E-DEEC- Enhanced Distributed Energy Efficient Clustering Scheme for heterogeneous WSN

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1 21 1st Internatonal Conference on Parallel, Dstrbuted and Grd Comutng (PDGC - 21) E-DEEC- Enhanced Dstrbuted Energy Effcent Clusterng Scheme for heterogeneous WSN Parul San Deartment of Comuter Scence & Engneerng, Dr. B. R. Ambedkar Natonal Insttute of Technology, Jalandhar,Punjab, 14411, Inda sgs112@gmal.com Ajay.K.Sharma Deartment of Comuter Scence & Engneerng, Dr. B. R. Ambedkar Natonal Insttute of Technology, Jalandhar,Punjab, 14411, Inda sharmaajayk@ntj.ac.n Abstract Many routng rotocols on clusterng structure have been roosed n recent years. In recent advances, achevng the energy effcency, lfetme, deloyment of nodes, fault tolerance, latency, n short hgh relablty and robustness have become the man research goals of wreless sensor network. Many routng rotocols on clusterng structure have been roosed n recent years based on heterogenety. We roose EDEEC for three tyes of nodes n rolongng the lfetme and stablty of the network. Hence, t ncreases the heterogenety and energy level of the network. Smulaton results show that EDEEC erforms better than SEP wth more stablty and effectve messages. 1. Introducton Wreless sensor networks s the network consstng of hundreds of comact and tny sensor nodes whch senses the hyscal envronment n terms of temerature, humdty, lght, sound, vbraton, etc. These sensor nodes gather the data from the sensng feld and send ths nformaton to the end user. These sensor nodes can be deloyed on many alcatons. Current wreless sensor network s workng on the roblems of low-ower communcaton, sensng, energy storage, and comutaton. Herarchcal-based routng s a cluster based routng n whch hgh energy nodes are randomly selected for rocessng and sendng data whle low energy nodes are used for sensng and send nformaton to the cluster heads. Clusterng technque enables the sensor network to work more effcently. It ncreases the energy consumton of the sensor network and hence the lfetme [1]. Clusterng can be done n two tyes of networks, homogeneous and heterogeneous networks on the bass of energy. Homogeneous are those n whch nodes have same ntal energy whle heterogeneous networks are those n whch nodes have dfferent ntal energy. Many Clusterng algorthms have been roosed for homogeneous wreless sensor networks such as LEACH [2], PEGASIS [3], and HEED [4] whch does not erform well n heterogeneous networks. SEP [5] uses two tyes of nodes normal and advanced nodes. Advanced nodes have more energy than normal ones. It rolongs the stablty erod of the network. It also does not ft for networks havng more than two tyes of energy. DEEC [6] s clusterng-based algorthm n whch cluster head s selected on the bass of robablty of rato of resdual energy and average energy of the network. In ths algorthm, node havng more energy has more chances to be a cluster head. It rolongs the lfetme of the network. Ours E-DEEC follows the thoughts of DEEC and adds another tye of node called suer nodes to ncrease the heterogenety. The rest of the aer s organzed as follows: Secton 2 contans the related work done. Secton3 exlans the rado energy dssaton model, Secton 4 and 5 gves the network model and assumton used followed by secton 6 whch descrbes the cluster head selecton method. Secton 7 lsts the erformance metrcs used for the smulaton whch gves the results shown n secton Related Work For homogeneous wreless sensor networks Henzelman, et. al. [2] ntroduced a herarchcal clusterng algorthm for sensor networks, called Low Proceedngs of the 1st Internatonal Conference on Parallel, Dstrbuted and Grd Comutng (PDGC-21) /1/$ IEEE

