Lifetime Maximisation of Multihop WSN using Cluster-based Cooperative MIMO Scheme

Transcription

1 Intenational Jounal of Compute Theoy and Engineeing, Vol., No. 1 Febuay, 010 Lifetime Maximisation of Multihop WSN using Cluste-based Coopeative MIMO Sheme J. Vidhya and P. Dananjayan * Abstat Wieless senso netwo (WSN) equies obust and enegy effiient ommuniation potools to minimise the enegy onsumption as muh as possible. Howeve, the lifetime of senso netwo edues due to the advese impats aused by adio iegulaity and fading in multihop WSN. A luste-based oopeative multi-input and multi-output (MIMO) sheme is poposed as a solution fo this poblem. The poposed sheme extends low enegy adaptive lusteing hieahy (LEACH) potool and enables multihop tansmissions among the lustes by inopoating oopeative MIMO sheme though the seletion of oopeative sending and eeiving nodes. The pefomane of the poposed MIMO system is evaluated intems of enegy effiieny and eliability. Simulation esults show that temendous enegy savings an be ahieved by adopting oopeative MIMO sheme among the lustes. The poposed oopeative MIMO sheme polongs the netwo lifetime with 75% of nodes emaining alive when ompaed to LEACH potool. Index Tems Coopeative MIMO, LEACH potool, multihop ommuniation, netwo lifetime, wieless senso netwo I. INTRODUCTION Wieless senso netwo ompises of hundeds to thousands of small nodes employed in a wide ange of data gatheing appliations suh as militay, envionmental monitoing and many othe fields [1]. Due to limited enegy and the diffiulty in ehaging a lage numbe of senso nodes, enegy effiieny and maximising the netwo lifetime ae the most impotant design goals of a senso netwo. Channel fading, intefeene and adio iegulaity futhe pose big hallenge on the design of enegy effiient ommuniation potools in wieless netwo. MIMO systems an damatially edue the tansmission enegy onsumption in wieless fading hannels [,3]. Coopeative tansmission and eeption of data among sensos is nown to diminish the pe-node enegy onsumption, ineasing the netwo lifetime [4]. In these shemes, multiple individual single antenna nodes oopeate on data tansmission and eeption fo enegy effiient ommuniation. Coopeative multi input single output (MISO) tansmission sheme based on LEACH potool is analysed in [5,6]. Howeve oopeative MISO pefoms only single hop tansmission and does not polong the netwo lifetime. To oveome these daw bas, the poposed model modifies the LEACH potool [7,8] and allows luste heads to fom a multihop babone and inopoates the oopeative MIMO sheme on eah single hop tansmission by utilising a set of sending and eeiving oopeative nodes in eah luste. Fo the poposed model, the enegy onsumed and the numbe of nodes alive fo eah ound of data tansmission is evaluated. The emainde of the pape is oganized as follows: setion II desibes the poposed luste based multihop MIMO sheme. The enegy onsumption model of poposed sheme is analysed in setion III. Simulation esults ae disussed in setion IV and onlusions ae dawn in setion V. II. PROPOSED CLUSTER- BASED MULTIHOP COOPERATIVE MIMO SCHEME Conside a wieless senso netwo with N sensing nodes distibuted andomly in a squae aea of side M metes. All senso nodes ae assumed to be stationay, heteogeneous and enegy-onstained, eah node an tansmit data to any othe node and sin. The sin node is assumed to have no enegy onstaints and is equipped with one o moe eeiving antennas. The senso nodes ae geogaphially gouped into lustes onsisting of a head node, oopeative sending and eeiving nodes and non-luste head nodes that sense the data fom the sensing field. The luste heads ae eeleted afte eah ound of data tansmission as in LEACH potool [7]. The poposed multihop oopeative MIMO tansmission model is illustated in Fig.1. The tansmission poedue of the poposed sheme is divided into multiple ounds. Eah ound has thee phases: Coesponding autho is with the Depatment of Eletonis and Communiation Engineeing, Pondihey Engineeing College, Pondihey, India. ( pdananjayan@ediffmail.om, pdananjayan@pe.edu) Fig.1 Multihop oopeative MIMO tansmission model 0

