CN102739817B - A RFID routing node address allocation method - Google Patents

Abstract

The invention discloses a method for assigning an RFID routing node address. The method includes the process of establishing an adjacency table, the process of determining the parent-child relationship between nodes and the process of assigning node address values. The size of the node address block is dynamically allocated according to the different node weights. This method fully considers the non-uniformity of node distribution, which can improve the success rate of node address allocation and reduce the average communication overhead.

Description

A RFID routing node address allocation method

technical field

The invention relates to a node address distribution technology in a wireless communication network, and relates to an RFID routing node address distribution method.

Background technique

In a wireless communication network, a node must have its own network address to communicate. The RFID wireless sensor network uses the default distributed address allocation mechanism to allocate addresses for nodes. Since the non-uniformity of the network topology is not considered, it is easy to cause a waste of network node address resources.

In the real wireless RFID network environment, due to the random distribution of nodes and the existence of random motion, the nodes will be unevenly distributed, and some nodes have rich address space and some nodes have insufficient address space. To solve this problem, the existing method is as follows:

The SLAR (Single Level Address Reorganization) algorithm is proposed for the problem of insufficient address space when the routing node is used as the parent node: by increasing the depth parameter d (d=d+1) to reduce the address offset C _skip (d) so that the parent node A solution for node address space growth.

Address borrowing scheme: The existing address borrowing algorithms are mainly divided into three types: 1) When the address space of the parent node is insufficient, notify the network coordinator to borrow the address and allocate the borrowed free address; 2) The parent node with insufficient address space is based on the remaining The priority of address nodes sends out address borrowing requests and allocates free addresses.

The disadvantages of the above methods are as follows:

The method of exchanging depth for width in the SLAR algorithm can improve the insufficient address space of routing nodes, but it will inevitably reduce the depth of the entire network, and the address reconfiguration operation will increase networking overhead and time-consuming, so it is suitable for networks with large depths.

The address borrowing algorithm needs to record the network address of the node providing the idle address and the node using it, so as to route data packets correctly. The existing borrowing address algorithm can increase the node network access rate, but it does not control the range of borrowing addresses, which destroys the "location-address" relationship of the sensor network, increases the redundant path of the tree network, and will cause problems during the operation of the cluster tree routing algorithm. Adding additional routing overhead and node storage overhead does not match the characteristics of low overhead and low cost of the sensor network.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a method for assigning an RFID routing node address, which can well improve the success rate of node address assignment and reduce the average communication overhead. The specific technical scheme is as follows.

A method for assigning RFID routing node addresses, which is characterized in that node weights are introduced to reflect the non-uniformity of node distribution, and the size of node address blocks is dynamically allocated according to the difference in node weights. Relationship determination process and node address value assignment process.

In the above-mentioned a kind of RFID routing node address assignment method, described adjacency table establishment process is started by coordinator, specifically includes:

(1) The coordinator sends a broadcast command Broad to initiate the process of establishing the adjacency table, and the initial value of the tree depth Depth of the neighbor device in the broadcast command Broad is 0;

(2) Neighboring nodes will perform the following processing after receiving the broadcast command Broad:

① If the broadcast command Broad is received for the first time, a corresponding record will be established in its neighbor table, and the Depth value in the neighbor table record will be the Depth value in the received broadcast command + 1; otherwise, the Whether the Depth value + 1 is smaller than the corresponding Depth value in the existing neighbor table record, if it is smaller, replace it, otherwise do not do any processing;

②According to the address of the broadcast command received, send a reply command Ack to the target; the target node creates a sub-node entry record table according to the received ACK command, and its sub-sign position is false;

③ If the adjacent node is a routing node, it will continue to forward the broadcast; if it is a terminal node, it will not forward the broadcast.

In the above-mentioned a kind of RFID routing node address allocation method, the process of determining the parent-child relationship between the nodes includes:

(1) The node selects the node with the smallest Depth value in the neighbor table entry as its parent node, and sends a child node application command Son-Request to the parent node; the application command Son-Request is used for the address to be issued by the Ex_address1 node to the Ex_address2 node As the request of its child nodes, it also reports its own device type De_type and the number of child nodes under its jurisdiction Unode_number;

(2) The parent node receives the child node application command Son-Request, queries in the child node entry record table, sets its child flag position as true, and modifies the number of subordinate nodes to a new value;

(3) If the value of a child node under the jurisdiction of a node changes, it will re-send the child node application command Son-Request to its parent node;

(4) After 2*L _m adjacent node information transmission time, the parent-child relationship of adjacent nodes is basically determined; the coordinator and routing nodes will calculate the weight of each routing child node to which they belong.

