Self-spatial topology distribution sensing method based on narrowband wireless network

Abstract

The invention provides a self-spatial topology distribution sensing method based on a narrowband wireless network, which is characterized in that a representative node is selected from numerous communication nodes in the network, the representative node has the functions of sending Beacon and radio transfer service, and in the algorithm, the representative node has the functions of sending Beacon and radio transfer service. Election is mainly carried out according to the proximity relation of communication nodes, connected areas or the weights of the nodes, and when the communication nodes have more than one connected area, the communication nodes can participate in election; when the communication area of the representative node is larger than one, executing a process of quitting the state; through the two functions, the normal operation of the network can be maintained only by specifying some representative nodes in numerous nodes, and the method enables the air interface overhead of the network to be less, can meet the wide area of the network, and can adaptively change the representative nodes according to the topological structure of the network.

Description

Technical Field

[0001] The present invention relates to the technical field of narrowband wireless network communication, and in particular to a method for selecting a representative node in a narrowband wireless network of multiple communication nodes. Background Art

[0002] In a narrowband all-wireless mobile network system based on PDT or DMR, when there are a large number of communication nodes, the effectiveness of the system may be affected by the transmission problem of beacons. Specifically, as the number of nodes increases, the beacon frames sent periodically by each node may collide on the shared wireless channel, which will cause the loss or delay of beacon information, affecting the stability of the network and the mutual perception between nodes. At the same time, in order to maintain the connectivity of the network and the perception between nodes, a certain bandwidth needs to be occupied on the channel to transmit these beacons, which will increase the air interface overhead and reduce the bandwidth utilization of the network. On the other hand, in order to ensure that the beacon can be received throughout the network, its wide-area propagation needs to be guaranteed, but if the transmission frequency or power of the beacon is reduced, some nodes may not be able to receive the beacon, thereby affecting the coverage of the network and the communication between nodes. Therefore, how to reduce channel collisions and air interface overhead while ensuring the wide-area propagation of the beacon is a key issue that needs to be solved in the design of such network systems. Summary of the invention

[0003] The present invention aims to provide a method for electing a representative node in a narrowband wireless network, so as to solve the contradiction between air interface overhead and wide area propagation and ensure the stability of the network.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: The method for sensing the distribution of self-spatial topology based on narrowband wireless networks can adaptively cite representative communication nodes, wherein the communication nodes include representative nodes and common nodes, and includes the following steps: Step 1: The communication node calculates the proximity relationship and the connected area; Step 2: The communication node is initially set as a representative node; Step 3: Compare the proximity relationship of the communication nodes with the connected area to select a representative node or execute the designated representative node exit process.

[0005] Preferably, the connected area is a community of nodes that can communicate with each other expressed in the proximity relationship of N of the communication nodes.

[0006] Preferably, the proximity relationship is a list of IDs of other representative nodes that are reachable within the proximity of each communication node.

[0007] Preferably, the representative node is a communication node capable of sending and forwarding Beacons and wireless relay services within the network, and the representative node regularly broadcasts Beacons containing its own node ID and device identification number and their proximity relationships.

[0008] Preferably, when the number of connected areas of the common node is greater than 1, the common node may participate in the election of representative nodes, and the common node may send an election Beacon, wherein the election Beacon includes its own node ID and device identification number and connected areas and their proximity relationships.

[0009] Preferably, when the representative node connected area is equal to 1, the proximity relationship of surrounding nodes is compared and it is decided whether to execute the representative node exit process according to the comparison result.

[0010] Preferably, the common node election steps are: Step 1: The common node that meets the election conditions sends the election Beacon to the representative node; Step 2: The representative node obtains a comparison result through the proximity relationship and connected area in the Beacon of the common node and the device identification number; Step 3: The representative node ID is obtained through comparison results, and the information is transmitted to each node. After receiving the information, the corresponding ID node transforms itself into the representative node.

[0011] Preferably, the representative node exit process execution steps are: Step 1: When the number of connected areas of the representative node is equal to 1, the proximity relationship of the surrounding adjacent nodes is obtained; Step 2: Compare its own proximity relationship with the proximity relationship of surrounding adjacent nodes; Step 3: Determine whether to downgrade to the common node according to the comparison result.

[0012] Preferably, when the number of connected areas of the representative node is greater than 1, the representative node state is maintained.

[0013] Preferably, if the representative node proximity relationship is the same as or does not exist in comparison with the surrounding node proximity relationship, the representative node state is maintained; if the representative node proximity relationship is the same as or does not exist in comparison with the surrounding node proximity relationship, the representative node state is downgraded to an ordinary node.

[0014] The beneficial effects of the present invention are that the air interface overhead of BEACON is extremely small; wide area propagation (real-time and coverage) is met; the performance of the entire system is adaptive to the physical topology and communication environment of the distribution of communication nodes and does not require the assistance of GPS. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of selecting representative nodes and designating representative nodes of the present invention.

[0016] Figure 2 This is a GRAND-QUIT process of the present invention.

[0017] Figure 3 A narrowband network topology diagram.

[0018] Figure 4 For Figure 1 The topology diagram after the network connection links are changed based on the network topology.

[0019] Figure 5 For Figure 1 The topology diagram after the network connection links are changed based on the network topology.

[0020] Figure 6 Schematic diagram of the local proximity relationship of communication nodes. DETAILED DESCRIPTION

[0021] In order to describe the embodiments of the present invention in detail, some basic terms used are explained in detail below: GRAND-NODE: A communication node that has the ability to send and forward Beacons and wireless relay services within a narrowband network system, also known as a representative node.

[0022] NODE: ordinary node.

[0023] Neighboring relationship: Each communication node has a list of GRAND-NODE IDs that can be communicated within its surrounding "field of vision".

