A method for implementing a dynamic collection system for forest environment

Abstract

The present invention provides a method for implementing a forest environment dynamic collection system, the system comprising a convergence node and a plurality of robots, the plurality of robots being configured as collection nodes, collection nodes and forwarding nodes; the plurality of robots are distributed in the forest and are used to collect forest environment data, the convergence node is responsible for collecting the forest environment data collected by the robots, and the staff can quickly obtain environmental monitoring data of the forest area, such as temperature, humidity, degree of drought, etc., through the forest environment dynamic collection system provided by the present invention, so as to take effective measures to carry out early warning and prevent the occurrence of forest fires. The system can effectively promote the healthy development of forests, reduce forest fires, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of forest protection, and in particular to a method for realizing a dynamic collection system of forest environment. Background Art

[0002] Forest environment collection and monitoring is an important means to ensure forest safety. Forest environment collection ensures forest safety and avoids fires by automatically collecting and monitoring soil drought, temperature and other parameters. The forest environment collection system uses broadcasting to transmit data, which leads to problems such as high power consumption and long delays in data collection. At the same time, the traditional irrigation area environmental monitoring and early warning system does not consider factors such as energy, which further increases the cost and delay of forest environment collection. At the same time, nodes with low energy cannot forward and process the collected data, resulting in the inability to realize forest environment collection and monitoring.

[0003] This system is designed to achieve forest environment collection and ensure forest safety. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for realizing a forest environment dynamic collection system in view of the deficiencies in the prior art.

[0005] Technical solution: The present invention discloses a method for implementing a dynamic forest environment collection system. The system comprises a convergence node and a plurality of robots, wherein the plurality of robots are configured as collection nodes, collection nodes and forwarding nodes. The plurality of robots are distributed in the forest and used to collect forest environment data. The convergence node is responsible for collecting the forest environment data collected by the robots. The method comprises:

[0006] The robot calculates its own weight w1 according to formula (1). If the robot's own weight is greater than the weights of all weight items in the weight table, it marks itself as a collection node.

[0007] (1)

[0008] Among them, b1 is the total number of robot entries, e1 is the remaining energy of the robot, and e2 is the initial energy value of the robot. and is the adjustment coefficient;

[0009] The aggregation node elects a forwarding node by sending an election message;

[0010] If the temporary table of the robot receiving the election message is an empty table and it is a collecting node, a confirmation message is sent;

[0011] If the temporary table of the robot that receives the election message is empty, it creates a temporary table entry, sets the node ID in the election message to its own node ID, and forwards the election message;

[0012] If the node ID of the robot receiving the confirmation message is equal to the node ID in the confirmation message and the temporary table is not empty, the robot identifies itself as a forwarding node and forwards the confirmation message;

[0013] The aggregation node collects the forest environment data through collection messages and data messages;

[0014] The collection node sends the collection message to the collection node, and the collection node that receives the collection message sends a data message; the forwarding node that receives the data message forwards the data message; and the aggregation node that receives the data message saves the data message.

[0015] In the invention,

[0016] Each robot or aggregation node is uniquely identified by a node ID;

[0017] In the initial state, each robot has the function of forwarding messages;

[0018] In the initial state, each robot is a collection node;

[0019] At the same time, the robot is in one of the following four states: collection node, collection node, forwarding node, and collection node and forwarding node at the same time;

[0020] Each robot or aggregation node stores a robot table. Each robot table entry contains the node ID, node type and life cycle. The node type value of the collection node is 1, the node type value of the collection node is 2, the node type value of the forwarding node is 3, and the node type value of both the collection node and the forwarding node is 4.

[0021] In the invention,

[0022] The method further comprises:

[0023] The robot sends a robot message; wherein the robot message includes its own node ID and node type;

[0024] The neighbor robot that receives the robot message determines whether there is a robot table entry whose node ID is equal to the node ID in the robot message. If so, the node type of the table entry is set to the node type in the robot message, and the life cycle of the table entry is set to the maximum value; otherwise, a robot table entry is created, the node ID of the table entry is equal to the node ID in the robot message, the node type of the table entry is set to the node type in the robot message, and the life cycle of the table entry is set to the maximum value.

