CN102014456A - Method and system for searching node - Google Patents

Abstract

The invention discloses a method and a system for searching nodes, belonging to the communication field of the Internet of Things. The method includes: the client sends a search request, the search request carries the search range and the location specified by the user; the proxy node receives the search request, broadcasts a query request to its neighbor nodes, and the query request carries the proxy node's code, message time, the location and the search range; the neighbor node receives the query request, and judges whether the query request has been received; if not, the neighbor node according to the location and the search range, Judging whether the self is located within the search range, if so, sending a response message to the proxy node, the response message carrying the message time, the code and the location of the neighbor node, and broadcasting the query request to its neighbor node; The proxy node receives the response message, and sends the response message to the client. The present invention can accurately search for nodes.

Description

A method and system for searching nodes

technical field

The invention relates to the communication field of the Internet of Things, in particular to a method and system for searching nodes.

Background technique

The Internet of Things is defined as a standards-based and interoperable communication protocol, which is a global network infrastructure with self-configuring capabilities and dynamic functions. Each node in the Internet of Things has attributes such as coding, and each node realizes seamless integration with the network through an intelligent interface. Many applications of the Internet of Things involve the search of nodes. Currently, the search technologies for nodes in the Internet of Things include:

The first, entity search technology based on RFID (Radio Frequency Identification, radio frequency identification) technology, specifically: the electronic label system provides each node with a unique and identifiable electronic label, and sets it in the transit stations deployed in various places The reader used to read electronic tags, each transit point within its own communication range, uses RFID technology to read electronic tags to search for nodes.

The second is the search method based on the earth's surface, specifically: setting up measurement equipment on the earth's surface, such as a base station, analyzing and estimating the node and its position by detecting the characteristic parameters of the signal propagated between the node and the base station, so as to realize the search node.

The third is the satellite-based search method, specifically: set up receiving equipment on the node in advance, use the receiving equipment to receive satellite signals, obtain the position of the node through the technology of ranging and rendezvous to determine the point according to the received satellite signal, and then Send the location of the node to the user, thus realizing the search for the node. Wherein, the receiving device may be a GPS (Global Positioning System, Global Positioning System).

In the process of realizing the present invention, the inventor finds that there are at least the following problems in the prior art:

In the above-mentioned first technology, due to the limitation of the number and density of readers, it is impossible to accurately search for nodes. In addition, readers belong to specific organizations, and users outside the organization cannot use readers to search node, so this technique is not universal.

In the above-mentioned second technique, the measurement equipment cannot accurately search for nodes in areas with poor coverage conditions. In addition, each measurement equipment is set up by the network operator, and usually the network operator does not disclose the relationship between the node and the base station. Propagate the signal, therefore, outsiders cannot use this technology to search for nodes, and therefore, it is not universal.

In the above-mentioned third technique, in places such as indoors, forests, high-rise buildings, mountains and bridges, satellite signals are blocked by existing objects, so that the receiving equipment cannot accurately obtain the position of the node, thus reducing the accuracy of the search node.

Contents of the invention

In order to improve the accuracy of searching nodes and provide a general method for searching nodes, the present invention provides a method and system for searching nodes. Described technical scheme is as follows:

A method of searching for a node, the method comprising:

The client sends a search request, and the search request carries the search range and the location specified by the user;

The proxy node receives the search request, broadcasts a query request to its neighbor nodes, and the query request carries the code of the proxy node, message time, the location and the search range;

The neighbor node receives the query request, and judges whether the query request has been received;

If not, the neighbor node judges whether it is located within the search range according to the position and the search range, and if so, sends a response message to the proxy node, the response message carrying message time, the neighbor node The code and position of the node, and broadcast the query request to its neighbor nodes;

The proxy node receives the response message, and sends the response message to the client.

The proxy node judges whether the query request has been received, including:

The neighbor node extracts the code of the proxy node and the message time from the query request, and judges whether the code of the proxy node and the message time have been stored, and if so, judges that the query request has been received , if not, it is judged that the query request is not received.

The neighbor node judges whether it is within the search range according to the position and the search range, including:

The neighbor node calculates the distance between itself and the location according to its own location and the location, and judges whether the distance is greater than the search range, and if not, judges that it is located in the search range.