[0024] Connected area: The number of reachable communication communities between nodes expressed in the proximity relationship of the surrounding N GRAND-NODEs.

[0025] For example, there are GRAND-NODE communication nodes with IDs 1, 2, 3, 4, 5, and 6; Among them, communication nodes 1, 2, and 3 are reachable to each other, and communication nodes 5 and 6 are reachable to each other, that is, the communication node has two connected areas 1-2-3 and 5-6; if 1, 2, 3, 4, 5, and 6 are reachable to each other, then the communication node has a connected area 1-2-3-4-5-6.

[0026] Beacon: A beacon that GRAND-NODE broadcasts periodically, containing its own node ID, device identification number, and its proximity relationship.

[0027] Campaign Beacon: The beacon emitted by a NODE during its participation in the GRAND-NODE campaign, which contains its own node ID, device identification number, connected area and its adjacent relationship.

[0028] Campaign for GRAND: NODE participates in the process of campaigning for GRAND-NODE.

[0029] GRAND-QUIT: The process by which a GRAND-NODE attempts to detect whether it should return to the NODE state, also known as the representative node exit process.

[0030] like Figure 1 A flowchart of selecting a representative node and specifying a representative node of the present invention is shown as follows: Step 1: The communication node calculates its own proximity relationship and connected area; Step 2: Get the status of your own node; Step 3: Determine the required operations for your own node based on the node status, neighboring relationship and connected area: If your own node status is NODE (ordinary node), if your own connected area is greater than 1, you need to execute the Beacon election operation; if your own connected area is equal to 1, you do not need to participate in the GRAND-NODE (representative node) election operation; if your own node status is GRAND-NODE (representative node), if your own connected area is greater than 1, you do not need to execute the GRAND-QUIT (representative node exit process) operation; if your own connected area is equal to 1, you need to execute the GRAND-QUIT (representative node exit process) operation.

[0031] The GRAND-NODE election process includes: the NODE node sends the election Beacon to the GRAND-NODE (representative node), and the election Beacon contains its own node ID and device identification number and connected area and its adjacent relationship. The election steps of this process are: Step 1: The common node that meets the election conditions sends the election Beacon to the representative node; Step 2: The representative node obtains a comparison result through the proximity relationship and connected area in the Beacon of the common node and the device identification number; Step 3: The representative node ID is obtained through comparison results, and the information is transmitted to each node. After receiving the information, the corresponding ID node itself becomes the representative node. The GRAND-NODE node has the ability to send and forward Beacons and wireless relay services in the narrowband network system, which contains its own node ID, device identification number and its proximity relationship.

[0032] like Figure 2 The process of GRAND-QUIT of the present invention is shown as follows: Step 1: When the number of connected areas of the representative node is equal to 1, the proximity relationship of the surrounding adjacent nodes is obtained; Step 2: Compare its own proximity relationship with the proximity relationship of surrounding adjacent nodes; Step 3: Determine whether to downgrade to the common node according to the comparison result.

[0033] When the connected area of ​​a GRAND-NODE node is equal to 1, the GRAND-QUIT process is executed; After collecting the proximity relationships of the surrounding neighboring nodes, the proximity relationship of the own node is compared with the proximity relationships of the surrounding neighboring nodes; For example, if the neighbor relationship of communication node 1 is GRAND-NODE of 1,2,7,10; the neighbor relationship of communication node 2 is 1,2, the neighbor relationship of communication node 7 is 1,7,11, and the neighbor relationship of communication node 10 is 1,10; the neighbor relationship of communication node 2 is included by communication node 1, the neighbor relationship of communication node 7 is not included by communication node 1, and the neighbor relationship of communication node 10 is included by the neighbor relationship of communication node 1, so the GRAND-QUIT process of communication node 1 ends and it is not downgraded to NODE; If the neighboring relationship of communication node 1 is GRAND-NODE 1, 2, 7, 10; the neighboring relationship of communication nodes 1, 2, 7, 10 is all 1, 2, 7, 10, then it is necessary to compare the ADDR values ​​of the communication nodes, and compare the ADDR value of communication node 1 with the ADDR values ​​of communication nodes 2, 7, 10 one by one. If the ADDR value of communication node 1 is larger than that of the neighboring nodes, then exit the GRAND-QUIT process and maintain GRAND-NODE; if the ADDR value of communication node 1 is smaller than the ADDR of one of the communication nodes, then communication node 1 will be downgraded to NODE after executing the GRAND-QUIT process.

[0034] If the neighboring relationships of the communication node 1 all include the neighboring relationships of the neighboring nodes, then the communication node 1 is not downgraded to a NODE after executing the GRAND-QUIT process.

[0035] In some embodiments, the GRAND-QUIT process is: When the connected area of ​​a GRAND-NODE is 1, the GRAND-QUIT process is executed; Collect the proximity relationships of the surrounding nodes and the weights between the surrounding communication nodes, and first compare the proximity relationships of the own node with the surrounding nodes; For example, if the neighbor relationship of communication node 1 is GRAND-NODE of 1,2,7,10; the neighbor relationship of communication node 2 is 1,2, the neighbor relationship of communication node 7 is 1,7,11, and the neighbor relationship of communication node 10 is 1,10; the neighbor relationship of communication node 2 is included by communication node 1, the neighbor relationship of communication node 7 is not included by communication node 1, and the neighbor relationship of communication node 10 is included by the neighbor relationship of communication node 1, so the GRAND-QUIT process of communication node 1 ends and it is not downgraded to NODE; If the adjacent relationships of the communication nodes are all equal, then the sum of the weights of the communication nodes are compared. If the sum of the weights of communication node 1 is greater than the sum of the weights of the adjacent nodes, then communication node 1 will not be downgraded to NODE when executing the GRAND-QUIT process. If the sum of the weights of communication node 1 is less than the sum of the weights of one of the surrounding adjacent nodes, then communication node 1 will be downgraded to NODE after executing the GRAND-QUIT process. If the sum of the weights of communication node 1 is equal to the sum of the weights of all adjacent nodes, then the ADDR of communication node 1 is compared with the ADDR of the adjacent nodes, and whether to downgrade to NODE is determined based on the comparison result. If the ADDR value is the largest, it will not be downgraded to NODE. If it is not the largest, it will be downgraded to NODE.

