CN102752785B - Interference model measurement method and device for wireless sensor network - Google Patents

Abstract

The invention provides a method and device for measuring an interference model in a wireless sensor network. By performing system initialization on the wireless sensor network, and then selecting some nodes in the wireless sensor network to form the first node set, by obtaining the node The sent data calculates the SINR value and the corresponding data packet acceptance rate PRR, then selects and updates the number of SINR intervals in the SINR interval measured by the node, and finally performs loop detection according to the judgment rule until the completion of the node set Select, this scheme is suitable for any static wireless sensor network, which can not only guarantee the accuracy but also reduce the network overhead.

Description

Method and device for measuring interference model in wireless sensor network

technical field

The invention relates to the technical field of information control, in particular to a method and device for measuring an interference model in a wireless sensor network.

Background technique

With the continuous development of science and technology, the application of wireless sensor network is more and more extensive. Wireless sensor networks first appeared in the US-Vietnam War in the 1970s. In recent years, with the improvement of sensor node computing capabilities and the reduction of volume, many wireless sensor networks have been put into commercial applications. Such as environmental monitoring, medical care and other fields. The wireless sensor network is composed of a large number of sensor nodes. The sensor nodes communicate through multi-hop wireless signals. When there are multiple communications in space at the same time, they may interfere with each other, resulting in the transmission of data Packet loss. The interference model describes the existence of interference in wireless sensor networks. Accurate interference models are beneficial to the design of some upper-layer network protocols, such as routing algorithms and channel scheduling. The research shows that there is a large error between the interference models that are often used in the past, such as those based on hop count and distance, and the actual situation, while the PRR-SINR interference model has high accuracy. PRR (Packet Reception Ratio) is the data packet reception rate, and SINR (Signal to Interference plus Noise Ratio) is the signal to interference plus noise ratio. The PRR-SINR model uses SINR to describe the intensity of interference, thereby describing the impact of interference on data packet reception. . The PRR-SINR model has the following characteristics: (1) The relationship between PRR and SINR has nothing to do with the sending nodes, which nodes are the interfering nodes, their transmitting power, and the transmission channel. (2) There is a conversion interval in the PRR-SINR model. When the SINR value changes within this interval, the value of PRR gradually changes from 0 to 1. (3) The PRR-SINR models measured by different sensor nodes at different times or in different locations are different.

It can be seen from the above characteristics of the PRR-SINR model that each node in the wireless sensor network needs to establish its own interference model through the implementation of local measurements. There are currently two types of measurement methods for the PRR-SINR model: one is the active measurement method, when the nodes in the network need to measure the PRR-SINR model, the data transmission in the network is suspended, and some nodes are selected to simultaneously A certain number of data packets are transmitted, and other nodes measure the corresponding SINR and PRR values by receiving these data packets, and repeat the above process, so that each node can establish its own interference model through the measured SINR and PRR values, One method of active measurement is to randomly select a certain number of nodes to send data packets at the same time; the other is a passive measurement method. When the network is a tree topology, it is necessary to measure the nodes of the PRR-SINR model and The nodes that will interfere with it send the time stamps of receiving and sending data packets in their daily data transmission to their common parent node, and the parent node calculates the interference model of the node. The advantage of the first method is that its PRR-SINR model can be measured for each node at any time, but the disadvantage is that the network overhead is large; the advantage of the second method is that the network overhead is small, and the disadvantage is that it cannot be guaranteed within a certain period of time Measure the PRR-SINR model of any sensor node.

In view of the problems existing in the active measurement method in the prior art, how to provide a fast and low-cost active measurement method constitutes the focus of wireless sensor network design. This scheme proposes an interference model measurement method in wireless sensor network and The device is one of the urgent problems to be solved in the field of information control technology.

Contents of the invention

In view of this, the embodiment of the present invention proposes a method and device for measuring interference models in a wireless sensor network, by performing system initialization on the wireless sensor network, and then selecting some nodes in the wireless sensor network to form the first node Set, calculate the SINR value and the corresponding packet acceptance rate PRR by obtaining the data sent by the node, then select and update the number of SINR intervals in the SINR interval measured by the node, and finally perform loop detection according to the judgment rule until After completing the selection of the node set, this scheme is applicable to any static wireless sensor network, which can not only ensure the accuracy but also reduce the network overhead.