2 Energy Adatve Clusterng Herarchy (LEACH). LEACH s a cluster-based rotocol, whch ncludes dstrbuted cluster formaton. LEACH randomly selects a few sensor nodes as cluster heads (CHs) and rotates ths role to evenly dstrbute the energy load among the sensors n the network [1]. PEGASIS [3] s a chan based rotocol whch avods cluster formaton and uses only one node n a chan to transmt to the BS nstead of usng multle nodes. Manjeshwar et. al. roosed Threshold senstve Energy Effcent sensor Network rotocol (TEEN) [7]. TEEN ursues a herarchcal aroach along wth the use of a data-centrc mechansm. the cluster head broadcasts two thresholds to the nodes. These thresholds are hard and soft thresholds for sensed attrbutes. TEEN s not good for alcatons where erodc reorts are needed snce the user may not get any data at all f the thresholds are not reached. Manjeshwar et. al. The Adatve Threshold senstve Energy Effcent sensor Network rotocol (APTEEN) [8] ams at both caturng erodc data collectons and reactng to tme-crtcal events. The archtecture s same as n TEEN. The man drawbacks of TEEN and APTEEN are the overhead and comlexty of formng clusters n multle levels mlementng thresholdbased functons and dealng wth attrbute-based namng of queres. Henzelman, et. al. [9] roosed LEACHcentralzed (LEACH-C), a rotocol that uses a centralzed clusterng algorthm and the same steadystate rotocol as LEACH. SEP (Stable Electon Protocol) [5] s roosed n whch every sensor node n a heterogeneous two-level herarchcal network ndeendently elects tself as a cluster head based on ts ntal energy relatve to that of other nodes. L Qng et. al. roosed DEEC [6] (Dstrbuted energy effcent Clusterng) algorthm n whch cluster head s selected on the bass of robablty of rato of resdual energy and average energy of the network. Smulatons show that ts erformance s better than other rotocols. B. Elbhr et al, roosed SBDEEC (Stochastc and Balanced Develoed Dstrbuted Energy-Effcent Clusterng (SBDEEC) [1] SBDEEC ntroduces a balanced and dynamc method where the cluster head electon robablty s more effcent. Moreover, t uses a stochastc scheme detecton to extend the network lfetme. Smulaton results show that ths rotocol erforms better than the Stable Electon Protocol (SEP) and the Dstrbuted Energy- Effcent Clusterng (DEEC) n terms of network lfetme. Our E-DEEC (Enhanced Dstrbuted Energy Effcent Clusterng) scheme s based on DEEC wth addton of suer nodes. We have extended the DEEC to three-level heterogenety. Smulaton results show that E-DEEC erforms better than SEP whch s too extended to three-level scheme. 3. Rado Energy Dssaton Model Rado Energy Model used s based on [2, 9]. Energy model for the rado hardware energy dssaton where the transmtter dssates energy to run the rado electroncs and the ower amlfer, and the recever dssates energy to run the rado electroncs s shown n Fgure 1 [2, 9]. Fgure 1. Rado Energy Dssaton Model Here both the free sace (d 2 ower loss) and the multath fadng (d 4 ower loss) channel models were used, deendng on the dstance between the transmtter and recever [2, 9]. Power control can be used to nvert ths loss by arorately settng the ower amlfer f the dstance s less than a threshold d o, the free sace model s used; otherwse, the multath model s used. Thus, to transmt an L-bt message a dstance, the rado exends E Tx L,d= L.E elec+ L.E fs.d 2 f d<do L.E elec + L.E am.d 4 (1) f ddo The electroncs energy, E elec, deends on factors such as the dgtal codng, modulaton, flterng, and sreadng of the sgnal, whereas the amlfer energy, E fs.d 2 or E am.d 4, deends on the dstance to the recever and the accetable bt-error rate [2,9]. Value of threshold dstance d o s gven by do= E fs (2) E am 4. Network Model Sensor network s used wth N nodes n M X M network feld as shown n Fgure 2. There are three tyes of sensor nodes [11, 12]. They are normal nodes, advanced nodes and suer nodes. Let m be the fracton of the total number of nodes N, and mo s the ercentage of the total number of nodes whch are equed wth b tmes more energy than the normal nodes, called as suer nodes, the number s N.m.mo. The rest N.m.(1-mo) nodes are equed wth a tmes more energy than the normal Proceedngs of the 1st Internatonal Conference on Parallel, Dstrbuted and Grd Comutng (PDGC-21) 26

3 nodes; called as advanced nodes and remanng N.(1- m) as normal nodes Fgure 2. Random Wreless Sensor network The total ntal energy of the three-level heterogeneous networks s gven by: E total =N.1-m.E o +N.m.1-mo.1+a.E o +N.m.mo.E o.1+b =N.E o.1+m.a+mo.b (3) Therefore, the three-level heterogeneous networks have m (a + mob) tmes more energy or we can say that the total energy of the system s ncreased by a factor of (1+ m.