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<div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/625c405f92dc900e6238aabe/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0">Energy Efficient Cross-Layer MAC Protocol for </div><div class="t m0 x2 h2 y2 ff1 fs0 fc0 sc0 ls1 ws1">Wireless Sensor Networks </div><div class="t m0 x3 h3 y3 ff1 fs1 fc0 sc0 ls2 ws2">Bouabdellah K<span class="_ _0"></span>ECHAR</div><div class="t m0 x4 h4 y4 ff1 fs2 fc0 sc0 ls0 ws3">1</div><div class="t m0 x5 h3 y3 ff1 fs1 fc0 sc0 ls0 ws3">,</div><div class="t m0 x6 h4 y4 ff1 fs2 fc0 sc0 ls0 ws3"> </div><div class="t m0 x7 h3 y3 ff1 fs1 fc0 sc0 ls3 ws4">Ahmed LOUAZANI</div><div class="t m0 x8 h4 y4 ff1 fs2 fc0 sc0 ls0 ws3">2</div><div class="t m0 x9 h3 y3 ff1 fs1 fc0 sc0 ls4 ws5">, Larbi SEKHRI</div><div class="t m0 xa h4 y4 ff1 fs2 fc0 sc0 ls0 ws3">1</div><div class="t m0 xb h3 y3 ff1 fs1 fc0 sc0 ls5 ws6">, Mohamed Faycal KHELFI</div><div class="t m0 xc h4 y4 ff1 fs2 fc0 sc0 ls0 ws3">3</div><div class="t m0 xd h3 y5 ff1 fs1 fc0 sc0 ls6 ws7">Department of Computer Scie<span class="ls4 ws5">nce, Faculty of Science, </span></div><div class="t m0 xe h3 y6 ff1 fs1 fc0 sc0 ls4 ws5">University of Oran Es-Senia, BP. 1524 Oran, Algeria </div><div class="t m0 xf h5 y7 ff2 fs2 fc0 sc0 ls0 ws3">1</div><div class="t m0 x10 h6 y8 ff2 fs1 fc0 sc0 ls7 ws3">{Kechar.bouabdellah, <span class="ls8">Larb<span class="_ _0"></span>i.sekhri}@univ-oran.d<span class="_ _0"></span>z<span class="ls9">, </span></span></div><div class="t m0 x11 h5 y7 ff2 fs2 fc0 sc0 ls0 ws3">2</div><div class="t m0 x12 h6 y8 ff2 fs1 fc0 sc0 ls2 ws3">choudangm@gmail.c<span class="_ _0"></span>om<span class="ls9">, </span></div><div class="t m0 x13 h5 y7 ff2 fs2 fc0 sc0 ls0 ws3">3</div><div class="t m0 x14 h6 y8 ff2 fs1 fc0 sc0 ls8 ws3">mf_khelfi@yahoo.fr </div><div class="t m0 x15 h7 y9 ff3 fs1 fc0 sc0 lsa ws3">Abstract </div><div class="t m0 x16 h7 ya ff3 fs1 fc0 sc0 lsb ws8">Technological A<span class="_ _1"></span>dvances in microe<span class="_ _1"></span>lectronic and telecommunication fie<span class="_ _1"></span>lds enable the ex<span class="_ _1"></span>istence of tiny </div><div class="t m0 x16 h7 yb ff3 fs1 fc0 sc0 ls0 ws9">computing units, very<span class="_ _1"></span> small and mo<span class="lsc wsa">re efficient. In the context of<span class="lsd wsb"> these new technologies, Wireless </span></span></div><div class="t m0 x16 h7 yc ff3 fs1 fc0 sc0 lse wsc">Sensor Networks (WSN) h<span class="_ _0"></span>ave emerged. The main resea<span class="_ _0"></span>rch objective in WSN domain<span class="_ _0"></span> is the development </div><div class="t m0 x16 h7 yd ff3 fs1 fc0 sc0 lsf wsd">of algorithms and protocol<span class="_ _0"></span>s ensuring minimal energ<span class="_ _0"></span>y<span class="lse wse"> consumption. Most propo<span class="_ _0"></span>sed solutions are based<span class="_ _0"></span> </span></div><div class="t m0 x16 h7 ye ff3 fs1 fc0 sc0 ls5 wsf">on one-layer stack model approach<span class="_ _0"></span>. Recently, other works tend to exploit to<span class="_ _0"></span>gether many layers in order </div><div class="t m0 x16 h7 yf ff3 fs1 fc0 sc0 ls10 ws10">to optimize energy<span class="_ _1"></span> consumption. In this pa<span class="_ _1"></span>per, <span class="ls11 ws11">we propose a Cro<span class="_ _0"></span>ss-Layer Medi<span class="_ _0"></span>um Access Con<span class="_ _0"></span>trol (CL-</span></div><div class="t m0 x16 h7 y10 ff3 fs1 fc0 sc0 ls7 ws12">MAC) protocol using two adjacent layer<span class="_ _0"></span>s (MAC and <span class="lsa ws13">Netw<span class="_ _0"></span>ork) to economize energ<span class="_ _0"></span>y for WSN. The basic<span class="_ _0"></span> </span></div><div class="t m0 x16 h7 y11 ff3 fs1 fc0 sc0 ls12 ws14">idea behind our protocol is to w<span class="ls13 ws15">ake-up only nodes belonging to a rout<span class="ls14 ws16">ing path from the source to the<span class="_ _1"></span> </span></span></div><div class="t m0 x16 h7 y12 ff3 fs1 fc0 sc0 lsc ws17">base station (Sink) by exploiting routing informatio<span class="_ _0"></span>n while other nodes leave maintained as lon<span class="_ _0"></span>g time as </div><div class="t m0 x16 h7 y13 ff3 fs1 fc0 sc0 ls10 ws18">possible in a <span class="_ _1"></span>sleep mode. The