If there are multiple response messages carrying the code of the same node, correspondingly,

The proxy node receives the response message, and sends the response message to the client, including:

The proxy node selects the response message whose message time is closest to the current time from the plurality of response messages, discards other response messages, and sends the response messages not discarded to the client.

The method also includes:

After the proxy node and/or the neighbor node broadcast the query request to its neighbor nodes, upload the query request to the B server;

The B server receives the query request, and according to the code of the node that uploaded the query request, searches for the corresponding The time of the message, the encoding of the reading node and the location of the uploading node;

The B server sends a response message to the proxy node, and the response message carries the message time, the code of the reading node and the location of the uploading node.

After the client sends the search request, it also includes:

The node receiving the search request judges whether its coverage includes the location carried in the search request;

If so, the node sets itself as a candidate agent node, and calculates its own weight, and sends a beacon message to its neighbor nodes, and the beacon message carries the weight;

If the candidate proxy node receives a beacon message carrying its own weight sent by a neighbor node, compare whether its own weight is greater than the weight of the neighbor node, if yes, recommend itself as a proxy node, if not, recommend the weight The largest node is the proxy node;

If the candidate proxy node does not receive the beacon message sent by the neighbor node, it recommends itself as a proxy node.

The query request also carries an anchor node sequence, correspondingly,

Before broadcasting the query request, the proxy node and/or the neighbor node adds its own identity to the anchor point sequence of the query request;

Correspondingly, the neighbor node receives the query request, and judges whether the query request has been received, specifically including:

The neighbor node receives the query request, and judges whether its own identity exists in the anchor point sequence of the query request. If it exists, it judges that the query request has been received; query request.

A system for searching nodes, said system comprising a client, an agent node and a neighbor node;

The client is configured to send a search request, the search request carries a search range and a location specified by the user;

The proxy node is configured to receive the search request, broadcast a query request to its neighbor nodes, and the query request carries the code of the proxy node, message time, the location and the search range; A response message of the node, sending the response message to the client;

The neighbor node is configured to receive the query request, and judge whether the query request has been received; if not, the neighbor node judges whether it is located in the search range according to the location and the search range, if Yes, sending a response message to the proxy node, the response message carrying the message time, the code and location of the neighbor node, and broadcasting the query request to its neighbor nodes.

The neighbor nodes include:

A judging module, configured to receive the query request, extract the code of the proxy node and the message time from the query request, and judge whether the code of the proxy node and the message time have been stored;

The response module is used to determine whether the query request is not received if the judgment result of the judging module is no, judge whether it is within the search range according to the location and the search range, and if so, send A response message is sent to the proxy node, the response message carries the message time, the code and the location of the neighbor node, and the query request is broadcast to its neighbor nodes.

The response module includes:

A judging unit, configured to calculate the distance between itself and the location according to its own location and the location, and judge whether the distance is greater than the search range, and if not, judge that the neighbor node is located in the search range within the scope;

A sending unit, configured to send a response message to the proxy node, the response message carrying message time, code and location of the neighbor node, and broadcast the query request to its neighbor nodes.

If there are multiple response messages carrying the code of the same node, correspondingly,

The proxy nodes include:

A broadcast module, configured to receive the search request, broadcast a query request to its neighbor nodes, the query request carries the code of the proxy node, message time, the location and the search range;

A sending module, configured to select a response message whose message time is closest to the current time from the plurality of response messages, discard other response messages, and send the non-discarded response messages to the client.

The system also includes a B server;

Correspondingly, after the proxy node and/or the neighbor node broadcast the query request to its neighbor nodes, it is also used to upload the query request to the B server;

The B server is configured to receive the query request, and according to the code of the node uploading the query request, from the stored corresponding relationship between the code of the upload node, the code of the read node, the time of the message, and the position of the upload node , find the corresponding message time, the code of the reading node, and the position of the uploading node; send a response message to the proxy node, and the response message carries the message time, the code of the reading node and the location of the uploading node Location.