2 A. Cluste fomation phase Intenational Jounal of Compute Theoy and Engineeing, Vol., No. 1 Febuay, 010 In this phase, lustes ae oganized and oopeative MIMO nodes ae seleted aoding to the steps desibed below: 1) Cluste head advetisement Initially, when lustes ae being eated, eah node deides whethe o not to beome a luste head fo eah ound as speified by the oiginal LEACH potool. Eah self-seleted luste head, boadasts an advetisement (ADV) message using non-pesistent aie sense multiple aess (CSMA) potool. The message ontains the heade identifie (ID). ) Cluste setup Eah non-luste head node hooses one of the stongest eeived signal stength (RSS) of the advetisement as its luste head, and tansmits a join-equest (Join-REQ) message ba to the hosen luste head. The infomation about the node s apability of being a oopeative node, i.e., its uent enegy status is added into the message. If a luste head eeives the advetisement message fom anothe luste head y, and if the eeived RSS exeeds a theshold, it will ma luste head y as the neighbouing luste head and it eod y s ID. If the sin eeives the advetisement message, it will find the luste head with the maximum RSS, and sends the sin-position message to that luste head maing it as the taget luste head (TCH). 3) Shedule eation Afte all the luste heads has eeived the join-req message, eah luste head eates a time division multiple aess (TDMA) shedule and boadasts the shedule to its luste membes as in oiginal LEACH potool. This pevents ollision among data messages and allows the adio of eah non-luste head node to be tuned off until its alloated tansmission time to save enegy. 4) Coopeative node seletion Afte the luste fomation, eah luste head will selet J oopeative sending and eeiving nodes fo oopeative MIMO ommuniation [5] with eah of its neighbouing luste head. Nodes with highe enegy lose to the luste head will be eleted as sending and eeiving oopeative nodes fo the luste. At the end of the phase, the luste head will boadast a oopeative equest (COOPERATE-REQ) message, whih ontains the ID of the luste itself, the ID of the neighbouing luste head y, the ID of the tansmitting and eeiving oopeative nodes and the index of oopeative nodes in the oopeative node set of eah luste head to eah oopeative node. The oopeative node on eeiving the COOPERATE- REQ message, stoes the luste head ID and sends ba a oopeate-anowledgement (ACK) message to the luste head. B. Routing table onstution Eah luste head will maintain a outing table whih ontains the destination luste ID, next hop luste ID, IDs of oopeative sending and eeiving nodes. The luste heads 1 will update the oute ost and advetise thei neighbouing luste heads about the modified outes. The TCH will flood a taget announement message ontaining its ID to eah luste head to enable tansmissions to the sin node. C. Data tansmission phase Duing this phase, the data sensed by senso nodes ae tansmitted to the luste head and fowaded to the sin using multihop MIMO sheme aoding to the outing table. 1) Inta luste tansmission In this phase, the non-luste head nodes send thei data fames to the luste head as in LEACH potool duing thei alloated time slot. The duation and the numbe of fames ae same fo all lustes and depend on the numbe of non-luste head nodes in the luste. ) Inte luste tansmission Afte a luste head eeives data fames fom its luste membes, it pefoms data aggegation and boadasts the data to J oopeative MIMO sending nodes. When eah oopeative sending node eeives the data paet, they enode the data using spae time blo ode (STBC) and tansmit the data oopeatively. The eeiving oopeative nodes use hannel state infomation to deode the spae time oded data [6,9]. The oopeative node elays the deoded data to the neighbouing luste head node and fowads the data paet to the