CN105873160A - Cluster establishing and routing method for cognitive radio sensor network without common control channel - Google Patents

Abstract

The invention discloses a cluster establishing and routing method for a cognitive radio sensor network without a common control channel. A plurality of clusters which are uneven in size are established through a plurality of turns of cluster establishing operation according to the near-to-distant sequence to an SN (sink node); except for sensor node SUs (secondary users) directly communicating with the SN, other SUs are covered with a unique cluster; in each turn of cluster establishing operation, cluster radius calculation, cluster head (CH) selection, cluster channel selection and cluster structure formation are sequentially executed; in the cluster radius calculation process, three energy consumption situations are analyzed, wherein the three situations comprise the energy consumption situation of a node near to the SN, the energy consumption situation of a cluster head of the cluster nearest to the SN, and the energy consumption situation of cluster heads of the clusters far away from the SN, and energy consumption of the nodes in the network is balanced by establishing an uneven cluster. The cluster head is selected by comprehensively considering the rest energy of the nodes, the number of available channels and the distance with an upstream cluster head. The energy consumption of the nodes in the network can be balanced easily, and the service life of the network can be prolonged.

Description

Without bunch structure and the method for routing of common channel in a kind of cognition wireless sensor network

Technical field

The invention belongs to wireless communication technology field, relate in a kind of cognition wireless sensor network without common channel Bunch build and method for routing.

Background technology

Cognitive radio (Cognitive Radio, CR) is a kind of intelligent communication system, and it can make without awarding The secondary user (Secondary Users, SUs) of power is to naive user (Primary Users, PUs) In the case of not producing interference, perception and use idle frequency spectrum.Can improve by being efficiently used frequency spectrum resource Network performance.CR functional configuration on wireless sensor node (Sensor), thus form a kind of new Network morphology, i.e. cognition wireless sensor network (Cognitive Radio Sensor Network, CRSN).

In CRSN, Sensor can detect available channel by frequency spectrum perception, and is selected by frequency spectrum decision-making Select communication channel.Once PU occurs in the communication channel of Sensor, and Sensor just can be detected immediately upon also It is transformed into other idle channels.

Owing to CRSN is WSN (Wireless Sensor Network, wireless sensor network) and CR In conjunction with, therefore in CRSN, not only need to consider from the energy constraint problem of WSN, and need gram The problem taking frequency spectrum perception and spectrum management.Existing research work shows that clustering architecture can efficiently reduce WSN In energy expenditure, the cooperation that CR operates can be supported, such as frequency spectrum perception and channel access, be a kind of effectively Management topology, increases power system capacity, network performance and the structural method of stability.

In recent years, some Chinese scholars proposes bunch developing algorithm in CRSN^[3-9].At these bunch of algorithm In research work, bunch formation and channel selection procedure in, all consider energy and spectrum issue, it is intended in Extend the life-span of network.There is weak point considered below in existing research work:

(1) network needs at least one overall situation common signal channel (CommonControl Channel, CCC) Transmitting for information, this is difficulty with under practical circumstances.

(2) worked and extended the life-span of network by minimizing total energy expenditure.But, net to be extended In the life-span of network, be inadequate only by minimizing total energy, in addition it is also necessary to the energy of equalising network interior joint disappears Consumption.

At present, CRSN is popular research topic, and domestic and international researcher divides with frequency spectrum for energy consumption therein Join and propose some bunch of algorithm^[3-9]。

In document [3], author proposes a kind of frequency spectrum perception bunch Routing Protocol SCR, and it is in CRSN first Individual consideration energy and the Routing Protocol of spectral constraints simultaneously.Document [4] proposes based on frequency on the basis of SCR The Energy Efficient multimedia Routing Protocol SCEEM of spectrum perception bunch.In SCEEM, to minimize due to bag The number that loss and the multimedia quality distortion postponing to cause are in constrained optimization network bunch.

Eletreby et al.^[5]Et al. propose CogLEACH agreement.CogLEACH uses idle channel number to make The weight of the probability of bunch head is become for each node.For comparing LEACH, which increase the handling capacity of network And the life-span.But, CogLEACH does not accounts for balancing energy and needs overall situation CCC.

Document [6] proposes a kind of distributed frequency spectrum perception bunch algorithm DSAC.DSAC is deduced optimum number of clusters Mesh and minimize communication energy consumption.In DSAC, organize cluster with power of communications minimum, by bunch in Data aggregate and bunch between relaying realize energy saving.But, in order to realize the balancing energy of bunch interior nodes, bunch Interior all nodes have identical probability to become a bunch head.

Ozger et al.^[7]Propose a kind of event-driven frequency spectrum perception bunch algorithm ESAC.ESAC is each thing Part forms interim bunch, and only cluster between event and sink node.During cluster, ESAC two Number of available channels between hop node and member node number are to guarantee the degree of communication of network.But, in ESAC, Communication bunch between member and bunch head CH is single-hop, and ESAC is event driven, inapplicable with Other network scenarios, such as event driven network.

In document [8], it is proposed that a kind of low-yield self adaptation Uneven Cluster algorithm LEAUCH (lowenergyadaptive uneven clustering hierarchy).LEAUCH not only allows for channel resource The advantage of unnecessary reduction energy expenditure, and by using Uneven Cluster to equalize the energy of CH in multi-hop transmission Consumption.But, LEAUCH assumes that in network, at least an overall CCC and a bunch radius only depend on CH Distance to sink.

In document [9], it is proposed that the compression cluster method using interim support node of a kind of Energy Efficient CENTER.Which introduce the formation that the interim concept supporting node improves bunch.Sensor can look for effectively To corresponding CH.But, interim support node needs to consume more energy and helps other nodes to find accordingly CH。

Above-mentioned strategy can preferably run in CRSN.But, in reality, overall situation CCC is difficult to Realize.In order to extend the life-span of network, it is necessary to the energy consumption of equalising network interior joint.

