Chain type sensor network service QoS (Quality of Service) guarantee method for electromagnetic perception of long strip region

Abstract

The invention relates to the field of network guarantee, in particular to a chain type sensor network service QoS (Quality of Service) guarantee method oriented to long-strip area electromagnetic sensing. Comprising the steps that a master node of the sensor network is specified, and other nodes of the sensor network are slave nodes; all node ID information tables of the sensor network are established and maintained at the main node; establishing a service data forwarding table communicating with each slave node at the master node, and establishing a receiving and sending forwarding table at each slave node; determining an information transmission strategy according to the transmission capability of the network; executing a necessary service guarantee process, a derating service guarantee process and an important service guarantee process; according to the invention, the ID in the frame structure is mapped with the node priority level and the service priority level of the sensing nodes of the sensor network, and automatic identification, storage and forwarding of service data can be realized through the service data transceiving mapping table of the sensor network. The method can be used for improving the availability of the sensing network when the transmission bandwidth is insufficient.

Description

Technical Field

[0001] The present invention relates to the field of network security, and in particular to a QoS security method for chain-type sensor network services oriented to long-strip electromagnetic perception. Background Art

[0002] With the rapid development of information technology, sensor networks have been widely used in environmental monitoring, military reconnaissance, border security and other fields. Among them, long-area electromagnetic sensing is an important sensing technology that uses the propagation characteristics of electromagnetic waves in the environment to achieve the perception and collection of information in a specific area. Chain sensor networks are a typical network topology structure, where nodes are arranged in chains, which is easy to deploy and manage and is widely used in the above fields.

[0003] Existing sensor networks usually use fixed data transmission methods and cannot effectively cope with dynamically changing environmental conditions. This often leads to delays, packet loss and excessive energy consumption during data transmission, affecting the real-time and integrity of the data. Summary of the invention

[0004] In order to solve the problems in the background technology, the present invention proposes a chain sensor network service QoS guarantee method for long-area electromagnetic perception, which aims to enable the sensor network to adjust the quantity and quality of service data when transmission resources are limited, thereby effectively improving the availability of the sensor network.

[0005] The technical solution adopted by the present invention is:

[0006] A QoS guarantee method for chain sensor network services for long-strip electromagnetic sensing includes the following steps:

[0007] Step 1, designate the master node of the sensor network, and the other nodes of the sensor network are slave nodes; the master node assigns each slave node ID and service priority, wherein the priority of the slave node is determined according to the importance of the node for collecting electromagnetic signals in the sensor network;

[0008] Step 2: Establish and maintain the ID information table of all nodes in the sensor network at the master node, including node ID, node type and priority, node coordinates, node MAC and node function; the master node sends "ID allocation frame" to the slave node according to the priority of each node in the ID information table from high to low, and the slave node replies with "ID confirmation frame" after receiving it; if the master node does not receive the "ID confirmation frame" from the slave node within the set time, it will send the "ID allocation frame" to the slave node again and wait for confirmation; if the master node still does not receive a reply after sending the set number of times, it will skip the slave node and proceed to the ID allocation of the next priority slave node until the last slave node;

[0009] Step 3, establish a business data forwarding table for communication with each slave node at the master node, the table item includes the ID and priority of each slave node, and each table item is associated with a sub-table, each table item of the sub-table includes 4 bytes, the first 2 bytes are the starting address of data storage, and the last 2 bytes are the data length; at the same time, establish a receiving and sending forwarding table at the slave node, each table item includes 4 bytes, the first 2 bytes are the starting address of data storage, and the last 2 bytes are the data length;

[0010] Step 4: During network operation, three transmission capacity thresholds A, B and C are set from high to low. The master node periodically queries the transmission capacity of the master and slave nodes, and determines the information transmission strategy according to the transmission capacity of the network, that is, when the transmission capacity is lower than A and better than B, execute the necessary service guarantee process in step 5; when the transmission capacity is lower than B and better than C, execute the reduced service guarantee process in step 6; when the transmission capacity is lower than C, execute the important service guarantee process in step 7;