TCH by multihop outing. III. ENERGY CONSUMPTION MODEL OF PROPOSED SCHEME The enegy onsumed duing eah ound of data tansmission esults fom the following soues suh as: luste membes tansmitting thei data to the luste head, outing table onstuted by the luste head, luste head tansmitting the aggegated data to the oopeative nodes [8], oopeative node tansmitting the data to the eeiving oopeative nodes and to the eeiving luste head. A. Enegy onsumption of luste membe The enegy onsumed by the soue nodes to tansmit one bit data to the luste head node is given by 1 Ebs( ) (1 α)nf σ ln(pb )G1M Ml π Pt P B is the numbe of lustes α is the effiieny of adio fequeny (RF) powe amplifie N f is the eeive noise figue σ =N o / is the powe density of additive white Gaussian noise (AWGN) hannel P b is the bit eo ate (BER) obtained while using phase shift eying G 1 is the gain fato M 1 is the gain magin B is the bandwidth P t is the iuit powe onsumption of the tansmitte P is the iuit powe onsumption of the eeive (1)

3 Intenational Jounal of Compute Theoy and Engineeing, Vol., No. 1 Febuay, 010 The total numbe of bits tansmitted to the luste head of eah luste in eah ound is given by 1 N S ( ) Fn Ps () F n is the numbe of symbols in a fame P is the tansmit pobability of eah node s is the paet size The enegy onsumed by a luste membe to tansmit data to the luste head is given by Es ( ) S ( )E ( ) (3) 1 bs B. Enegy onsumption of luste heads To onstut the outing table, the enegy onsumed by the luste head node is given by E ( ) R ts R bt 1 α M N l f N P G b 4π M P 4P t / G λ π B 0 t (4) R bt is the time equied fo exhanging outing infomation R ts is the outing table size G t is the gain of tansmitting antenna G is the gain of eeiving antenna λ is the wavelength of tansmission The enegy pe bit onsumed by the luste head node to tansmit the aggegated data to J oopeative nodes is given by 1 Eb0(, J) (1 α)nf σ ln(pb )G1M Ml π (5) Pt JP B The amount of data afte aggegation fo eah ound by luste head node is given by S1 ( ) S ( ) (6) ([N/ ]Pagg agg 1) agg is the aggegation fato The enegy onsumed by luste head node to tansmit the aggegated data to J oopeative nodes is given by E0 (, J) S ( )Eb0(, J) (7) C. Enegy onsumption of oopeative nodes The tansmitte oopeative nodes of the luste will enode and tansmit the sequene aoding to othogonal STBC [3] to the luste head node. Conside the blo size of the STBC ode is F symbols and in eah blo pj taining symbols ae inluded and ae tansmitted in L symbol duation. The atual amount of data equied to tansmit the S ( ) bits is given by Se (, J) FS ( )/R(F pj) (8) R is the tansmission ate The enegy onsumed by J oopeative sending nodes to tansmit MIMO data to the J oopeative eeiving nodes is given by E s (, J) S ( e, J) 1 αm ln JPt JP B f P JN 0 1/J b Gt 4π M G λ π / Similaly, the enegy onsumed by J eeiving oopeative nodes to tansmit data to the neighbouing luste head is given by E (, J) S ( e, J) 1 αm ln JPt P B f P JN 0 1/J b Gt 4π M G λ π D. Oveall enegy onsumption fo a ound / (9) (10) The enegy onsumption fo eah ound of oopeative multihop MIMO data tansmission an be obtained fom Equations (3), (4), (7), (9) and (10) and it is given by E(, J) E ( ) E ( ) n E (, J) s n E s (, J) n E n is the aveage numbe of hops IV. 0 (, J) SIMULATION RESULTS (11) The analysis of the poposed oopeative multihop MIMO sheme is aied out using MATLAB to evaluate the enegy onsumption and maximise the lifetime of the senso netwo. A sensing field of dimension M x M (M =100 m) with a population of N= 100 nodes is onsideed fo simulation. A heteogeneous netwo onsisting of 80 nomal nodes and 0 advaned nodes ae deployed ove the egion andomly. The initial enegy of a nomal node is set to 0.5 J and the enegy of the advaned node is J. Sin node is assumed to be loated at the ente of the sensing field (50, 50), povided with suffiient enegy esoues. The system paametes used fo the simulation is listed in Table 1.