List of references

[1]O.B.Akan,O.B.Karli,and O.Ergul,“Cognitive Radio Sensor Networks,” IEEE Network,vol.23,no.4,pp.34-40,Jul.-Aug.2009.

[2]J.Y.Yu,and P.H.J.Chong,“A Survey of Clustering schemes for mobile ad hoc networks,”IEEE Communications Surveys&Tutorials,vol.7,no.1,pp.32-48, First Qtr.2005.

[3]Shah G,Akan O B.Spectrum-aware cluster-based routing for cognitive radio sensor networks[C]//Communications(ICC),2013IEEE International Conference on. IEEE,2013:2885-2889.

[4]Shah G,Alagoz F,Fadel E,et al.A spectrum-aware clustering for efficient multimedia routing in cognitive radio sensor networks[J].Vehicular Technology, IEEE Transactions on,2014,63(7):3369-3380.

[5]Eletreby R M,Elsayed H M,Khairy M M.CogLEACH:A spectrum aware clustering protocol for cognitive radio sensor networks[C]//Cognitive Radio Oriented Wireless Networks and Communications(CROWNCOM),2014 9th International Conference on.IEEE,2014:179-184.

[6]Zhang H,Zhang Z,Dai H,et al.Distributed spectrum-aware clustering in cognitive radio sensor networks[C]//Global Telecommunications Conference (GLOBECOM 2011),2011IEEE.IEEE,2011:1-6.

[7]Ozger M,Akan O B.Event-Driven spectrum-aware clustering in cognitive radio sensor networks[C]//INFOCOM,2013Proceedings IEEE.IEEE,2013: 1483-1491.

[8]Pei E,Han H,Sun Z,et al.LEAUCH:low-energy adaptive uneven clustering hierarchy for cognitive radio sensor network[J].EURASIP Journal on Wireless Communications and Networking,2015,2015(1):1-8.

[9]Salim S,Moh S,Choi D,et al.An Energy-Efficient and Compact Clustering Scheme with Temporary Support Nodes for Cognitive Radio Sensor Networks[J]. Sensors,2014,14(8):14634-14653.

[10]X.B.Wu,G.Chen,Sajal K.Das,Avoiding energy holes in wireless sensor networks with non-uniform node distribution,IEEE Transactions on Parallel and Distributed Systems 19(5)(2008)710–720.

[11]Villas L A,Boukerche A,Ramos H S,et al.DRINA:A lightweight and reliable routing approach for in-network aggregation in wireless sensor networks[J]. Computers,IEEE Transactions on,2013,62(4):676-689.

Summary of the invention

Solved by the invention technical problem is that, for the deficiencies in the prior art, it is provided that a kind of cognition wireless sensing Without bunch structure and the method for routing, the beneficially energy consumption of equalising network interior joint of common channel in device network, extend Network life.

The technical solution adopted in the present invention is:

Without bunch construction method of common channel in a kind of cognition wireless sensor network, if in cognition wireless sensor network There are an aggregation node SN (Sink Node), M naive user PUs and N number of secondary user SUs；N number of SUs, as the sensor node of collection data, is evenly distributed on the radius border circular areas as R centered by SN In, node density is ρ；

Given parameters r₀, with aggregation node SN closely, i.e. distance is less than r₀Sensor node SUs straight Connect and convey data to SN；Other SUs is organized by clustering architecture, and by bunch routing mode data Transfer to SN；

According to distance SN by closely to remote order, if bunch build operation by some wheel to build size uneven Dry bunch；Except the sensor node SUs, other SUs directly communicated with aggregation node SN is by uniquely Bunch cover；Each bunch structure of taking turns operates execution bunch radius calculation, bunch head i.e. CH selection, bunch channel choosing the most successively Select and formed with clustering architecture；Bunch head referred to as i-th obtained in i-th (i >=1) wheel bunch building process takes turns a bunch head, is formed Bunch be referred to as i-th and take turns bunch；

1st takes turns a bunch radius r₁Calculate and carry out according to below equation group:

Wherein, E₀For the unit interval maximum energy consumption of node in-plant with SN,For node data production rate； E_elecFor unit Bit data energy expenditure on transmission line；ε_fsAnd ε_ampPut for sensor wireless signal The big device energy expenditure parameter when near, long-distance transmissions；

E₁Be the 1st unit interval energy consumption taking turns bunch head, i.e. near SN bunch bunch head (without upper bunch head) Unit interval energy consumption；r₁It it is the 1st bunch radius taken turns bunch；For data aggregate rate, E_dfFor unit data aggregate Required energy consumption；d_1,sinkIt it is the 1st average distance taking turns bunch head and SN；

I-th (i > 1) takes turns bunch radius r_iCalculate and carry out according to below equation group:

E_iBeing the i-th unit interval energy consumption taking turns bunch head, i-th takes turns bunch head from SN farther out, has upper bunch head；r_iFor The i-th bunch radius taken turns bunch, r_i-1It it is then the i-th-1 bunch radius taken turns bunch；d_i,sinkIt is i-th to take turns the flat of bunch head and SN All distances,It it is the i-th average distance taking turns bunch head and its upper bunch head；ε_fsAnd ε_ampFor sensor wireless signal The amplifier energy expenditure parameter when near, long-distance transmissions.