The proxy node is recommended and obtained in the following manner;

The node receiving the search request judges whether its coverage includes the location carried in the search request;

If so, the node sets itself as a candidate agent node, and calculates its own weight, and sends a beacon message to its neighbor nodes, and the beacon message carries the weight;

If the candidate proxy node receives a beacon message carrying its own weight sent by a neighbor node, compare whether its own weight is greater than the weight of the neighbor node, if yes, recommend itself as a proxy node, if not, recommend the weight The largest node is the proxy node;

If the candidate proxy node does not receive the beacon message sent by the neighbor node, it recommends itself as a proxy node.

The query request also carries an anchor node sequence,

Correspondingly, the proxy node and/or the neighbor node is further configured to add its own identity to the anchor point sequence of the query request before broadcasting the query request;

Correspondingly,

The neighbor node receives the query request, judges whether its own identity exists in the anchor point sequence of the query request, if not, judges that the query request is not received, and according to the location and the search range, Judging whether it is within the search range, if so, sending a response message to the proxy node, the response message carrying the message time, the code and location of the neighbor node, and broadcasting the query request to its neighbor nodes.

After the proxy node receives the search request, it broadcasts the query request to its neighbor nodes. After the neighbor node receives the query request, it judges whether it has received the query request. If not, it judges whether it is within the search range carried by the query request. If it is, then Send a response message carrying its own location, code, and message time to the proxy node, and the proxy node sends the response message to the client. Among them, the proxy node is selected near the specified position, and the proxy node is used to search for nodes within the search range, and the proxy node can be in the vicinity of the specified position for a long time, thereby improving the accuracy of the search node; the coverage includes the specified position All nodes may become proxy nodes without any restrictions, so they are universal.

Description of drawings

FIG. 1 is a flowchart of a method for searching nodes provided in Embodiment 1 of the present invention;

FIG. 2 is a flowchart of a method for searching nodes provided in Embodiment 2 of the present invention;

Fig. 3 is a system schematic diagram of a search node provided by Embodiment 3 of the present invention.

Detailed ways

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

Example 1

As shown in Figure 1, the embodiment of the present invention provides a method for searching nodes, including:

Step 101: the client sends a search request, wherein the search request carries the search range and the location specified by the user;

Step 102: the proxy node receives the search request, and broadcasts the query request to its neighbor nodes, wherein the query request carries the code of the proxy node, message time, location and search range carried by the search request;

Step 103: The neighbor node receives the query request, and judges whether the query request has been received;

Step 104: If not, the neighbor node judges whether it is located in the search range according to the location and search range carried in the query request, and if yes, sends a response message to the proxy node, wherein the response message carries the message time, the code of the neighbor node and location, broadcast the query request to its neighbor nodes;

Step 105: the proxy node receives the response message, and sends the response message to the client.

In the embodiment of the present invention, after the proxy node receives the search request, it broadcasts the query request to its neighbor nodes. After the neighbor node receives the query request, it judges whether it has received the query request. If not, it judges whether it is located in the search range carried by the query request. If it is located, it will send a response message carrying its own location, code and message time to the proxy node, and the proxy node will send the response message to the client. Among them, the proxy node is selected near the specified position, and the proxy node is used to search for nodes within the search range, and the proxy node can be in the vicinity of the specified position for a long time, thereby improving the accuracy of the search node; the coverage includes the specified position All nodes may become proxy nodes without any restrictions, so they are universal.

Example 2

As shown in Figure 2, the embodiment of the present invention provides a method for searching nodes, including:

Step 201: The client broadcasts a search request to the Internet of Things, and the search request carries the location and search range specified by the user;

Wherein, the user specifies a specific location in the client in advance, and the location can be a coordinate or a specific longitude and latitude, and the user can also input a search range to the client, and the search range can be a search radius. Then, the client generates a search request carrying the location and search range specified by the user. In addition, a default search range is set in advance in the client. If the user does not input a search range to the client, the client generates a search request carrying the specified location and the default search range. For example, if the location specified by the user is coordinates (x0, y0) and the search radius is L0, then the client generates a search request carrying the coordinates (x0, y0) and the search radius L0.

Step 202: The node in the Internet of Things receives the search request, judges whether its own communication range covers the location carried by the search request, and if so, sets itself as a candidate proxy node;

For example, after each node in the Internet of Things receives a search request, it extracts the location from the search request as coordinates (x0, y0), and all nodes whose communication range covers coordinates (x0, y0) set themselves as candidate agents node.