(a + mo.b)) 5. Assumtons and Proertes of the Network In the network model descrbed n revous secton some assumtons have been made for the sensor nodes as well as for the network. Hence the assumtons and roertes of the network and sensor nodes are: Sensor Nodes are unformly randomly deloyed n the network. There s one Base Staton whch s located at the centre of the sensng feld. Nodes always have the data to send to the base staton. Nodes are locaton-unaware,.e. not equed wth GPS-caable antennae. All nodes have smlar caabltes n terms of rocessng and communcaton and of equal sgnfcance. Ths motvates the need for extendng the lfetme of every sensor. Sensor nodes have heterogenety n terms of energy.e., dfferent energy levels. All nodes have dfferent ntal energy; some nodes are equed wth more energy than the normal nodes. 6. Cluster Head Selecton Method Tradtonally as er LEACH, Cluster head algorthm s broken nto rounds. At each round node decdes whether to become a cluster head based on threshold calculated by the suggested ercentage of cluster heads for the network (determned a ror) and the number of tmes the node has been a cluster-head so far. Ths decson s made by the nodes by choosng the random number between and 1. If the number s less than a threshold T(s) the node becomes a clusterhead for the current round. The threshold s set as: Ts= 1-.(r mod 1 ) f sg Otherwse (4) where, r, and G reresent, resectvely, the desred ercentage of cluster-heads, the current round number, and the set of nodes that have not been cluster-heads n the last 1/ rounds. Usng ths threshold, each node wll be a cluster head, just once at some ont wthn 1/ rounds. In the three level heterogeneous networks there are three tyes of nodes normal nodes, advanced nodes and suer nodes, as dscussed n secton 4, based on ther ntal energy. Hence the reference value of s dfferent for these tyes of nodes. The robabltes of normal, advanced and suer nodes are: = ot E r 1+m.a+mo.bEr ot 1+aE r 1+m.a+mo.bEr ot 1+bE r 1+m.a+mo.bEr f s s the normal node f s s the advanced node f s s the suer node Threshold for cluster head selecton s calculated for normal, advanced, suer nodes by uttng above values n Eq. (4). f 1-.r mod 1 G ' f 1-.r mod 1 G '' Ts = (6) f 1-.r mod 1 G ''' Otherwse where s the set of normal nodes that have not become cluster heads wthn the last 1/ rounds of the eoch where s s normal node, s the set of advanced nodes that have not become cluster heads wthn the last 1/ rounds of the eoch where s s advanced node, s the set of suer nodes that have not become (5) Proceedngs of the 1st Internatonal Conference on Parallel, Dstrbuted and Grd Comutng (PDGC-21) 27

4 cluster heads wthn the last 1/ rounds of the eoch where s s suer node. E-DEEC mlements the same strategy for estmatng the energy n the network as roosed n DEEC [6]. Snce the robabltes calculated deend on the average energy of the network at round r, hence ths s to be calculated. Ths average energy s estmated as: Er= 1 E N total1- r (7) R where R denotes the total rounds of the network lfetme. R can be calculated as R= E total E round (8) E round s the energy dssated n the network n a round. The total energy dssated E round s equal to 4 2 ) (9) E round =L(2NE elec +NE DA +ke am d tobs +NE fs d toch where k s number of clusters d tobs s the average dstance between cluster head and the base staton and d toch s the average dstance between the cluster members and the cluster head. Now,d toch = M 2k,d tobs=.765 M 2 (1) By calculatng the dervatve of E round wth resect to k to zero we get otmal number of clusters as k ot = N 2 M 2 E fs d tobs E am (11) Hence we can fnd the energy dssated er round by substtutng equatons (1) & (11) n (9).Due to the heterogenety factors R s taken as 1.5 R (Snce Er wll be too large at the end from Eq.(7), some wll not de fnally) 7. Performance Crtera Used The erformance metrcs or arameters used to study and evaluate the clusterng rotocols are lfetme, number of nodes alve and number of data ackets receved at base staton. Data Packets receved at base staton: It s total number of data ackets or messages that are receved by the base staton. Ths measure vares lnearly for all rotocols. Number of alve nodes: Ths nstantaneous measure reflects the total number of nodes and that of each tye that has not yet exended all of ther energy. Network remanng energy: It measures the total remanng energy of the network. It s calculated at each transmsson round of the rotocol. These metrcs used allow us to conclude about the stablty erod of the network whch s the tme nterval from the start of network oeraton