protoc<span class="_ _1"></span>ol is modeled usi<span class="_ _1"></span>ng a time Petri net a<span class="_ _1"></span>nd validated by TiNA<span class="_ _1"></span> tool. The </div><div class="t m0 x16 h7 y14 ff3 fs1 fc0 sc0 lse ws19">simulation results demonstrate the effecti<span class="_ _0"></span>veness of our proposal in<span class="_ _0"></span> terms of energy consumption<span class="_ _0"></span> and </div><div class="t m0 x16 h7 y15 ff3 fs1 fc0 sc0 ls15 ws1a">latency. </div><div class="t m0 x17 h8 y16 ff4 fs3 fc0 sc0 ls0 ws3"> <span class="ff5 fs1 ls16">Keywords:<span class="ff2 ls6 ws7"> Wireless Sensor Networks, Cross-la<span class="ls17 ws1b">yer optimization, MAC Protocol, Energy <span class="_ _0"></span>consumption, Time Petri net.</span></span></span><span class="fs1"> </span></div><div class="t m0 x17 h9 y17 ff3 fs4 fc0 sc0 ls18 ws1c">1. INTRODUCTION </div><div class="t m0 x17 ha y18 ff1 fs4 fc0 sc0 ls19 ws1d">Wireless Sensor Networks (WSN) are comp<span class="_ _1"></span>osed by tiny<span class="ls1a ws1e"> sensors called sensor nodes. A sen<span class="_ _1"></span>sor node ensures </span></div><div class="t m0 x17 ha y19 ff1 fs4 fc0 sc0 ls19 ws1f">main functions like acquisi<span class="_ _1"></span>tion of environmental physical <span class="ls0 ws20">measures, local processing of collected d<span class="_ _1"></span>ata and their </span></div><div class="t m0 x17 ha y1a ff1 fs4 fc0 sc0 ls0 ws21">transmission to the Sink. These functions are performed by an electronicall<span class="_ _1"></span>y modules composing the node’s </div><div class="t m0 x17 ha y1b ff1 fs4 fc0 sc0 ls1a ws22">hardware architecture. Other componen<span class="_ _1"></span>ts can be added to <span class="ls1b ws23">ensure mobility function and energy self-recharging. A<span class="_ _1"></span> </span></div><div class="t m0 x17 ha y1c ff1 fs4 fc0 sc0 ls0 ws24">node is alimented by a limited quantity of energy (battery<span class="_ _1"></span>) <span class="ls1c ws25">and communicates wirelessly using a radi<span class="_ _1"></span>o signal. </span></div><div class="t m0 x17 ha y1d ff1 fs4 fc0 sc0 ls19 ws26">Generally, communication betwe<span class="_ _1"></span>en nodes consumes more <span class="_ _1"></span>energy than local processing or <span class="_ _1"></span>collecting data </div><div class="t m0 x17 ha y1e ff1 fs4 fc0 sc0 ls1b ws27">operation. The geographical nature of t<span class="ls1c ws28">he deployment space of nodes make<span class="_ _1"></span>s qua<span class="ls1d ws29">si impossible the replacement or </span></span></div><div class="t m0 x17 ha y1f ff1 fs4 fc0 sc0 ls1e ws2a">the recharging operations of batteries. T<span class="_ _1"></span>he challenge is to eco<span class="_ _1"></span>nomize energy inside every node in order to maintai<span class="_ _1"></span>n </div><div class="t m0 x17 ha y20 ff1 fs4 fc0 sc0 ls1d ws2b">as long as possible the network functionality. Many resear<span class="_ _1"></span>ch works are developed for energy efficiency at each<span class="_ _1"></span> </div><div class="t m0 x17 ha y21 ff1 fs4 fc0 sc0 ls0 ws2c">layer of protocol stack by propo<span class="_ _1"></span>sing new algorithms and protocols. In parti<span class="_ _1"></span>cular, MAC layer was of great int<span class="_ _1"></span>erest for </div><div class="t m0 x17 ha y22 ff1 fs4 fc0 sc0 ls1f ws2d">many researchers because it is consi<span class="_ _1"></span>dered as an impor<span class="ls20 ws2e">tant source of energy wast<span class="ls1d ws2f">age that we summari<span class="_ _1"></span>ze as </span></span></div><div class="t m0 x17 ha y23 ff1 fs4 fc0 sc0 ls21 ws30">follows [1, 2]: </div><div class="t m0 x18 ha y24 ff6 fs4 fc0 sc0 ls0 ws3">•<span class="ff1 ls1d ws31"> <span class="_ _2"> </span>Overhearing: a sensor nod<span class="_ _1"></span>e receives packets that are transmitted for other<span class="ls1f ws32"> nodes. This is due<span class="_ _1"></span> essentially </span></span></div><div class="t m0 x19 ha y25 ff1 fs4 fc0 sc0 ls20 ws33">to the radio transmission nature (omni-directional<span class="ls1d ws34">) forci<span class="_ _1"></span>ng every node of the neighbou<span class="_ _1"></span>rhood to waste </span></div><div class="t m0 x19 ha y26 ff1 fs4 fc0 sc0 ls1b ws35">energy when receiving this