[0036] In some embodiments, the method for calculating the sum of the communication node weights is as follows: like Figure 4 As shown in the local topology diagram of communication nodes, the neighboring nodes of communication node 3 are 5, 6, 7, 8, and 11; The average delays from communication node 3 to communication nodes 5, 6, 7, 8, and 11 are d 3，5 , d 3，6 , d 3，7 , d 3，8 , d 3，11 ; The distances from communication node 3 to communication nodes 5, 6, 7, 8, and 11 are D 3，5 , d 3，6 , d 3，7 , D 3，8 , D 3，11 ; Then define a time delay correlation function ∈ = ∑ j d 3，j ; Considering that the energy consumption of data when transmitting K bits between two nodes is E i，j , then the total energy consumption from node 3 to communication nodes 5, 6, 7, 8, 11 is Q = ∑ j E 3，j (K,D 3，j), where j = 5, 6, 7, 8, 11; The weight calculation formula of communication node 3 is w = e -(αQ+β∈) , where α+β=1, and α>0, β>0; Depending on different application scenarios, the values ​​of α and β may also be different. In the application scenario of drone control, it is necessary to focus on latency. For example, in the application scenario of emergency communication, it is necessary to consider latency and energy consumption between the entire network. At this time, the values ​​of α and β may be relatively more balanced. In this embodiment, the values ​​of α and β are 0.531 and 0.469 respectively in order to take into account various application scenarios. Similarly, relevant operators can also adjust the values ​​of α and β in different application scenarios.

[0037] In some embodiments, the method for a communication node to calculate a connected area is as follows: like Figure 3 The communication structure with ID 1 shown in the narrowband network topology has adjacent relationships of 1, 3, 4, and 8 (the narrowband network initialization scenario); The neighboring relationship of communication node 3 is 2, 3, 4, 7, 9, the neighboring relationship of communication node 8 is 8, and the neighboring relationship of communication node 4 is 3, 5, 6; According to the above adjacency relationship, the adjacency matrix A can be obtained: The first row of the matrix is ​​a1, the second row is a2, and the third row is a3; remember in G(a i , a j )=a i *a i T , where when G(a i , a j )>0, G(a i , a j )=1;G(a i , a j )=0, G(a i , a j )=0; taking a1 and a2 as an example, G(a1, a2)=0*0+1*0+1*0+1*0+0*0+0*0+1*0+0*1+1*0=0; The matrix U is obtained as: Take the first row of U as the initial connected area, set the initial connected area to one, and set the connectivity variable to U0 = {(1,0,1)}; When traversing to the second row, it is found that (1,0,1) and (0,1,0) in U0 perform G((1,0,1), (1,0,1))=0, so the adjacent vector of (0,1,0) does not belong to the connected variable set U0, and a new connected variable U1={(0,1,0)} is added; when traversing to the third row, (1,0,1) and (1,0,1) in U0 perform G((1,0,1), (1,0,1))=2>0, G((1,0,1), (1,0,1))=1, and (1,0,1) in U0 performs XOR operation with (1,0,1), obtaining a new connected variable U0={(1,0,1)}, U i If the adjacent vector x in U j The adjacent vector y of executes G(x, y) = 1, then the adjacent vectors x and y are XORed so that the connected variable U i with U j Merge, if G(x, y) = 0, then connect the variable U i with U j Do not merge; when all adjacent vectors are traversed, there are connected variables U0 and U1, and from the elements in the connected variables, we can know that G((1, 0, 1), (0, 1, 0)) = 0, then the connected variables U0 and U1 are not merged, and there are two connected areas, that is, there are two connected areas.

[0038] In some embodiments, the method for a communication node to calculate a connected area is as follows: like Figure 6 The communication structure with ID 3 shown in the narrowband network topology has adjacent relationships of 1, 2, 3, 4, 7, 9 (the narrowband network initialization scenario); The neighboring relationship of communication node 1 is 3, 4, 8, the neighboring relationship of communication node 2 is 3, 7, the neighboring relationship of communication node 4 is 1, 3, 5, 6, the neighboring relationship of communication node 7 is 2, 5, 7, and the neighboring relationship of communication node 9 is 3; And the average communication delay between communication node 8 and communication node 1 is d 1，8 , and the average communication delay between communication node 4 and communication node 1 is d 1，4 , and the average communication delay between communication node 4 and communication node 6 is d 4，6 , and the average communication delay between communication node 4 and communication node 5 is d 1，8 , and the average communication delay between communication node 5 and communication node 7 is d 5，7 , and the average communication delay between communication node 2 and communication node 7 is d 2，7 The average communication delay between communication node i and communication node j is d i，j, where (i, j = 1, 2, 4, 5, 6, 7, 8, 9), if i = j or there is no connection between the two points, the value is 0; similarly, the transmission E between communication node i and communication node j i，j (k,D i，j ), where (i,j=1,2,4,5,6,7,8,9), if i=j, the value is 0; record w i，j =-(αE i，j (k,D i，j )+βd i，j )); According to the above adjacency relationship and related data, the adjacency matrix W can be obtained: From the connection relationship, we can see that only w1 ，8， w1 ，4， w4 ，6， w4 ，5， w 5，7 , w 2，7 The value is not 0, that is, the matrix W is According to the above embodiment, the weight of a communication node can be w i =e -(αQ+β∈) , where α+β=1, and α>0, β>0, Q=∑ j E i，j (K,D i，j ),∈=∑ j d i，j , j∈N i , N i is the communication node ID of the neighboring communication node i; Remember i =lo g ew i , we can get d i =∑ j w i，j , j∈N i ; The weight logarithm matrix D can be constructed as: The Laplace matrix L of the narrowband network is constructed to obtain; L = DW, the L matrix is: The Laplace matrix rank is 6, 8-6=2, and we know that the characteristic multiplicity of the Laplace matrix 0 is two, which means that there are two connected subgraphs, that is, there are two connected components and two communication node connected areas.