[0025] In the invention,

[0026] Each robot or aggregation node stores a weight table, each weight table entry includes a node ID, a weight and a life cycle; the method further includes:

[0027] The robot sends a weight message; wherein the weight message includes its own node ID and weight;

[0028] The neighbor robot that receives the weight message determines whether there is a weight table entry whose node ID is equal to the node ID in the weight message. If so, the weight of the table entry is updated to the weight in the weight message, and the life cycle is set to the maximum value; otherwise, a robot table entry is created, whose node ID is equal to the node ID in the weight message, the weight of the table entry is set to the weight in the weight message, and the life cycle of the table entry is set to the maximum value.

[0029] In the invention,

[0030] The collection message contains the node ID;

[0031] If the node type values ​​of all robot entries of the robot are 1 or 3, a weight entry is selected, the weight value in the entry is not less than the weight value of any weight entry, and a collection message is sent, the node ID of the collection message is equal to the node ID in the weight entry;

[0032] If the node ID of the robot received in the collection message is equal to the node ID in the collection message, it identifies itself as a collection node.

[0033] In the invention,

[0034] Each robot maintains a temporary table. A temporary table entry contains the node ID and life cycle. In the initial state, the temporary table is empty.

[0035] The election message contains the node ID; the confirmation message contains the node ID;

[0036] The method further comprises:

[0037] In the confirmation message sent by the robot that receives the election message, the node ID is equal to the node ID in the election message;

[0038] After receiving the confirmation message, the robot identifies itself as a forwarding node, updates the node ID in the confirmation message to the node ID in its own temporary table entry, clears the temporary table, and forwards the confirmation message.

[0039] In the invention,

[0040] The collection message contains the node ID and data; the data message contains the data;

[0041] The method further comprises:

[0042] In the collection message sent by the collection node, the node ID is equal to the node ID in the robot table entry with node type equal to 2 or 4, and the data is equal to the data collected by itself;

[0043] If the node ID of the robot receiving the collection message is equal to the node ID in the collection message, a data message is sent, and the data of the data message is equal to the data in the collection message.

[0044] In the invention,

[0045] The reselection message contains the node ID; the response message contains the node ID;

[0046] If the node types of all robot entries of the collecting node are 1 or 2, a reselect message is sent, and the node ID of the message is its own node ID.

[0047] In the invention,

[0048] The method further comprises:

[0049] If the robot that receives the reselection message is a forwarding node, it sends a response message with the node ID of the message being equal to the node ID in the reselection message; otherwise, if the temporary table of the robot that receives the reselection message is an empty table, it creates a temporary table entry with the node ID of the entry being equal to the node ID in the reselection message, sets the lifecycle to the maximum value, sets the node ID in the reselection message to its own node ID, and forwards the reselection message.

[0050] In the invention,

[0051] The method further comprises:

[0052] If the collecting node that sends the reselection message receives a response message, it stops forwarding the response message; otherwise, if the node ID of the robot that receives the response message is equal to the node ID in the response message and the temporary table is not empty, it identifies itself as a forwarding node, updates the node ID in the response message to the node ID in its own temporary table entry, clears the temporary table, and forwards the response message.

[0053] Beneficial effects: The present invention provides a method for implementing a dynamic forest environment collection system. The dynamic forest environment collection system provided by the present invention can quickly obtain environmental monitoring data of forest areas, such as temperature, humidity, drought level, etc., so as to take effective measures to warn and prevent the occurrence of forest fires. The system can effectively promote the healthy development of forests and reduce forest fires, and has broad application prospects. Since the forest area is large and it is impossible to arrange infrastructure, the system distributes robot nodes in the forest area according to the characteristics of the forest environment. The robot transmits the collected environmental parameters of the forest area, such as soil moisture content, humidity, temperature and other environmental parameters, to the collection node through multi-hop transmission, thereby collecting and monitoring the forest environmental parameters in real time, promoting the healthy development of forests and preventing the occurrence of forest fires. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0055] Figure 1 It is a flow chart of the implementation method of the forest environment dynamic collection system of the present invention;

[0056] Figure 2 This is a schematic diagram of the process of establishing a robot table according to the present invention;

[0057] Figure 3 This is a schematic diagram of the process of establishing a weight table according to the present invention;