Wherein,

d_1,sink=r₀+r₁；

$d_i^c=r_{i-1}+r_i;$

$d_{i,\sin k}=r_0+2{\Σ}_{j=1}^{i-1}{r}_j+r_i.$

Described bunch of head selects to comprise the following steps:

Definition nodal value NV is as the module selecting CH；

Taking turns a bunch structure operation for i-th, calculating with SN distance is l and l+2r_iBetween annular region in each Not by a bunch nodal value NV for the node covered, select there is the node of maximum node value NV as CH；

Wherein, node s_iNodal value NV (i) be defined as follows:

$\left\{\begin{array}{c}NV\left(i\right)=\mathrm{\α}f\left(E\right)+\mathrm{\β}g\left(C\right)+\mathrm{\γ}h\left(D\right)\\ f\left(E\right)=E_i^{res}/E_{ini}\\ g\left(C\right)=\left(\right|C_i|+|C_c\left|\right)/\left|C\right|\\ h\left(D\right)=e^{-\left|\frac{d_{s_i,\sin k}-l-r_i}{r_i}\right|}\end{array}\right.$

In formula, f (E), g (C) and h (D) represent energy factors, channel factors and the distance factor respectively, for joint Point dump energy, available channel and the normalized function of distance；α, β and γ are respectively f's (E), g (C) and h (D) Weight coefficient, and have alpha+beta+γ=1；E_iniFor node s_iPrimary power,For node s_iResidual energy Amount, | C_c| for node s_iWith the common signal channel number of its upper CH, | C_i| for node s_iNumber of available channels, | C | for Total number of channels,For node s_iWith the distance of SN, l be i-th take turns annular region inner boundary and SN away from From, have

Self information is sent to SN by each node, and self information includes: dump energy, available channel And position；SN is by introversion to outward, and i.e. by near to far selecting CH, each wheel all selects have maximum node value The node of NV is as CH.

Described bunch of Channel assignment comprises the following steps:

Definition channel value CV represents the value of channel, it is alternatively that the module of bunch channel；

Each the available channel to current cluster CH, calculates its channel value CV；Selection has maximum channel value The available channel of CV is as a bunch channel；

If the available channel of current cluster CH integrates as C_h, the available channel of upper bunch CH integrates as C_uph, C_c=C_h∩C_uphShared channel set for current cluster CH with upper bunch CH；Then current cluster CH is available Channel c_iChannel value CV_iIt is defined as follows:

In formula, | NM_i| and | NN_i| represent that bunch channel is c respectively_iTime bunch member and the quantity of via node；K is Preset constant, can value be 1.

Described clustering architecture forming process is: make s_mIt is bunch head of bunch H, when clustering architecture is formed, first by s_mBroadcast Bunch set up information CEM, CEM contains s_mPositional information；Then, receive CEM and meet about The SU of bundle condition is to s_mReply bunch addition information CJM, become bunch member of bunch H；Finally, s_mObtaining A bunch information about firms be sent to SN, SN and update node state and enter the clustering architecture forming process of next bunch；

Wherein, constraints refers to:

Make s_mCorresponding bunch channel and bunch radius are c_mAnd r_m；SUs_i(s_i∈ S) belong to bunch H and need to meet Below constraint:

(1) it is not belonging to other bunch, and each SU can only belong to one bunch；

(2)s_iAvailable channel in comprise a bunch channel c_m；

(3)s_mWith s_iBetween distance less than or equal to bunch radius r_m, i.e.

Without the method for routing of common channel, with SN closely, i.e. distance in a kind of cognition wireless sensor network Less than r₀SUs directly convey data to SN；Other SUs is by bunch structure described in claim 1～6 Construction method forms clustering architecture, and by following bunch of routing mode, data is transferred to SN；

(1) down hop of bunch member: if node to the distance of CH less than communication radius, then data are direct Send to CH；Otherwise, send the data to from CH nearest bunch in neighbor node；By bunch in many jump set Defeated transfer data to SN；

(2) down hop of CH:

For not having the CH of upper CH, CH directly sends the data to SN；

For there being the CH of upper CH, if CH has common signal channel with upper CH, then CH directly will Data send to its upper CH；Otherwise, CH sends data to via node, turning by via node It is dealt into and reaches upper CH；Note CH place bunch is current cluster, and upper CH place bunch is upper bunch, then at upstream In bunch, adjacent with current cluster, and the node that bunch channel is its available channel of current cluster be referred to as CH relaying joint Point；The node the most adjacent due to geographical position can perceive identical channel, and therefore via node is present in The junction of current cluster and upper bunch coverage or adjacent, via node can realize current cluster head with upper Data relaying between bunch head.

The principle of the present invention is:

Network model

If network has an aggregation node SN (Sink Node), M naive user PUs and N number of two grades of use Family SUs, N number of SUs are as the sensor node of collection data, and being evenly distributed on radius centered by SN is In the border circular areas of R, node density is ρ；

Following carried node, if no special instructions, refers both to the sensor node as SU.Each SU cycle Property ground perception environmental information generate data, all of SUs has identical data genaration rate P={p₁,p₂,…,p_MAnd S={s₁,s₂,…,s_NBe respectively PUs and SUs set；Network has Q Orthogonal channel, uses C={c₁,c₂,…,c_QRepresent, wherein c_iRepresent i-th channel；PUs can directly use The channel being authorized to, SUs monitors available channel by frequency spectrum perception and can only make with a kind of random manner With the channel not used by PUs；Each node i has an available channel collection, uses C_iRepresent；

In the present invention, it is assumed that the channel-aware stage is over and idle channel will not occur during cluster Change, say, that the present invention does not consider the frequency spectrum perception stage.SUs once after having disposed with regard to static not Dynamic, therefore, for any one node, its neighbor node will not change until node is dead. Two SU (s_iAnd s_j) can be in communication with each other and need to meet following two constraint simultaneously:

(1) there is identical idle channel, i.e.