In order to solve the above technical problems, the purpose of the embodiments of the present invention is achieved through the following technical solutions:

A method for measuring an interference model in a wireless sensor network, comprising:

Step 1, system initialization of the wireless sensor network;

Step 2. Select some nodes in the wireless sensor network to form the first node set, and calculate the SINR value and the corresponding packet acceptance rate PRR by obtaining the data sent by the nodes;

Step 3, select and update according to the number of SINR intervals in the SINR interval measured by the node;

Step 4: Carry out loop detection according to the judgment rules until the selection of the node set is completed.

Preferably, in the above step 1, the system initialization means that all nodes in the network do not measure any (SINR, PRR) points, PRR means packet reception rate, and SINR means signal-to-interference-plus-noise ratio.

Preferably, in the above step 2, it further includes selecting some partial nodes in the network to form the first node set.

Preferably, the above further includes optional one node to join the node set, when there is only one node in the network to send data packets, since there are only sending nodes and no interfering nodes, other nodes cannot measure the SINR value, Therefore, all nodes can measure the number of SINR intervals where (SINR, PRR) points fall within a certain SINR interval M1=0.

Preferably, in the above step three, it further includes traversing all nodes other than the node set in the network, and calculating if a certain node is added to this node set, all nodes can measure (SINR, PRR) points The number M2 of SINR intervals falling within a certain SINR interval.

Preferably, in the above step 3, it further includes selecting the node with the largest M2 value, if there are multiple such nodes, choose one, and when its M2 value is greater than the M1 value, add this node to the node Point set, get a new node set, and update the value of M1 at the same time, that is, M1=M2.

Preferably, the above step four further includes repeating step three until the maximum M2 value is less than or equal to the M1 value, indicating that adding any node to the current node set cannot make the node set satisfy the number of SINR intervals increases, the selection of nodes in the node set ends, that is, a node set is selected.

Preferably, in the above step four, it further includes that if all nodes in the network can measure at least one (SINR, PRR) point in each SINR interval, then the selection of the node set ends, otherwise repeat step three and step Fourth, select the next node set.

An interference model measurement device in a wireless sensor network, including an initialization unit, a calculation unit, a selection unit and a cycle detection unit, through system initialization of the wireless sensor network, and then selecting some nodes in the wireless sensor network to form the first The node set calculates the SINR value and the corresponding packet acceptance rate PRR by obtaining the data sent by the node, then selects and updates the number of SINR intervals in the SINR interval measured by the node, and finally performs loop detection according to the judgment rule , until the selection of the node set is completed.

Preferably, the above initialization unit is used for system initialization of the wireless sensor network.

Preferably, the calculation unit is used to select some nodes in the wireless sensor network to form the first node set, and calculate the SINR value and the corresponding data packet acceptance rate PRR by acquiring the data sent by the nodes.

Preferably, the selection unit is configured to select and update according to the number of SINR intervals in the SINR interval measured by the node.

Preferably, the loop detection unit is configured to perform loop detection according to the judgment rule until the selection of the node set is completed.

In summary, the present invention provides a method and device for measuring an interference model in a wireless sensor network, by performing system initialization on the wireless sensor network, and then selecting some nodes in the wireless sensor network to form the first node set , by obtaining the data sent by the node to calculate the SINR value and the corresponding packet acceptance rate PRR, then select and update the number of SINR intervals in the SINR interval measured by the node, and finally perform loop detection according to the judgment rule until the completion For the selection of node set, this scheme is applicable to any static wireless sensor network, which can not only guarantee the accuracy but also reduce the network overhead.

Description of drawings

Figure 1 shows the PRR-SINR model of this scheme;

Fig. 2 is a schematic diagram of an interference model measurement method in a wireless sensor network of the present invention;

Fig. 3 is the block diagram of the active measurement method of this scheme;

Fig. 4 is a method flowchart of a specific embodiment of the present invention;

FIG. 5 is a schematic diagram of an interference model measuring device in a wireless sensor network according to the present invention.