4 Intenational Jounal of Compute Theoy and Engineeing, Vol., No. 1 Febuay, 010 Table I. COMMUNICATION SYSTEM PARAMETERS Paamete Value Effiieny of RF powe amplifie (α) Lin magin (M 1 ) 40 db Gain fato (G 1 ) 30 db Powe density of AWGN hannel (σ ) -134 dbm /Hz Reeive noise figue (N f ) 10 db Path loss() 3-5 Caie fequeny (f ) Bandwidth (B).5 GHz 0 KHz BER pefomane (P b ) 10-3 Ciuit powe onsumption of tansmitte ( P t ) 98. mw Ciuit powe onsumption of eeive (P ) 11.6 mw Antenna gain of tansmitte and eeive (G t, G ) 5 db Time fo exhanging outing table fo eah ound (R bt ) 5 Routing table size (R ts ) 100 Tansmission ate (R) 0.75 Paet size (s) Numbe of fames pe ound (F n ) Tansmission pobability of eah node (P) 0.8 bits Fig. Compaison of enegy onsumption and numbe of ounds Fig.3 shows the peentage of nodes alive in the netwo with the inease in numbe of ounds. It is vivid that the lifetime of WSN using multihop MIMO sheme is 75% moe when ompaed to the LEACH potool. Futhemoe, with the inease in the divesity ode fom 1x to 3x3, 30% moe nodes ae alive ontibuting to the inease in netwo life time with the exploitation of divesity gain and multihop ommuniation among luste head nodes. The pefomane of the poposed multihop oopeative MIMO LEACH sheme is ompaed with that of the oiginal LEACH sheme intems of enegy. The esults obtained ae shown in Fig.. As the numbe of oopeative nodes is ineased, the enegy onsumption of the netwo is deeased due to the divesity gain. Fom the gaph it is lea that the poposed sheme utilising 3 oopeative sending and eeiving nodes an ahieve 50% of enegy savings than the LEACH potool. Fig.3 Compaison of netwo lifetime with numbe of ounds Fig.4 10% of node death with numbe of ounds 3

5 Intenational Jounal of Compute Theoy and Engineeing, Vol., No. 1 Febuay, 010 the LEACH potool onsumes moe enegy and has shote lifetime of 7000 ounds due to the advese hannel fading effets. The poposed oopeative 3x3 MIMO sheme pefoms bette and extends ounds moe than the LEACH sheme fo data tansmission and saves upto 50% enegy by the exploitation of the divesity gain and multihop ommuniation among the luste head nodes. Fig.5 80 % of node death with numbe of ounds The numbe of ounds possible fo data tansmission with 10%, 80% and last node death (100%) ae illustated in Figs. 4, 5 and 6. 10% of node death ous at 1000 ounds with LEACH potool. Fo the poposed multihop MIMO onfiguations, as the ode of divesity ineases, the numbe of ounds fo whih the nodes ae alive also ineases. 3x3 MIMO onfiguation an tansmit data fo about 3500 ounds and is appoximately about 500 ounds bette in data tansmission ompaed to the LEACH potool. Simila analysis is pesented in Fig.5 showing 80% node death. In LEACH potool 80% of node death ous at 354 ounds as fo MIMO onfiguations 1x, x3, 3x, 1x3, x, 3x3 node death ous at 1489, 1350, 14001, 14999, 151 and espetively. Thus 3x3 MIMO sheme an povide lifetime of 1000 ounds moe when ompaed to the LEACH potool. ACKNOWLEDGMENT The authos would lie to expess thei sinee gatitude to the following: M. S. Rajesh, M. N. Jayapaash and M. T. G. Hai Munishwa. REFERENCES [1] L. Ayildiz, W. Su, Y. Sanaasubamanian and E. Cayii, A suvey on senso netwos, IEEE Communiations Magazine, vol. 40. no. 8, pp , 00. [] G. N. Bavos and G. Efthymoglou, MIMO-based and SISO