Energy Efficinet Cluster Head Selection and Data Convening in Wireless Sensor Networks

Transcription

1 Idia Joural of Sciece ad Techology, Vol 9(15), DOI: /ijst/216/v9i15/77749, April 216 ISSN (Prit) : ISSN (Olie) : Eergy Efficiet Cluster Head Selectio ad Data Coveig i Wireless Sesor Networks E. Themozhi 1 * ad S. Auditha 2 1 Departmet of Iformatio Techology, St Peters Uiversity, Cheai - 654, Tamil Nadu, Idia; themozhistpeters@gmail.com 2 Departmet of Computer Sciece ad Egieerig, PRIST Uiversity, Kumbakoam , Tamil Nadu, Idia Abstract: Objectives: Wireless Sesor Network (WSN) cotais several distributed sesor odes. Those odes are limited i power. Rechargig the battery of the sesor ode is cosidered to be a difficult task. The key itet of this paper is to achieve better eergy efficiecy i WSNs. Methods/Aalysis: I this paper, a Eergy Efficiet Cluster Head selectio ad Data Coveig (EECHDC) is proposed i WSNs. Cluster Head (CH) selectio is based o residual eergy, coectio desity, capability of the ode ad degree of the ode. Fidigs: The EECHDC scheme has proved better performace i terms of packet delivery rate, packet loss rate, delay, throughput ad residual eergy durig data trasmissio. Applicatio/ Improvemets: Simulatio results show that the EECHDC achieves higher eergy efficiecy compared to the existig schemes. Keywords: Capability, Cluster Head, Coectio Desity, Degree, Residual Eergy, Wireless Sesor Network 1. Itroductio Wireless Sesor Network (WSN) cosists of large umber of static odes that are able to iterface with each other for trasferrig data more proficietly ad autoomously 1. It is a growig field with more umber of applicatios. It is used for several evirometal applicatios that exteds to military applicatios ad health related applicatios. The process of dividig the etire commuicatio etwork ito itercoected sub-structures is called clusters. I each cluster, a particular ode is elected as the Cluster Head (CH). The CH is selected based o a specific or a combiatio of metrics such as idetity; mobility; degree; desity; weight etc. I the etwork, the CH plays the coordiator role withi its substructure. All CHs commuicates with other CHs ad withi its cluster each CH acts as a temporary base statio. However CH must be able to commuicate with the odes of other clusters which ca be directly or through the respective CH or through gateways. Commuicatio is doe i three steps. Iitially the CH receives the data set by its members. Next it compresses the data ad fially trasmits the data to the Base Statio (BS) or other CH. Suitable CH ca reduce the utilizatio of eergy ad ehaces the etwork lifetime. Oe CH per cluster must be selected durig a electio process, because multiple CHs withi a sigle cluster ca give rise to cluster reformatio, Quality of Service (QoS) ad routig maagemet issues. The key cotributios of EECHDC are as follows: The desig of a ovel Cluster Head (CH) selectio algorithm i WSNs, that selects the CHs to create a coected etwork. Performig extesive simulatio experimets to calculate the performace of EECHDC algorithm by meas of several metrics. The various existig methods are described as follows: Low Eergy Adaptive Clusterig Hierarchy (LEACH) protocol 2 is a cluster based protocol that has ivolved its eergy efficiecy, load balacig properties ad simplicity. This protocol orgaizes the odes ito clusters with oe ode from each cluster servig as a CH ad the rest of the ode as cluster members. The LEACH protocol *Author for correspodece

