CN101808390A - Construction method of aggregation tree for collecting self health state of wireless sensor network - Google Patents

Abstract

The invention relates to a construction method of an aggregation tree for collecting the self health state of a wireless sensor network, which is characterized in that the method comprises the following steps that: firstly, an sink node initiates tree construction information, and a tree construction information packet contains the geographical position information, the grid coordinates and the grid widths of the sink and a source node; nodes receiving the information determine the grid coordinates in which the nodes are arranged per se according to the content of the information and the self geographical position information and participate in the election of cluster heads according to the self position information and the residual energy; the nodes of all the cluster heads form the backbone of the network and then transmit the received data along a backbone network until reaching the sink after the nodes of the cluster heads carries out aggregation processing on the received data; and when the residual energy of the cluster heads is lowered to one half of the energy when being elected, local replacement is carried out. The invention has the advantages that the condition that the newly elected aggregation nodes come to an untimely end because of too low energy is avoided; the problem of overlarge energy consumption caused by the periodic reconstruction of a cluster structure is avoided; and the energy consumption of the network can be reduced, and the life time of the network is prolonged.

Description

Be used to collect the fusion tree constructing method of own health status of wireless sensor network

Technical field

The present invention relates to a kind of fusion tree constructing method, relate in particular to a kind of fusion tree constructing method that is used to collect own health status of wireless sensor network.

Background technology

In the wireless sensor network (WSN, Wireless Sensor Network), node resource is height-limited, and particularly energy height is limited is one of most important " bottleneck " of hindering wireless sensor network development and application thereof.The main thought of data fusion is to send in the way of sink node in data, merge node by the data from different nodes that receive are made up, and simply handle and eliminate redundant data, make data arrive the preceding minimise data transmission quantity of sink node and reduce energy consumption to prolong network lifetime.Making up a good fusion tree can be so that data merges in transmission course more efficiently, thereby more saves the network energy consumption, prolong network lifetime.Mainly can be divided into three kinds of structures about the research of merging tree at present: plane tree, bunch type structure, bunch-tree.Bunch-tree structure fusion tree is as shown in Figure 1.

Bunch-the tree type merges the data collection that tree can be used for massive wireless sensor, at present for bunch-to merge tree at first is that network is divided into clustering architecture to tree structure, forms a plane tree between all leader cluster nodes, constitutes the trunk of whole network.When the election leader cluster node, lay particular emphasis on the position of considering leader cluster node.In order to make energy consumption balance, generally adopt the new method of contributing of periodicity emphasis, can cause bigger energy dissipation.

Summary of the invention

The object of the present invention is to provide a kind of fusion tree constructing method that is used to collect own health status of wireless sensor network, avoid periodically rebuliding the energy consumption problems of too that clustering architecture brings; Can reduce the network energy consumption, prolong network lifetime.

The present invention is achieved like this, and at first initiates achievement message by the sink node, comprises geographical location information, mesh coordinate and the mesh width of sink and source node in the achievement message bag; The node that receives message is determined self place mesh coordinate and is participated in a bunch head election contest according to self-position information and dump energy according to message content and self geographical position information; All leader cluster nodes constitute the trunk of network, and leader cluster node carries out transmitting until arriving sink along backbone network after the fusion treatment to the data that receive again; A half that drops to when elected when the dump energy of bunch head carries out part replacement.

Step of the present invention is as follows:

(1) initiation of contributing and ordering: sink node broadcasts achievement command messages, the order of contributing has comprised the geographical location information of sink node, the geographical location information of source node, the father node of source node, mesh width.Communication radius should guarantee that all nodes of campaigning for the zone all can receive this order;

(2) calculate self place grid: the node that receives achievement message is at first according to self-position information (X _N, Y _N) with the achievement that the receives grid (X at following formula computing node self place of feeling the pulse with three fingers simulataneously that disappears _Nr, Y _Nr):

Wherein, Xs and Ys are the geographical location information of sink; X _SrWith Y _SrBe sink place mesh coordinate;

For rounding operation downwards; ε is an infinitesimal positive number, is used to solve the net boundary node problems;