Among them, after receiving the search request, other nodes in the Internet of Things will directly forward the search request if they judge that their own communication range cannot cover the location carried by the search request.

Step 203: Each candidate proxy node calculates its own weight, and sends a beacon message to its neighbor nodes, and the beacon message carries the node's own weight;

Wherein, each candidate proxy node calculates its own weight value Wi according to the following formula (1).

${\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}{{\mathrm{<span\; class="notranslate">\; w</span>}}_{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}{{\mathrm{<span\; class="notranslate">\; w</span>}}_{{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}{{\mathrm{<span\; class="notranslate">\; w</span>}}_{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&chi;</span>}}{{\mathrm{<span\; class="notranslate">\; w</span>}}_{{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; PRE</span>}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Where α+β+γ+χ+ε=1, i∈{2,...,K}, K≥2, K is the number of candidate proxy nodes that can communicate with each other. α, β, γ, χ, ε are the coefficients set in each candidate node by the technician in advance, and the technician can set the value of each coefficient according to the actual service demand, and usually α>χ>β>γ, if A candidate agent node becomes an agent node voluntarily, then PRE=1, otherwise, PRE=0.

in, $w_{d_i}=\frac{d_i}{\underset{j=1}{\overset{K}{\mathrm{\&Sigma;}}}{d}_j},K\&Greater\; Equal;2,$

Among them, d _i is the Euclidean distance between the candidate proxy node and the specified position, and the candidate proxy node calculates the Euclidean distance between the candidate proxy node and the specified position according to its own position and the specified position.

in, $w_{v_i}=\frac{v_i}{\underset{j=1}{\overset{K}{\mathrm{\&Sigma;}}}{v}_j},K\&Greater\; Equal;2,$

Among them, v _i is the motion velocity scalar of the candidate proxy node, and the candidate proxy node can measure its own motion velocity scalar.

in, $w_{a_i}=\frac{a_i}{\underset{j=1}{\overset{K}{\mathrm{\&Sigma;}}}{a}_j},K\&Greater\; Equal;2,$

Among them, a _i is the acceleration scalar of the candidate node, and the candidate proxy node can measure its own acceleration scalar.

是候选节点的通信半径的标准化后的权值。计算公式如下：

is the normalized weight of the communication radius of the candidate node. Calculated as follows:

其中r_i是候选节点的通讯半径。

where _ri is the communication radius of the candidate node.

Step 204: If the candidate proxy node receives the beacon message sent by its neighbor candidate proxy node, then extract the weight value of each neighbor candidate proxy node from the beacon message;

Wherein, if a non-candidate proxy node receives a beacon message sent by its neighbor candidate proxy node, it directly discards the received beacon message.

Step 205: The candidate proxy node compares its own weight with the weight of each neighbor candidate proxy node, if its own weight is greater than each neighbor candidate proxy node, then recommend itself as a proxy node, otherwise, it will be from Among the neighbor candidate proxy nodes, the candidate proxy node with the largest weight is recommended as the proxy node;

Step 206: If the candidate proxy node does not receive the beacon message, the candidate proxy node elects itself as a proxy node;

Among them, in this embodiment, when selecting the proxy node, various factors such as the distance between the candidate proxy node and the specified location, the node communication radius, the node speed, the node acceleration, and the voluntary nature are taken into consideration to ensure that the proxy node can It is located near the specified location for a long time, and will not leave the search range for a short time, thereby improving the accuracy of the search node.

Among them, in this embodiment, the user can input the code and search range of a node to the client, and the user generates a search request carrying the search range, and sends the search request to the corresponding node according to the code of the node input by the user, if If the node has the ability to receive and send messages, the node will recommend itself as a proxy node; if the node does not have the ability to receive and send messages, the user will re-input a specific location and search range to the client, and start from the step 201 starts to execute.

Wherein, for a proxy node, the following steps 207 to 211 are performed to search for nodes satisfying the search condition within the search range.

Step 207: The proxy node generates a query request, wherein the query request carries the code of the proxy node, the message time, the anchor sequence, the location and the search range carried by the search request, wherein the identifier of the proxy node is stored in the anchor sequence, and then Broadcast query requests to its neighbor nodes;

Specifically, the proxy node obtains the current time, uses the obtained current time as the message time, generates a query request, adds its own code, message time, search request carrying location and search range to the query request, and adds its own identity to The sequence of anchors for the search request.