2 Eergy Efficiet Cluster Head Selectio ad Data Coveig i Wireless Sesor Networks arbitrarily selects fixed odes as CH. The CHs gathers the data from their cluster members ad combied it before sedig it to the other CHs or BS. The cluster costructio step is repeated after drop of time so that differet odes are give aopportuity to become CHs. Power Efficiet Gatherig i Sesor Iformatio System 3 (PEGASIS) that has a ehacemet over LEACH protocol. I PEGASIS, each ode itercommuicates oly with the closest adjacet ad trasmittig to the BS, thus miimizig the amout of eergy exhausted per roud. Usig greedy algorithm, the odes are structured to form a chai. After that the BS ca compute this chai ad broadcast it to all the sesor odes i the etwork. The PEGASIS is better tha LEACH by restrictig the umber of trasmissios ad removig the overhead of dyamic cluster formatio. Load-Balaced Clusterig Algorithm with Distributed Self-Orgaizatio for WSNs 4 (DSBCA), a load balaced clusterig algorithm deals the stochastic distributio of sesor odes. This algorithm geerates balaced clusters. The radius of the cluster ca be determied by the desity ad the distace from the BS. With farther distace from the BS ad lower coectivity desity the cluster radius is larger. Each member i the cluster calculates its weight. The ode with highest weight is take as the CH. Weight is calculated based o residual eergy, umber of eighbors ad the umber of times the ode was elected as CH. DSBCA also limits the umber of odes i a cluster. The mai drawback is that it cosumes more eergy for commuicatio ad also it takes more time for calculatig weight durig CH selectio. A clusterig based techique for data moitorig 5 i WSNs is a evet drive clusterig techique that reports data oly whe a evet occurs. I this techique, a threshold is set ad the sesors data with sigificat chage more tha the threshold are trasmitted to the BS. Upo the detectio of a evet the sesors are grouped ito clusters ad oe sesor was selected as CH ad that will sed data to BS i the etwork. The drawback is that it is ot suitable for applicatios which require cotiuous moitorig. A ew clusterig based o K-meas algorithm 6 was used to form the clusters based o Euclidea distaces betwee odes. This algorithm selects k-odes radomly as CHs. Accordig to the Euclidea distace, odes decide its CH. The cetroid of the cluster is thus calculated. A ode which is ear to the cetroid will be take as ew CH ad the it does reclusterig based o the ew CH i the etwork. This approach miimizes the eergy cosumptio for the sesor odes to sed data to the CH. But this K-meas algorithm speds most of the time i clusterig ad reclusterig process ad thus leads to greater eergy cosumptio. A Mobility Predictio Based Clusterig (MPBC) scheme for Ad Hoc Networks 7 ivolves the relative mobility of odes as a criterio i the CH selectio. The odes with low mobility as selected as CHs because they provide more stability i the etwork. A Flexible Weighted Clusterig Algorithm based o Battery Power 8 (FWCABP) for MANETs was proposed to maitai stable clusters by prevetig odes with low battery power from beig elected as a CH. This miimizes the umber of clusters ad the commuicatio overhead of the etwork. A grid clusterig routig protocol for WSN 9 (GROUP) provides efficiet ad scalable data packet routig for WSNs. I this protocol, the CHs are arraged i a grid maer ad sik eergetically ad arbitrarily establish the cluster grid. Greed Seed (GS) is a ode withi a give commuicatio rage from the sik. The queries from sik to odes are propagated from GS to its CHs. Ehaced LEACH-R 1 itroduced the eergy efficiecy clusterig algorithm for WSN that is based o Low Eergy Adaptive Clusterig Hierarchy. I this protocol cotai both the advace ad ormal odes, though the advace odes have more eergy tha the ormal odes. This protocol improves the regios of cluster based hierarchical process usig heterogeeity parameters. A hierarchical routig algorithm with high eergy efficiecy amed EECA 11 is costructed by usig distace ad residual eergy. For cluster