(2)s_iAnd s_jDistance d between and_i,jAt the communication range allowed, i.e. communication radius R_tIn, i.e. d_i,j≤R_t。

Energy model

If the primary power of all SUs is all E in network_ini, and use the energy consumption model as document [10], I.e. node-node transmission l Bit data to d apart from required energy expenditure E_memberFor:

$\left\{\begin{array}{ccc}{E}_{menber}={\mathrm{lE}}_{elec}+{\mathrm{l\&epsiv;}}_{fs}{d}^2& if& d<d_0\\ E_{menber}={\mathrm{lE}}_{elec}+{\mathrm{l\&epsiv;}}_{amp}{d}^4& if& d\&GreaterEqual;d_0\end{array}\right.---\left(1\right)$

Wherein, E_elecFor unit Bit data energy expenditure on transmission line, circuit the coding used, Model, wave filter etc. determine.d₀Being a threshold value, value is launched with sensor wireless signal to be had with reception equipment Close, short range transmission (transmission range d ＜ d₀) time, the power amplification energy that unit of transfer's Bit data brings Consume as ε_fsd²；As the relatively big (d >=d of transmission range₀) time, barrier increases, and interference increases, and thus brings Per bit data power amplify sharply increase as ε_ampd⁴；ε_fsAnd ε_ampFor amplifier near, remote Energy expenditure parameter during transmission, determines when hardware designs.

Energy expenditure required for node reception l Bit data is:

E_R(l)=lE_elec (2)

In order to reduce energy consumption, a bunch head CH will collect data and first carry out polymerization and be then forwarded to down hop；Assume number According to aggregate rate it isE_dfEnergy consumption required for being polymerized for unit Bit data.

Bunch construction method

The present invention proposes bunch structure without common channel and routing mechanism (Non Common Channel Clustering and Routing, NCCCR), including bunch developing algorithm and routing mechanism thereof, routing mechanism exists Lower joint specifically describes.Wherein, bunch main target built is: whole network is divided into multiple region, and Guarantee in the case of network does not has overall common signal channel CCC, it is ensured that the degree of communication between region, and realize Balancing energy.Owing to network not having overall common signal channel CCC, thereby it is ensured that network-in-dialing degree is one Challenge.

Given parameters r₀, with SN closely, i.e. distance is less than r₀(closely) SUs is directly data Send SN to；Other SUs is organized by clustering architecture, and by a bunch routing mode, data is transferred to SN； NCCCR bunch of algorithm is by some take turns that operation builds that size is uneven some bunches；Except direct and SN node The SUs of communication, other SUs node is all by unique bunch of covering；Each take turns operation perform bunch radius calculation, Bunch head selects, bunch Channel assignment and clustering architecture are formed.NCCCR bunch of algorithm performs process as shown in annex Fig. 1.

Each wheel is built bunch for specific annular region node, and the size of bunch radius is according to real-time power Expenditure Levels Determine, realize network energy by non-homogeneous bunch and equalize.As shown in annex Fig. 2, with the most remote bunch of SN distance Radius is the biggest, and it is exactly in the drawings in gray area that algorithm i-th is taken turns, and selects bunch head, sets up several with r_iFor bunch Radius bunch, all nodes in overlay area.I-th data taking turns bunch head will take turns a bunch head via neighbouring i-th-1 Forward and arrive SN.Assume a bunch head CH_iData by its adjacent clusters head CH_jForward, then claim CH_jFor CH_i's Upper bunch head (Upstream CH).

The foundation of one bunch comprises four-stage: bunch radius calculation, bunch head selection, bunch Channel assignment, clustering architecture Formed.Next in NCCCR bunch of algorithm bunch of radius calculation, bunch head selection, bunch Channel assignment, clustering architecture Forming process carries out labor and explanation.

1, bunch radius calculation

In multihop network, node energy consumption is unbalanced is the key factor restricting network life, and the present invention uses non- The uniform bunch of energy consumption carrying out equalising network interior joint.The wireless sensor network that the present invention is paid close attention to is for collector node Produce data and converge at SN node, according to present invention assumes that and the feature of clustering architecture, data transmission procedure It is divided into three kinds of situations: (1) and the in-plant node of SN directly send data to SN；(2) to first Wheel produce bunch, that is to say near SN bunch, in bunch, data are transmitted directly to SN by a bunch head；(3) right Other from SN farther out bunch, in bunch, data are given upper bunch head by its bunch of hair, (many through other bunch of head Jump) forward arrival SN.Bunch head be responsible for converging bunch in data, simultaneously need to forward the data from other bunch, It it is the node of energy expenditure maximum.

Analyze the Energy Expenditure Levels of above-mentioned three kinds of situations:

(1) with SN in-plant node energy Expenditure Levels

If SU node is less than or equal to r to the distance of SN₀, then data are sent directly to SN by node； According to energy model, the unit interval maximum energy consumption of node is:

Wherein,For node data production rate, the value of a and b is according to r₀Whether more than d₀It is fixed to take, and sees formula (1), If r₀Less than d₀, then a=ε_fs, b=2；Otherwise, a=ε_amp, b=4.

(2) near SN bunch bunch head Energy Expenditure Levels

Use Ch₁Represent that the CH not having upper CH gathers, then Ch₁In CH directly transfer data to SN；In NCCCR algorithm, Ch₁In bunch head take turns bunch head of generation corresponding to NCCCR algorithm the 1st, Being referred to as down the 1st and take turns a bunch head, its bunch of radius is r₁, unit interval energy consumption is E₁。

A bunch head, unit interval energy consumption E is taken turns to the arbitrary 1st₁For bunch in bunch between the unit interval energy consumption sum that communicates, Such as formula (4):

$E_1=E_1^{in}+E_1^{out}---\left(4\right)$

In formula (4),WithBe respectively the 1st take turns bunch head for bunch in bunch between the unit interval energy consumption that communicates ；Ch₁In bunch head sum Num (Ch₁) be the region gross area divided by a bunch area, see formula (5).