multihop senso netwo: Enegy effiieny evaluation, Poeedings of IEEE Intenational Confeene on Wieless and Mobile Computing, Netwoing and Communiations, 007 [3] S. Cui, A. J. Goldsmith and A. Bahai, Enegy-effiieny of MIMO and oopeative tehniques in senso netwos, IEEE Jounal on Seleted Aeas in Communiations, vol., no.6, pp , 004. [4] S. K. Jayaweea, Enegy analysis of MIMO tehniques in wieless senso netwos, Poeedings of Annual Confeene on Infomation Sienes and Systems, Pineton, NJ, 004 [5] X. Li, M. Chen and W. Liu, Appliation of STBC-enoded oopeative tansmissions in wieless senso netwos, IEEE Signal Poessing Lettes, vol., no., pp , 005. [6] Y. Yuan, Z. He and M. Chen, Vitual MIMO- based oss-laye design fo wieless senso netwos, IEEE Tansations on Vehiula Tehnology, vol. 55, no.3, pp , 006. [7] W.R. Heinzelman, A. Chandaasan and H. Balaishnan, An appliation-speifi potool ahitetue fo wieless miosenso netwos, IEEE Tansations on Wieless Communiations, vol.1, no.4, pp , 00. [8] W. Cheng, K. Xu, Z. Yang and Z. Feng, An enegy-effiient oopeative MIMO tansmission sheme fo wieless senso netwos, Poeedings of Intenational Confeene on Wieless Communiation, Netwoing and Mobile Computing, pp. 1-4, 006. [9] V. Taoh, H. Jafahani and A. R. Caldeban, Spae-time blo odes fom othogonal designs, IEEE Tansations on Infomation Theoy, vol. 45, no.5, pp , Fig.6 100% of node death with numbe of ounds Fig.6 shows the time duing whih the last node dies in the netwo. Fom the esults it is evident that the lifetime of LEACH potool is limited to 7000 ounds and the poposed MIMO sheme extends upto 6000 ounds. The poposed 3x3 multihop MIMO sheme povides an enhaned life time of about 3.5 times moe than the LEACH potool. V. CONCLUSION A luste-based oopeative MIMO sheme fo multihop WSN has been exploed and the pefomane of the system is evaluated to minimise the enegy onsumption and inease the lifetime of senso nodes. The simulation esults eveal that J. Vidhya eeived B.E degee in Eletonis and Communiation Engineeing fom Bhaathidasan Univesity, Tihy in 1999 and M.Teh degee in Eletonis and Communiation Engineeing fom Pondihey Engineeing College, Pondihey in 001. She is pusuing he Ph.D. pogamme in Depatment of Eletonis and Communiation Engineeing, Pondihey Univesity. She is uently woing as Assistant Pofesso in Depatment of Eletonis and Communiation Engineeing at Rajiv Gandhi College of Engineeing and Tehnology affiliated to Pondihey Univesity. He eseah inteests inlude ompute netwos, wieless ad ho and senso netwos. P. Dananjayan eeived Bahelo of Siene fom Univesity of Madas in 1979, Bahelo of Tehnology in 198 and Maste of Engineeing in 1984 fom the Madas Institute of Tehnology, Chennai and Ph.D. degee fom Anna Univesity, Chennai in He is woing as Pofesso in the Depatment of Eletonis and Communiation Engineeing, Pondihey Engineeing College, Pondihey, India. He is also a visiting pofesso to AIT, Bango. He has moe than 80 publiations in 4

6 Intenational Jounal of Compute Theoy and Engineeing, Vol., No. 1 Febuay, 010 National and Intenational Jounals. He has pesented moe than 150 papes in National and Intenational Confeenes. He has guided 7 Ph.D andidates and is uently guiding 8 Ph.D students. His eseah inteests inlude spead spetum tehniques and wieless ommuniation, wieless adho and senso netwos. 5