costructio, the first step is to elect a cluster head. Therefore distace ad residual eergy of all odes is calculated i a oe hop eighbor who helps to select cluster head by usig CH rotatio. From those results, ew CH would be elected. The mai objective is to reduce the cosumptio of eergy i its applicatio. The mai objective of this paper is to balace the load amog the dissimilar clusters i the etwork such that lifetime of the etwork is improved by usig Load Balaced Clusterig Algorithm (LBCA). I LBCA 12, the odes are grouped ito clusters such that etwork is cotrolled by the gateway istead of CH. This ehaces the performace of the etwork. Load Balaced Clusterig Algorithm, improves the commuicatio amog dissimilar sesors i the etwork. To aalyze the effectiveess of the techique, the performace of WSNs spread over umerous dissimilar routig procedures are cosidered. 2 Vol 9 (15) April Idia Joural of Sciece ad Techology

3 E. Themozhi ad S. Auditha 2. Eergy Efficiet Cluster Head Selectio Most of the existig clusterig algorithms use oly oe metric: Power, lower-id, highest degree, mobility, ode coectivity to elect cluster head. Weight based cluster algorithms use combiatio of degree; mobility; umber of members ad ode stability. Noe of the algorithms use the combiatio of importat metrics. I ECSHA 13, CH is selected based o the umber of eighbors, residual eergy ad distace of a ode from the middle of the cluster. CH selectio is restricted to odes ear the cetre of the cluster oly. It affects the performace of the etwork. Hece we have proposed a algorithm to elect a CH i WSNS based o the parameters Residual Eergy (E res ), Coectio Desity (CD), Capability of the ode (C) ad Degree of the ode (D). The followig assumptios are made i this proposed work. The positio of sesor odes ad BS are fixed. The liks are symmetric. The odes are radomly distributed. All the sesor odes sese the eviromet ad they have the data to sed to BS. Distace betwee two odes is computed based o Received Sigal Stregth Idicator (RSSI). The etwork is represeted by the graph G(V, E) where V is the set of sesors ad E is the set of edges. The flow chart for EECHDC scheme is show i Figure 1. The algorithm for CH selectio ca be broke dow ito the followig: 2.1 Setup Phase I this phase, BS broadcasts a message to the sesor odes. The sesor odes that receive the broadcast message will leave a reply message which icludes the positio of the ode, ode s ID ad the distace betwee the odes. 2.2 Cluster Head Selectio Phase I CH selectio phase, all the sesor odes will keep their receivers o. The CHs are selected from all the sesor odes preset iside the commuicatio etwork. The CH selectio is based o residual eergy, coectio desity, capability of the ode ad the degree of the ode Residual Eergy The eergy remaiig i a ode at the curret istace of time is called as residual eergy (E res ). For a ode to become Figure 1. EECHDC strategy. a CH it should have more residual eergy compared to its eighborig odes. Cosider E i be the iitial eergy of the ode. The eergy cosumed by the ode (E(t)) after t time period is give by the Equatio (1). E(t) = ( tpkts a) + ( rpkts b) (1) where tpkts = Number of data packets trasmitted. rpkts = Number of data packets received. a, b = Costats i the rage (,1). The E res of a ode at time t is computed usig the Equatio (2) Coectio Desity E res = E i E(t) (2) Coectio Desity (CD(x)) of the ode is calculated from ratio of average distace from other odes i same cluster ad iter-ode distace. Coectio desity is give i Equatio (3). N( x) CD(x)= [( x, y) E/ y Nx ( )]/ Nx ( ) (3) 1 where N(x) = Number of eighbors of ode x. Y = ode Capability of the Node The ability of the ode to become a CH from a group of sesor odes is termed as the capability of the ode. A large value of capability idicates more ability of a ode to become a CH. If capability>threshold (T) % (1 to 1), the the ode becomes a challeger ode for beig a CH. The threshold value must be selected such Vol 9 (15) April Idia Joural of Sciece ad Techology 3