radio. </div><div class="t m0 x18 ha y27 ff6 fs4 fc0 sc0 ls0 ws3">•<span class="ff1 ls1a ws36"> <span class="_ _2"> </span>Collision: since radio channel is <span class="ls0 ws37">shared by many nodes, a collision take <span class="_ _1"></span>place every time when two nodes </span></span></div><div class="t m0 x19 ha y28 ff1 fs4 fc0 sc0 ls20 ws38">try to send in the same time their packets. Collisions<span class="ls1d ws39"> increase energy co<span class="_ _1"></span>nsumption and latency in case of </span></div><div class="t m0 x19 ha y29 ff1 fs4 fc0 sc0 ls20 ws3a">packets deliverance m<span class="_ _1"></span>echanism due to retransmissions. </div><div class="t m0 x18 hb y2a ff6 fs4 fc0 sc0 ls0 ws3">•<span class="ff1 ls22 ws3b"> Control <span class="_ _3"></span>packets <span class="_ _3"></span><span class="ff2 ls19 ws3">(overhead)<span class="ff1 ls1e ws3c">: packet hea<span class="_ _1"></span>ders and control packet<span class="_ _1"></span>s (<span class="ff2 ls23 ws3">RTS/CTS/ACK</span><span class="ls1a ws3d">) used by a MAC protocol<span class="_ _1"></span> </span></span></span></span></div><div class="t m0 x19 hb y2b ff1 fs4 fc0 sc0 ls19 ws3e">do not contain application data, thus they<span class="ls20 ws3f"> are con<span class="_ _1"></span>sidered as supplementary data (<span class="ff2 ls24 ws3">overhead</span><span class="ls1a ws40">). Control </span></span></div><div class="t m0 x19 ha y2c ff1 fs4 fc0 sc0 ls19 ws41">packets can be of importance sin<span class="_ _1"></span>ce most applic<span class="ls1d ws42">ations use data packets with reduced size. </span></div><div class="t m0 x18 ha y2d ff6 fs4 fc0 sc0 ls0 ws3">•<span class="ff1 ls20 ws43"> <span class="_ _4"> </span>Idle listening: when a node is not active, leaves listeni<span class="_ _1"></span>ng t<span class="ls19">he signal carrier to knowing if it is the receiver of </span></span></div><div class="t m0 x19 ha y2e ff1 fs4 fc0 sc0 ls1b ws44">an eventually traffic. In this sit<span class="ls25 ws45">uation, the amount of ener<span class="ls1e ws46">gy waste is equal to t<span class="ls1a ws47">he energy dissipated by a </span></span></span></div><div class="t m0 x19 ha y2f ff1 fs4 fc0 sc0 ls1e ws48">normal reception. </div><div class="t m0 x18 ha y30 ff6 fs4 fc0 sc0 ls0 ws3">•<span class="ff1 ls1d ws49"> <span class="_ _5"> </span>Over emitting: This case arrive<span class="_ _1"></span>s when a sensor node re<span class="_ _1"></span>ceives a packet while is in a sle<span class="_ _1"></span>ep mode. This </span></div><div class="t m0 x19 ha y31 ff1 fs4 fc0 sc0 ls1e ws4a">situation forces the sender to perform new ret<span class="_ _1"></span>ransmissions that are stron<span class="_ _1"></span>gly linked to non-synchronisation </div><div class="t m0 x19 ha y32 ff1 fs4 fc0 sc0 ls20 ws3a">problem and therefore con<span class="_ _1"></span>sume more energy. </div><div class="t m0 x1a hc y33 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x1b h9 y34 ff3 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 ha y35 ff1 fs4 fc0 sc0 ls1e ws4b">In order to decrease</div><div class="t m0 x1c ha y34 ff1 fs4 fc0 sc0 ls1f ws4c">or if possible to eliminate these vario<span class="_ _1"></span>us sour<span class="ls25 ws4d">ces of energy wastage, several protocol<span class="_ _1"></span>s has </span></div><div class="t m0 x17 ha y36 ff1 fs4 fc0 sc0 ls19 ws41">been proposed these last years and <span class="_ _1"></span>which <span class="ls1b ws35">are divided into two main classes: </span></div><div class="t m0 x1d hd y37 ff2 fs5 fc0 sc0 ls26 ws4e">International Workshop on Verifi<span class="ls27 ws4f">cation and Evaluation of Computer and Co<span class="_ _0"></span>mmunication Systems </span></div><div class="t m0 x1e he y38 ff1 fs5 fc0 sc0 ls26 ws4e">VECoS 2008 </div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></div></div>