[0011] Step 5, set time Δt1, the master node selects k slave nodes with the highest priority, sends data control frames to the slave nodes in descending order of priority, the slave nodes reply to the master node with data control response frames, and then the slave nodes send level 1 electromagnetic processing data to the master node, and the master node stores the level 1 electromagnetic processing data from the slave nodes according to the business data forwarding table after receiving the data; wherein Δt1 is not greater than 10*k;

[0012] Step 6, set time Δt1, the master node selects k slave nodes with the highest priority, and sends data control frames to the slave nodes in order from high to low priority, the slave nodes reply to the master node with data control response frames, and then the slave nodes send level 1 electromagnetic processing derating data to the master node, and the master node receives the level 1 electromagnetic processing derating data from the slave nodes and stores it according to the business data forwarding table;

[0013] Step 7, set the time Δt2, the master node selects the slave node with the highest priority to send a data control frame, the slave node replies to the master node by sending a data control response frame, and then the slave node sends the updated part of the level 1 electromagnetic processing derating data to the master node. After the master node receives the updated part of the level 1 electromagnetic processing derating data from the slave node, it is stored according to the business data transfer table; wherein, Δt2 is not less than 3*Δt1.

[0014] Furthermore, in step 1, the first four digits of the ID are mapped to the nodes of the sensor network, and the last four digits of the ID are mapped to the services of the corresponding nodes of the sensor network; the first four digits of the ID of the master node are 0000, which is the node with the highest priority in the sensor network; the other nodes are slave nodes of the sensor network, and the ID and priority of the slave node are determined according to the electromagnetic sensing function and deployment location of the slave node in the application, among which the ID with the smaller four digits has a higher priority.

[0015] Further, the communication protocol frame structure for information transmission between the master node and the slave node in step 2-7 includes a frame header field, an ID field, a type field, a data field, and a check field;

[0016] The frame header field is 1 byte, fixed to 7E. In the data field of the frame, if it is 7E during encapsulation, it is converted to 7D5E, and if it is 7D, it is converted to 7D 5E; if it is 7D 5E during decapsulation, it is converted to 7D or 7E.

[0017] The ID field is 1 byte and is used to identify "slave node + slave node service type";

[0018] The type field is 1 byte and is used to define the frame type; it includes 6 types of frames: the node ID allocation frame is used by the master node to allocate the slave node ID to the slave node; the send data control frame is used by the master node to control the slave node to send data; the send data control response frame is used to respond to the send data control frame of the master node; the downlink data frame is used to transmit data from the master node to the slave node; the uplink data frame is used to transmit data from the slave node to the master node; the send data end frame is sent after the slave node and the master node finish sending the data frame; the data field adopts the encapsulation format defined in RFC 894, and the maximum value of the payload data length is recorded as Lmax, Lmax = Ethernet payload data maximum length - frame header field length - type field length - ID field length - check field length; the check field is 1 byte and uses CRC8 checksum.

[0019] The advantages of the present invention compared with the prior art are:

[0020] (1) All services transmitted in the chain sensor network of the present invention are encapsulated and transmitted using the protocol frame structure.

[0021] (2) The ID in the frame structure of the present invention is mapped to the node priority and service priority of the sensor network sensing node, and the automatic identification, storage and forwarding of service data can be achieved through the service data receiving and sending mapping table of the sensor network.

[0022] (3) The present invention provides a QoS guarantee process for sensor network service transmission under normal conditions and resource-constrained conditions.

[0023] (4) The present invention can be used to improve the availability of the perception network when the transmission bandwidth is insufficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a chain sensor network inquiry-type QoS guarantee method for long-strip area electromagnetic perception according to the present invention.

[0025] Figure 2 This is a flowchart of the slave node ID allocation of the present invention.

[0026] Figure 3 It is the normal process of sending data from the node to the master node.