4 Eergy Efficiet Cluster Head Selectio ad Data Coveig i Wireless Sesor Networks that it guaratees eough challeger odes for quality CH selectio Degree of the Node The degree of the ode x deoted by d(x) is the umber of eighbors of odex (i.e.) the umber of liks. CH is selected based o the ode with maximum umber of eighbors. A ode of d(x) = is isolated (o eighbors). The degree of graph G is deoted i Equatio (4). 2.3 Data Collectio Phase d(g) = {d(x)} (4) Oce the CH is selected ad is kow to all the cluster members, the cluster members sed the data packets to their CHs. O receivig the data packets from the cluster members, the CH performs data aggregatio. 2.4 Data Trasmissio Phase I data trasmissio phase, the aggregated data packets are relayed to BS through several CHs if the sik is ot i commuicatio rage or directly to sik if the sik is withi the commuicatio rage. 3. Performace Evaluatio The performace of the proposed scheme is aalyzed by usig NS2. NS2 is a discrete evet time drive simulator which is used to maily model the protocols i the etwork. The odes are distributed i the simulatio eviromet. The parameters used for the simulatio of the proposed scheme are tabulated i Table 1. The simulatio of the proposed scheme has 5 odes deployed i the simulatio area 9 9. The odes commuicate with each other by usig the commuicatio protocol User Datagram Protocol (UDP). The traffic is hadled usig the traffic model CBR. The radio waves are propagated by usig the propagatio model two ray groud. The performace of the EECHDC scheme is evaluated by the parameters packet delivery rate, packet loss rate, average delay, throughput, residual eergy ad etwork lifetime. 3.1 Packet Delivery Rate The Packet Delivery Rate (PDR) is the rate of umber of packets delivered to all receivers to the umber of data packets set by the source ode. The PDR is calculated by Equatio (5). PDR = PacketsReceived PacketsSet (5) From Figure 2, the PDR of the proposed schemeis icreased by 18% compared to the existig scheme ECSHA. This is because of the QoS improved durig the estimatio of the coectio desity ad residual eergy parameters i the route selectio process of the method proposed. The greater value of PDR meas good performace of the etwork protocol. 3.2 Packet Loss Rate The Packet Loss Rate (PLR) is the rate of the umber of packets dropped to the umber of data packets set. The formula used to calculate the PLR is calculated i Equatio (6). Table 1. Simulatio parameters Parameter Value Chael Type Wireless Chael Simulatio Time 1 ms Number of odes 5 MAC type Traffic model CBR Simulatio Area 9 9 Trasmissio rage 25 m Network iterface Type Wireless Phy Figure 2. Packet delivery rate. 4 Vol 9 (15) April Idia Joural of Sciece ad Techology

5 E. Themozhi ad S. Auditha PLR = PacketsDropped PacketsSet (6) The PLR of the EECHDC scheme is lower by more tha 11% compared to the existig ECSHA i Figure 3. Lower the PLR, higher the performace of the etwork. 3.3 Average Delay The average delay is defied as the time differece betwee the previous packet received ad the curret packet set. It is measured by Equatio (7). ( ) 1 Average Delay = Pkt Recvd Time Pkt SetTime (7) Figure 4 shows that the average delay is low by more tha 23% for the proposed scheme RVSPR tha the existig ECSHA. The miimum value of delay meas higher value of the throughput i the etwork. This graph justifies the fact that the hidraces i the commuicatio are lesser amog the odes i the etwork, which shows a sigificat average delay. 