Wherein, the identifier of the proxy node may be the current location or network address of the proxy node.

Further, if the proxy node is also connected to the B server of its affiliated organization, it will send a query request to the B server at the same time.

Correspondingly, server B receives the query request, extracts the code of the node that uploaded the query request, that is, the code of the proxy node, and the message time from the query request, and judges whether the query has been received according to the extracted code and message time of the uploaded node request, if yes, discard the query request, if not, store the code and message time of the upload node, and read the code, read time and In the corresponding relationship between the position of the uploading node, find the code of the corresponding reading node, the message time and the position of the uploading node, and send a response message to the proxy node, and the response message carries the code of the reading node, the message time and the location of the uploading node. Location.

Wherein, the B server judges whether the code and the message time of the extracted uploading node have been stored, if yes, then it is judged that the query request has been received, if not, the query request has not been received before.

Among them, each node in the network is deployed by a different organization, so each node belongs to a different organization, and each organization has its own B server.

Among them, when a node in the network reads the information of other nodes, if the node is still connected to the B server of its affiliated organization, the node will send its own code, the code of the read node, the message time and its own The position of the node is uploaded to the B server, and the B server stores the code of the node, the code of the read node, the message time and the position of the node in the code of the upload node, the code of the read node, the time of the message and the position of the upload node in the corresponding relationship. Among them, every other node in the network also performs the same operation as this node when reading other nodes.

Among them, if the proxy node is the proxy node directly designated by the user, the proxy node obtains the current time and its own position, uses the current time as the message time, and generates a query request, and the query request carries the code of the proxy node, message time, anchor The sequence of points, the obtained position, and the search scope carried by the search request.

Step 208: When the neighbor node receives the query request, extract the code and message time of the proxy node from the query request, and judge whether the query request has been received according to the extracted code and message time of the proxy node; if so, directly discard the query request , otherwise, go to step 209;

Wherein, each time the neighbor node receives a new query request, it stores the code and message time of the proxy node carried in the query request. Therefore, when the neighbor node extracts the code and message time of the proxy node from the query request, it judges whether it has stored the code and message time of the proxy node extracted. If not, it judges that the neighbor node has not received the query request. If If yes, it is determined that the neighbor node has received the query request.

In addition, the neighbor node can also extract the anchor point sequence from the query request, and judge whether its own identity exists in the extracted anchor point sequence. If it exists, it can be judged that the query request has been received; The query request.

Step 209: The neighbor node extracts the location and the search range from the query request, and judges whether it is within the search range according to its own location and the extracted location, if yes, execute step 210, if not, end the operation;

Specifically, the neighbor node extracts the location and search range from the query request, calculates the distance between itself and the extracted location according to the extracted location and its own location, and judges whether the distance is less than or equal to the search range, and if so, then indicates that the neighbor node is within the search range, and if not, indicates that the neighbor node is outside the search range.

Step 210: The neighbor node sends a response message to the proxy node, the response message carries its own code, its own location information and the current time, adds its own identity to the anchor sequence of the search request, and then broadcasts to its neighbor nodes Added search request;

Further, if the neighbor node is also connected to the B server of its affiliated organization, the neighbor node uploads the query request to the B server;

Correspondingly, server B receives the query request, extracts the code of the node that uploaded the query request from the query request, that is, the code of the neighbor node and the message time, and judges whether the code and message time of the extracted upload node have been received. Query request, if yes, discard the query request, if not, store the code and message time of the upload node, read the code of the node, message time and In the corresponding relationship of the position of the uploading node, search for the code of the corresponding reading node, message time and the position of the uploading node, and send a response message to the proxy node, and the response message carries the code of the reading node, message time and uploading node. The position of the node.

Wherein, each node in the network performs the same operation as the neighbor node after receiving the query request.

Step 211: When the proxy node receives the first response message, it starts to receive the response message within a preset time, packs the received response message, and sends it to the client.

Further, if there are multiple response messages carrying the code of the same node, the proxy node selects the response message whose message time is closest to the current time from the multiple response messages according to the message time carried by each response message, and discards other Answer message. Correspondingly, the proxy node packages the undiscarded reply message and sends it to the client.