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<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/625c405f92dc900e6238aabe/bg2.jpg"><div class="t m0 x1f hf y39 ff7 fs5 fc0 sc0 ls0 ws50">Energy Efficient Cross-Layer MAC Prot<span class="ls28 ws51">ocol for Wireless Sensor Networks </span></div><div class="t m0 x17 ha y3a ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hb y3b ff1 fs4 fc0 sc0 ls25 ws52">1. TDMA-based <span class="_ _6"></span>protocols<span class="ff2 ls0 ws3">:</span><span class="ws53"> these protocols known<span class="_ _1"></span> as deterministic are <span class="ls1d ws54">employed t<span class="_ _1"></span>o avoid collisions by associ<span class="_ _1"></span>ating </span></span></div><div class="t m0 x20 ha y3c ff1 fs4 fc0 sc0 ls0 ws2c">a slot time for each sensor node in a giv<span class="_ _1"></span>en cluster, and <span class="ls1d ws54">to mitigate the effects of <span class="_ _1"></span>overhearing problem, be<span class="_ _1"></span>cause </span></div><div class="t m0 x20 ha y3d ff1 fs4 fc0 sc0 ls1f ws2d">in this situation each node knows his <span class="_ _1"></span>corresponding sl<span class="ls29 ws55">ot time to transmit data packet [3]. However, these </span></div><div class="t m0 x20 ha y3e ff1 fs4 fc0 sc0 ls1d ws56">protocols require the presen<span class="_ _1"></span>ce of a management aut<span class="ls19 ws57">hority (for example a dedicated access poi<span class="_ _1"></span>nt) to </span></div><div class="t m0 x20 ha y3f ff1 fs4 fc0 sc0 ls19 ws58">orchestrate the various ac<span class="_ _1"></span>tivities inside a cluster. This<span class="ls1a ws59"> makes the use of the<span class="_ _1"></span>se protocols more complex in <span class="_ _1"></span>the </span></div><div class="t m0 x20 ha y40 ff1 fs4 fc0 sc0 ls1b ws35">WSN where the nodes in general have a same p<span class="_ _1"></span>riority and very limited resources. </div><div class="t m0 x17 ha y41 ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 ha y42 ff1 fs4 fc0 sc0 ls1b ws5a">2. Contention-based <span class="_ _6"></span>protocol<span class="ls20 ws5b">s: these protocols known as CSMA<span class="_ _1"></span>-based are usually used in the <span class="_ _1"></span>multi-hop wireless </span></div><div class="t m0 x20 ha y43 ff1 fs4 fc0 sc0 ls1a ws5c">networking due to their si<span class="_ _1"></span>mplicity and their adequacy to be implemented in a decentralized<span class="_ _1"></span> environment like </div><div class="t m0 x20 ha y44 ff1 fs4 fc0 sc0 ls20 ws5d">WSN. When these protocols ar<span class="ls1e ws2a">e u<span class="_ _1"></span>sed, collisions can be occur in <span class="_ _1"></span>case of a receiver is locate<span class="_ _1"></span>d in the radio range </span></div><div class="t m0 x20 ha y45 ff1 fs4 fc0 sc0 ls20 ws5e">of at least two sensor nodes transmitting simultaneo<span class="_ _1"></span>usly data packets to it. In this situation, this node will not </div><div class="t m0 x20 ha y46 ff1 fs4 fc0 sc0 ls20 ws5f">succeed in receiving any data packet. These collision<span class="_ _1"></span>s gen<span class="ls1f ws60">erate useless retransmissions <span class="_ _1"></span>which cause energy </span></div><div class="t m0 x20 ha y47 ff1 fs4 fc0 sc0 ls19 ws61">consumption wastage a<span class="_ _1"></span>nd time consuming in data transmiss<span class="ls1e ws62">ion. To decre<span class="_ _1"></span>ase these collisions a<span class="_ _1"></span>nd to reduce </span></div><div class="t m0 x20 ha y48 ff1 fs4 fc0 sc0 ls0 ws63">considerably other sources of energy wastage, the <span class="ls1e ws64">Wake-up/Sleep me<span class="_ _1"></span>chanisms a<span class="ls0 ws65">nd/or the co<span class="_ _1"></span>ntrol messages </span></span></div><div class="t m0 x20 hb y49 ff2 fs4 fc0 sc0 ls23 ws3">RTS/CTS/ACK<span class="ff1 ls19 ws66"> defined in 802.11x standard, are used to design <span class="ls20 ws67">energy efficient MAC protocols for WSN like <span class="_ _7"></span> </span></span></div><div class="t m0 x20 ha y4a ff1 fs4 fc0 sc0 ls25 ws68">S-MAC, T-MAC, B-MAC and Z-MAC. </div><div class="t m0 x17 ha y4b ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hb y4c ff1 fs4 fc0 sc0 ls1e ws69">Recently, a new generatio<span class="_ _1"></span>n of MAC protocols (<span class="ff2 ls25 ws6a">Cross-layer MA<span class="_ _1"></span>C protocols) <span class="ff1 ls2a ws6b">using several layers in order to optimize </span></span></div><div class="t m0 x17 hb y4d ff1 fs4 fc0 sc0 ls20 ws3a">energy consumption has been emerged. These <span class="ls25 ws68">layers can be exploited into two modes: <span class="ff2 ls22 ws3">interaction</span><span class="ls19 ws41"> or <span class="ff2 ls1b ws3">unification<span class="ff1 