(3) bunch head election contest: when node and source node are in same grid, then source node is added as own leader cluster node and merge tree, will add fusion and set mark and be made as 1 and also write down bunch header; If being neighbours' grid (four grids in a grid and its upper and lower, left and right are neighbours' grid each other), node grid of living in and source node place grid check at first then whether it has added the fusion tree:

Merge tree if node has added, check at first then whether the father node field that receives message is oneself, if, then source node as oneself child nodes and write down the relevant information of child nodes; Otherwise, be left intact; Do not merge tree if node adds, then participate in the election contest of leader cluster node;

Election contest is mainly finished by timing mechanism, and the election contest process prescription is as follows:

The node that participates in election contest is set up timer according to self geographical position information, the achievement message that receives and is delayed time and send a bunch head election contest message.The communication radius of the election contest message that sends should guarantee to be received by all nodes in the same grid, comprises the time delay of timer in the election contest message, time-delay T=T ₁+ T ₂+ T ₃, wherein: ${\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="HSA00000050455600011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1=\left\{\begin{array}{ccc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_c^2}{E_{\mathrm{ini}}}& \mathrm{if}& d_c<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_c^4}{E_{\mathrm{ini}}}& \mathrm{if}& d_c\&GreaterEqual;d_0\end{array}\right.$ ${\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HSA00000050455600011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=\left\{\begin{array}{ccc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_{\mathrm{nc}}^2}{E_{\mathrm{ini}}}& \mathrm{if}& d_{\mathrm{nc}}<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_{\mathrm{nc}}^4}{E_{\mathrm{ini}}}& \mathrm{if}& d_{\mathrm{nc}}\&GreaterEqual;d_0\end{array}\right.$ $T_3=\left\{\begin{array}{ccc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_f^2}{E_{\mathrm{res}}}& \mathrm{if}& d_f<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_f^4}{E_{\mathrm{res}}}& \mathrm{if}& d_f\&GreaterEqual;{\mathrm{<figure-callout\; id="0"\; label="d"\; filenames="HSA00000050455600011.png"\; state="\{\{state\}\}">d</figure-callout>}}_0\end{array}\right.$

In the formula, d _cBe the distance in solstics in node and the grid, d _fFor and father node (higher level's leader cluster node) between distance, d _NcBe the ultimate range of node and neighbours' grid element center point, E _ResBe the residual energy value of node, E _IniPrimary power value for node.In energy consumption model, when communication distance greater than d ₀The time, adopt the multichannel attenuation model, when communication distance less than d ₀Shi Caiyong free space model.E _ElecBe to send or receive the energy that 1 Bit data transtation mission circuit is consumed, ε _FsAnd ε _AmpThen be illustrated respectively in the energy that power amplification consumed in free space model and the multichannel attenuation model;

If node received before timer expiry from the then cancellation time-delay earlier of the achievement message of other neighbor nodes, the achievement message of sending according to self rest energy, geographical location information and neighbours' grid node that all receive is reselected a more excellent candidate parent node and is rebulid the election contest that time-delay participates in leader cluster node.

Send a bunch head election contest message during timer expiry, if received bunch head election contest message with other nodes in the grid before timer expiry, and the time-delay of oneself is bigger illustrates then that other nodes are more suitable for becoming leader cluster node and the election contest of abandoning bunch head; If oneself time-delay is littler, then illustrate oneself be more suitable for becoming leader cluster node and

Broadcasting bunch head election contest message;

After waiting for a period of time, the node of Last call bunch head election contest message is transmitted achievement message, and this process continues always, sets up up to whole fusion tree and finishes;

(4) transfer of data: after all bunches head is all elected, all leader cluster nodes form the trunk of network, bunch member node sends the data to leader cluster node, leader cluster node carries out the data of its bunch member node and subordinate's leader cluster node (child nodes) to send to higher level's leader cluster node after the fusion treatment, arrive the sink node up to data, in data transmission procedure, all nodes are according to adjusting transmitting power with the actual range of next jumping;

(5) bunch head is replaced: if leader cluster node detects a half of not enough its energy when becoming bunch of self rest energy, send bunch head and replace message, the message of transmission should be received by nodes all in the grid of sender of the message place, its father node and subordinate's leader cluster node thereof; It is as follows to receive that bunch great wheel is changed the node processing of message:

If be in same grid with source node, then at first state is changed into not add and merged tree state, participate in the election contest of leader cluster node afterwards according to information such as message that receives and self rest energy; If with source node place grid neighbours' grid each other, the deletion routing iinformation relevant then with source node, treating that new leader cluster node is campaigned for successfully upgrades afterwards relevant information.