$Num\left({\mathrm{Ch}}_1\right)=\frac{\mathrm{\&pi;}\&lsqb;{(r_0+2r_1)}^2-{r_0}^2\&rsqb;}{{{\mathrm{\&pi;r}}_1}^2}=\frac{4(r_0+r_1)}{r_1}---\left(5\right)$

Need Ch₁In the unit interval data total amount Data (Ch that forwards of each bunch of head₁) close with node for relevant area Degree and the product of data production rate, be shown in formula (6):

Be the 1st take turns bunch head for bunch in the unit interval energy consumption of data communication, computational methods are shown in formula (7):

Wherein,For data aggregate rate, E_dfFor the energy consumption required for unit data aggregate, d_1,sinkIt is the 1st to take turns The average distance of bunch head and SN, owing to bunch radius is r₁, bunch edge is about r with the beeline of SN₀, can Approximation value is d_1,sink=r₀+r₁；

Being the 1st to take turns bunch head unit interval communication energy consumption for bunch outer data, computational methods are shown in formula (8):

The value of a with b is similar, according to d with situation (3)_1,sinkWhether more than d₀It is fixed to take, and sees formula (1).

(3) other from SN farther out bunch bunch head Energy Expenditure Levels

Make Ch_xBunch head set produced for algorithm i-th (i > 1) wheel, the data of these bunch of head need to be turned by a upper bunch head Issue SN；Arbitrary i-th (i > 1) is taken turns bunch head, its unit interval energy consumption E_iFor bunch in bunch between communicate unit time Between energy consumption sum, such as formula (9):

$E_i=E_i^{in}+E_i^{out}---\left(9\right)$

If r_iIt is that the i-th bunch radius taken turns bunch, with situation (2) are analyzed in like manner, i-th can be obtained and take turns annular region bunch Head node number and this region bunch head need to forward bunch between data total amount, thus obtain formula (10) and (11).

Wherein, d_i,sinkSN is the i-th average distance taking turns bunch head and SN,It is that i-th to take turns bunch head upper with it The distance of CH.Owing to i-th takes turns the upstream bunch head of bunch head last round of (i-th-1 takes turns) it has been determined that i-th takes turns bunch The beeline of edge bunch and its upper CH be about r_i, its upper bunch radius is r_i-1, thenUpper with it Can approximate value isIn like manner can obtain formula (12):

$d_{i,si}=r_0+2{\&Sigma;}_{j=1}^{i-1}{r}_j+r_i---\left(12\right)$

To sum up can obtain formula (13).

From the above mentioned, E₁R in expression formula₁For unique unknown quantity, E_iR in expression formula_iFor unique unknown quantity；For reality Existing algorithm each take turns structure bunch energy consumption balance, then have E₀=E₁And E₀=E_i；So, if given One r₀, can calculate and meet E₀=E₁And E₀=E_iR₁And r_i。

2, bunch head selects

Assuming that take turns at the i-th of NCCCR bunch of algorithm, it is being l and l+2r with SN distance_iBetween annular region InNeed to investigate each node and carry out bunch head to select.NCCCR bunch of algorithm is combined Close and consider that the dump energy of node, number of available channels and three aspects of distance with upper bunch head select CH. One good CH should possess:

(1) dump energy is many.Need to consume more energy, in order to equalize net owing to CH compares other SU The energy consumption of network interior joint, CH should have more dump energy.

(2) number of available channels is many.CH needs and a bunch member communicates, in addition it is also necessary to lead to other CH Letter transfers data to SN.Owing to network not having the CCC of the overall situation, therefore, in order to ensure the connection of network Degree, CH should have more available channel.

(3) with upper bunch head apart from moderate, abundant node can be covered.

Based on principles above, definition nodal value NV (Node Value) is as the tolerance selecting CH；

Node s_iNodal value NV (i) be defined as follows formula (14):

$\left\{\begin{array}{c}NV\left(i\right)=\mathrm{\&alpha;}f\left(E\right)+\mathrm{\&beta;}g\left(C\right)+\mathrm{\&gamma;}h\left(D\right)\\ f\left(E\right)=E_i^{res}/E_{ini}\\ g\left(C\right)=\left(\right|C_i|+|C_c\left|\right)/\left|C\right|\\ h\left(D\right)=e^{-\left|\frac{d_{s_i,\sin k}-l-r_i}{r_i}\right|}\end{array}\right.---\left(14\right)$

In formula (14), f (E), g (C) and h (D) represent energy factors, channel factors and the distance factor respectively, Normalized function for residue energy of node, available channel and distance.α, β and γ be respectively f (E), g (C) and The weight coefficient of h (D), and have alpha+beta+γ=1；E_iniFor node s_iPrimary power,For node s_i's Dump energy, | C_c| for node s_iWith the common signal channel number of its upper CH, | C_i| for node s_iNumber of available channels, | C | is total number of channels,For node s_iWith the distance of SN, l is i-th to take turns annular zone boundary and SN Distance, has

The nodal value NV of node reflects the energy of node, number of available channels and distance situation, is by CH The major criterion selected.The present invention sets the ratio of α, β and γ as 1:1:1.At concrete application scenarios In, different α, β and γ-value can be set, be used for the residue energy of node in regulation bunch head selection course, can use Channel and the influence of node location.

Each node is required for self information is sent to SN, including: dump energy, available channel and position Put；Completed the selection work of bunch head by SN, advantageously reduce the energy consumption of SU.SN by introversion to outer (by Closely to remote) select CH, each take turns the joint selecting that in not by bunch node covered there is maximum node value NV Point is as CH.

3, bunch Channel assignment

Once a SU is chosen as CH, it is necessary to selects a bunch of channel, then carries out a bunch building process. Owing to network not having overall CCC, therefore bunch channel to bunch in and bunch between communication have critically important shadow Ring.

In order to ensure the degree of communication of network, select a bunch channel according to bunch number of members and via node number.That is, one Individual good bunch channel should possess:

(1) make to have clustered round more bunches of members；

(2) can make bunch to communicate with upper bunch.

Based on principles above, definition channel value CV (Channel Value) represents the value of channel, as Select the primary metric standard of bunch channel；

If the available channel of current cluster CH integrates as C_h, the available channel of upper bunch CH integrates as C_uph, C_c=C_h∩C_uphShared channel set for current cluster CH with upper bunch CH；

The present invention is by the available channel c of current cluster CH_iCV value define such as formula (15).