ls2b">. In </span></span></span></span></div><div class="t m0 x17 ha y4e ff1 fs4 fc0 sc0 ls19 ws6c">the interaction mode, the MAC protocol is built by ex<span class="ls20">ploiting the data generat<span class="_ _1"></span>ed by other adjacent layers. <span class="_ _7"></span> MAC-</span></div><div class="t m0 x17 ha y4f ff1 fs4 fc0 sc0 ls20 ws5d">CROSS Protocol [4] is an example of Cross-layer approach <span class="_ _1"></span><span class="ls1d ws6d">which allow the routing informati<span class="_ _1"></span>on of the network layer </span></div><div class="t m0 x17 ha y50 ff1 fs4 fc0 sc0 ls1d ws6e">to be exploited by MAC layer (intera<span class="_ _1"></span>ction between MAC <span class="_ _1"></span><span class="ls25 ws6f">and network layers) by leaving on<span class="_ _1"></span>ly the communicating </span></div><div class="t m0 x17 ha y51 ff1 fs4 fc0 sc0 ls19 ws70">nodes in activity and by putting into Sleep mode the <span class="ls1d ws71">other neighbour nodes (not concerned by this </span></div><div class="t m0 x17 hb y52 ff1 fs4 fc0 sc0 ls19 ws41">communication). In ord<span class="_ _1"></span>er to avoid collisions, MAC-CROSS uses the co<span class="_ _1"></span>ntrol messages <span class="ff2 ls2c ws3">RTS/CTS/ACK</span><span class="ls2a ws72">. On the other </span></div><div class="t m0 x17 ha y53 ff1 fs4 fc0 sc0 ls1e ws73">hand, a Cross-layer desig<span class="_ _1"></span>n mode by unification requires <span class="ls0 ws74">the development of only one layer including at the same </span></div><div class="t m0 x17 ha y54 ff1 fs4 fc0 sc0 ls25 ws68">time functionalities of considered layers. </div><div class="t m0 x17 ha y55 ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 ha y56 ff1 fs4 fc0 sc0 ls2d ws75">In this paper, we propose a Cross-laye<span class="_ _1"></span>r protocol na<span class="ls1e ws2a">med CL<span class="_ _1"></span>-MAC, based on the same <span class="ls25 ws76">ideas used by MAC-CROSS. </span></span></div><div class="t m0 x17 ha y57 ff1 fs4 fc0 sc0 ls19 ws77">The fundamental difference between our pro<span class="_ _1"></span>posal and MAC-CR<span class="ls1b ws78">OSS is at the level of the number of consecutive </span></div><div class="t m0 x17 ha y58 ff1 fs4 fc0 sc0 ls20 ws79">nodes that are implied in MAC functioning at each frame. Indeed, MAC-CROS<span class="_ _1"></span>S acts on three consecutive nodes </div><div class="t m0 x17 ha y59 ff1 fs4 fc0 sc0 ls1e ws7a">while CL-MAC uses all the nodes inclu<span class="_ _1"></span>ded in a given routi<span class="ls19 ws58">ng path from the source to the Sink in one frame, thus </span></div><div class="t m0 x17 ha y5a ff1 fs4 fc0 sc0 ls20 ws7b">making it possible to take place simultaneously wi<span class="_ _1"></span>th <span class="ls1a ws7c">two main operations: data packets transmission <span class="_ _1"></span>between </span></div><div class="t m0 x17 ha y5b ff1 fs4 fc0 sc0 ls1a ws7d">communicating no<span class="_ _1"></span>des (a process relatively slow) wh<span class="_ _1"></span>ich ad<span class="ls0 ws74">vances progressively, and contro<span class="_ _1"></span>l packets transmission </span></div><div class="t m0 x17 ha y5c ff1 fs4 fc0 sc0 ls1c ws7e">which advances quickly toward<span class="_ _1"></span>s the Sink, by preparing <span class="ls1d ws7f">a path in which only nodes belongin<span class="_ _1"></span>g the routing path </span></div><div class="t m0 x17 ha y5d ff1 fs4 fc0 sc0 ls25 ws68">remain in activity and all other nodes ent<span class="_ _1"></span>er into Sleep mode for a given time interval. </div><div class="t m0 x17 ha y5e ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 ha y5f ff1 fs4 fc0 sc0 ls1a ws80">Temporal Petri nets are introduced in<span class="_ _1"></span> order to model t<span class="ls0 ws81">he proposed protocol and TiNA tool is carried<span class="_ _1"></span> out for </span></div><div class="t m0 x17 ha y60 ff1 fs4 fc0 sc0 ls2e ws82">validation purpose. A comparative study between <span class="_ _1"></span>CL-MAC and S-MAC in term of energy efficiency and latency h<span class="_ _1"></span>as </div><div class="t m0 x17 ha y61 ff1 fs4 fc0 sc0 ls19 ws41">been performed for evaluat<span class="_ _1"></span>ion purpose. </div><div class="t m0 x17 ha y62 ff1 fs4 fc1 sc0 ls0 ws3"> </div><div class="t