the corresponding entry for that sensor node in the relay node's forwarding table. C. Upon receiving a re-registration or parameter change instruction from a sensor node, update the corresponding entry in the relay node's forwarding table. D. The relay node reports the data information of inserting, deleting, and updating the relay node forwarding table to the access gateway.

5. The unattended sensor self-organizing communication method according to claim 2, characterized in that, In step 3, when the access gateway detects that the connection with the management and control center has been lost, the access gateway switches its working mode to the relay node working mode, and at the same time triggers the sensor nodes or relay nodes under the access gateway to search for and find a new access gateway. The access gateway forwarding table includes a serial number, a unique communication address for the sensor node, a unique communication address for the relay node, and link information between the access gateway and the relay node. The access gateway forwarding table stores entries for all relay nodes and sensor nodes under that access gateway, with each sensor node corresponding to a unique entry. The access gateway forwarding table update and maintenance process is as follows: a. After a sensor node or relay node is successfully registered, an access gateway forwarding table entry for that sensor node or relay node is generated and inserted into the access gateway forwarding table. b. If the access gateway detects a link failure or disconnection of a relay node or sensor node, it deletes the entry for the sensor node or relay node itself and all sensor nodes under the relay node from the access gateway's forwarding table. c. Upon receiving a re-registration or parameter change instruction from a sensor node or relay node, update the corresponding entry in the access gateway forwarding table. d. The access gateway reports the data information of insertion, deletion and update of the access gateway forwarding table to the management and control center.

6. The unattended sensor self-organizing communication method according to claim 2, characterized in that, The data information in the public channel information list includes device node type, received signal strength, received power, transmission rate, transmission bandwidth, bit error rate, transmission delay, and bandwidth utilization.

7. The unattended sensor self-organizing communication method according to claim 2, characterized in that, The processing flow of the collision avoidance mechanism is as follows: Step (1): The node listens to the pre-configured public channel to determine whether the channel is idle; Step (2): If the channel is idle, send a data transmission request command through the public channel, and wait for the sensor node, relay node or access gateway to reply with a data transmission permission command before sending the data. Step (3): If the channel is occupied or data information from other nodes is received during data transmission, resulting in a data collision at the same time, the node immediately stops transmitting data and waits for T. i Time, where T i =e i ×Δt, where i is the i-th wait, T is the Δt, and T is the Δt. i Let Δt be the waiting time for the i-th time and Δt be the waiting time interval. After the waiting time ends, if there is still data that has not been sent, continue to execute steps (1) and (2).

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