[0058] Figure 4 This is a schematic diagram of the election collection node process described in the present invention;

[0059] Figure 5 This is a schematic diagram of the process of selecting a forwarding node according to the present invention;

[0060] Figure 6 This is a schematic diagram of the data acquisition process of the present invention;

[0061] Figure 7 The figure is a schematic diagram of the process of reselecting a forwarding node according to the present invention. DETAILED DESCRIPTION

[0062] Beneficial effects: The present invention provides a method for implementing a dynamic forest environment collection system. The dynamic forest environment collection system provided by the present invention can quickly obtain environmental monitoring data of forest areas, such as temperature, humidity, drought level, etc., so as to take effective measures to warn and prevent the occurrence of forest fires. The system can effectively promote the healthy development of forests and reduce forest fires, and has broad application prospects. Since the forest area is large and it is impossible to arrange infrastructure, the system distributes robot nodes in the forest area according to the characteristics of the forest environment. The robot transmits the collected environmental parameters of the forest area, such as soil moisture content, humidity, temperature and other environmental parameters, to the collection node through multi-hop transmission, thereby collecting and monitoring the forest environmental parameters in real time, promoting the healthy development of forests and preventing the occurrence of forest fires.

[0063] Figure 1 It is a flow chart of the implementation method of the forest environment dynamic collection system of the present invention; Figure 2 This is a schematic diagram of the process of establishing a robot table according to the present invention.

[0064] The method comprises a plurality of robots and a sink node, wherein the robots are divided into a collection node, a collection node and a forwarding node; the robots are distributed in the forest and are used to collect forest data and transmit the data to the sink node; the sink node is linked to at least one robot; the robots and the sink node can move freely;

[0065] Each robot or aggregation node is uniquely identified by a node ID, such as a MAC address;

[0066] In the initial state, each robot is a collection node;

[0067] Each robot has a forwarding function;

[0068] At the same time, the robot is in one of the following four states: collection node, collection node, forwarding node, and collection node and forwarding node at the same time;

[0069] Each robot or aggregation node stores a robot table. Each robot table entry contains the node ID, node type, and life cycle. The node type value of the collection node is 1, the node type value of the collection node is 2, the node type value of the forwarding node is 3, and the node type value of both the collection node and the forwarding node is 4.

[0070] The robot message contains the message ID, node ID and node type;

[0071] Robot RN1 periodically sends robot messages to establish a robot table. The process is as follows:

[0072] Step 101: Start;

[0073] Step 102: Robot RN1 sends a robot message, the message ID is 1, and the node ID and node type are its own node ID and node type;

[0074] Step 103: The neighbor robot that receives the robot message determines whether there is a robot table entry whose node ID is equal to the node ID in the robot message. If so, the node type of the table entry is set to the node type in the robot message, and the life cycle of the table entry is set to the maximum value. Otherwise, a robot table entry is created, whose node ID is equal to the node ID in the robot message, the node type of the table entry is set to the node type in the robot message, and the life cycle of the table entry is set to the maximum value.

[0075] Step 104: End.

[0076] In the above process, the robot establishes a robot table by sending robot messages, thereby obtaining the number of neighbor nodes.

[0077] Figure 3 The figure is a schematic diagram of the process of establishing a weight table according to the present invention. After the robot RN1 establishes the robot table, it calculates its own weight w1 according to formula (1), where b1 is the total number of robot table items, e1 is the remaining energy of the robot RN1, and e2 is the initial energy value of the robot RN1. and is the adjustment coefficient;

[0078] (1)

[0079] The weight message contains the message ID, node ID and weight;

[0080] Each robot or aggregation node stores a weight table, and each weight table entry contains the node ID, weight, and life cycle;

[0081] Robot RN1 establishes the weight table through the following process:

[0082] Step 201: Start;

[0083] Step 202: Robot RN1 sends a weight message, the message ID is 2, the node ID and weight are its own node ID and weight respectively;

[0084] Step 203: The neighbor robot that receives the weight message determines whether there is a weight table entry whose node ID is equal to the node ID in the weight message. If so, the weight of the table entry is updated to the weight in the weight message, and the life cycle is set to the maximum value. Otherwise, a robot table entry is created, whose node ID is equal to the node ID in the weight message, the weight of the table entry is set to the weight in the weight message, and the life cycle of the table entry is set to the maximum value.