m0 x17 ha y63 ff1 fs4 fc0 sc0 ls25 ws68">The rest of the paper is organized as follow: In next secti<span class="ls0 ws83">on, we introduce main works in literature related to energy </span></div><div class="t m0 x17 ha y64 ff1 fs4 fc0 sc0 ls1a ws7d">saving at MAC layer level. Some OSI-based proto<span class="_ _1"></span>cols <span class="ls0 ws74">and others based on Cross-layering approach are<span class="_ _1"></span> given in </span></div><div class="t m0 x17 ha y65 ff1 fs4 fc0 sc0 ls20 ws84">this section. In section 3, we give more details about <span class="ls25 ws45">the propo<span class="_ _1"></span>sed protocol CL-MAC. In Section 4, we present a </span></div><div class="t m0 x17 ha y66 ff1 fs4 fc0 sc0 ls19 ws85">formal representation of CL-MAC proto<span class="_ _1"></span>col using time Petri nets modeling approach. Analyse and performa<span class="_ _1"></span>nce </div><div class="t m0 x17 ha y67 ff1 fs4 fc0 sc0 ls0 ws86">evaluation of CL-MAC protocol are pres<span class="ls20">ented in secti<span class="_ _1"></span>on 5. Finally, we concl<span class="ls1e ws87">ude our work and discuss some future<span class="_ _1"></span> </span></span></div><div class="t m0 x17 ha y68 ff1 fs4 fc0 sc0 ls2f ws88">perspectives.<span class="_ _1"></span> </div><div class="t m0 x17 h9 y69 ff3 fs4 fc0 sc0 ls30 ws89">2. RELATED WORK </div><div class="t m0 x17 ha y6a ff1 fs4 fc0 sc0 ls1a ws8a">In this section, we present some MAC l<span class="_ _1"></span>ayer protocols <span class="ls19">developed some year<span class="_ _1"></span>s ago enabling energy conservation in </span></div><div class="t m0 x17 ha y6b ff1 fs4 fc0 sc0 ls22 ws8b">WSN. Firstly, compatible OSI protoc<span class="ls20 ws8c">ols are presented and follo<span class="_ _1"></span>wed by two im<span class="ls1b ws78">portant cross-layer protoc<span class="_ _1"></span>ols: MAC-</span></span></div><div class="t m0 x17 ha y6c ff1 fs4 fc0 sc0 ls22 ws8d">CROSS and XLM. Especially, MAC-CROSS protocol is consid<span class="_ _1"></span>er<span class="ls0 ws83">ed as a basis of the development of our proposal. </span></div><div class="t m0 x17 h9 y6d ff3 fs4 fc0 sc0 ls2a ws72">2.1 Compatible OSI protocols </div><div class="t m0 x17 ha y6e ff1 fs4 fc0 sc0 ls1a ws8e">Many Studies in WSN showed that <span class="ws8f">energy consumption durin<span class="_ _1"></span>g a communicati<span class="ls1e">on is four greater than the energy </span></span></div><div class="t m0 x17 ha y6f ff1 fs4 fc0 sc0 ls19 ws90">consumed in proce<span class="_ _1"></span>ssing and sensing operation<span class="_ _1"></span>s together. Th<span class="ls25 ws91">is fact leads communication protocols designers t<span class="_ _1"></span>o </span></div><div class="t m0 x17 ha y70 ff1 fs4 fc0 sc0 ls19 ws6c">take a particular interest to WSN-MAC layer and to propose<span class="ls1e ws92"> some original i<span class="_ _1"></span>deas to manage efficiently this layer. </span></div><div class="t m0 x17 ha y71 ff1 fs4 fc0 sc0 ls19 ws41">The medium access must take into a<span class="_ _1"></span>ccount all sources of energy wastage co<span class="_ _1"></span>nsiderations. </div><div class="t m0 x17 ha y72 ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x21 hd y73 ff2 fs5 fc0 sc0 ls27 ws4f">International Workshop on Verification and Eval<span class="ls31 ws93">uation of Computer and Co<span class="_ _0"></span>mmunication Systems </span></div><div class="t m0 x22 he y74 ff1 fs5 fc0 sc0 ls26 ws93"> VECoS 2008 </div><div class="t m0 x23 hc y75 ff7 fs4 fc0 sc0 ls0 ws3">2</div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></div></div>
<div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/625c405f92dc900e6238aabe/bg3.jpg"><div class="t m0 x1f hf y39 ff7 fs5 fc0 sc0 ls0 ws50">Energy Efficient Cross-Layer MAC Prot<span class="ls28 ws51">ocol for Wireless Sensor Networks </span></div><div class="t m0 x17 ha y3a ff1 fs4 fc0 sc0 ls1c ws94">S-MAC or Sensor-MAC is a very popul<span class="_ _1"></span>ar protocol developed at<span class="_ _1"></span><span class="ls20 ws5d"> California University [5, 6, 1] and is considered as a </span></div><div class="t m0 x17 ha y76 ff1 fs4 fc0 sc0 ls20 ws43">MAC protocol referenced by the WSN-sc<span class="ls19">ientific <span class="_ _1"></span>community. The principle of<span