[0027] Figure 4 It is a flow chart of QoS guarantee of services under the condition of limited transmission resources in the present invention.

[0028] Figure 5 It is a flow chart of the QoS guarantee method for essential services under the condition of limited transmission resources of the present invention.

[0029] Figure 6 It is a flow chart of the QoS guarantee method for reduced-rate services under the condition of limited transmission resources of the present invention.

[0030] Figure 7 This is a flow chart of the QoS guarantee method for the most important services under the condition of limited transmission resources of the present invention. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1-7 The present invention is further explained.

[0032] The present invention provides a chain sensor network service QoS guarantee method for long-strip electromagnetic sensing, and designs a communication protocol frame structure. The protocol frame format is designed as shown in Table 1.

[0033] Table 1 Communication protocol frame structure of sensor network

[0034]

[0035] 1) Frame header field: 1 byte, fixed to 7E. In the data field of the frame, if 7E is encountered during encapsulation, it needs to be converted to 7D 5E, and if 7D is encountered, it needs to be converted to 7D 5E; the reverse operation is performed during decapsulation.

[0036] 2) ID field: 1 byte, used to identify "slave node + slave node service type" (the master node operator specifies 0000 (upper four bits), which is the gateway node for the sensor network to send and receive external information. The master node 0000 (upper four bits) only appears inside the sensor network, and the node identifier of the master node sending data from the sensor network only has the slave node identifier). The sensor network designed by the present invention supports up to 1 master node (0000) + 15 slave nodes (0001~1111), and the node priority is 15 levels (0001~1111, the same as the assigned slave node number, and has nothing to do with other slave node numbers); the slave node service types are up to 16 types (0000~1111), and the slave node service priority is 16 levels (0000~1111, the same as the number assigned to the slave node service, and has nothing to do with other slave node numbers). Sensor network networking application diagram for personnel Figure 1 shown.

[0037] 3) Type field: represented by 1 byte, up to 256 frame types can be defined.

[0038] Currently, six types of frames have been designed, namely:

[0039] Node ID allocation frame: used by the master node to allocate slave node IDs to slave nodes;

[0040] Send data control frame: used by the master node to control the slave node to send data;

[0041] Send data control response frame: used to respond to the master node's "send data control frame" and send data frames;

[0042] Downlink data frame: used to transmit data from the master node to the slave node;

[0043] Uplink data frame: used to transmit data from the slave node to the master node;

[0044] Send data end frame: sent after the master node finishes sending the data frame.

[0045] 4) Data domain: This protocol is carried on Ethernet. The Ethernet layer adopts the encapsulation format defined in RFC 894. The maximum length of the payload data is 1500 bytes. The maximum length of the payload data of this protocol is recorded as Lmax, where Lmax = maximum length of Ethernet payload data - frame header field length - type field length - ID field length - check field length = 1500 bytes - 1 byte - 1 byte - 1 byte - 1 byte = 1496 bytes. That is, the maximum length of the payload data of this protocol is 1496 bytes.

[0046] 5) Checksum field: represented by 1 byte, using CRC8 checksum.

[0047] ID and node, node priority, and node service priority in the protocol frame.

[0048] 1) Nodes and node priority: The first four bits of the ID (high 4 bits) are mapped to the nodes of the sensor network. The master node ID is set to 0000, and the slave node IDs are set to 0001 to 1111 (up to 15 nodes). The priority of the slave nodes is 0001 to 1111 from high to low.

[0049] 2) Node services and node service priorities: The last four bits (lower 4 bits) of the ID are mapped to the services of the corresponding nodes of the sensor network. The 7 types of services that have been determined are marked as follows: sensor network control protocol data---marked as 0000, perception network status data---marked as 0001, task data---marked as 0010, perception electromagnetic information processing data---marked as 0011, voice data---marked as 1001, slave node video data marked as -1011, perception electromagnetic information raw data -1111, and the others are reserved for user expansion. The service data priorities of the slave nodes are 0000 to 1111 from high to low (up to 16).