In above-mentioned a kind of RFID routing node address distribution method, described node address value distribution process comprises:

Define C _m and R _m as the maximum number of nodes and the number of routing nodes that can be allocated by the full-function equipment of the network respectively, and L _m is the maximum depth of the network, then the address block C _skip that can be allocated to routing nodes with a network depth of d (d) is:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; skip</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ \frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; *</span>{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}^{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}& <span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&NotEqual;</span>\mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right.<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><span\; class="notranslate">\; ;</span>$

The bit network address (Net_address) of the coordinator is set to 0, and the network address (Net_address) of the child nodes in the area to which it belongs is allocated according to the following strategy,

If the child node type is a routing node, assign an address to the child node according to formula (2),

If the sub-node type is a terminal node, the address assigned to the sub-node is:

Among them: A _son-z represents the address of the terminal child node, A _son-1 represents the address of the first routing child node, A _son-i represents the address of the i-th routing child node, w _parent represents the weight of the parent node, w _i-1 represents the weight of the i-1th child node, n represents the nth routing child node, and the value range is 1≤n≤C _m -R _m .

In the above method for assigning an address to an RFID routing node, the ACK command is used for the node whose address is Ex_address1 to send a response message to the node whose address is Ex_address2.

Compared with the prior art, the present invention has the following advantages and technical effects:

The RFID routing node address allocation method of the present invention introduces node weights to reflect the non-uniformity of node distribution, and the size of node address blocks is dynamically allocated according to the different node weights, fully considering the non-uniformity of node distribution, and can be well Improve the success rate of node address allocation and reduce the average communication overhead.

Description of drawings

Fig. 1 is a schematic diagram of the process of establishing an adjacency table in the RFID routing node address allocation of the present invention.

Detailed ways

The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings, but the implementation and protection scope of the present invention are not limited thereto.

The method for assigning RFID routing addresses in this example is divided into three stages: establishment of adjacency list, determination of parent-child relationship between nodes, and assignment of node address values.

1. The process of establishing an adjacency list, as shown in Figure 1:

Firstly, there is a process of inquiring between nodes to understand the status of their neighbor nodes, and the time is about 2*L _m adjacent node information transmission time. The specific process is as follows:

(1) The coordinator sends a broadcast command Broad to initiate the establishment process of the adjacency list; the initial value of its Depth is 0.

(2) Neighboring nodes will perform the following processing after receiving the broadcast command:

① If the broadcast command of the address node is received for the first time, a corresponding neighbor table entry will be established for it, and its Depth value is the Depth value in the received broadcast command + 1; otherwise, it will be judged whether the Depth value + 1 is less than Already have the corresponding Depth value in the entry? If it is less than, it will be modified, otherwise it will not be processed;

②According to the received broadcast address, send a reply command Ack to the target; the destination node creates possible sub-node entry records according to the received ACK command;

③ If it is a routing node, it will continue to forward the broadcast; if it is a terminal node, it will not forward the broadcast.

2. Determine the parent-child relationship, including the following steps:

(1) The node selects the node with the smallest Depth value in the neighbor table entry as its parent node, and sends the child node application command Son-Request to it;

(2) The node receives the child node application command, inquires in the possible child node entry record table, finds the position of its child flag as true, and modifies the number of subordinate nodes to a new value;

(3) If the value of the child node under the node changes, re-send the child node application command to the parent node.

(4) After about 2*L _m adjacent node information transmission time, the parent-child relationship of adjacent nodes is basically determined. The coordinator and routing nodes will calculate the weight of each routing sub-node they belong to.

3. The distribution process of the node address value is as follows:

Define C _m and R _m as the maximum number of nodes and the number of routing nodes that can be allocated by the full-function equipment of the network respectively, and L _m is the maximum depth of the network, then the address block C _skip that can be allocated to routing nodes with a network depth of d (d) is:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; skip</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>& <span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ \frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; *</span>{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}^{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}& <span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&NotEqual;</span>\mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right.<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><span\; class="notranslate">\; ;</span>$

The 16-bit network address (Net_address) of the coordinator is set to 0, and the network address (Net_address) of the child nodes in the area to which it belongs is allocated according to the following strategy.

If the type of the child node is a routing node, assign an address to the child node according to formula (2).

If the child node type is a terminal node, assign an address to the child node according to formula (3):

Among them: A _son-z represents the address of the terminal child node (A _son-1 represents the address of the first routing child node, A _son-i represents the address of the i-th routing child node), w _parent represents the weight of the parent node , w _i-1 represents the weight of the i-1th child node, 1≤n≤C _m -R _m .

