Invention content
In order to solve above-mentioned technical problem, the present invention provides a kind of wireless sensor network node and makes decisions on one's own formula
Routing Protocol (Node Autonomous Decision routing protocol, NAD).The agreement is joined according to virtual coordinates
Amount determines next-hop;Pass through ad-hoc communication build path tree;Utilize local energy balance policy path optimizing tree.Balanced node
Energy consumption extends network lifecycle.
The purpose of the present invention is what is be achieved through the following technical solutions:
Wireless sensor network node is made decisions on one's own formula Routing Protocol, which is characterized in that is included the following steps:
Step 1:Netinit:Sink node is to the message initiated network operations of all the sensors node broadcasts MSG_ADV;
All the sensors node receives the MSG_ADV message of Sink node broadcast, is calculated according to RSSI received signal strengths and is saved away from Sink
Point distance;
Step 2:Neighbours have found:All nodes are carried out with half radial its neighbors broadcast MSG_HELLO message of initial communication
Neighbours have found that the message includes distance of the node itself away from Sink node;All the sensors node receives the broadcast of its neighbor node
MSG_HELLO message, according to RSSI received signal strengths calculate the distance away from neighbor node, create information of neighbor nodes table;
Step 3:It establishes virtual coordinates model and selects next-hop:Node determines whether oneself can be to Sink node first
Directly transmit data;If containing Sink node in the forward direction neighborhood of node, node is by the way of single-hop to Sink node
Transmission data;If establishing virtual coordinates model without Sink node in the forward direction neighborhood of node, the virtual of neighbors is calculated
Coordinate parameter simultaneously selects next-hop;
Step 4:Establish connection:Node establishes connection by broadcasting RTS/CTS control messages with next-hop;Disappeared using CTS
Residue energy of node information in breath update information of neighbor nodes table;
Step 5:Data communicate:Node gathered data is simultaneously encapsulated into DATA packets, and the mode of wireless communication is sent to next
Hop node;Confirm data transmission state according to ACK message;
Step 6:Data fusion.Branch node in path tree carries out data fusion to the data packet from multiple neighbors
Processing.Redundant data is reduced to improve data transmission efficiency.
Step 7:Dump energy inspection:Node checks whether self rest energy is sufficient after completing a wheel data transmission;Such as
Fruit residue energy of node is insufficient, thens follow the steps 9;If residue energy of node is sufficient, information of neighbor nodes table is checked, will remain
The insufficient node of complementary energy is deleted from table and executes step 8;
Step 8:Balancing energy controls:Sink node one jumps the node outside neighborhood according under the selection of local energy balance policy
One jumps;Endpoint node selects next-hop further combined with current oneself state.If endpoint node is currently not branch node, but
But select the forward direction node outside its initial communication radius neighborhood as next-hop, then the neighbors into its initial communication radius is wide
It broadcasts the declaration of MSG_CHANGE message and establishes branch.The node for receiving MSG_CHANGE message will be in oneself backward neighborhood
Endpoint node is as next-hop.If endpoint node is currently branch node, but is selected in its initial communication radius neighborhood
Node is as next-hop, then the node broadcasts MSG_CANCEL message into its initial communication radius cancels branch.It receives
The node of MSG_CANCEL message reselects the neighbors in itself forward direction neighborhood as next-hop;Node determines next-hop
Afterwards, step 4 is gone to;
Step 9:It exits network:The insufficient node of dump energy no longer transmission data packet.If receiving RTS requests to disappear
Breath then sends the CTS control messages of subsidiary energy information, and non-failure node is made to timely update information of neighbor nodes table.
The process that virtual coordinates model is established described in step 3 is as follows:
(1) division in neighbor domain of node space, such as Fig. 1, the A that sets up an office indicate that Sink node, point Ni indicate sensor node;With point
Ni is the center of circle, and R0 is the initial communication radius that radius makees circle Ni, wherein R0 as sensor node;Using point A as the center of circle, Ri is radius
It is distances of the sensor node Ni away from Sink node, Ri=d (Ni, Sink) to make circle A, wherein Ri);The intersection of circle Ni and circle A
Domain, as the forward direction neighborhood of node Ni, the disjoint regions the interior and round A of circle Ni, the as backward neighborhood of node Ni;
(2) the virtual coordinates model of node Ni is established according to the neighborhood space of node Ni.Make a tie point A, i.e. Sink
Node, the straight line Li with point Ni;If straight line Li is the virtual coordinates axis of node Ni, Sink node direction is virtual coordinates axis Li's
It is positive;It is the coordinate origin on the virtual coordinates axis of node Ni that straight line Li and circle Ni, which intersects at point an Oi, the Oi that sets up an office in round A,;
(3) node Nx is set as a certain neighbors in the forward direction neighborhood of node Ni, that is, is free of the point on arc BNiC, is claimed node
Nx is the forward direction neighbors of node Ni;Coordinates of the node Nx in the virtual coordinates model of node Ni is indicated with formula (4).