[0050] The specific implementation steps are as follows:

[0051] Step 1, specify the master node of the sensor network. The first 4 digits of the master node's ID are: 0000, which is the node with the highest priority in the sensor network; the other nodes in the sensor network are slave nodes; the master node assigns each slave node ID and service priority, where the priority of the slave node is determined according to the importance of the node in the sensor network for collecting electromagnetic signals.

[0052] Step 2, establish and maintain the ID information table of all nodes in the sensor network at the master node (such as Table 2), including node ID, node type and priority, node coordinates, node MAC and node function; the master node sends an "ID allocation frame" to the slave node according to the priority level of each node in the ID information table from high to low, and the slave node replies with an "ID confirmation frame" after receiving it; if the master node does not receive the "ID confirmation frame" from the slave node within the set time, it will send the "ID allocation frame" to the slave node again, and then wait for confirmation; if the master node still does not receive a reply after sending the set number of times (this embodiment is set to 3 times), then skip the slave node and allocate the ID of the next priority slave node until the last slave node; after the "ID allocation" of the last perception network node is completed, the "ID allocation" of the unsuccessful node is allocated again; after repeating three times, the "ID allocation" of the slave node will no longer be performed (unless manually driven). After the allocation is completed, the priority order of all nodes is also confirmed. The allocation process is as follows Figure 2 .

[0053] Table 2 Perception network node ID information table

[0054]

[0055]

[0056] Note: 1. The smaller the first four digits of the ID, the higher the priority level;

[0057] 2. Node MAC: The MAC address of the communication port of the master node to the slave node.

[0058] Step 3, establish a business data forwarding table for communication between the master node and each slave node, as shown in Table 4, including N1~N15, the table entry contains the ID and priority of each slave node, and each table entry is associated with a sub-table Sub-N, the sub-table Sub-N is shown in Table 3, each table entry of the sub-table includes 4 bytes, the first 2 bytes are the starting address of data storage, and the last 2 bytes are the data length; at the same time, establish a receiving and sending forwarding table in the slave node, as shown in Table 3, each table entry includes 4 bytes, the first 2 bytes are the starting address of data storage, and the last 2 bytes are the data length.

[0059] Table 3 Slave node service data forwarding table

[0060]

[0061]

[0062] Table 4: Business data transfer table between master node and slave node

[0063]

[0064] Step 4: During the operation of the network, three transmission capacity thresholds A, B and C are set from high to low. The master node periodically queries the transmission capacity of the master and slave nodes, and determines the information transmission strategy based on the transmission capacity of the network to ensure the latest electromagnetic perception information required by the system. Figure 4 That is, when the transmission capacity is lower than A and better than B, the necessary service guarantee process in step 5 is executed, such as Figure 5 As shown; when the transmission capacity is lower than B and better than C, execute step 6 of the reduced service guarantee process, such as Figure 6 As shown; when the transmission capacity is lower than C, execute step 7 important business guarantee process, such as Figure 7 As shown; under normal circumstances, execution Figure 3 The normal process.

[0065] Step 5, set the time Δt1, the master node selects k slave nodes with the highest priority, and sends data control frames to the slave nodes in order from high to low priority. The slave nodes reply to the master node by sending data control response frames, and then the slave nodes send level 1 electromagnetic processing data to the master node. After the master node receives the level 1 electromagnetic processing data from the slave node, it stores it according to the business data forwarding table, where Δt1 is generally selected not to exceed 10*k milliseconds.

[0066] In this embodiment, the service transmission mode of the sensor network is: with 20ms as a Δt, three necessary slave nodes are implemented to perform level 1 electromagnetic processing data rotation training and upload, basically maintaining the normal operation of the electromagnetic sensing system.

[0067] Slave nodes: Select the 3 highest priority perception slave nodes (the 3 with the smallest ID).