3.4 Throughput Throughput is the average of successful messages delivered to the destiatio. The average throughput is estimated usig Equatio (8). PktsReceived ( )* PktSize Throughput = 1 (8) Figure 5 shows that the EECHDC scheme has more tha 18% throughput compared to the existig scheme ECSHA. Sice there is icrease i packet delivery ratio, the throughput is automatically icreased. 3.5 Residual Eergy The amout of eergy residual i a ode at the preset istace of time is called as residual eergy. The eergy efficiecy is show i the Figure 6. Figure 3. Packet loss rate. Figure 5. Throughput. Figure 4. Average delay. Figure 6. Residual eergy. Vol 9 (15) April Idia Joural of Sciece ad Techology 5

6 Eergy Efficiet Cluster Head Selectio ad Data Coveig i Wireless Sesor Networks Figure 6 shows that the residual eergy of the etwork is better for the EECHDC scheme whe compared with the existig ECSHA. 4. Coclusio Lots of research are goig o i eergy efficiecy which is a importat issue i WSN. Cluster Head (CH) selectio plays a vital role i clusterig based techiques. I this paper, a Eergy Efficiet Cluster Head selectio scheme for Data Coveig (EECHDC) i WSNs is proposed. CH selectio is based o residual eergy, coectio desity, capability of the ode ad degree of the ode. Simulatio results show that the EECHDC algorithm achieve higher eergy efficiecy compared to the ECSHA scheme. 5. Refereces 1. Sheikhpour R, Jabbehdari S, Khadem-Zadeh A. Compariso of eergy efficiet clusterig protocols i heterogeeous Wireless Sesor Networks. Iteratioal Joural of Advaced Sciece ad Techology. 211 Nov; 36: Heizelma WR, Chadrakasa A, Balakrisha H. Eergy-efficiet commuicatio protocol for wireless microsesor etworks. Proceedigs of the 33rd IEEE Aual Iteratioal Coferece o System Scieces; Hawaii. 2 Ja 4-7. p Lidsey S, Raghavedra CS. PEGASIS: Power-Efficiet Gatherig i Sesor Iformatio Systems. Proceedigs of the IEEE Coferece o Aerospace; Los Ageles, CA p Liao Y, Qi H, Li W. Load balaced clusterig algorithm with distributed self-orgaizatio for Wireless Sesor Networks. IEEE Sesors Joural. 213 May; 13(5): Adulyasas A, Su Z, Wag N. A evet-drive clusterig based techique for data moitorig i Wireless Sesor Networks. IEEE Coferece o Cosumer Commuicatios ad Networkig; Las vegas, NV. 213 Ja p Park GY, Kim H, Jeog HW, You HY. A ovel cluster head selectio method based o K-meas algorithm for eergy efficiet Wireless Sesor Network. IEEE 27th Iteratioal Coferece o Advaced Iformatio Networkig ad Applicatios; Barceloa. 213 Mar p Ni M, Zhog Z, Zhao D. MPBC: A Mobility Predictio-Based Clusterig Scheme for ad hoc etworks. IEEE Trasactios o Vehicular Techology. 211 Nov; 6(9): Fathi A, Taheri H. Ehace Topology Cotrol Protocol (ECEC) to coserve eergy based clusterig i wireless ad hoc etworks. 3rd IEEE Iteratioal Coferece o Computer Sciece ad Iformatio Techology; Chegdu. 21 Jul p Yu L, Wag N, Zhag W, Zheg C. GROUP: A Grid-Clusterig Routig Protocol for Wireless Sesor Networks. IEEE Iteratioal Coferece o Wireless Commuicatios Networkig ad Mobile Computig; Wuha. 26 Sep p Kaur J, Gaba GS, Miglai R, Pasricha R. Eergy Efficiet ad Reliable WSN based o Improved Leach-R Clusterig Techiques. Idia Joural of Sciece ad Techology. 215 Jul; 8(16): Syed SSA, Kumara TS. A Eergy Efficiecy Distributed Routig Algorithm based o HAC Clusterig Method for WSNs. Idia Joural of Sciece ad Techology. 214 Nov; 7(S7): Revathi AR, Sathi B. Efficiet clusterig for Wireless Sesor Networks usig Evolutioary Computig. Idia Joural of Sciece ad Techology. 215 Jul; 8(14): Varalakshmi P, Nadakumar R, Umadevi M. A Efficiet Cluster Head Selectio ad Aggregatio for Wireless Sesor Networks. Iteratioal Coferece o Commuicatios ad Sigal Processig (ICCSP); Melmaruvathur. 214 Apr 3-5. p Vol 9 (15) April Idia Joural of Sciece ad Techology