[0039] In some embodiments, the edge weights can also be considered as 1 to facilitate the calculation of the eigenvalues ​​of the Laplacian matrix. Figure 1 Taking the ID 3 shown in the narrowband network topology as an example, the proximity relationship of the communication nodes is 1, 2, 3, 4, 7, 9 (the narrowband network initialization scenario); The neighboring relationship of communication node 1 is 3, 4, 8, the neighboring relationship of communication node 2 is 3, 7, the neighboring relationship of communication node 4 is 1, 3, 5, 6, the neighboring relationship of communication node 7 is 2, 5, 7, and the neighboring relationship of communication node 9 is 3; From the connection relationship, we can see that only w 1，8 , w 1，4 , w 4，6 , w 4，5 , w 5，7 , w 2，7 The value is not 0, that is, the matrix W is The matrix D is, where d i =∑ j w i，j , j∈N i ; That is, the Laplace matrix L is L=DW, L is: The eigenvalues ​​of the Laplace matrix are 0, 0, 0.260, 0.626, 1.405, 2.2274, 3.100, 4.4334, and the multiplicity of eigenvalue 0 is 2, that is, it is connected and the corresponding eigenvectors are (1, 1, 1, 1, 1, 1, 0) and (0, 0, 0, 0, 0, 0, 1), so the connected areas are 1-2-4-5-6-7-8 and 9, and the connected areas can be determined according to their eigenvectors.

[0040] In some embodiments, when a narrowband network system is just started and is still in the initial state, if the communication nodes on it are not specifically designated as GRAND-NODEs, the number of connected areas of these nodes will be initialized to zero. At this stage, the nodes in the network will not perform any specific operations because they have not yet established an effective communication connection or recognized the existence of other nodes. In order for the network to operate effectively, at least one or more communication nodes need to be configured as GRAND-NODEs in the initial state of the network. GRAND-NODE is a special role that plays a key coordination and connection role in the network. At this stage, there will be no election Beacon in the network, because election Beacon usually appears when the network has been partially established and nodes need to vote to decide who is the GRAND-NODE. Once the communication node is set as GRAND-NODE, there will be at least one GRAND-NODE with a connected area of ​​1 in the network. These GRAND-NODEs are of special importance because they are responsible for maintaining the connectivity and stability of the network. At this stage, the GRAND-NODE will try to execute a process called GRAND-QUIT. The GRAND-QUIT process is a mechanism that allows a GRAND-NODE to give up its GRAND-NODE identity and become an ordinary NODE after meeting certain conditions.

[0041] like Figure 3 A narrowband network topology diagram is shown. It can be seen from the diagram that there are 10 communication nodes, which are communication nodes with IDs 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. When the network in the diagram is just started, the communication nodes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are respectively set as GRAND-NODE, where: The neighboring relationships of communication node 1 are GRAND-NODEs 1, 3, 4, and 8. Communication node 1 has two connected areas, namely 3-4-5-6-9 and 8; The neighboring relationship of communication node 2 is GRAND-NODE 2, 3, 7, and the number of connected regions of communication node 2 is 1, which is 3-4-1-9-7-5; The neighboring relationships of communication node 3 are GRAND-NODEs 1, 2, 3, 4, and 9. The connected areas of communication node 3 are 2, namely 1-2-4-5-6-6 and 9; The neighboring relationships of communication node 4 are GRAND-NODEs 1, 3, 4, 5, and 6. The connected areas of communication node 4 are 2, namely 1-2-3-5-7-8-10 and 6; The neighboring relationships of communication node 5 are GRAND-NODEs 4, 5, 7, and 10. The connected areas of communication node 5 are 2, namely 2-3-4-6-7 and 10; The neighboring relationship of communication node 6 is GRAND-NODE 4,6, and the connected area of ​​communication node 6 is 1, which is 1-3-4-5; the neighboring relationship of communication node 7 is GRAND-NODE 3,5,7, and the connected area of ​​communication node 7 is 1, which is 1-2-3-4-9-5-10; The neighboring relationship of communication node 8 is 1, GRAND-NODE 8, and the connected area of ​​communication node 8 is 1, which is 1-3-4; the neighboring relationship of communication node 9 is 3, GRAND-NODE 9, and the connected area of ​​communication node 9 is 1, which is 1-3-7; the neighboring relationship of communication node 10 is 5, GRAND-NODE 10, and the connected area of ​​communication node 10 is 1, which is 3-5-7.