class="ls0"> S-MAC protocol is based on <span class="_ _1"></span>a number </span></span></div><div class="t m0 x17 ha y77 ff1 fs4 fc0 sc0 ls1d ws49">of frame delays entering i<span class="_ _1"></span>n a communication. Each fram<span class="ls1c ws95">e i<span class="_ _1"></span>s divided into two equal periods: wake<span class="_ _1"></span>-up and sleep </span></div><div class="t m0 x17 ha y78 ff1 fs4 fc0 sc0 ls1a ws3d">periods. Synchronization of nodes ta<span class="_ _1"></span>kes place in a neighbourhood’ node and exchang<span class="_ _1"></span>e their calendars. A wake-up </div><div class="t m0 x17 ha y79 ff1 fs4 fc0 sc0 ls30 ws96">period enables for t<span class="_ _1"></span>wo neighbour nodes in a wa<span class="_ _1"></span>ke-up st<span class="ls2e ws97">ate to remain active during all<span class="_ _1"></span> the duration of the </span></div><div class="t m0 x17 ha y7a ff1 fs4 fc0 sc0 ls19 ws98">communication. In the sle<span class="_ _1"></span>ep period, when a communication ends, com<span class="_ _1"></span>municating nodes enter in slee<span class="_ _1"></span>p mode by </div><div class="t m0 x17 ha y7b ff1 fs4 fc0 sc0 ls19 ws41">switching off their transceiv<span class="_ _1"></span>ers. This mechanism <span class="ls0 ws83">makes it possible to prolong net<span class="_ _1"></span>work lifetime. </span></div><div class="t m0 x17 ha y41 ff1 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 ha y42 ff1 fs4 fc0 sc0 ls20 ws99">Several energy efficient protocols in the literature ar<span class="ls19">e based on Wake-up/Sle<span class="_ _1"></span>ep mechanism: T-MAC [6], Z-MAC [2], </span></div><div class="t m0 x17 ha y43 ff1 fs4 fc0 sc0 ls19 ws9a">X-MAC and B-MAC [7]. T-MAC and B-MAC are considered <span class="ls1b ws9b">like S-MAC protocol with<span class="ls0 ws9c"> adaptive Wake-up/Sle<span class="_ _1"></span>ep </span></span></div><div class="t m0 x17 ha y44 ff1 fs4 fc0 sc0 ls1a ws9d">periods. In these protocol<span class="_ _1"></span>s, as early as a node detects that<span class="ls25 ws6a"> a medium is o<span class="_ _1"></span>ccupied, enter immediately in sleep mode </span></div><div class="t m0 x17 ha y45 ff1 fs4 fc0 sc0 ls1a ws9e">so as to preserve more energy and red<span class="_ _1"></span>uce a collision risks in his <span class="_ _1"></span>neighbourhood. </div><div class="t m0 x17 h9 y7c ff3 fs4 fc0 sc0 ls19 ws41">2.2 Cross-layer protocol<span class="_ _1"></span>s </div><div class="t m0 x17 ha y7d ff1 fs4 fc0 sc0 ls19 ws9f">Other protocols based o<span class="_ _1"></span>n OSI layer models try to reduce <span class="ls1a ws7d">p<span class="_ _1"></span>roblems encountered in WSN.<span class="ls2c wsa0"> <span class="_ _1"></span>Network layer protocols </span></span></div><div class="t m0 x17 ha y7e ff1 fs4 fc0 sc0 ls1d ws39">tend to optimize paths between network’ node<span class="_ _1"></span>s and the Sink <span class="ls19 wsa1">while application layer prot<span class="_ _1"></span>ocols try to obtain correct, </span></div><div class="t m0 x17 ha y7f ff1 fs4 fc0 sc0 ls0 ws24">accurate and compressed<span class="_ _1"></span> and/or aggregated information [8, <span class="ls20 ws7b">9] so as to reduce the amount of packets in the </span></div><div class="t m0 x17 ha y80 ff1 fs4 fc0 sc0 ls0 wsa2">network. OSI-based protocol<span class="_ _1"></span>s are not flexible, not optim<span class="ls1d wsa3">al and consequently reduce net<span class="_ _1"></span>work performances. To </span></div><div class="t m0 x17 ha y81 ff1 fs4 fc0 sc0 ls0 wsa4">mitigate these drawbacks, a new MAC approach b<span class="_ _1"></span>ased on intera<span class="ls20">ction or unification of two o<span class="_ _1"></span>r more adjacent layers, </span></div><div class="t m0 x17 ha y82 ff1 fs4 fc0 sc0 ls1b wsa5">called Cross-layer MAC optimization, is emerged [10, 4, 11]. Some<span class="fc1 ls0 ws3"> <span class="_ _8"> </span><span class="fc0 wsa2">protocols using a Cross-layer technique in </span></span></div><div class="t m0 x17 ha y83 ff1 fs4 fc0 sc0 ls20 ws3a">medium access cont<span class="_ _1"></span>rol layer can be found in literature such as MAC-CROSS [4] and XLM [11]. </div><div class="t m0 x17 hb y84 ff2 fs4 fc0 sc0 ls29 wsa6">2.2.1 MAC-CROSS <span class="_ _9"></span>protocol </div><div class="t m0 x17 