Among them, other proxy nodes in the network perform the same operations as the proxy node.

Among them, in this embodiment, the user specifies a specific location and search range, and then selects a proxy node, and uses the proxy node to search for nodes near the specified location, thereby improving the accuracy of the search node.

Among them, there are nodes in the network that do not have the ability to receive and send messages. If such nodes receive query requests, they will not perform any operations, but this type of nodes can be read by other nodes nearby. If other nodes read For the information of the node, the code of the node and its own location information are uploaded to the B server. In this embodiment, each node uploads the query request to the B server, and the information such as the code of the node read by the node can be sent to the agent node from the B server. Ability node. In this way, the accuracy of searching for nodes is improved.

In the embodiment of the present invention, after the proxy node receives the search request, it broadcasts the query request to its neighbor nodes. After the neighbor node receives the query request, it judges whether it has received the query request. If not, it judges whether it is located in the search range carried by the query request. If it is located, it will send a response message carrying its own location, code and message time to the proxy node, and the proxy node will send the response message to the client. Among them, the proxy node is selected near the specified location, and the proxy node is used to search for nodes within the search range, and the selection of the proxy node takes into account various factors such as communication radius, node speed, node acceleration, uploading ability, and voluntariness, so as to ensure It ensures that the proxy node can be near the specified location for a long time, thereby improving the accuracy of the search node; any node whose coverage includes the specified location may become a proxy node, which is not limited by conditions, so it has versatility.

Example 3

As shown in Figure 3, the embodiment of the present invention provides a system for searching nodes, including a client 301, a proxy node 302 and a neighbor node 303;

The client 301 is configured to send a search request, wherein the search request carries a search range and a location specified by the user;

The proxy node 302 is used to receive the search request, and broadcast the query request to its neighbor node 303, wherein the query request carries the code of the proxy node 302, the message time, the location and the search range carried by the search request; The response message of the response message is sent to the client 301;

The neighbor node 303 is used to receive the query request, and judge whether the query request has been received; if not, judge whether it is located in the search range according to the location and search range carried by the query request, and if so, send a response message to the agent Node 302, wherein the response message carries the message time, the code and the location of the neighbor node 302, and broadcasts the query request to its neighbor nodes;

Wherein, the neighbor node 303 includes:

Judging module, used to receive the query request, extract the code and message time of the proxy node 302 from the query request, and judge whether the code and message time of the proxy node 302 have been stored;

Response module, if the result judged by the judging module is no, it is judged that the query request has not been received, and according to the location and search range carried by the query request, it is judged whether itself is within the search range, and if so, a response message is sent to The proxy node 302, wherein the response message carries the message time, the code and the location of the neighbor node 302, and broadcasts the query request to its neighbor nodes;

Among them, the response module includes:

The judging unit is used to calculate the distance between itself and the position carried by the query request according to its own position and the position carried by the query request, and judge whether the distance is greater than the search range, if not, then judge that the neighbor node 303 is located in within the search range;

The sending unit is used to send a response message to the proxy node 302, wherein the response message carries the message time, the code and the location of the neighbor node 303, and broadcasts the query request to its neighbor nodes;

Among them, if there are multiple response messages carrying the code of the same node, correspondingly,

Proxy node 302 includes:

A broadcast module, configured to receive the search request and broadcast the query request to its neighbor nodes, wherein the query request carries the code of the proxy node 301, message time, the location and search range carried by the search request;

A sending module, configured to select a response message whose message time is closest to the current time from multiple response messages, discard other response messages, and send the undiscarded response messages to the client;

Further, the system also includes a B server;

Correspondingly, after the proxy node 302 and/or the neighbor node 303 broadcasts the query request to its neighbor nodes, it is also used to upload the query request to the B server;

The B server is used to receive the query request, and according to the code of the node that uploaded the query request, find the corresponding message from the stored corresponding relationship between the code of the upload node, the code of the read node, the message time and the location of the upload node time, the code of the reading node and the position of the uploading node; sending a response message to the proxy node 302, wherein the response message carries the message time, the coding of the reading node and the position of the uploading node;

Wherein, the proxy node 302 is recommended and obtained in the following manner;