[0042] Among the above communication nodes, the number of connected regions of 1, 3, 4, and 5 is 2, so the GRAND-QUIT process is not executed. However, the number of connected regions of 2, 6, 7, 8, 9, and 10 is 1. The specific process of trying to execute the GRAND-QUIT process is as follows: When communication node 8 executes the GRAND-QUIT process, the communication node adjacent to node 8 is communication node 1, and the proximity relationship of communication node 1 is GRAND-NODE of 1, 3, 4, 8, and the proximity relationship of communication node 8 is GRAND-NODE of 1, 8. From the proximity relationship between communication node 1 and communication node 8, it can be seen that the proximity relationship of communication node 1 includes the proximity relationship of communication node 8, so communication node 8 is downgraded to NODE after executing the GRAND-QUIT process; When communication node 9 executes the GRAND-QUIT process, the communication node adjacent to node 9 is communication node 3. The proximity relationship of communication node 3 is GRAND-NODE of 1, 2, 3, 4, 7, 9, and the proximity relationship of communication node 9 is GRAND-NODE of 3, 9. From the proximity relationship between communication node 3 and communication node 9, it can be seen that the proximity relationship of communication node 3 includes the proximity relationship of communication node 9, so communication node 9 is downgraded to NODE after executing the GRAND-QUIT process. When communication node 10 executes the GRAND-QUIT process, the communication node adjacent to node 10 is communication node 5. The proximity relationship of communication node 5 is GRAND-NODE of 4, 5, 7, 10, and the proximity relationship of communication node 10 is GRAND-NODE of 5, 10. From the proximity relationship between communication node 5 and communication node 10, it can be seen that the proximity relationship of communication node 5 includes the proximity relationship of communication node 10, so communication node 5 is downgraded to NODE after executing the GRAND-QUIT process. When communication node 6 executes the GRAND-QUIT process, the communication node adjacent to node 6 is communication node 4. The proximity relationship of communication node 4 is GRAND-NODE of 1, 3, 4, 5, 6, and the proximity relationship of communication node 6 is GRAND-NODE of 4, 6. From the proximity relationship between communication node 4 and communication node 6, it can be seen that the proximity relationship of communication node 4 includes the proximity relationship of communication node 6, so communication node 6 is downgraded to NODE after executing the GRAND-QUIT process. When communication node 2 executes the GRAND-QUIT process, the communication nodes adjacent to node 2 are communication node 3 and communication node 7. The proximity relationship of communication node 3 is 1, 2, 3, 4, 7, the proximity relationship of communication node 7 is 2, 3, 5, 7, and the proximity relationship of communication node 2 is 2, 3, 7. From the proximity relationship of communication node 3, communication node 7 and communication node 2, it can be seen that the proximity relationship of communication node 3 and communication node 7 includes the proximity relationship of communication node 2, so communication node 2 is downgraded to NODE after executing the GRAND-QUIT process; When communication node 7 executes the GRAND-QUIT process, the communication nodes adjacent to node 7 are communication node 2, communication node 3 and communication node 7. The proximity relationship of communication node 2 is 3, 7, the proximity relationship of communication node 3 is 3, 5, 7, and the proximity relationship of communication node 7 is 3, 5, 7. From the proximity relationships of communication node 2, communication node 3 and communication node 7, it can be seen that the proximity relationship of communication node 2 and communication node 3 does not include the proximity relationship of communication node 7, so communication node 7 maintains the GRAND-NODE state after executing the GRAND-QUIT process.

[0043] When the narrowband network is initialized, the proximity relationship of the network nodes and their connected areas change, where: the proximity relationship of communication node 1 is 1, 3, 4, and the connected area of ​​communication node 1 is 1, which is 3-4-5-7; The neighbor relationship of communication node 2 is 3, and the number of connected areas of communication node 2 is 1, which is 1-3-4-7; The neighboring relationship of communication node 3 is 1, 3, 4, 7, and the connected area of ​​communication node 3 is 1, which is 1-4-5-7; The neighboring relationship of communication node 4 is 1, 3, 4, and the connected area of ​​communication node 4 is 1, which is 1-3-5-7 The neighboring relationship of communication node 5 is 4,7, and the connected area of ​​communication node 5 is 1, which is 1-3-4-7; The neighbor relationship of communication node 6 is 4, and the connected area of ​​communication node 6 is 1, which is 1-3-4-5; The neighboring relationship of communication node 7 is 3, 5, 7, and the connected area of ​​communication node 7 is 1, which is 1-3-4-5; The proximity relationship of communication node 8 is 1, and the connected area of ​​communication node 8 is 1, which is 1-3-4; The proximity relationship of communication node 9 is 3, and the connected area of ​​communication node 9 is 1, which is 1-3-4-7; The proximity relationship of communication node 10 is 5, and the connected area of ​​communication node 10 is 1, which is 4-5-7.

[0044] In the above communication nodes, GRAND-NODE is 1, 3, 4, 5, 7, the number of connected areas of the nodes in GRAND-NODE is greater than 1, and the GRAND-QUIT process is executed.