Posi(Nx)=(ρix, hix) (4)
Wherein, Posi (Nx) indicates that virtual coordinates of the neighbors Nx in the forward direction neighborhood of node Ni, ρ ix indicate node Nx
To the distance of the virtual coordinates origin Oi of node Ni, ρ ix=d (Nx, Oi), hix indicate the virtual coordinates of node Nx to node Ni
The distance of axis Li, hix=d (Nx, Li).The coordinate parameter ρ ix of node Nx can be calculated according to the cosine law and be acquired, such as formula
(5);
Wherein cos θ ix are the cosine value of ∠ NxNiA in triangle NiNxA, and the value of cos θ ix can be counted according to formula (6)
It acquires;
Second coordinate parameter hix of node Nx can be calculated according to triangle area formula and be acquired, such as formula (7).
Wherein S Δs ix is the area of triangle NiNxA, and the value of S Δs ix can be calculated according to Heron's formula to be acquired,
Such as formula (8);
Wherein pix is the half of the perimeter of triangle NiNxA, such as formula (9);
For the node Nx (without the point on arc BNiC) in the forward direction neighborhood of arbitrary node Ni and node Ni, differ
Formula d (Ni, Sink)>D (Nx, Sink) is set up.Node Ni selected out of its forward direction neighborhood before to neighbors as next-hop, can be with
It avoids generating route loop.
If the length of line segment NiOi is r, wherein r=R0, R0 are the initial communication radiuses of node Ni, and line segment NiOi is distinguished
It is divided into n sections and n+1 sections;Formula (10) and (11) can be derived according to energy consumption model used by LEACH agreements;
Since radio frequency coefficient of energy dissipation Eelec is much larger than power amplification coefficient power amplification ratio Efs, for same section of straight line path, increase road
Section will cause the multiple of Eelec to increase and consume more energy;The nearest neighbors of chosen distance is not most to close as next-hop
Suitable selection, and chosen distance is farthest and is then helped avoid on local road as next-hop near the neighbors of Sink node
Diameter increases section, reduces energy consumption.In the forward direction neighborhood of node Ni, distances of the point Oi away from Sink node is most short, through point Oi institutes shape
At path near straight line Li.When network is initial selection close to straight line neighbors as next-hop contribute to establish quickly to
The convergent path of Sink node.For the virtual coordinates model of arbitrary node Ni, the position of virtual coordinates origin Oi is section
The optimal location of next-hop node in the forward direction neighborhood of point Ni;Position on reference axis Li in line segment NiOi is the forward direction of node Ni
The suboptimal position of next-hop node in neighborhood.