Detailed ways

A method and device for measuring an interference model in a wireless sensor network provided by an embodiment of the present invention performs system initialization on the wireless sensor network, and then selects some nodes in the wireless sensor network to form the first node set, and obtains The data sent by the node calculates the SINR value and the corresponding data packet acceptance rate PRR, then selects and updates the number of SINR intervals in the SINR interval measured by the node, and finally performs loop detection according to the judgment rule until the completion of the node Set selection, this scheme is suitable for any static wireless sensor network, which can not only guarantee the accuracy but also reduce the network overhead.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

PRR (Packet Reception Ratio) is the data packet reception rate, and SINR (Signal to Interference plus Noise Ratio) is the signal to interference plus noise ratio. The PRR-SINR model uses SINR to describe the intensity of interference, thereby describing the impact of interference on data packet reception. .

The main idea of the present invention is: to design an active measurement method and select several node sets composed of some nodes in the network. In each round, all nodes in a node set send data packets at the same time, and other nodes in the network measure their SINR values and corresponding data packet acceptance rates by monitoring these datagrams. When a node measures When the (SINR, PRR) points are distributed in enough transition intervals in the PRR-SINR model, it can build its own interference model. After several selected node sets send data packets in sequence, each node in the network can measure its PRR-SINR model.

In addition, in order to ensure that each node can quickly and efficiently measure the high-precision PRR-SINR model, this scheme divides the conversion interval of the PRR-SINR model into several equal parts, and the measurement is guaranteed to be within each divided SINR interval Can measure at least one (SINR, PRR) point. When the (SINR, PRR) points measured by the nodes are distributed outside the conversion interval or gathered in a small range, it is not conducive to the establishment of the PRR-SINR model, and it will cause waste of network overhead. As shown in Figure 1, it is the PRR-SINR model of this scheme.

An embodiment of the present invention provides a method for measuring an interference model in a wireless sensor network, as shown in FIG. 2 , and the specific steps include:

Step 1, system initialization of the wireless sensor network;

Specifically, in the embodiment of the present invention, this solution provides a centralized measurement method that can ensure accuracy and reduce network overhead. This method is applicable to any static wireless sensor network. In this solution, it is assumed that Know the location information and transmit power of all nodes in the network

Among them, in this scheme, the system initialization means that all nodes in the network have not measured any (SINR, PRR) points, and are ready to calculate and select the first node set. PRR (Packet Reception Ratio) is the packet reception rate, and SINR (Signal to Interference plus Noise Ratio) is the signal to interference plus noise ratio.

Step 2. Select some nodes in the wireless sensor network to form the first node set, and calculate the SINR value and the corresponding packet acceptance rate PRR by obtaining the data sent by the nodes;

Specifically, in the embodiment of the present invention, several partial nodes in the network are selected to form the first node set. In each round, all nodes in a node set send data packets at the same time, and other nodes in the network measure the SINR value and the corresponding data packet acceptance rate PRR by monitoring these datagrams.

Further, in this scheme, the node set is initialized as an empty set, and then a node is selected to be added to the node set. When only one node in the network sends data packets, there is no interference because there is only the sending node Nodes, other nodes cannot measure the SINR value, so all nodes can measure the number of SINR intervals where (SINR, PRR) points fall within a certain SINR interval M1=0.

Step 3, select and update according to the number of SINR intervals in the SINR interval measured by the node;

Specifically, in the embodiment of the present invention, all nodes other than the node set in the network will be traversed, and if a certain node is added to the node set, all nodes can measure (SINR, PRR) The number M2 of SINR intervals where points fall within a certain SINR interval.

Further, the node with the largest M2 value will be selected. If there are multiple such nodes, choose one. When its M2 value is greater than the M1 value, add this node to the node set to obtain a new node point set, and update the value of M1 at the same time, that is, M1=M2.

Step 4: Carry out loop detection according to the judgment rules until the selection of the node set is completed.

Specifically, in the embodiment of the present invention, the above step three will be repeated until the maximum M2 value is less than or equal to the M1 value, indicating that adding any node to the current node set cannot satisfy the node set When the number of SINR intervals increases, the selection of nodes in the node set ends, that is, a node set is selected.

Further, if all nodes in the network can measure at least one (SINR, PRR) point in each SINR interval, the selection of the node set ends, otherwise, repeat steps 3 and 4 to select the next node set.