[0045] When communication node 1 executes the GRAND-QUIT process, the communication nodes adjacent to node 1 are communication node 3, communication node 4 and communication node 8; the proximity relationship of communication node 1 is 1,3,4, the proximity relationship of communication node 4 is 1,3,4,5, the proximity relationship of communication node 3 is 1,3,4,7, and the proximity relationship of communication node 8 is 1; if the proximity relationship of communication node 1 is 1,3,4, compared with the proximity relationship of communication node 4 is 1,3,4,5, the proximity relationship of communication node 1 is included in the proximity relationship of communication node 4, so communication node 1 is downgraded to a NODE node when executing the GRAND-QUIT process; When communication node 3 executes the GRAND-QUIT process, the communication nodes adjacent to node 3 are communication node 1, communication node 4, communication node 7 and communication node 9; the proximity relationship of communication node 1 is 1,3,4, the proximity relationship of communication node 4 is 1,3,4,5, the proximity relationship of communication node 7 is 3,5,7, and the proximity relationship of communication node 3 is 1,3,4,7; the proximity relationship 1,3,4 of communication node 1 is included by the proximity relationship 1,3,4,7 of communication node 3, the proximity relationship 1,3,4,5 of communication node 4 is not included compared with the proximity relationship 1,3,4,7 of communication node 3, the proximity relationship 3,5,7 of communication node 7 is not included with the proximity relationship 1,3,4,7 of communication node 3, and the proximity relationship 3 of communication node 9 is included by the proximity relationship 1,3,4,7 of communication node 3 compared with the proximity relationship 1,3,4,7 of communication node 3; therefore, communication node 3 is not downgraded to NODE after executing the GRAND-QUIT process; When communication node 4 executes the GRAND-QUIT process, the communication nodes adjacent to node 4 are communication node 1, communication node 3, communication node 5 and communication node 6; the proximity relationship of communication node 1 is 1, 3, 4, the proximity relationship of communication node 3 is 1, 3, 4, 7, the proximity relationship of communication node 5 is 4, 5, 7, the proximity relationship of communication node 6 is 4, and the proximity relationship of communication node 4 is 1, 3, 4, 5; the proximity relationship of communication node 1 is 1, 3, 4 and the proximity relationship of communication node 4 is 1, 3, 4, 5. It can be seen that the neighboring relationship of communication node 4 includes the neighboring relationship of communication node 1, the neighboring relationships 1, 3, 4, 7 of communication node 3 are not included in the neighboring relationship 1, 3, 4, 4 of communication node 4, the neighboring relationships 4, 5, 7 of communication node 5 are not included in the neighboring relationship 1, 3, 4, 5 of communication node 4, and the neighboring relationship 4 of communication node 6 is included in the neighboring relationship 1, 3, 4, 5 of communication node 4; therefore, communication node 4 is not downgraded to NODE after executing the GRAND-QUIT process; When communication node 5 executes the GRAND-QUIT process, the communication nodes adjacent to node 5 are communication node 4, communication node 7 and communication node 10; the proximity relationship of communication node 4 is 1, 3, 4, 5, the proximity relationship of communication node 7 is 3, 5, 7, the proximity relationship of communication node 10 is 5, and the proximity relationship of communication node 5 is 4, 5, 7; the proximity relationship 1, 3, 4, 5 of communication node 4 is not included in the proximity relationship 4, 5, 7 of communication node 5, the proximity relationship 3, 5, 7 of communication node 7 is not included in the proximity relationship 4, 5, 7 of communication node 5, and the proximity relationship 5 of communication node 10 is included in the proximity relationship 4, 5, 7 of communication node 5; therefore, communication node 4 is not downgraded to NODE after executing the GRAND-QUIT process; When communication node 7 executes the GRAND-QUIT process, the communication nodes adjacent to node 2 are communication node 3 and communication node 5 respectively; the proximity relationship of communication node 3 is 1,3,4,7, the proximity relationship of communication node 5 is 4,5,7, and the proximity relationship of communication node 7 is 3,5,7; the proximity relationship 1,3,4,7 of communication node 3 is not included in the proximity relationship 3,5,7 of communication node 7, and the proximity relationship 4,5,7 of communication node 5 is not included in the proximity relationship 3,5 of communication node 7; therefore, communication node 7 is not downgraded to NODE after executing the GRAND-QUIT process; In this way, only four nodes 3, 4, 5, and 7 need to be selected from communication nodes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 as GRAND-NODEs to maintain the normal operation of the narrowband network. When these four nodes are used as GRAND-NODEs, the network Beacon air interface overhead is extremely small, and at the same time, the feasibility and extensiveness of Beacon propagation can be met.

[0046] However, when the narrowband network is running, the network topology changes due to the disconnection or addition of network connection links. The following embodiment describes this situation in detail: like Figure 4 Shown in Figure 1 Based on the network topology structure, the network connection between communication node 2 and communication node 7 is disconnected, and the network connection between communication node 5 and communication node 7 is disconnected. It can be seen from the above embodiment that communication nodes 3, 4, 5, and 7 are GRAND-NODEs. When the network connection link in the narrowband network is disconnected, the proximity relationship of each node and the corresponding connected area may change; The neighboring relationship and connected areas of the GRAND-NODE are as follows: The neighboring relationship of communication node 3 is 3, 4, 7, and the connected areas are 2, namely 1-4-5 and 7; The neighboring relationships of communication node 4 are 1, 3, 4, and 5, and the connected areas are 2, namely 1-3-7 and 5; Communication node 5 has a neighbor relationship of 4 and a connected area of ​​1, which is 1-3-4-7; The proximity relationship of communication node 7 is 3, and the connected area is 1, which is 1-3-4-5; The connected area of ​​NODE nodes in this network topology is 1, so they do not participate in the GRAND-NODE election process; In the above GRAND-NODE, the number of connected areas between communication node 5 and communication node 7 is 1, and the GRAND-QUIT process is executed; When communication node 5 executes the GRAND-QUIT process, the communication nodes adjacent to communication node 5 are communication node 4 and communication node 10; the proximity relationship of communication node 4 is 1,3,4,5, the proximity relationship of communication node 10 is 5, and the proximity relationship of communication node 5 is 4,5; compared with the proximity relationship 4,5 of communication node 5 and the proximity relationship 5 of communication node 10, the proximity relationship of communication node 10 is included by the proximity relationship of communication node 5, and compared with the proximity relationship 4,5 of communication node 4 and the proximity relationship 1,3,4,5 of communication node 5 and the proximity relationship 4,5 of communication node 5, the proximity relationship of communication node 4 includes the proximity relationship of communication node 5, so communication node 5 is downgraded to NODE after executing the GRAND-QUIT process; When communication node 7 executes the GRAND-QUIT process, the communication nodes adjacent to communication node 7 include communication node 3; the proximity relationship of communication node 3 is 3, 4, 7, and the proximity relationship of communication node 7 is 3, 7; compared with the proximity relationship 3, 7 of communication node 7, the proximity relationship 3, 4, 7 of communication node 3, and the proximity relationship 3, 7 of communication node 7, communication node 3 includes the proximity relationship of communication node 7; therefore, communication node 7 is downgraded to NODE after executing the GRAND-NODE process.