Advantage of the present invention is: avoid new elected fusion node to cross low premature dead because of energy; Avoid periodically rebuliding the energy consumption problems of too that clustering architecture brings; Can reduce the network energy consumption, prolong network lifetime.

Description of drawings

Fig. 1 divides schematic diagram for network grid of the present invention.

Fig. 2 is the present invention's message format schematic diagram of contributing.

Fig. 3 is the present invention's bunch head election contest flow chart.

Fig. 4 merges the tree schematic diagram for the present invention.

Embodiment

As shown in Figure 1, the sink node is positioned at (0,0) grid, at first is that sink initiates achievement message, is a form of the achievement message of sink node transmission as Fig. 2, and wherein Type represents type of message, is achievement message herein; SID, DID are respectively source node and destination node ID; SX, SY and BSX, BSY are respectively the geographical location information of source node and sink; FCH is father node ID; GRIDWidth is a mesh width; The communication radius that sends this message is the distance of this node to neighbours' grid solstics.Among Fig. 1, neighbours' grid of (1,1) grid is (0,1), (2,1), (1,2), (1,0).

The node that receives achievement message is at first according to self-position information (X _N, Y _N) be calculated as follows the grid (X at node self place with the achievement message that receives _Nr, Y _Nr):

Wherein, Xs and Ys are the geographical location information of sink;

For rounding operation downwards; ε is an infinitesimal positive number, gets the treatable minimum number of node, is used to solve the net boundary node problems.After adding ε, the interface between nets line node that is positioned at sink node top considered to be in its below grid, otherwise then thinks and be positioned at its top grid; The node that is positioned on the Box junction line of sink node left considered to be in the grid on its right side, otherwise then thinks and be in its left side grid.

Node carries out different disposal according to the relation of self place grid and source node place grid, its processing procedure is as shown in Figure 3: when node and source node are in same grid, then source node add is merged tree as oneself leader cluster node, will add and merge the tree mark and be made as 1 and write down bunch header; If node grid of living in and source node place grid are neighbours' grid, check at first then whether it has added the fusion tree:

Merge tree if node has added, check at first then whether the father node field that receives message is oneself, if, then source node as oneself child nodes and write down the relevant information of child nodes; Otherwise, be left intact; Do not merge tree if node adds, then participate in the election contest of leader cluster node;

Election contest is mainly finished by timing mechanism, and the election contest process prescription is as follows:

The node that participates in election contest is set up timer according to self geographical position information, the achievement message that receives and is delayed time and send a bunch head election contest message.The communication radius of the election contest message that sends should guarantee to be received by all nodes in the same grid, comprises the time delay of timer in the election contest message, time-delay T=T ₁+ T ₂+ T ₃, wherein: ${\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="HSA00000050455600011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1=\left\{\begin{array}{ccc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_c^2}{E_{\mathrm{ini}}}& \mathrm{if}& d_c<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_c^4}{E_{\mathrm{ini}}}& \mathrm{if}& d_c\&GreaterEqual;d_0\end{array}\right.$ ${\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HSA00000050455600011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=\left\{\begin{array}{ccc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_{\mathrm{nc}}^2}{E_{\mathrm{ini}}}& \mathrm{if}& d_{\mathrm{nc}}<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_{\mathrm{nc}}^4}{E_{\mathrm{ini}}}& \mathrm{if}& d_{\mathrm{nc}}\&GreaterEqual;d_0\end{array}\right.$ $T_3=\left\{\begin{array}{ccc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_f^2}{E_{\mathrm{res}}}& \mathrm{if}& d_f<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_f^4}{E_{\mathrm{res}}}& \mathrm{if}& d_f\&GreaterEqual;{\mathrm{<figure-callout\; id="0"\; label="d"\; filenames="HSA00000050455600011.png"\; state="\{\{state\}\}">d</figure-callout>}}_0\end{array}\right.$

In the formula, d _cBe the distance in solstics in node and the grid, d _fFor and father node (higher level's leader cluster node) between distance, d _NcUltimate range for node and neighbours' grid element center point.E _ResBe the residual energy value of node, E _IniPrimary power value for node.In energy consumption model, when communication distance greater than d ₀The time, adopt the multichannel attenuation model, when communication distance less than d ₀Shi Caiyong free space model.E _ElecBe to send or receive the energy that 1 Bit data transtation mission circuit is consumed, ε _FsAnd ε _AmpThen be illustrated respectively in the energy that power amplification consumed in free space model and the multichannel attenuation model.