${\mathrm{CV}}_i=\left\{\begin{array}{cc}\left|{\mathrm{NM}}_i\right|& c_i\&Element;C_c\\ \frac{\left|{\mathrm{NM}}_i\right|\left|{\mathrm{NN}}_i\right|}{\left|{\mathrm{NN}}_i\right|+k}& otherwise\end{array}\right.---\left(15\right)$

In formula (15), | NM_i| and | NN_i| represent that bunch channel is c respectively_iTime bunch member and the quantity of via node； Via node, when bunch head does not has shared channel with a upper bunch head, with thinking both interim datas, is specifically defined and sees Lower joint routing mechanism part.K is preset constant, between k means the most greatly to tend to use shared channel to carry out bunch Communication；K is zero and shows, it is the same for using shared channel to communicate between carrying out with via node bunch, only considers Bunch number of members.It is 1 that the present invention arranges k, it is desirable to pay the utmost attention to shared channel.

In NCCCR bunch of algorithm, each channel value building the available channel according to current cluster CH taken turns bunch CV selects a bunch channel, selects have the available channel of maximum channel value CV as a bunch channel.

4, clustering architecture is formed

Once CH and bunch Channel assignment well after, clustering architecture formation stages begin to perform；

Make s_mBeing bunch head of bunch H, corresponding bunch channel and bunch radius are c_mAnd r_m；SUs_i(s_i∈ S) ownership Need to retrain below satisfied in bunch H:

(1) it is not belonging to other bunch, and each SU can only belong to one bunch；

(2)s_iAvailable channel in comprise a bunch channel c_m；

(3)s_mWith s_iBetween distance less than or equal to bunch radius r_m, i.e.

When clustering architecture is formed, first by CH broadcast bunch set up information (Cluster Establishment Message, CEM), CEM contains the positional information of CH；Then, receive CEM and meet constraints above SU to CH reply bunch add information (Cluster Joining Message, CJM), become bunch H bunch Member；Finally, CH is sent to SN, SN renewal node state bunch information about firms obtained and enters the next one Bunch clustering architecture forming process.In clustering architecture forming process, bunch head and other node proceed as follows:

(1) bunch head s_mCarry out following operation:

1. notify when the elected bunch of head receiving SN, and obtain bunch channel and bunch radius (c_mAnd r_mAfter), trigger Clustering architecture forming process, broadcasts CEM on each available channel；

2. when receiving bunch addition information CJM, comparison destination node identifies, if one's own CJM, then Therefrom obtain message source node information, and add it in a bunch membership table CMT (Cluster Member Table).

3. CMT table does not update in T time, then clustering architecture is formed and terminates, and CMT table is sent to SN, SN updates node state accordingly；T sets: sets bunch hair and goes out moment of CEM broadcast message as t₁, bunch head The moment receiving CJM information for the last time is t₂, then T=2 × (t₂-t₁)。

(2) other nodal operation

1., after receiving CEM, if having been received by this CEM before, then abandon this CEM and do not process； Otherwise, according to the information provided in CEM, above-mentioned 3 constraints are checked；If 3 constraints are satisfied by, then Perform 2.；Otherwise perform 3..

2. using leader cluster node as destination node, and the node identification of oneself, position and bunch radius r_mIt is encapsulated in In CJM message, broadcast CJM at each available channel；

If 3. present node and the distance of leader cluster nodeThen forward CEM at each available channel； Otherwise, abandon this CEM and do not process；

4. when receiving CJM, if the distance of present node and CJM source node is more than r_m, then this CJM is abandoned And do not process；Otherwise, this CJM message is forwarded at each available channel.

Clustering architecture forming process the radius of influence is r_mIn region and neighbouring node, network overhead is controlled.

Based on bunch routing mechanism

The essence of routing mechanism is to find next-hop node for sender, until it reaches SN.Designed by the present invention NCCCR routing mechanism be described as follows:

(1) distance with SN is less than or equal to r₀The down hop of node: in order to reduce energy consumption, if node arrives The distance of SN is less than or equal to r₀, then node directly sends the data to SN.

(2) down hop of bunch member: if node to the distance of CH less than communication radius, then data are direct Send to CH；Otherwise, send the data to from CH nearest bunch in neighbor node；Due to bunch at least deposit At a common signal channel (i.e. bunch channel), can by bunch in multi-hop transmission transfer data to SN；

(3) down hop of CH: owing to not having the CCC of the overall situation, the therefore selection of the down hop of CH in network Become the key of routing algorithm.The down hop of CH selects design as follows: if CH has public with upper CH Channel, then CH directly sends data to its upper CH (Path1 as in annex Fig. 3).Otherwise, CH sends data to via node, arrives upper CH by the forwarding of via node；Note CH place bunch For current cluster, upper CH place bunch is upper bunch, then in upper bunch, adjacent with current cluster, and current cluster The node that bunch channel is its available channel be referred to as the via node of CH；Due to the joint that geographical position is the most adjacent Point can perceive identical channel, and therefore via node is present in the handing-over of current cluster and upper bunch coverage Place or adjacent, the data that via node can realize between current cluster head and upper bunch head relay (such as annex figure Path2 in 3).

(4) down hop of via node

Owing to via node belongs to a bunch member, therefore the selection of via node down hop is as bunch member node.

Beneficial effect:

1) in multihop network, node energy consumption is unbalanced is the key factor restricting network life, and the present invention exists During bunch radius calculation, analyze the Energy Expenditure Levels of three kinds of situations: node energy in-plant with SN disappears Consumption situation, near SN bunch bunch head Energy Expenditure Levels, other from SN farther out bunch bunch head energy Expenditure Levels, by building the non-homogeneous bunch of energy consumption carrying out equalising network interior joint.