In addition, a specific embodiment of the present invention is as follows:

First of all, the method of active measurement is explained in conjunction with Figure 3. First of all, the system needs to know some external information, including: the location information and transmission rate of all nodes in the wireless sensor network, and determine the equal parts of the conversion interval according to the accuracy of the measured PRR-SINR model. Then, according to these information, calculate the set of nodes that send data packets at the same time. When the nodes in the network need to measure the PRR-SINR model, the data transmission in the network is suspended, and a round of data packets are sent in turn according to the calculated node set, and all nodes are measured according to the received data packets (SINR, PRR ) points to establish the PRR-SINR model. Otherwise, the network performs routine data transfers.

Accompanying drawing 4 is a flow chart of the method of a specific embodiment of the present invention, and the accompanying drawing describes in detail the algorithm of the calculation node set designed by the present invention, including the following steps:

(1) System initialization, all nodes in the network have not measured any (SINR, PRR) points, that is, the number of SINR intervals that can be satisfied M1=0, the first node set S selected is calculated below;

(2) The node set S is initialized as an empty set, and then a node is selected to be added to S. When only one node in the network sends data packets, since there are only sending nodes and no interfering nodes, other nodes cannot The SINR value is measured, so all nodes can measure the number of SINR intervals where (SINR, PRR) points fall within a certain SINR interval M1=0;

(3) Traverse all nodes other than the node set S in the network, and calculate that if a certain node k is added to this node set, all nodes can measure (SINR, PRR) points fall in a certain SINR interval The number M2(k) of the SINR intervals within;

(4) In addition, the maximum value of M2(k) is M2. When its M2>M1 value, select a node whose M2(k) value is equal to M2 and add it to the node set to obtain a new node set S, and update it at the same time The value of M1, that is, M1=M2;

(5) Repeat steps (3) and (4) until the value of M2 is less than or equal to the value of M1, indicating that adding any node to the current node set cannot increase the number of SINR intervals that the node set satisfies , the selection of nodes in the node set ends, that is, a node set is selected;

(6) If the measurement requirements of the PRR-SINR model are met, the algorithm ends, otherwise, repeat steps (2) (3) (4) (5) to select the next node set.

The measurement requirement of the PRR-SINR model is that each node can measure at least one (SINR, PRR) point in each SINR interval after the conversion interval is equally divided.

In addition, the embodiment of the present invention also provides a device for measuring interference models in a wireless sensor network. As shown in FIG. 5 , it is a schematic diagram of an interference model measurement device in a wireless sensor network provided by an embodiment of the present invention.

An interference model measurement device in a wireless sensor network, comprising an initialization unit 11 , a calculation unit 22 , a selection unit 33 and a cycle detection unit 44 .

The initialization unit 11 is used for system initialization of the wireless sensor network;

Specifically, in the embodiment of the present invention, this solution provides a centralized measurement method that can ensure accuracy and reduce network overhead. This method is applicable to any static wireless sensor network. In this solution, it is assumed that Know the location information and transmit power of all nodes in the network

Among them, in this scheme, the system initialization means that all nodes in the network have not measured any (SINR, PRR) points, and are ready to calculate and select the first node set. PRR (Packet Reception Ratio) is the packet reception rate, and SINR (Signal to Interference plus Noise Ratio) is the signal to interference plus noise ratio.

The calculation unit 22 is used to select some nodes in the wireless sensor network to form the first node set, and calculate the SINR value and the corresponding data packet acceptance rate PRR by obtaining the data sent by the nodes;

Specifically, in the embodiment of the present invention, several partial nodes in the network are selected to form the first node set. In each round, all nodes in a node set send data packets at the same time, and other nodes in the network measure the SINR value and the corresponding data packet acceptance rate PRR by monitoring these datagrams.

Further, in this scheme, the node set is initialized as an empty set, and then a node is selected to be added to the node set. When only one node in the network sends data packets, there is no interference because only the sending node Nodes, other nodes cannot measure the SINR value, so all nodes can measure the number of SINR intervals where (SINR, PRR) points fall within a certain SINR interval M1=0.

The selection unit 33 is used to select and update according to the number of SINR intervals in the SINR interval measured by the node;

Specifically, in the embodiment of the present invention, all nodes other than the node set in the network will be traversed, and if a certain node is added to the node set, all nodes can measure (SINR, PRR) The number M2 of SINR intervals where points fall within a certain SINR interval.