[0068] Services: including the networking protocol for sensor network operation, system command and control services, voice of all nodes, and level 1 electromagnetic processing data of three necessary slave nodes.

[0069] (5*0.3ms networking protocol and command + 5*2*0.6ms voice + 3*1*4.5ms); the sensor network can ensure the networking of all slave nodes and the transmission of necessary services (3*1-level processing data + 5*2-channel voice + networking protocol).

[0070] The master node reconstructs the network service forwarding table according to the service scale of the sensor network, and transmits services according to the service forwarding table: 20ms as the time slice, slave nodes and service priority order. The implementation method is shown in the figure below.

[0071] Step 6, set time Δt1, the master node selects k slave nodes with the highest priority, and sends data control frames to the slave nodes in order from high to low priority. The slave nodes reply to the master node by sending data control response frames, and then the slave nodes send level 1 electromagnetic processing derating data to the master node. After the master node receives the level 1 electromagnetic processing derating data from the slave nodes, it stores it according to the business data transfer table.

[0072] In this embodiment, the service transmission mode of the sensor network is: with 20ms as a Δt, the first-level electromagnetic processing data of the three necessary slave nodes is uploaded at a reduced rate to maintain the minimum operating state of the electromagnetic sensing system.

[0073] Slave nodes: Select the 3 slave nodes with the highest priority (the 3 with the smallest IDs).

[0074] Services: including the networking protocol for sensor network operation, command and control services of the system, 1-way derated voice for all nodes, and 1-level electromagnetic processing derated data for 3 necessary slave nodes.

[0075] (5*0.6ms for networking protocol and command + 5*1*0.6ms for voice + 2*1*4.5ms, voice services and data processing are reduced by 50%)

[0076] The master node innovatively constructs a network service forwarding table according to the service scale of the sensor network. According to the service forwarding table, the service is transmitted in the order of 20ms time slice, slave node and service priority.

[0077] Step 7, set time Δt2, the master node selects the slave node with the highest priority to send a data control frame, the slave node replies to the master node by sending a data control response frame, and then the slave node sends the updated part of the level 1 electromagnetic processing derating data to the master node. After the master node receives the updated part of the level 1 electromagnetic processing derating data from the slave node, it is stored according to the business data transfer table; among them, Δt2 is generally selected to be not less than 3*Δt1.

[0078] In this embodiment, the service transmission mode of the sensor network is: with 100ms as a Δt, the update content of the first-level processing data of one most important slave node is uploaded to maintain the operation of the most important node of the electromagnetic perception system.

[0079] Slave node: Select the slave node with the highest priority (with a minimum ID of 1).

[0080] Services: including the networking protocol for sensor network operation, 1-way derated voice for all nodes, command and control services for the system, and the update of the 1st level electromagnetic processing derated data of 1 most important slave node.

[0081] The master node interacts according to the protocol to maintain network operation, with 100ms as the time slice, to realize the update partial upload of the most important slave node 1 level processing derated data, as well as the command voice of other nodes.