[0047] like Figure 5 Shown in Figure 1 7 communication nodes are added on the basis of the network topology structure, and the communication node IDs are 11, 12, 13, and 14 respectively; and the newly added communication node is assumed to be GRAND-NODE; the newly added network connection links are: the network connection link between communication node 10 and communication node 14, the network connection link between communication node 10 and communication node 12, the network connection link between communication node 12 and communication node 13, the network connection link between communication node 2 and communication node 11, the network connection link between communication node 9 and communication node 15, the network connection link between communication node 16 and communication node 3, communication node 7, communication node 5 and communication node 17, and the network connection link between communication node 7 and communication node 2 is disconnected; the adjacent relationship and connected area of ​​the original communication nodes may change, among which: The original GRAND-NODEs are 3, 4, 5, and 7; In the original NODE node: The neighboring relationships of communication node 10 are 5, 12, and 14, and the number of connected regions is 3, namely 4-5-7, 12-13, and 14; The neighboring relationships of communication node 2 are 3, 7, and 11, and the number of connected areas is 2, namely 1-3-4-5-7-16-17 and 11; The neighboring relationship of communication node 9 is 3, 15, and the number of connected areas is 2, namely 3-4-5-7-16-17 and 15; The neighboring relationship of communication node 1 is 3,4, and the connected area is 1, which is 3-4-5-7-16; The neighbor relationship of communication node 6 is 4, and the connected area is 1, which is 1-4-5; Among the above NODEs, only communication nodes 2, 9, and 10 have a connected area greater than 1, so only communication nodes 2, 9, and 10 execute the GRAND-NODE election process, which is as follows: The neighboring relationship of communication node 10 is 5, 12, 14, the neighboring relationship of communication node 9 is 3, 15, and the neighboring relationship of communication node 2 is 3, 7, 11; the neighboring relationships of communication node 10, communication node 2 and communication node 9 are not included in each other, so communication nodes 2, 9, 10 are elected as GRAND-NODE; Based on the above steps, the GRAND-NODE node includes the original GRAND-NODE and the newly added nodes, where their proximity relationship and connected areas are: The neighboring relationship of communication node 2 is 3, 11, and the connected areas are 2, namely 1-3-4-5-7-16-17 and 11; The neighboring relationship of communication node 9 is 3, 15, and the number of connected areas is 2, namely 3-4-5-7-16-17 and 15; The neighboring relationships of communication node 10 are 5, 12, and 14, and the number of connected regions is 3, namely 4-5-7, 12-13, and 14; The neighboring relationship of communication node 3 is 2, 3, 4, 7, 9, 16, and the connected areas are 2, 3, 4, 5, 7, 11, 16 and 9-15; the neighboring relationship of communication node 4 is 3, 5, and the connected area is 1, which is 2, 3, 5, 7, 9, 10, 11; The neighboring relationship of communication node 5 is 4, 5, 7, 16, and there are 2 connected areas, which are 10-12-14 and 2-3-4-5-7-11-16-17; the neighboring relationship of communication node 7 is 3, 5, 7, 16, and there is 1 connected area, which is 2-3-4-5-7-10-11-16-17; The neighbor relationship of communication node 11 is 2,11, and there is one connected area, which is 2-3-7; The neighboring relationship of communication node 12 is 10, 12, 13, and there are two connected areas, namely 5-10-14 and 13; The neighboring relationship of communication node 13 is 12, 13, and the connected area is 1, which is 10-12; The neighbor relationship of communication node 14 is 10, 14, and there is one connected area, which is 5-10-12; The neighbor relationship of communication node 15 is 9,15, and the connected area is 1, which is 3-9; The neighboring relationships of communication node 16 are 3, 5, 7, 16, 17, and there are two connected areas, namely 2-3-4-5-7-9-10 and 17; In the above GRAND-NODE, the communication nodes with a connected area of ​​1 are communication node 4, communication node 7, communication node 11, communication node 13, communication node 14 and communication node 15; the communication nodes perform the GRAND-QUIT operation as follows: when communication node 4 performs the GRAND-QUIT process, the communication nodes adjacent to communication node 4 are communication node 1, communication node 3, communication node 5 and communication node 6; the proximity relationship of communication node 1 is 3, 4, the proximity relationship of communication node 3 is 2, 3, 4, 7, 9, 16, the proximity relationship of communication node 5 is 4, 5, 7, 10, the proximity relationship of communication node 6 is 4, and the proximity relationship of communication node 4 is 3, 5; the proximity relationship of communication node 3 is not included in the proximity relationship of communication node 4, the proximity relationship of communication node 5 is not included in the proximity relationship of communication node 5, and the proximity relationship of communication node 6 is included in the proximity relationship of communication node 4, so communication node 4 is not downgraded to NODE when performing the GRAND-QUIT process; When communication node 7 executes the GRAND-QUIT process, the adjacent communication nodes to communication node 7 are communication node 2, communication node 3, communication node 5 and communication node 16; the adjacent relationship of communication node 2 is 3, 7, 11, the adjacent relationship of communication node 3 is 2, 3, 4, 7, 9, 16, the adjacent relationship of communication node 5 is 4, 5, 7, 10, the adjacent relationship of communication node 16 is 3, 5, 7, 16, 17, and the adjacent relationship of communication node 7 is 2, 3, 5, 16; the adjacent relationship of communication node 2 is not included in the adjacent relationship of communication node 7, the adjacent relationship of communication node 3 is not included in the adjacent relationship of communication node 7, the adjacent relationship of communication node 5 is not included in the adjacent relationship of communication node 4, and the adjacent relationship of communication node 16 is included in the adjacent relationship of communication node 16 compared with the adjacent relationship of communication node 7; therefore, communication node 7 is downgraded to NODE when executing the GRAND-QUIT process; When communication node 11 executes the GRAND-NODE process, the communication node adjacent to communication node 11 is communication node 2; the proximity relationship of communication node 2 is 2, 3, 11, and the proximity relationship of communication node 11 is 2, 11; the proximity relationship of communication node 11 is included in the proximity relationship of communication node 2, so communication node 11 is downgraded to NODE after executing the GRAND-QUIT process; when communication node 13 executes the GRAND-NODE process, the communication node adjacent to communication node 13 is communication node 12; the proximity relationship of communication node 12 is 12, 13, 10, and the proximity relationship of communication node 13 is 12, 13; the proximity relationship of communication node 13 is included in the proximity relationship of communication node 12, so communication node 13 is downgraded to NODE after executing the GRAND-QUIT process; When communication node 14 executes the GRAND-NODE process, the communication node adjacent to communication node 11 is communication node 10; the neighboring relationship of communication node 10 is 5, 12, 14, and the neighboring relationship of communication node 14 is 10, 14; the neighboring relationship of communication node 14 is included in the neighboring relationship of communication node 10, so communication node 14 is downgraded to NODE after executing the GRAND-QUIT process; When communication node 15 executes the GRAND-NODE process, the communication node adjacent to communication node 15 is communication node 9; the neighboring relationship of communication node 9 is 3, 9, 15, and the neighboring relationship of communication node 15 is 9, 15; the neighboring relationship of communication node 15 is included in the neighboring relationship of communication node 9, so communication node 15 is downgraded to NODE after executing the GRAND-QUIT process; It can be seen from the above embodiments that when the narrowband network topology changes, the method can re-elect GRAND-NODE or specify which GRAND-NODEs to withdraw according to the network topology, so that the newly elected GRAND-NODE can maintain the normal operation of the network and the stability of the network.