If node received before timer expiry from the then cancellation time-delay earlier of the achievement message of other neighbor nodes, the achievement message of sending according to self rest energy, geographical location information and neighbours' grid node that all receive is reselected a more excellent candidate parent node and is rebulid the election contest that time-delay participates in leader cluster node.

Send a bunch head election contest message during timer expiry, if received bunch head election contest message with other nodes in the grid before timer expiry, and the time-delay of oneself is bigger illustrates then that other nodes are more suitable for becoming leader cluster node and the election contest of abandoning bunch head; If own time-delay is littler, then illustrate oneself to be more suitable for becoming leader cluster node and to broadcast bunch head and campaign for a message.

After waiting for a period of time, the node of Last call bunch head election contest message is transmitted achievement message, and this process continues always, sets up up to whole fusion tree and finishes.

After all bunches head was all elected, all leader cluster nodes formed the trunk of network, and the fusion tree of foundation as shown in Figure 4.Bunch member node sends the data to leader cluster node, and leader cluster node carries out the data of its bunch member node and subordinate's leader cluster node (child nodes) to send to higher level's leader cluster node after the fusion treatment, arrives the sink node up to data.In data transmission procedure, all nodes are according to adjusting transmitting power with the actual range of next jumping.

As shown in Figure 4, if leader cluster node C1 detects a half of not enough its energy when becoming bunch of self rest energy, send bunch head and replace a message, the message of transmission should its all member node, sink and the leader cluster node C3 of subordinate thereof receive; It is as follows to receive that bunch great wheel is changed the node processing of message:

Its member node is then at first changed into state not add and is merged tree state, participates in the election contest of leader cluster node afterwards according to information such as message that receives and self rest energy; Sink node and the relevant routing iinformation of its child nodes C3 deletion treat that new leader cluster node such as A campaign for the successfully relevant routing iinformation of back renewal.

Claims (2)

1. fusion tree constructing method that is used to collect own health status of wireless sensor network, it is characterized in that method at first initiating achievement message by the sink node, comprises geographical location information, mesh coordinate and the mesh width of sink and source node in the achievement message bag; The node that receives message is determined self place mesh coordinate and is participated in a bunch head election contest according to self-position information and dump energy according to message content and self geographical position information; All leader cluster nodes constitute the trunk of network, and leader cluster node carries out transmitting until arriving sink along backbone network after the fusion treatment to the data that receive again; A half that drops to when elected when the dump energy of bunch head carries out part replacement.

2. a kind of fusion tree constructing method of collecting own health status of wireless sensor network according to claim 1, it is characterized in that, if all nodes are randomly distributed in 2 dimensional region, the known self geographical position information of node, node can change communication radius by adjusting transmitting power as required, and the structure that merges tree comprises the steps:

(1) initiation of contributing and ordering: sink node broadcasts achievement command messages, the order of contributing has comprised the geographical location information of sink node, the geographical location information of source node, the father node of source node, mesh width.Communication radius should guarantee that all nodes of campaigning for the zone all can receive this order;

(2) calculate self place grid: the node that receives achievement message is at first according to self-position information (X _N, Y _N) be calculated as follows the grid (X at node self place with the achievement message that receives _Nr, Y _Nr):

Wherein, Xs and Ys are the geographical location information of sink; X _SrWith Y _SrBe sink place mesh coordinate;

For rounding operation downwards; ε is an infinitesimal positive number, is used to solve the net boundary node problems;

(3) bunch head election contest: when node and source node are in same grid, then source node is added as own leader cluster node and merge tree, will add fusion and set mark and be made as 1 and also write down bunch header; If node grid of living in and source node place grid are neighbours' grid, check at first then whether it has added the fusion tree:

Merge tree if node has added, check at first then whether the father node field that receives message is oneself, if, then source node as oneself child nodes and write down the relevant information of child nodes; Otherwise, be left intact; Do not merge tree if node adds, then participate in the election contest of leader cluster node;

Election contest is mainly finished by timing mechanism, and the election contest process prescription is as follows:

The node that participates in election contest is set up timer according to self geographical position information, the achievement message that receives and is delayed time and send a bunch head election contest message, the communication radius of the election contest message that sends should guarantee to be received by all nodes in the same grid, the time delay that comprises timer in the election contest message, time-delay T=T ₁+ T ₂+ T ₃, wherein:

$T_1=\left\{\begin{array}{cc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_c^2}{E_{\mathrm{ini}}}& \mathrm{if}{d}_c<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_c^4}{E_{\mathrm{ini}}}& \mathrm{if}{d}_c\&GreaterEqual;d_0\end{array}\right.$ $T_2=\left\{\begin{array}{cc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_{\mathrm{nc}}^2}{E_{\mathrm{ini}}}& \mathrm{if}{d}_{\mathrm{nc}}<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_{\mathrm{nc}}^4}{E_{\mathrm{ini}}}& \mathrm{if}{d}_{\mathrm{nc}}\&GreaterEqual;d_0\end{array}\right.$ $T_3=\left\{\begin{array}{cc}\frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{fs}}{d}_f^2}{E_{\mathrm{res}}}& \mathrm{if}{d}_f<d_0\\ \frac{E_{\mathrm{elec}}+{\mathrm{\&epsiv;}}_{\mathrm{amp}}{d}_f^4}{E_{\mathrm{res}}}& \mathrm{if}{d}_f\&GreaterEqual;d_0\end{array}\right.$

In the formula, d _cBe the distance in solstics in node and the grid, d _fFor and father node between distance, d _NcBe the ultimate range of node and neighbours' grid element center point, E _ResBe the residual energy value of node, E _IniPrimary power value for node.In energy consumption model, when communication distance greater than d ₀The time, adopt the multichannel attenuation model, when communication distance less than d ₀Shi Caiyong free space model, E _ElecBe to send or receive the energy that 1 Bit data transtation mission circuit is consumed, ε _FsAnd ε _AmpThen be illustrated respectively in the energy that power amplification consumed in free space model and the multichannel attenuation model;

If node received before timer expiry from the then cancellation time-delay earlier of the achievement message of other neighbor nodes, the achievement message of sending according to self rest energy, geographical location information and neighbours' grid node that all receive is reselected a more excellent candidate parent node and is rebulid the election contest that time-delay participates in leader cluster node;

Send a bunch head election contest message during timer expiry, if received bunch head election contest message with other nodes in the grid before timer expiry, and the time-delay of oneself is bigger illustrates then that other nodes are more suitable for becoming leader cluster node and the election contest of abandoning bunch head; If own time-delay is littler, then illustrate oneself to be more suitable for becoming leader cluster node and to broadcast bunch head and campaign for a message;

After waiting for a period of time, the node of Last call bunch head election contest message is transmitted achievement message, and this process continues always, sets up up to whole fusion tree and finishes;

(4) transfer of data: after all bunches head is all elected, all leader cluster nodes form the trunk of network, bunch member node sends the data to leader cluster node, leader cluster node carries out the data of its bunch member node and subordinate's leader cluster node to send to higher level's leader cluster node after the fusion treatment, arrive the sink node up to data, in data transmission procedure, all nodes are according to adjusting transmitting power with the actual range of next jumping;

(5) bunch head is replaced: if leader cluster node detects a half of not enough its energy when becoming bunch of self rest energy, send bunch head and replace message, the message of transmission should be received by nodes all in the grid of sender of the message place, its father node and subordinate's leader cluster node thereof; It is as follows to receive that bunch great wheel is changed the node processing of message:

If be in same grid with source node, then at first state is changed into not add and merged tree state, participate in the election contest of leader cluster node afterwards according to information such as message that receives and self rest energy; If with source node place grid neighbours' grid each other, the deletion routing iinformation relevant then with source node, treating that new leader cluster node is campaigned for successfully upgrades afterwards relevant information.

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