The above node address allocation method introduces node weights to reflect the non-uniformity of node distribution. The size of the node address block is dynamically allocated according to the different node weights, which fully considers the non-uniformity of node distribution, so it can improve the node address well. Allocation success rate, lower average communication overhead.

The relevant definitions and commands involved in this example are as follows.

1 related definitions

1.1 Neighbor table

The neighbor table (BTR table) is used to store the information of each device within the transmission range, and its format is shown in Table 1.

Table 1 Neighbor table directory format

1.2 Sub-node entry record table

The sub-node table (STR table) saves the information of the sub-node devices of the node, and its format is shown in Table 2.

Table 2 Child node table directory format

1.3 Related commands

The definition related command format is as follows:

(1) Broadcast command Broad (including Ex_address, De_type, Depth): used for the node to broadcast its own 64-bit device address, type and depth to the surrounding.

(2) Reply command Ack (including Ex_address1, Ex_address2): used for sending a response message from the node whose address is Ex_address1 to the node whose address is Ex_address2.

(3) Sub-node application command Son-Request (including Ex_address1, Ex_address2, De_type, Unode_number): used for the node whose address is Ex_address1 to send a request to the node whose address is Ex_address2 as its sub-node, and report its own device type, subordinate number of child nodes.

Claims (2)

1. a kind of RFID routing node address distribution method, comprise adjacency table establishment process, parent-child relationship determination process and node address value distribution process between nodes, it is characterized in that introducing node weights to reflect the inhomogeneity of node distribution, the node address block The size is dynamically allocated according to different node weights, and the node address value allocation process includes: Define C _m and R _m as the maximum number of nodes and routing nodes that can be allocated by the full-featured equipment of the network respectively, and L _m is the maximum depth of the network, then the address block C _skip that can be allocated to routing nodes with a network depth of d (d) is: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; skip</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}\\ \frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; *</span>{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}^{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&NotEqual;</span>\mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right.<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><span\; class="notranslate">\; ;</span>$ The network address of the coordinator is set to 0, and the sub-node network address allocation in the area to which it belongs is carried out according to the following strategy. If the sub-node type is a routing node, the sub-node is assigned an address according to formula (2), If the sub-node type is a terminal node, the address assigned to the sub-node is: Among them: A _son-z represents the address of the terminal child node, A _son-1 represents the address of the first routing child node, A _son-i represents the address of the i-th routing child node, w _parent represents the weight of the parent node, w _i-1 represents the weight of the i-1th child node, n represents the nth routing child node, and the value range is 1≤n≤C _m -R _m ; The process of establishing the adjacency list is initiated by the coordinator, and specifically includes: (1) The coordinator sends a broadcast command Broad to initiate the process of establishing the adjacency table, and the initial value of the tree depth Depth of the neighbor device in the broadcast command Broad is 0; (2) Neighboring nodes will perform the following processing after receiving the broadcast command Broad: ① If the broadcast command Broad is received for the first time, a corresponding record will be established in its neighbor table, and the Depth value in the neighbor table record will be the Depth value in the received broadcast command + 1; otherwise, the Whether the Depth value + 1 is smaller than the corresponding Depth value in the existing neighbor table record, if it is smaller, replace it, otherwise do not do any processing; ② Send a reply command Ack to the target according to the address of the broadcast command received; the target node creates a sub-node entry record table according to the received ACK command, and the flag position of its sub-node is false; ③ If the adjacent node is a routing node, it will continue to forward the broadcast; if it is a terminal node, it will not forward the broadcast; The process of determining the parent-child relationship between nodes includes: (1) The node selects the node with the smallest Depth value in the neighbor table entry as its parent node, and sends the child node application command Son-Request to the parent node; the application command Son-Request is used for the address of the Ex_address1 node to send the address to the Ex_address2 node As the request of its child nodes, it also reports its own device type De_type and the number of child nodes under its jurisdiction Unode_number; (2) The parent node receives the sub-node application command Son-Request, queries in the sub-node entry record table, sets the flag position of the sub-node as true, and modifies the number of subordinate nodes to a new value; (3) If the value of a child node under the jurisdiction of a node changes, it will re-send the child node application command Son-Request to its parent node; (4) After 2*L _m adjacent node information transmission time, the parent-child relationship of adjacent nodes is determined; the coordinator and routing nodes will calculate the weight of each routing child node to which they belong. 2. A method for assigning an RFID routing node address according to claim 1, wherein the ACK command is used for the node whose address is Ex_address1 to send a response message to the node whose address is Ex_address2.