[0085] Step 204: End.

[0086] In the above process, the robot obtains the weight of the neighboring robot by sending weight messages.

[0087] Figure 4 This is a schematic diagram of the process of selecting a collection node according to the present invention. If the weight of the robot RN1 is greater than the weights of all weight items in the weight table, it will mark itself as a collection node; the collection message includes a message ID and a node ID;

[0088] If the node type values ​​of all robot entries of robot RN1 are 1 or 3, the following process is performed:

[0089] Step 301: Start;

[0090] Step 302: The robot RN1 selects a weight table entry, the weight value in the entry is not less than the weight value of any weight table entry, and sends a collection message, the message ID of the message is 3, and the node ID is equal to the node ID in the weight table entry;

[0091] Step 303: The robot receiving the collection message determines whether its node ID is equal to the node ID in the collection message. If yes, execute step 304; otherwise, execute step 305;

[0092] Step 304: The robot receiving the collection message identifies itself as a collection node;

[0093] Step 305: End.

[0094] The robot elects neighbor collecting nodes through the above process so that all collecting nodes cover the forest.

[0095] Figure 5 This is a schematic diagram of the process of selecting a forwarding node according to the present invention. Each robot maintains a temporary table, and a temporary table entry includes a node ID and a life cycle. In the initial state, the temporary table is an empty table;

[0096] The election message contains the message ID and the node ID;

[0097] The confirmation message contains the message ID and node ID;

[0098] The aggregation node SN1 selects the forwarding node through the following process:

[0099] Step 401: Start;

[0100] Step 402: The sink node SN1 sends an election message, the message ID of which is 4, and the node ID is its own node ID;

[0101] Step 403: The robot that receives the election message determines whether its temporary table is an empty table. If so, it executes step 404; otherwise, it executes step 407;

[0102] Step 404: The robot that receives the election message creates a temporary table entry, the node ID of the table entry is equal to the node ID in the election message, and the life cycle is set to the maximum value, such as 500ms. If the robot is a collection node, execute step 405, otherwise execute step 406;

[0103] Step 405: The robot that receives the election message sends a confirmation message, the message ID of which is 5, and the node ID is equal to the node ID in the election message;

[0104] Step 406: The robot that receives the election message sets the node ID in the election message as its own node ID, forwards the election message, and executes step 403;

[0105] Step 407: If the sink node receives the confirmation message, execute step 410, otherwise execute step 408;

[0106] Step 408: If the node ID of the robot receiving the confirmation message is equal to the node ID in the confirmation message and the temporary table is not empty, execute step 409, otherwise execute step 410;

[0107] Step 409: The robot that receives the confirmation message identifies itself as a forwarding node, updates the node ID in the confirmation message to the node ID in its temporary table entry, clears the temporary table, forwards the confirmation message, and executes step 407;

[0108] Step 410: End.

[0109] The above process selects forwarding nodes through temporary tables and confirmation messages, thereby realizing data collection.

[0110] Figure 6 The data acquisition process diagram of the present invention is as follows: The acquisition message includes a message ID, a node ID and data;

[0111] Data messages contain message ID and data;

[0112] The collection node AN1 sends the collected data to the aggregation node through the following process;

[0113] Step 501: Start;

[0114] Step 502: the collection node AN1 selects a robot table entry whose node type is 2 or 4, and sends a collection message whose message ID is 6, whose node ID is equal to the node ID in the robot table entry, and whose data is equal to the data collected by itself;

[0115] Step 503: The robot that receives the collection message determines whether its node ID is equal to the node ID in the collection message. If yes, it executes step 504; otherwise, it executes step 509;

[0116] Step 504: the robot that receives the collection message sends a data message, the message ID of which is equal to 7, and the data is equal to the data in the collection message;

[0117] Step 505: If the sink node receives the data message, execute step 508, otherwise execute step 506;

[0118] Step 506: The robot that receives the data message determines whether it is a forwarding node. If so, it executes step 507; otherwise, it executes step 509;

[0119] Step 507: The robot that receives the data message forwards the data message and executes step 505;

[0120] Step 508: The aggregation node saves the received data message;

[0121] Step 509: End.