Local energy balance policy described in step 8 is specially:
After completing netinit and first run data transmission, node controls the surplus of attendant message by monitoring neighbors CTS
Complementary energy information is updated itself information of neighbor nodes table;
If the current next-hop node of node is the node of the preceding dump energy minimum into neighbors, referred to as local residual energy
Measure minimum node);Then node reselects the maximum node of dump energy as next-hop out of forward direction neighborhood, and referred to as part is surplus
Complementary energy maximum node;
For on network edge some not after to neighbors node, these nodes are typically the end segment of path tree
Point, abbreviation endpoint node;If endpoint node according to original path tree transmission data, will never receive and handle it is any its
The data of his node;
Endpoint node m updates neighbors dump energy information after completing a wheel data transmission by CTS control messages;
If the dump energy of endpoint node m is more than all neighbors of node m, node m increases power, expands communication radius,
The communication radius after expanding is asked still to be less than the limitation radius d0 in multipath attenuation model;Search meets restrictive condition and distance
Forward direction node in nearest non-initial communication radius neighborhood;This is preceding need to meet following restrictive condition to node n, to guarantee
Data link is established, and does not generate route loop;
1) dump energy of node n is sufficient, it is possible to increase power is communicated with m;
2) distances of the node n away from Sink node is smaller than node m;
3) any endpoint node is free of in the backward neighborhood of node n;
4) the forward direction neighbors of any endpoint node is free of in the forward direction neighborhood of node n;
Wherein, endpoint node is selected after suitable forward direction node as next-hop, and to its initial communication radius
Forward direction neighbors broadcast branch message in neighborhood is announced to become branch node;
The endpoint node received in the node and neighborhood of branch message establishes connection, and sends the data to end segment
Point;
After endpoint node receives data, fusion treatment is carried out to data, and the data after fusion are sent to expansion and are led to
The forward direction node of connection is established after letter radius;When the endpoint node as branch node detects its initial communication radius neighborhood
The dump energy of interior all neighbors declares off branch when all more than oneself;Endpoint node continues from itself initial communication half
Next-hop, the neighbors of endpoint node is selected also all to be selected from the forward direction neighbors in itself forward direction neighborhood in the forward direction neighborhood of diameter
Next-hop is selected, the data transmission of a new round is prepared.
Beneficial effects of the present invention:The present invention using the above scheme, not for wireless sensor network node energy expenditure
Balanced problem, divides the neighborhood space of node;Using the virtual coordinates model of proposition, according to the virtual seat of neighbors
Parameter selection next-hop is marked, convergence rate of the path to Sink node is accelerated;It is built using Distributed Calculation and ad-hoc communication
One using Sink node as the path tree of root;Using the local energy balance policy of proposition, according to the dump energy information of node
Path optimizing tree.It is emulated under OMNeT++ platforms, compared with DEBUC agreements and UAUC agreements, NAD agreements are first
71.8% and 66.5% are extended respectively on the time of node death;It is respectively increased on the average residual energy of node
45.8% and 27.9%;51.2% and 34.2% has been respectively increased in the dump energy standard deviation of node.Simulation result shows:
NAD agreements can effectively extend network lifecycle, balanced node energy consumption.
Specific implementation mode
The present invention provides a kind of wireless sensor network node and makes decisions on one's own formula Routing Protocol (Node Autonomous
Decision routing protocol, NAD), which includes the following steps:
Step 1:Netinit:Sink node is to the message initiated network operations of all the sensors node broadcasts MSG_ADV;
All the sensors node receives the MSG_ADV message of Sink node broadcast, is calculated according to RSSI received signal strengths and is saved away from Sink
Point distance;
Step 2:Neighbours have found:All nodes are carried out with half radial its neighbors broadcast MSG_HELLO message of initial communication
Neighbours have found that the message includes distance of the node itself away from Sink node;All the sensors node receives the broadcast of its neighbor node
MSG_HELLO message, according to RSSI received signal strengths calculate the distance away from neighbor node, create information of neighbor nodes table;
Step 3:It establishes virtual coordinates model and selects next-hop:Node determines whether oneself can be to Sink node first
Directly transmit data;If containing Sink node in the forward direction neighborhood of node, node is by the way of single-hop to Sink node
Transmission data;If establishing virtual coordinates model without Sink node in the forward direction neighborhood of node, the virtual of neighbors is calculated
Coordinate parameter simultaneously selects next-hop;
Step 4:Establish connection:Node establishes connection by broadcasting RTS/CTS control messages with next-hop;Disappeared using CTS
Residue energy of node information in breath update information of neighbor nodes table;
Step 5:Data communicate:Node gathered data is simultaneously encapsulated into DATA packets, and the mode of wireless communication is sent to next
Hop node;Confirm data transmission state according to ACK message;
Step 6:Data fusion.Branch node in path tree carries out data fusion to the data packet from multiple neighbors
Processing.Redundant data is reduced to improve data transmission efficiency.