2) bunch developing algorithm of the present invention consider the dump energy of node, number of available channels and with upper bunch Three aspects of distance of head select a bunch head.Be conducive to the energy consumption of equalising network interior joint, extend network life.

3) a bunch channel is selected according to bunch number of members and via node number, it is ensured that the degree of communication of network.Bunch knot Being configured to process the radius of influence is r_mIn region and neighbouring node, network overhead is controlled.

4) owing to network not having overall CCC, the most existing routing algorithm can not effectively run.This Bright on the basis of bunch developing algorithm design go for the router that do not has the sight of overall CCC in network System.The routing mechanism of design, unlike existing algorithm, carrying out down hop selection when, not only considers Distance between sender and recipient and the dump energy of recipient, it is also contemplated that both common signal channels.

Accompanying drawing explanation

Fig. 1 is a bunch algorithm flow；

Fig. 2 takes turns schematic diagram for bunch developing algorithm i-th；

Fig. 3 is routed path；

Fig. 4 is that the present invention (NCCCR) contrasts with LEAUCH network life；

Fig. 5 is residue energy of node；Fig. 5 (a) is NCCCR interior joint dump energy, and Fig. 5 (b) is LEAUCH Interior joint dump energy；

Fig. 6 is NCCCR degree of communication.

Detailed description of the invention

The present invention utilizes OMNet++ that NCCCR is simulated emulation, and to calculation on the basis of emulation Effectiveness and the performance of method are analyzed.Network be a radius be the border circular areas of 200m, aggregation node (Sink Node, SN) is positioned at the center (0,0) of network area, has 5 naive user (Primary in network Users, PUs) and 500 secondary users (Secondary Users, SUs), the number of channel is 8.Each Individual node the most periodically perception environment also generates data, and its data genaration rate is 0.2.Other major experimental are joined Number is arranged as shown in table 1.

Table 1 experiment parameter is arranged

In terms of network life, balancing energy, network-in-dialing degree etc., NCCCR is carried out Performance Evaluation below.

1, network life

WSN is energy constraint, and node once runs out of energy will be dead.In the present invention, with live Nodes reflects the life-span of network.It is illustrated in figure 4 the relation of nodes and the data transfer wheel number lived. It can be seen that along with the increase of data transfer wheel number, use NCCCR and LEAUCH^[8]Time, The nodes lived in network is substantially uniform.In LEAUCH, node becomes the probability of bunch head and depends on joint The number of available channels of point, in candidate cluster head, the node of dump energy maximum becomes real bunch head.Bunch radius Only with the distance dependent of bunch head to SN.But in NCCCR, definition node value (Node Value, NV) for select bunch head, NV consider simultaneously the dump energy of node, channel situation (number of available channels with And with the common signal channel number of upper bunch head) and distance situation (with the distance of aggregation node and with upper bunch head Distance).Bunch radius is also the real-time power situation according to bunch head and the distance to down hop determines, thus Extend the life-span of network.

2, balancing energy

In a WSN, balancing energy has critically important impact for the life-span extending whole network.In order to prolong In the life-span of long network, the energy consumption balance of nodes is necessary.Fig. 5 shows first node in network Time dead, the dump energy situation of all nodes in network.As seen in Figure 5, NCCCR ratio is used LEAUCH is used to have more preferable balancing energy situation.In LEAUCH, distance aggregation node is near Node has higher energy expenditure.In NCCCR, the energy consumption relative equilibrium of all CH, this is because: Real-time power situation according to bunch head is carried out determinant radius and is advantageously implemented balancing energy.

3, network-in-dialing degree

Network-in-dialing degree is bunch critically important measurement index forming strategy.The most complete In the case of office CCC, network-in-dialing degree is particularly important.Network-in-dialing degree is defined as each CH's Average communication neighbor node number, for the via node number sum in upper CH number and relay area.Network-in-dialing Degree situation as shown in Figure 6, from fig. 6, it can be seen that NCCCR has reasonable connectivity.This be because of For, in NCCCR, in order to ensure the degree of communication of network, in the forming process of whole bunch, it is contemplated that bunch Number of members and via node number.

The present invention is not under network has the scene of overall common signal channel, it is proposed that a kind of balancing energy bunch build with Routing mechanism NCCCR.By using Uneven Cluster to realize the balancing energy of network, bunch radius according to Bunch head real-time power determines.And during route is formed, the selection of next-hop node have also contemplated that energy Amount factor.Owing to network not having overall CCC, in order to ensure the degree of communication of network, during cluster, Not only allow for the common signal channel between bunch head and bunch member, but also consider the common signal channel feelings between bunch head Condition.Test result indicate that, NCCCR can overcome in network the constraint not having CCC, with other algorithm phase Ratio has better performance to show.Above theory analysis and experiment simulation demonstrate effectiveness of the invention and advantage.

Claims (8)

1. without bunch construction method of common channel in a cognition wireless sensor network, it is characterised in that:

If cognition wireless sensor network has an aggregation node SN (Sink Node), M naive user PUs and N number of secondary user SUs；N number of SUs as gather data sensor node, be evenly distributed on In centered by SN, radius is the border circular areas of R, node density is ρ；

Given parameters r₀, sensor node in-plant with aggregation node SN, i.e. distance is less than r₀Sensing Device node SUs directly conveys data to SN；Other SUs is organized by clustering architecture, and by bunch road By mode, data are transferred to SN；

According to distance SN by closely to remote order, if bunch build operation by some wheel to build size uneven Dry bunch；Except the sensor node SUs, other SUs directly communicated with aggregation node SN is by uniquely Bunch cover；Each bunch structure of taking turns operates execution bunch radius calculation, bunch head i.e. CH selection, bunch channel choosing the most successively Select and formed with clustering architecture；I-th takes turns bunch head referred to as i-th obtained in bunch structure operation takes turns a bunch head, bunch title of formation It is i-th to take turns bunch, i >=1；