The node receiving the search request judges whether its coverage includes the location carried by the search request;

If so, the node sets itself as a candidate proxy node, calculates its own weight, and sends a beacon message to its neighbor nodes, where the beacon message carries the weight;

If the candidate proxy node receives the beacon message with its own weight sent by the neighbor node, compare whether its own weight is greater than the weight of the neighbor node, if yes, recommend itself as a proxy node, if not, recommend the one with the largest weight The node is an agent node;

If the candidate agent node does not receive the beacon message sent by the neighbor node, it will recommend itself as the agent node;

Further, the query request also carries an anchor node sequence,

Correspondingly, the proxy node 302 and/or the neighbor node 303 is further configured to add its own identity to the anchor point sequence of the query request before broadcasting the query request;

Correspondingly,

Wherein, the neighbor node 303 receives the query request, judges whether its own identity exists in the anchor point sequence of the query request, if not, then judges that the query request is not received, and judges according to the location and search range carried by the query request Whether itself is within the search range, if so, send a response message to the proxy node 302, wherein the response message carries the message time, code and location of the neighbor node 303, and broadcast the query request to its neighbor nodes.

In the embodiment of the present invention, after the proxy node receives the search request, it broadcasts the query request to its neighbor nodes. After the neighbor node receives the query request, it judges whether it has received the query request. If not, it judges whether it is located in the search range carried by the query request. If it is located, it will send a response message carrying its own location, code and message time to the proxy node, and the proxy node will send the response message to the client. Among them, the proxy node is selected near the specified position, and the proxy node is used to search for nodes within the search range, and the proxy node can be in the vicinity of the specified position for a long time, thereby improving the accuracy of the search node; the coverage includes the specified position All nodes may become proxy nodes without any restrictions, so they are universal.

All or part of the technical solutions provided by the above embodiments can be realized by software programming, and the software program is stored in a readable storage medium, such as a hard disk, an optical disk or a floppy disk in a computer.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (14)