Step 7:Dump energy inspection:Node checks whether self rest energy is sufficient after completing a wheel data transmission;Such as
Fruit residue energy of node is insufficient, thens follow the steps 9;If residue energy of node is sufficient, information of neighbor nodes table is checked, will remain
The insufficient node of complementary energy is deleted from table and executes step 8;
Step 8:Balancing energy controls:Sink node one jumps the node outside neighborhood according under the selection of local energy balance policy
One jumps;Endpoint node selects next-hop further combined with current oneself state.If endpoint node is currently not branch node, but
But select the forward direction node outside its initial communication radius neighborhood as next-hop, then the neighbors into its initial communication radius is wide
It broadcasts the declaration of MSG_CHANGE message and establishes branch.The node for receiving MSG_CHANGE message will be in oneself backward neighborhood
Endpoint node is as next-hop.If endpoint node is currently branch node, but is selected in its initial communication radius neighborhood
Node is as next-hop, then the node broadcasts MSG_CANCEL message into its initial communication radius cancels branch.It receives
The node of MSG_CANCEL message reselects the neighbors in itself forward direction neighborhood as next-hop;Node determines next-hop
Afterwards, step 4 is gone to;
Step 9:It exits network:The insufficient node of dump energy no longer transmission data packet.If receiving RTS requests to disappear
Breath then sends the CTS control messages of subsidiary energy information, and non-failure node is made to timely update information of neighbor nodes table.
This agreement based on system model, Routing Protocol, corresponding strategies, concrete application flow and verification process be described in detail such as
Under:
Network model
This paper agreements are suitable for the application of higher wireless sensor network of periodical gathered data.Sensor node in network model
It is randomly dispersed in monitoring region, Sink node position is fixed, energy is sufficient.Sensor node property is as follows:
Node has the unique ID numbers of the whole network.
Position is fixed after node deployment, finite energy.
Node structure is identical, and initial communication radius is identical.
3) node power of communications is adjustable, can adjust transmission power according to distance.
4) node uses RSSI approximation rangings.
Energy consumption model
Wireless communication energy consumption model identical with LEACH agreements is used herein.The energy consumption of node transmission data is hair
The sum of transmit-receive radio road is lost and power amplification circuit is lost, as shown in formula (1).
Wherein, k is the data volume that node sends information;D is transmission range;Eelec is radio frequency coefficient of energy dissipation;Efs and Emp
For the power amplification coefficient power amplification ratio under different channels propagation model;D0 is the limitation radius in multipath attenuation model, calculation formula
As shown in formula (2).
When transmission range is more than d0, routing cost can be quite big, therefore transmission range is usually no more than d0.Node receives
The energy consumption of data, as shown in formula (3).
ERx(k)=kEelec (3)
NAD Routing Protocols
After node deployment, Sink node broadcast message starts the operation of all the sensors node.Each node according to
The signal strength received is calculated away from Sink node distance.Hello message is mutually sent between node and is calculated according to RSSI mutual
Between distance, generate information of neighbor nodes table.It is adjacent away from Sink node distance, nodal point separation that neighbors is had recorded in information of neighbor nodes table
The distance of node and the dump energy information of neighbors.
Since node location and neighbors number are not quite similar, node energy consumption can be caused uneven using fixed route.Node
Necessary periodicity adjusts path is with balance nodes energy consumption.Therefore, NAD agreements use Round Robin, and each round includes three phases:
It selects next-hop, establish connection build path tree and data transmission.Node energy is all identical when network is initial, the first run first stage
Node is according to the coordinate parameter selection next-hop in virtual coordinates model.The first stage node often taken turns later is according to neighbor node
Dump energy information selects next-hop using local energy balance policy.
Virtual coordinates model
The division in neighbor domain of node space, as shown in Figure 1.The A that sets up an office indicates that Sink node, point Ni indicate sensor node.With
Point Ni is the center of circle, and R0 is that radius makees circle Ni (R0 is the initial communication radius of sensor node).Using point A as the center of circle, Ri is radius
Make circle A (Ri is distances of the sensor node Ni away from Sink node, Ri=d (Ni, Sink)).The intersecting area of circle Ni and circle A, i.e.,
For the forward direction neighborhood (shadow region in such as Fig. 1) of node Ni, circle Ni is interior and justifies the disjoint regions A, after as node Ni
To neighborhood.
The virtual coordinates model of node Ni is established according to the neighborhood space of node Ni, as shown in Figure 2.Make a tie point A
The straight line Li of (Sink node) and point Ni.If straight line Li is the virtual coordinates axis of node Ni, Sink node direction is virtual coordinates
The forward direction of axis Li.It is that the coordinate on the virtual coordinates axis of node Ni is former that straight line Li and circle Ni, which intersects at point an Oi, the Oi that sets up an office in round A,
Point.