[0122] The aggregation node obtains the data collected by the collection node through the above process, realizing the collection and monitoring of forest environment data.

[0123] Figure 7 The figure is a schematic diagram of the process of reselecting a forwarding node according to the present invention. The reselection message includes a message ID and a node ID;

[0124] The response message contains the message ID and node ID;

[0125] If the node type of all robot entries of the collection node CN1 is 1 or 2, the following process is performed to elect a forwarding node:

[0126] Step 601: Start;

[0127] Step 602: The collecting node CN1 sends a reselection message, the message ID of which is 8, and the node ID is its own node ID;

[0128] Step 603: The robot that receives the reselection message determines whether it is a forwarding node. If so, it executes step 606; otherwise, it executes step 604;

[0129] Step 604: The robot that receives the reselection message determines whether its temporary table is empty. If so, it executes step 605; otherwise, it executes step 607;

[0130] Step 605: The robot that receives the reselection message creates a temporary table entry whose node ID is equal to the node ID in the reselection message, sets the life cycle to the maximum value, for example, 500ms, sets the node ID in the reselection message to its own node ID, forwards the reselection message, and executes step 603;

[0131] Step 606: The robot that receives the reselect message sends a response message, the message ID of which is 9 and the node ID is equal to the node ID in the reselect message;

[0132] Step 607: If the collection node CN1 receives the response message, execute step 610, otherwise execute step 608;

[0133] Step 608: If the node ID of the robot receiving the response message is equal to the node ID in the response message and the temporary table is not empty, execute step 609, otherwise execute step 610;

[0134] Step 609: The robot that receives the response message identifies itself as a forwarding node, updates the node ID in the response message to the node ID in its temporary table entry, clears the temporary table, forwards the response message, and executes step 607;

[0135] Step 610: End.

[0136] The above process elects new forwarding nodes through temporary tables and response messages, thereby ensuring that the aggregation node receives forest data.

[0137] Example 1

[0138] Based on the simulation parameters in Table 1, this embodiment simulates a method for implementing a dynamic forest environment collection system in the present invention. The performance analysis is as follows: when the distance between the collection node and the aggregation node is far, the success rate of the aggregation node acquiring data decreases, and when the distance between the collection node and the aggregation node is close, the success rate of the aggregation node acquiring data increases, and the average success rate of the aggregation node acquiring data is 99.1%.

[0139] Table 1

[0140]

[0141] The present invention provides a method for implementing a dynamic collection system for a forest environment. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the protection scope of the present invention. All components not specified in this embodiment can be implemented using existing technologies.

Claims

1. A method for implementing a forest environment dynamic collection system, characterized in that: The system includes a convergence node and a plurality of robots, wherein the plurality of robots are configured as acquisition nodes, collection nodes and forwarding nodes; The multiple robots are distributed in the forest and are used to collect forest environment data. The aggregation node is responsible for collecting the forest environment data collected by the robots. The method includes: The robot calculates its own weight w1 according to formula (1). If the robot's own weight is greater than the weights of all weight items in the weight table, it marks itself as a collection node. Each robot or aggregation node stores a weight table, and each weight table item contains a node ID, a weight, and a life cycle. (1) Among them, b1 is the total number of robot entries, e1 is the remaining energy of the robot, and e2 is the initial energy value of the robot. and is the adjustment coefficient; each robot or aggregation node stores a robot table, and each robot table entry contains the node ID, node type and life cycle; The aggregation node elects a forwarding node by sending an election message; If the temporary table of the robot receiving the election message is empty and it is a collection node, a confirmation message is sent; wherein each robot maintains a temporary table, and a temporary table entry includes a node ID and a life cycle; If the temporary table of the robot that receives the election message is empty, it creates a temporary table entry, sets the node ID in the election message to its own node ID, and forwards the election message; If the node ID of the robot receiving the confirmation message is equal to the node ID in the confirmation message and the temporary table is not empty, the robot identifies itself as a forwarding node and forwards the confirmation message; The aggregation node collects the forest environment data through collection messages and data messages; The collection node sends the collection message to the collection node, and the collection node that receives the collection message sends a data message; the forwarding node that receives the data message forwards the data message; and the aggregation node that receives the data message saves the data message.