1. A method for searching nodes, characterized in that the method comprises: The client sends a search request, and the search request carries the search range and the location specified by the user; The proxy node receives the search request, broadcasts a query request to its neighbor nodes, and the query request carries the code of the proxy node, message time, the location and the search range; The neighbor node receives the query request, and judges whether the query request has been received; If not, the neighbor node judges whether it is located within the search range according to the position and the search range, and if so, sends a response message to the proxy node, the response message carrying message time, the neighbor node The code and position of the node, and broadcast the query request to its neighbor nodes; The proxy node receives the response message, and sends the response message to the client. 2. The method according to claim 1, wherein the proxy node judging whether the query request has been received comprises: The neighbor node extracts the code of the proxy node and the message time from the query request, and judges whether the code of the proxy node and the message time have been stored, and if so, judges that the query request has been received , if not, it is judged that the query request is not received. 3. The method according to claim 1, wherein the neighbor node judges whether itself is located within the search range according to the position and the search range, comprising: The neighbor node calculates the distance between itself and the location according to its own location and the location, and judges whether the distance is greater than the search range, and if not, judges that it is located in the search range. 4. The method according to claim 1, wherein if there are multiple reply messages carrying the code of the same node, correspondingly, The proxy node receives the response message, and sends the response message to the client, including: The proxy node selects the response message whose message time is closest to the current time from the plurality of response messages, discards other response messages, and sends the response messages not discarded to the client. 5. The method of claim 1, further comprising: After the proxy node and/or the neighbor node broadcast the query request to its neighbor nodes, upload the query request to the B server; The B server receives the query request, and according to the code of the node that uploaded the query request, searches for the corresponding The time of the message, the encoding of the reading node and the location of the uploading node; The B server sends a response message to the proxy node, and the response message carries the message time, the code of the reading node and the location of the uploading node. 6. The method according to claim 1, further comprising: after the client sends the search request: The node receiving the search request judges whether its coverage includes the location carried in the search request; If so, the node sets itself as a candidate agent node, and calculates its own weight, and sends a beacon message to its neighbor nodes, and the beacon message carries the weight; If the candidate proxy node receives a beacon message carrying its own weight sent by a neighbor node, compare whether its own weight is greater than the weight of the neighbor node, if yes, recommend itself as a proxy node, if not, recommend the weight The largest node is the proxy node; If the candidate proxy node does not receive the beacon message sent by the neighbor node, it recommends itself as a proxy node. 7. The method according to claim 1, wherein the query request also carries an anchor node sequence, and accordingly, Before broadcasting the query request, the proxy node and/or the neighbor node adds its own identity to the anchor point sequence of the query request; Correspondingly, the neighbor node receives the query request, and judges whether the query request has been received, specifically including: The neighbor node receives the query request, and judges whether its own identity exists in the anchor point sequence of the query request. If it exists, it judges that the query request has been received; query request. 8. A system for searching nodes, characterized in that the system includes a client, a proxy node and a neighbor node; The client is configured to send a search request, the search request carries a search range and a location specified by the user; The proxy node is configured to receive the search request, broadcast a query request to its neighbor nodes, and the query request carries the code of the proxy node, message time, the location and the search range; A response message of the node, sending the response message to the client; The neighbor node is configured to receive the query request, and judge whether the query request has been received; if not, judge whether it is within the search range according to the location and the search range, and if so, send a response message to the proxy node, the response message carries the message time, the code and location of the neighbor node, and broadcasts the query request to its neighbor nodes. 9. The system according to claim 8, wherein the neighbor nodes comprise: A judging module, configured to receive the query request, extract the code of the proxy node and the message time from the query request, and judge whether the code of the proxy node and the message time have been stored; The response module is used to determine whether the query request is not received if the judgment result of the judging module is no, judge whether it is within the search range according to the location and the search range, and if so, send A response message is sent to the proxy node, the response message carries the message time, the code and the location of the neighbor node, and the query request is broadcast to its neighbor nodes. 10. The system according to claim 9, wherein the response module comprises: A judging unit, configured to calculate the distance between itself and the location according to its own location and the location, and judge whether the distance is greater than the search range, and if not, judge that the neighbor node is located in the search range within the scope; A sending unit, configured to send a response message to the proxy node, the response message carrying message time, code and location of the neighbor node, and broadcast the query request to its neighbor nodes. 11. The system according to claim 8, wherein if there are multiple response messages carrying the code of the same node, correspondingly, The proxy nodes include: A broadcast module, configured to receive the search request, broadcast a query request to its neighbor nodes, the query request carries the code of the proxy node, message time, the location and the search range; A sending module, configured to select a response message whose message time is closest to the current time from the plurality of response messages, discard other response messages, and send the non-discarded response messages to the client. 12. The system according to claim 8, further comprising a B server; Correspondingly, after the proxy node and/or the neighbor node broadcast the query request to its neighbor nodes, it is also used to upload the query request to the B server; The B server is configured to receive the query request, and according to the code of the node uploading the query request, from the stored corresponding relationship between the code of the upload node, the code of the read node, the time of the message, and the position of the upload node , find the corresponding message time, the code of the reading node, and the position of the uploading node; send a response message to the proxy node, and the response message carries the message time, the code of the reading node and the location of the uploading node Location. 13. The system according to claim 8, wherein the proxy node is obtained through recommendation in the following manner; The node receiving the search request judges whether its coverage includes the location carried by the search request; If so, the node sets itself as a candidate agent node, and calculates its own weight, and sends a beacon message to its neighbor nodes, and the beacon message carries the weight; If the candidate proxy node receives a beacon message carrying its own weight sent by a neighbor node, compare whether its own weight is greater than the weight of the neighbor node, if yes, recommend itself as a proxy node, if not, recommend the weight The largest node is the proxy node; If the candidate proxy node does not receive the beacon message sent by the neighbor node, it recommends itself as a proxy node. 14. The system according to claim 8, wherein the query request also carries an anchor node sequence, Correspondingly, the proxy node and/or the neighbor node is further configured to add its own identity to the anchor point sequence of the query request before broadcasting the query request; Correspondingly, The neighbor node receives the query request, judges whether its own identity exists in the anchor point sequence of the query request, if not, judges that the query request is not received, and according to the location and the search range, Judging whether it is within the search range, if so, sending a response message to the proxy node, the response message carrying the message time, the code and location of the neighbor node, and broadcasting the query request to its neighbor nodes.

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