If node Nx is a certain neighbors (without the point on arc BNiC) in the forward direction neighborhood of node Ni, node Nx is referred to as
The forward direction neighbors of node Ni.Coordinates of the node Nx in the virtual coordinates model of node Ni is indicated with formula (4).
Posi(Nx)=(ρix, hix) (4)
Wherein, Posi (Nx) indicates that virtual coordinates of the neighbors Nx in the forward direction neighborhood of node Ni, ρ ix indicate node Nx
To the distance of the virtual coordinates origin Oi of node Ni, ρ ix=d (Nx, Oi), hix indicate the virtual coordinates of node Nx to node Ni
The distance of axis Li, hix=d (Nx, Li).The coordinate parameter ρ ix of node Nx can be calculated according to the cosine law and be acquired, such as formula
(5)。
Wherein cos θ ix are the cosine value of ∠ NxNiA in triangle NiNxA, and the value of cos θ ix can be counted according to formula (6)
It acquires.
Second coordinate parameter hix of node Nx can be calculated according to triangle area formula and be acquired, such as formula (7).
Wherein S Δs ix is the area of triangle NiNxA, and the value of S Δs ix can be calculated according to Heron's formula to be acquired, such as formula
(8)。
Wherein pix is the half of the perimeter of triangle NiNxA, such as formula (9).
By the virtual coordinates model established in Fig. 2 it is found that in the forward direction neighborhood of arbitrary node Ni and node Ni
Node Nx (without the point on arc BNiC), there is inequality d (Ni, Sink)>D (Nx, Sink) is set up.Node Ni is adjacent from its forward direction
It, can be to avoid generation route loop to neighbors as next-hop before being selected in domain.
If the length of line segment NiOi is r (r=R0, R0 are the initial communication radiuses of node Ni), line segment NiOi is divided respectively
At n sections and n+1 sections.Formula (10) and (11) can be derived according to formula (1).
In energy consumption model cited in earlier, radio frequency coefficient of energy dissipation Eelec is much larger than power amplification coefficient power amplification ratio Efs, for same
One section of straight line path, increasing section will cause the multiple of Eelec to increase and consume more energy.The nearest neighbors of chosen distance
Be not most suitable selection as next-hop, and chosen distance it is farthest and near the neighbors of Sink node as next-hop then
It helps avoid increasing section in local path, reduces energy consumption.In the forward direction neighborhood of node Ni, point Oi away from Sink node away from
It is short from most, path is formed by near straight line Li through point Oi.The neighbors of selection close to straight line makees next-hop when network is initial
Help to establish quickly to the convergent path of Sink node.For the virtual coordinates model of arbitrary node Ni, virtual coordinates
The position of origin Oi is the optimal location of next-hop node in the forward direction neighborhood of node Ni;Position on reference axis Li in line segment NiOi
Set be next-hop node in the forward direction neighborhood of node Ni suboptimal position.
The first run first stage, node Ni is according to virtual coordinates parameter ρ ix of its forward direction neighbors Nx, the node of hix and Nx
Number IDx determines its next-hop node NextHop (Ni).The adjacent section that node Ni selects ρ ix minimum first from forward direction neighbors
Point is used as next-hop;It is identical if there is the ρ ix of multiple neighbors, then the neighbour of hix minimums is selected from the identical neighbors of ρ ix
Node is as next-hop;It is identical if there is the hix of multiple neighbors, then select IDx numbers small from the identical neighbors of hix
Neighbors as next-hop.
Local energy balance policy
All nodes are adjusted path according to neighbors dump energy information since taking turns second.It is initial to complete network
Change with after first run data transmission, node controls the dump energy information of attendant message by monitoring neighbors CTS, to itself neighbour
Informational table of nodes is updated.If the current next-hop node of node is the node (letter of the preceding dump energy minimum into neighbors
Claim local dump energy minimum node), then node reselects the maximum node of dump energy as next out of forward direction neighborhood
It jumps (referred to as local dump energy maximum node).