Further, the node with the largest M2 value will be selected. If there are multiple such nodes, choose one. When its M2 value is greater than the M1 value, add this node to the node set to obtain a new node point set, and update the value of M1 at the same time, that is, M1=M2.

The cycle detection unit 44 is configured to perform cycle detection according to the judgment rule until the selection of the node set is completed.

Specifically, in the embodiment of the present invention, the above step three will be repeated until the maximum M2 value is less than or equal to the M1 value, indicating that adding any node to the current node set cannot satisfy the node set When the number of SINR intervals increases, the selection of nodes in the node set ends, that is, a node set is selected.

Further, if all nodes in the network can measure at least one (SINR, PRR) point in each SINR interval, the selection of the node set ends, otherwise, repeat steps 3 and 4 to select the next node set.

The time complexity of the algorithm for calculating and selecting which node sets to send data packets in the embodiment of the present invention is polynomial time, which shows that this measurement method is suitable for wireless sensor networks with large scale and large number of nodes. The present invention designs a measurement method of active measurement, which can be implemented at any time, so that the PRR-SINR model can be measured when needed. By rationally arranging the node sets that send data packets at the same time, the invention can establish an interference model for each node in the network quickly and with low consumption on the premise of ensuring that the measured PRR-SINR model has a certain accuracy. The present invention is applicable to any static wireless sensor network, and the experimental results of simulation experiments prove the reliability and superiority of the present invention.

Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and the program can be executed when executed , including one or a combination of the steps of the method embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, each unit may exist separately physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. If the integrated modules are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer-readable storage medium.

In summary, this paper provides a method and device for measuring interference models in wireless sensor networks. By initializing the system of the wireless sensor network, and then selecting some nodes in the wireless sensor network to form the first node set, Calculate the SINR value and the corresponding data packet acceptance rate PRR by obtaining the data sent by the node, then select and update the number of SINR intervals in the SINR interval measured by the node, and finally perform loop detection according to the judgment rule until the completion of the SINR interval The choice of node set, this scheme is suitable for any static wireless sensor network, which can not only guarantee the accuracy but also reduce the network overhead.

The method and device for measuring interference models in a wireless sensor network provided by the present invention have been described in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for To help understand the solution of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as Limitations on the Invention.

Claims (3)

1. an interference model measuring method in a wireless sensor network, it is characterized in that, the method comprises: Step 1, system initialization of the wireless sensor network; Step 2. Select some nodes in the wireless sensor network to form the first node set, and calculate the SINR value and the corresponding packet acceptance rate PRR by obtaining the data sent by the nodes; choose a node to join this node set , when only one node in the network sends a data packet, since there is only the sending node and no interfering node, other nodes cannot measure the SINR value, so all nodes can measure the (SINR, PRR) point falls in a certain The number of SINR intervals in the SINR interval M1=0; Step 3: Select and update the number of SINR intervals in the SINR interval measured by the node; traverse all nodes other than the node set in the network, and calculate if a certain node is added to the node set, All nodes can measure (SINR, PRR) the number M2 of the SINR intervals that fall within a certain SINR interval; the node with the largest M2 value will be selected, and if there are multiple such nodes, choose one , when its M2 value is greater than the M1 value, add this node to the node set to obtain a new node set, and update the value of M1 at the same time, that is, M1=M2; Step 4. Carry out loop detection according to the judgment rules until the selection of the node set is completed; including repeating step 3 until the maximum M2 value is less than or equal to the M1 value, indicating that any node is added to the current node set. If the number of SINR intervals satisfied by the node set cannot be increased, the selection of nodes in the node set ends, that is, a node set is selected. 2. method according to claim 1, it is characterized in that, in described step 1, system initialization promptly all nodes in the network all do not measure any (SINR, PRR) point, and PRR is the packet receiving rate, and SINR is Signal-to-interference-plus-noise ratio. 3. method according to claim 1, is characterized in that, in described step 4, further comprises if all nodes in the network can measure at least one (SINR, PRR) point in each SINR interval, then to The selection of the node set ends, otherwise, repeat steps 3 and 4 to select the next node set.