[0048] The present invention deeply explains its purpose, technical scheme and beneficial effects through specific embodiments, but these embodiments are only used as examples to show the application mode of the invention and do not constitute a limitation on the protection scope of the present invention. We explicitly point out that any reasonable modification, equivalent substitution or technical improvement under the guidance of the spirit and principles of the present invention should be included in the protection scope of the present invention. This means that as long as these changes do not deviate from the core idea and basic function of the invention, they should be protected by patent rights. The scope of protection of the present invention should be broad, including all direct and obvious variants and non-obvious innovations that can be reasonably deduced by technical experts based on the disclosure of the present invention. This broad protection is intended to promote further research and development based on the present invention, while ensuring that its innovation and practicality are fully protected by law.

Claims

1. A method for sensing spatial topology distribution based on narrowband wireless networks, characterized in that: The method for sensing the distribution of self-spatial topology based on narrowband wireless networks can adaptively cite representative communication nodes, wherein the communication nodes include representative nodes and common nodes, and includes the following steps: Step 1: The communication node calculates the proximity relationship and the connected area; Step 2: The communication node is initially set as a representative node; Step 3: Compare the proximity relationship of the communication nodes with the connected area to select a representative node or execute the designated representative node exit process.

2. The method for sensing the spatial topology distribution based on narrowband wireless network according to claim 1, characterized in that: The connected area is a community of nodes that can communicate with each other as expressed in the proximity relationship of the N communication nodes.

3. A method for sensing narrowband wireless network self-spatial topology distribution according to any one of claims 1 or 2, characterized in that: The proximity relationship is a list of IDs of other representative nodes that each communication node can reach within its proximity.

4. The method for self-spatial topology distribution perception based on narrowband wireless network according to any one of claim 3, characterized in that: The representative node is a communication node that has the ability to send and forward Beacons and wirelessly relay services within the network, and the representative node regularly broadcasts Beacons that contain its own node ID and device identification number and their proximity relationships.

5. A method for sensing spatial topology distribution based on narrowband wireless network according to any one of claims 2 or 4, characterized in that: When the number of connected areas of the common node is greater than 1, the common node can participate in the election of representative nodes, and the common node can send an election Beacon, which includes its own node ID and device identification number and connected areas and their proximity relationships.

6. A method for sensing distribution based on narrowband wireless network self-spatial topology according to claim 2 or 4, characterized in that: When the representative node connected area is equal to 1, the neighboring nodes are compared to determine whether to execute the representative node exit process according to the comparison result.

7. The method for self-spatial topology distribution perception based on narrowband wireless network according to claim 5, characterized in that: The common node election steps are: Step 1: The common node that meets the election conditions sends the election Beacon to the representative node; Step 2: The representative node obtains a comparison result through the proximity relationship and connected area in the Beacon of the common node and the device identification number; Step 3: The representative node ID is obtained through comparison results, and the information is transmitted to each node. After receiving the information, the corresponding ID node transforms itself into the representative node.

8. The method for sensing the spatial topology distribution based on narrowband wireless network according to claim 2 or 6, characterized in that: The representative node exit process execution steps are: Step 1: When the number of connected areas of the representative node is equal to 1, the proximity relationship of the surrounding adjacent nodes is obtained; Step 2: Compare its own proximity relationship with the proximity relationship of surrounding adjacent nodes; Step 3: Determine whether to downgrade to the common node according to the comparison result.

9. The method for sensing the spatial topology distribution based on narrowband wireless network according to claim 8, characterized in that: When the number of connected areas of the representative node is greater than 1, the representative node state is maintained.

10. The method for self-spatial topology distribution perception based on narrowband wireless network according to claim 8, characterized in that: If the representative node proximity relationship is the same as or does not exist in comparison with the surrounding node proximity relationship, the representative node status is maintained; if the representative node proximity relationship is the same as or does not exist in comparison with the surrounding node proximity relationship, the representative node status is downgraded to an ordinary node.

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