For on network edge some not after to neighbors node, these nodes are typically the endpoint node of path tree
(abbreviation endpoint node, such as the node m) in Fig. 3 (a).If endpoint node, will never according to original path tree transmission data
It can receive and handle the data of any other node.This will cause the energy consumption of network uneven, increase the energy difference between node.For
Further equalising network energy consumption, now optimizes original path tree, as shown in Fig. 3 (b).Endpoint node m completes a wheel
After data transmission, neighbors dump energy information is updated by CTS control messages.If the dump energy of endpoint node m is more than
All neighbors of node m, then node m increases power, expands communication radius (it is required that the communication radius after expanding is still less than more
Limitation radius d0 in path attenuation model).Search meets restrictive condition and in nearest non-initial communication radius neighborhood
Forward direction node (the node n) in such as Fig. 3 (b).This is preceding need to meet following restrictive condition to node n, to guarantee to establish number
According to communication link, and do not generate route loop.
1) dump energy of node n is sufficient, it is possible to increase power is communicated with m.
2) distances of the node n away from Sink node is smaller than node m.
3) any endpoint node is free of in the backward neighborhood of node n.
4) the forward direction neighbors of any endpoint node is free of in the forward direction neighborhood of node n.
Endpoint node is selected after suitable forward direction node as next-hop, and into its initial communication radius neighborhood
Forward direction neighbors broadcast branch message announce become branch node.Receive the end segment in the node and neighborhood of branch message
Point establishes connection, and sends the data to endpoint node.After endpoint node receives data, fusion treatment is carried out to data, and
Data after fusion are sent to the forward direction node that connection is established after expanding communication radius.When the end segment as branch node
Point detects declares off branch when the dump energy of all neighbors in its initial communication radius neighborhood is all more than oneself.End
End node continuation selects next-hop out of itself initial communication radius forward direction neighborhood, and the neighbors of endpoint node is also all from itself
Next-hop is selected in forward direction neighbors in forward direction neighborhood, prepares the data transmission of a new round.
Data transmission
All nodes in neighborhood are jumped by the way of single-hop to Sink node transmission data positioned at Sink node one.Sink
All nodes that node one is jumped outside neighborhood send data to Sink node by the way of multi-hop.
Arbitrary node down hop node send DATA data packets, next-hop node receive DATA data packets to data into
Row fusion treatment and feeding back ACK confirmation message, node complete a wheel data transmission after receiving ACK confirmation messages.Next-hop
Node may receive the data packet of multiple nodes simultaneously, often there is a large amount of redundant data between these data packets.Such as
These data packets are directly forwarded to next-hop by fruit node, can reduce communication efficiency, waste node energy.It is necessary to institute for node
The data of the multiple nodes received carry out Data Fusion, then the data after fusion are sent to next-hop node.
Routing cavity
It need to ensure basic coverage rate and the connectivity when network is initial when random dispensing deployment node as possible.When network formation
All nodes all with before half path search of initial communication to neighbors, if node is found in its forward direction neighborhood without neighbors,
Increase power and expand communication radius with the nearest forward direction node of detection range, void node or orphan are generated when avoiding network initial
Vertical node.
Network operation later stage, the node less than minimum energy threshold value enter failure state.The backward neighbour of failure node at this time
Node would be possible to become void node or isolated node.Failure node responds the control information of neighbors using dump energy,
Maintain the link adjustment of network.Non- failure node deletes the neighbors of failure from neighbor information table.If not failing section
To neighbors before also having in the neighbor information table of point, then the forward direction neighbors for therefrom selecting dump energy most is as next-hop;
If without preceding to neighbors in neighbor information table, non-failure node becomes void node;If neighbor information table is sky,
Non- failure node becomes isolated node.Non- failure node as void node or isolated node need to increase transmission power and expansion
Communication radius searches for the nearest forward direction node in its communication range, continues transmission data as next-hop.
The framework and application process of this protocol model carry out associated verification by emulation experiment, and detailed process is:
The performance of NAD agreements is verified using OMNeT++5.2 simulated environment.By NAD agreements and DEBUC agreements and
UAUC agreements compare in terms of the two network lifecycle and node energy are harmonious.
1, experiment parameter is arranged
100 nodes of selection are randomly dispersed in the region of 100 × 100m2, and Sink node is located at rectangular area bottom edge
Centre position.Node primary power is 0.5J, and minimum energy threshold value is 0.25J.The value of each parameter is respectively in energy consumption model:
Efs=10pJ/ (bitm2), Emp=0.0013pJ/ (bitm4), Eelec=50nJ/bit, d0=87.7m.Data packet
Size is 4000bit, and control packet size is 200bit.Node initial communication radius R0=20m.Communication frequency is 2.4GHz, is adopted
It is carried out wireless communication with RTS/CTS/DATA/ACK communication modes.