untl the death of the frst sensor node, unstable erod of the network whch s the tme nterval from the death of the frst node untl the death of the last node, energy consumton, the data send that are receved by the base staton [5] and the lfetme of the network whch s number of rounds untl the frst node de whch s smly the stablty erod of the network ( We have assume all the nodes havng equal mortance). More stable s the network; more s the lfetme of the network. Table 1. Smulaton Parameters Parameters Value Network Feld (1,1) Number of nodes 1 Eo ( Intal energy of.5 J normal nodes) Message Sze 4 Bts E elec 5nJ/bt E fs 1nJ/bt/m 2 E am.13j/bt/m 4 E DA 5nJ/bt/sgnal d o ( Threshold Dstance) 7m ot.1 8. Smulaton and Results We have smulated our wreless sensor network n a sensng feld of 1m 1 m. Smulaton arameters used are lsted n table 1. In our scenaro, we have deloyed 2% advanced nodes deloyed wth 1.5 tmes more energy than normal nodes and 3% suer nodes deloyed wth 3 tmes more energy than the normal nodes (m=.5, mo=.4, a=1.5, b=3). Hence more total ntal energy. We have comared E-DEEC wth SEP whch s too extended to three-level based on the same aroach. Fgure 3 reresent the number of nodes alve durng the lfetme of the network. It clearly shows that by ntroducng suer nodes lfetme ncreases. Stablty erod and lfetme of EDEEC s longer as comared to SEP and unstable erod of SEP s longer than EDEEC. EDEEC s better than SEP as t uses the resdual energy. In SEP death of nodes starts after 12 rounds whle for EDEEC t starts after 15 rounds. Last node for SEP and E-DEEC des at 6 and 41 rounds. Proceedngs of the 1st Internatonal Conference on Parallel, Dstrbuted and Grd Comutng (PDGC-21) 28

5 number of alve nodes SEP E-DEEC total remanng energy n joules SEP E-DEEC data ackets receved at base staton number of rounds Fgure 3. Number of nodes alve over rounds under three-level heterogenety of SEP and E-DEEC Fgure 4 shows the comarson n terms of number of data ackets receved at the base staton. The results show that for both the rotocols t goes lnearly for around 3 rounds and after that the dfference can be seen. It s clear E-DEEC has more numbers of data ackets receved at base staton n comarson to SEP. Fgure 5 show total remanng energy over tme.e., number of rounds. Here total ntal energy s 12.5 J whch decreases lnearly u to around 2 rounds for both E-DEEC and SEP. Energy er round s more n E- DEEC as comared to SEP u to around 3 rounds then grah changes for both E-DEEC and SEP from the round where frst node des n resect to them. Most of the energy s consumed n the frst 3 rounds x 14 SEP E-DEEC number of rounds Fgure 4. Data Packets over rounds under three-level heterogenety of SEP and E-DEEC number of rounds Fgure 5. Total remanng energy over rounds under three-level heterogenety of SEP and E-DEEC 9. Concluson Wreless sensor network s a combnaton of wreless communcaton and sensor nodes. The network should be energy effcent wth stablty and longer lfetme. In ths aer, roosed E-DEEC adds heterogenety n the network by ntroducng the suer nodes havng energy more than normal and advanced nodes and resectve robabltes. Smulaton results shows that E-DEEC has better erformance as comared to SEP n terms of arameters used. It extends the lfetme and stablty of the network. 1. References [1] Jamal N. Al-Karak, Ahmed E. Kamal, Routng Technques In Wreless Sensor Networks: A Survey, IEEE Wreless Communcatons, Volume: 11, Issue: 6, 26-28, December 24. [2] W.Henzelman, A. Chandrakasan, and H. Balakrshnan, "Energy-effcent communcaton rotocol for wreless sensor networks," n the Proceedng of the Hawa Internatonal Conference System Scences, Hawa, January 2. [3] S. Lndsey and C. S. Raghavendra, "PEGASIS: Power Effcent Gatherng n Sensor Informaton Systems," n the Proceedngs of the IEEE Aerosace Conference, Bg Sky, Montana, March 22. [4] O. Youns, S. Fahmy, "HEED: A hybrd, energy effcent, dstrbuted clusterng aroach for adhoc sensor networks", IEEE Transactons on Moble Comutng vol 3, no 4, , 24. [5] G. Smaragdaks, I. Matta, A. Bestavros, SEP: A Stable Electon Protocol for clustered heterogeneous wreless sensor networks, n: Second Internatonal Worksho on Sensor and Proceedngs of the 1st Internatonal Conference on Parallel, Dstrbuted and Grd Comutng (PDGC-21) 29

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