2. The method for implementing a forest environment dynamic collection system according to claim 1, characterized in that: Each robot or aggregation node is uniquely identified by a node ID; In the initial state, each robot has the function of forwarding messages; In the initial state, each robot is a collection node; At the same time, the robot is in one of the following four states: collection node, collection node, forwarding node, and collection node and forwarding node at the same time; The node type value of the collection node is 1, the node type value of the collection node is 2, the node type value of the forwarding node is 3, and the node type value of the node that is both a collection node and a forwarding node is 4.

3. The method for implementing a forest environment dynamic collection system according to claim 1, characterized in that: The method further comprises: The robot sends a robot message; wherein the robot message includes its own node ID and node type; The neighbor robot that receives the robot message determines whether there is a robot table entry whose node ID is equal to the node ID in the robot message. If so, the node type of the table entry is set to the node type in the robot message, and the life cycle of the table entry is set to the maximum value; otherwise, a robot table entry is created, the node ID of the table entry is equal to the node ID in the robot message, the node type of the table entry is set to the node type in the robot message, and the life cycle of the table entry is set to the maximum value.

4. The method for implementing a forest environment dynamic collection system according to claim 1, characterized in that: The method further comprises: The robot sends a weight message; wherein the weight message includes its own node ID and weight; The neighbor robot that receives the weight message determines whether there is a weight table entry whose node ID is equal to the node ID in the weight message. If so, the weight of the table entry is updated to the weight in the weight message, and the life cycle is set to the maximum value; otherwise, a robot table entry is created, whose node ID is equal to the node ID in the weight message, the weight of the table entry is set to the weight in the weight message, and the life cycle of the table entry is set to the maximum value.

5. The method for implementing a forest environment dynamic collection system according to claim 1, characterized in that: The collection message contains the node ID; If the node type values ​​of all robot entries of the robot are 1 or 3, a weight entry is selected, the weight value in the entry is not less than the weight value of any weight entry, and a collection message is sent, the node ID of the collection message is equal to the node ID in the weight entry; If the node ID of the robot received in the collection message is equal to the node ID in the collection message, it identifies itself as a collection node.

6. The method for implementing a forest environment dynamic collection system according to claim 1, characterized in that: In the initial state, the temporary table is an empty table; The election message contains the node ID; the confirmation message contains the node ID; The method further comprises: In the confirmation message sent by the robot that receives the election message, the node ID is equal to the node ID in the election message; After receiving the confirmation message, the robot identifies itself as a forwarding node, updates the node ID in the confirmation message to the node ID in its own temporary table entry, forwards the confirmation message, and clears the temporary table.

7. The method for implementing a forest environment dynamic collection system according to claim 2, characterized in that: The collection message contains the node ID and data; the data message contains the data; The method further comprises: In the collection message sent by the collection node, the node ID is equal to the node ID in the robot table entry whose node type value is equal to 2 or 4, and the data is equal to the data collected by itself; If the node ID of the robot receiving the collection message is equal to the node ID in the collection message, a data message is sent, and the data of the data message is equal to the data in the collection message.

8. The method for implementing a forest environment dynamic collection system according to claim 7, characterized in that: The reselection message contains the node ID; the response message contains the node ID; If the node type values ​​of all robot entries of the collecting node are 1 or 2, a reselect message is sent, and the node ID of the message is its own node ID.

9. The method for implementing a forest environment dynamic collection system according to claim 8, characterized in that: The method further comprises: If the robot that receives the reselection message is a forwarding node, it sends a response message with the node ID of the message being equal to the node ID in the reselection message; otherwise, if the temporary table of the robot that receives the reselection message is an empty table, it creates a temporary table entry with the node ID of the entry being equal to the node ID in the reselection message, sets the lifecycle to the maximum value, sets the node ID in the reselection message to its own node ID, and forwards the reselection message.

10. The method for implementing a forest environment dynamic collection system according to claim 9, characterized in that: The method further comprises: If the collecting node that sends the reselection message receives a response message, it stops forwarding the response message; otherwise, if the node ID of the robot that receives the response message is equal to the node ID in the response message and the temporary table is not empty, it identifies itself as a forwarding node, updates the node ID in the response message to the node ID in its own temporary table entry, clears the temporary table, and forwards the response message.

Images