2, network lifecycle
From the life for being defined as network when network initial launch to the period undergone when first node failure in network
Order the period.It is compared herein by the network lifecycle of three kinds of Routing Protocols of survival rate pair of statistics node.It uses
Statistical formula such as formula (12).
Lifenet(t)=[Nrest(t)/Ninital] 100% (12)
Wherein Lifenet (t) indicates node survival rates of the network net when simulation time is t;Nrest (t) indicates emulation
Remaining node number when time is t in network;Ninital indicates node number when network is initial.
Comparison diagram of three kinds of Routing Protocols in node survival rate is shown in Fig. 4.It can be seen that UAUC agreements and DEBUC associations
The network lifecycle of view is both less than NAD agreements.This is because NAD agreements use local energy balance policy, certainly using node
Local dump energy information in body communication radius is most worth with the dump energy in local neighborhood and adjusts data for criterion
Transmission path and path optimizing tree, to reduce the poor dump energy between node, equilibrium node energy consumption and extend network life
Period.And UAUC agreements are the average residual energy for carrying out calculate node according to subregion when selecting cluster head, are used again in cluster
Nearby principle selects cluster head.The transregional cluster of node leads to the reality of the residue energy of node average value and regional nodes of cluster head calculating
Border dump energy average value has differences, and affects the reasonability of cluster-leader selected.And it is used for selecting neighbours' cluster head in DEBUC agreements
Least cost function cannot be satisfied the actual needs that path is established between cluster head node, lead to the distal end cluster head that cluster radius is excessive
Energy consumption increases, and keeps node energy consumption unbalanced, reduces Network morals.Therefore compared with other two kinds of Routing Protocols, herein
NAD agreements the energy expenditure of node is significantly reduced by local energy balance policy, extend network lifecycle.
3, the average residual energy of node
The calculation formula such as formula (13) of node average residual energy.
WhereinIndicate the average residual energy of all nodes in network when simulation time is t.When Ei (t) indicates emulation
Between be t when node i dump energy.N represent network it is initial when node number.
The comparison diagram of three kinds of protocol node average residual energy is shown in Fig. 5.From figure 5 it can be seen that with UAUC agreements and DEBUC agreements
It compares, the average residual energy of NAD agreement interior joints is higher.DEBUC agreements not between cluster data carry out fusion treatment but
It directly forwards, cluster head energy expenditure is fast.Cluster head in UAUC agreements in each region needs to receive and process the data of multiple nodes,
Cluster head energy consumption is big.NAD agreements carry out multi-stage data fusion treatment using the branch node in path tree, will handle the task of data
Disperse to more nodes, equalising network energy consumption.
4, the dump energy standard deviation of node
The calculation formula of residue energy of node average value such as formula (14).
Wherein STDnet (t) indicates that residue energy of node standard deviations of the network net when simulation time is t, N represent network
Start node number, Ei (t) indicate simulation time be t when node i dump energy;Indicate net when simulation time is t
The average residual energy of all nodes in network.
The dump energy standard deviation comparison diagram of three kinds of protocol nodes is shown in Fig. 6.As seen from Figure 6, UAUC agreements and DEBUC agreements
Residue energy of node standard deviation be all higher than NAD agreements.This is because NAD agreements are more using the branch node progress in path tree
Level data fusion treatment reduces the energy expenditure caused by directly forwarding data packet.Network-end node is utilized simultaneously
Particularity, using local energy balance policy adjusts path tree, the dump energy further reduced between node is poor, balanced node energy
Consumption.And UAUC agreements select cluster head by subregion, but according to nearby principle cluster, cluster member may be from different subregions.Cluster head is in cluster
Interior rotation can cause to make to be separated by a subregion foundation communication between cluster head without cluster head in certain subregions, increase cluster head energy consumption, envoy
Point energy consumption is uneven.Different competition radiuses generates different size of cluster in DEBUC agreements, competes member in the big cluster head cluster of radius
More, reception data are more, and energy expenditure is fast, and the energy consumption for be easy to causeing nodes is uneven.Therefore, in Network morals
Interior, NAD agreements are better than other two kinds of Routing Protocols in network node energy harmony.