I-th takes turns a bunch radius r_iCalculate according to below equation group:

Wherein, E₀For the unit interval maximum energy consumption of sensor node in-plant with SN,For node data Production rate；E_elecFor unit Bit data energy expenditure on transmission line；ε_fsAnd ε_ampFor sensor without The line signal amplifier energy expenditure parameter when near, long-distance transmissions；For data aggregate rate, E_dfFor unit Energy consumption required for data aggregate；

E_iIt it is the i-th unit interval energy consumption taking turns bunch head；r_iIt is the i-th bunch radius taken turns bunch, r_i-1It is then i-th-1 to take turns Bunch bunch radius；d_i,sinkIt is the i-th average distance taking turns bunch head and SN,Be i-th take turns bunch head with its upper bunch The average distance of head, as i=1, the corresponding 1st takes turns a bunch head, without upper bunch head, then makes

Without bunch construction method of common channel in cognition wireless sensor network the most according to claim 1, It is characterized in that,

$d_i^c=r_{i-1}+r_i;$

During i=1, d_1,sink=r₀+r₁；

During i ＞ 1,

Without bunch construction method of common channel in cognition wireless sensor network the most according to claim 2, It is characterized in that, described bunch of head selects to comprise the following steps:

Definition nodal value NV is as the module selecting bunch head CH；

Taking turns a bunch structure operation for i-th, calculating with SN distance is l and l+2r_iBetween annular region in each Not by a bunch nodal value NV for the node covered, select there is the node of maximum node value NV as CH；

Wherein, node s_iNodal value NV (i) be defined as follows:

$\left\{\begin{array}{c}NV\left(i\right)=\mathrm{\&alpha;}f\left(E\right)+\mathrm{\&beta;}g\left(C\right)+\mathrm{\&gamma;}h\left(D\right)\\ f\left(E\right)=E_i^{res}/E_{ini}\\ g\left(C\right)=\left(\right|C_i|+|C_c\left|\right)/\left|C\right|\\ h\left(D\right)=e^{-\left|\frac{d_{s_i,\sin k}-l-r_i}{r_i}\right|}\end{array}\right.$

In formula, f (E), g (C) and h (D) represent energy factors, channel factors and the distance factor respectively, for joint Point dump energy, available channel and the normalized function of distance；α, β and γ are respectively f's (E), g (C) and h (D) Weight coefficient, and have alpha+beta+γ=1；E_iniFor node s_iPrimary power,For node s_iResidual energy Amount, | C_c| for node s_iWith the common signal channel number of its upper CH, | C_i| for node s_iNumber of available channels, | C | for Total number of channels,For node s_iWith the distance of SN, l is i-th to take turns bunch and to build an operation annular region inner boundary With the distance of SN, have

Without bunch construction method of common channel in cognition wireless sensor network the most according to claim 3, It is characterized in that, self information is sent to SN by each node, and self information includes: dump energy, Available channel and position；SN is by introversion to outward, and i.e. by near to far selecting CH, each wheel all selects to have The node of big nodal value NV is as CH.

Without bunch construction method of common channel in cognition wireless sensor network the most according to claim 4, It is characterized in that, described bunch of Channel assignment comprises the following steps:

Definition channel value CV represents the value of channel, it is alternatively that the module of bunch channel；

Each the available channel to current cluster CH, calculates its channel value CV；Selection has maximum channel value The available channel of CV is as a bunch channel；

If the available channel of current cluster CH integrates as C_h, the available channel of upper bunch CH integrates as C_uph, C_c=C_h∩C_uphShared channel set for current cluster CH with upper bunch CH；Then current cluster CH is available Channel c_iChannel value CV_iIt is defined as follows:

In formula, | NM_i| and | NN_i| represent that bunch channel is c respectively_iTime bunch member and the quantity of via node；K is Preset constant.

Without bunch construction method of common channel in cognition wireless sensor network the most according to claim 4, It is characterized in that, k is 1.

Without bunch construction method of common channel in cognition wireless sensor network the most according to claim 6, It is characterized in that, described clustering architecture forming process is: make s_mIt is bunch head of bunch H, when clustering architecture is formed, first By s_mInformation CEM is set up in broadcast bunch, contains s in CEM_mPositional information；Then, CEM is received also And meet the SU of constraints to s_mReply bunch addition information CJM, become bunch member of bunch H；Finally, s_m? Bunch information about firms obtained is sent to SN, SN and updates the clustering architecture forming process of next bunch of node state entrance；

Wherein, constraints refers to:

Make s_mCorresponding bunch channel and bunch radius are c_mAnd r_m；SU s_i(s_i∈ S) belong to bunch H and need to meet Below constraint:

(1) it is not belonging to other bunch, and each SU can only belong to one bunch；

(2)s_iAvailable channel in comprise a bunch channel c_m；

(3)s_mWith s_iBetween distance less than or equal to bunch radius r_m, i.e.

8. without the method for routing of common channel in a cognition wireless sensor network, it is characterised in that with SN Closely, i.e. distance is less than r₀SUs directly convey data to SN；Other SUs passes through claim Bunch construction method described in 1～7 forms clustering architecture, and by following bunch of routing mode, data is transferred to SN:

(1) down hop of bunch member: if node to the distance of CH less than communication radius, then data are direct Send to CH；Otherwise, send the data to from CH nearest bunch in neighbor node；By bunch in many jump set Defeated transfer data to SN；

(2) down hop of CH:

For not having the CH of upper CH, CH directly sends the data to SN；

For there being the CH of upper CH, if CH has common signal channel with upper CH, then CH directly will Data send to its upper CH；Otherwise, CH sends data to via node, turning by via node It is dealt into and reaches upper CH；Note CH place bunch is current cluster, and upper CH place bunch is upper bunch, then at upstream In bunch, adjacent with current cluster, and the node that bunch channel is its available channel of current cluster be referred to as CH relaying joint Point.