Claims

1. A QoS guarantee method for chain sensor network services for long-strip electromagnetic sensing, characterized in that: The following steps are involved: Step 1, specify the master node of the sensor network, and the other nodes of the sensor network are slave nodes; The master node allocates the ID and service priority of each slave node, wherein the priority of the slave node is determined according to the importance of the node for collecting electromagnetic signals in the sensor network; Step 2: Establish and maintain the ID information table of all nodes in the sensor network at the master node, including node ID, node type and priority, node coordinates, node MAC and node function; the master node sends "ID allocation frame" to the slave node according to the priority of each node in the ID information table from high to low, and the slave node replies with "ID confirmation frame" after receiving it; if the master node does not receive the "ID confirmation frame" from the slave node within the set time, it will send the "ID allocation frame" to the slave node again and wait for confirmation; if the master node still does not receive a reply after sending the set number of times, it will skip the slave node and proceed to the ID allocation of the next priority slave node until the last slave node; Step 3, establish a business data forwarding table for communication with each slave node at the master node, the table item includes the ID and priority of each slave node, and each table item is associated with a sub-table, each table item of the sub-table includes 4 bytes, the first 2 bytes are the starting address of data storage, and the last 2 bytes are the data length; at the same time, establish a receiving and sending forwarding table at the slave node, each table item includes 4 bytes, the first 2 bytes are the starting address of data storage, and the last 2 bytes are the data length; Step 4: During network operation, three transmission capacity thresholds A, B and C are set from high to low. The master node periodically queries the transmission capacity of the master and slave nodes, and determines the information transmission strategy according to the transmission capacity of the network, that is, when the transmission capacity is lower than A and better than B, execute the necessary service guarantee process in step 5; when the transmission capacity is lower than B and better than C, execute the reduced service guarantee process in step 6; when the transmission capacity is lower than C, execute the important service guarantee process in step 7; Step 5, set time Δt1, the master node selects k slave nodes with the highest priority, sends data control frames to the slave nodes in descending order of priority, the slave nodes reply to the master node with data control response frames, and then the slave nodes send level 1 electromagnetic processing data to the master node, and the master node stores the level 1 electromagnetic processing data from the slave nodes according to the business data forwarding table after receiving the data; wherein Δt1 is not greater than 10*k; Step 6, set time Δt1, the master node selects k slave nodes with the highest priority, and sends data control frames to the slave nodes in order from high to low priority, the slave nodes reply to the master node with data control response frames, and then the slave nodes send level 1 electromagnetic processing derating data to the master node, and the master node receives the level 1 electromagnetic processing derating data from the slave nodes and stores it according to the business data forwarding table; Step 7, set the time Δt2, the master node selects the slave node with the highest priority to send a data control frame, the slave node replies to the master node by sending a data control response frame, and then the slave node sends the updated part of the level 1 electromagnetic processing derating data to the master node. After the master node receives the updated part of the level 1 electromagnetic processing derating data from the slave node, it is stored according to the business data transfer table; wherein, Δt2 is not less than 3*Δt1.

2. According to claim 1, a chain sensor network service QoS guarantee method for long-strip electromagnetic sensing is characterized in that: In step 1, the first four digits of the ID are mapped to the nodes of the sensor network, and the last four digits of the ID are mapped to the services of the corresponding nodes of the sensor network; the first four digits of the ID of the master node are 0000, which is the node with the highest priority in the sensor network; The other nodes are slave nodes of the sensor network. The ID and priority of the slave node are determined according to the electromagnetic sensing function and deployment location of the slave node in the application. The ID with the smaller four digits has a higher priority.

3. According to claim 1, a chain sensor network service QoS guarantee method for long-strip electromagnetic sensing is characterized in that: The communication protocol frame structure for information transmission between the master node and the slave node in step 2-7 includes a frame header field, an ID field, a type field, a data field, and a check field; The frame header field is 1 byte, fixed to 7E. In the data field of the frame, if it is 7E during encapsulation, it is converted to 7D 5E, and if it is 7D, it is converted to 7D 5E; if it is 7D 5E during decapsulation, it is converted to 7D or 7E. The ID field is 1 byte and is used to identify "slave node + slave node service type"; The type field is 1 byte and is used to define the frame type. It includes 6 types of frames: the node ID allocation frame is used by the master node to allocate the slave node ID to the slave node; the data transmission control frame is used by the master node to control the slave node to send data; The send data control response frame is used to respond to the send data control frame of the master node; the downlink data frame is used to transmit data from the master node to the slave node; the uplink data frame is used to transmit data from the slave node to the master node; The data sending end frame is used to send after the slave node and the master node finish sending the data frame; the data field adopts the encapsulation format defined in RFC 894, and the maximum value of the payload data length is recorded as Lmax, Lmax = maximum value of Ethernet payload data length - frame header field length - type field length - ID field length - check field length; the check field is 1 byte and uses CRC8 checksum.

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