ha y85 ff1 fs4 fc0 sc0 ls1b wsa7">In MAC-CROSS protocol, only a few nodes concerned of t<span class="ls1f wsa8">he actual data transmission are a<span class="_ _1"></span>sked to wake-up, while </span></div><div class="t m0 x17 ha y86 ff1 fs4 fc0 sc0 ls1d ws49">other nodes that are not i<span class="_ _1"></span>ncluded on a routing path and h<span class="_ _1"></span>ence <span class="ls0 wsa9">not involved in the actual transmi<span class="_ _1"></span>ssion at all. In </span></div><div class="t m0 x17 hb y87 ff1 fs4 fc0 sc0 ls1d ws3">exchanging <span class="_ _a"> </span><span class="ff2 ls24">RTS</span><span class="ls1f wsaa"> and </span><span class="ff2 ls32">CTS</span><span class="wsab"> packets, a field corresponding t<span class="_ _1"></span>o a final destination address is added. The </span></div><div class="t m0 x17 ha y88 ff1 fs4 fc0 sc0 ls1d wsac">neighbourhood nod<span class="_ _1"></span>es belonging to the path extend t<span class="_ _1"></span>heir wa<span class="ls1e wsad">ke-up time while other n<span class="_ _1"></span>odes prolong their sl<span class="_ _1"></span>eep time. </span></div><div class="t m0 x17 ha y89 ff1 fs4 fc0 sc0 ls1c wsae">Destination address is given by a rout<span class="_ _1"></span><span class="ls0 wsaf">ing table in the network layer. A sim<span class="ls1d wsb0">ilar mechanism to ARP protocol of IP </span></span></div><div class="t m0 x17 ha y8a ff1 fs4 fc0 sc0 ls1f wsb1">network has been proposed if different addressi<span class="_ _1"></span>ng mechanisms are used in MAC and ro<span class="_ _1"></span>uting layers separately </div><div class="t m0 x17 ha y8b ff1 fs4 fc0 sc0 ls25 ws68">(see Figure 1). </div><div class="t m0 x24 hc y8c ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x22 h3 y8d ff1 fs1 fc0 sc0 ls2 ws2">High level layer </div><div class="t m0 x25 h10 y8e ff7 fs1 fc0 sc0 ls4 wsb2">MAC layer </div><div class="t m0 x26 h3 y8f ff1 fs1 fc0 sc0 ls5 ws6">Address conversion </div><div class="t m0 x27 h3 y90 ff1 fs1 fc0 sc0 ls33 wsb3">module (Similar to ARP) </div><div class="t m0 x24 hc y91 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc y92 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc y93 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc y94 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc y95 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc y96 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hc y97 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hc y98 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x6 h7 y99 ff3 fs1 fc0 sc0 lsd wsb4">FIGURE 1:<span class="ff1 ls7 wsb5"> Address conversion scheme </span></div><div class="t m0 x17 hb y9a ff2 fs4 fc0 sc0 ls25 wsb6">2.2.2 XLM <span class="_ _9"></span>protocol </div><div class="t m0 x17 hb y9b ff1 fs4 fc0 sc0 ls34 wsb7">XLM (<span class="ff2 ls19 wsb8">Cross-Layer Module for Wi<span class="ls1f wsb9">reless Sensor Ne<span class="_ _1"></span>tworks<span class="ff1 ls1e wsba">) proceeds differently comparin<span class="_ _1"></span>g to others traditional </span></span></span></div><div class="t m0 x17 h11 y9c ff1 fs4 fc0 sc0 ls19 wsbb">architecture based protocol<span class="_ _1"></span>s for WSN. The communication in XLM is ba<span class="_ _1"></span>sed on <span class="ff2 ls0 ws3">initiative<span class="ff5"> <span class="_ _b"></span></span></span><span class="ls1a wsbc">concept considere<span class="_ _1"></span>d as the </span></div><div class="t m0 x17 ha y9d ff1 fs4 fc0 sc0 ls1a ws22">core of XLM and implicitly <span class="_ _1"></span>incorporates the intrinsi<span class="_ _1"></span>c func<span class="ls19 wsbd">tionalities required for successful communication in WSN. </span></div><div class="t m0 x17 hb y9e ff1 fs4 fc0 sc0 ls1e ws3c">A node starts a transmissi<span class="_ _1"></span>on by transmitting to his neighbourhood an <span class="ff2 ls24 ws3">RTS</span><span class="ls25 wsbe"> packet to indicate that it has a packet t<span class="_ _1"></span>o </span></div><div class="t m0 x17 hb y9f ff1 fs4 fc0 sc0 ls19 wsbf">send. Upon receiving an <span class="ff2 ls24 ws3">RTS</span><span class="ls1d wsc0"> packet<span class="_ _1"></span>, each neighbourhood node decide<span class="_ _1"></span>s to participate to communication by </span></div><div class="t m0 x17 hb ya0 ff1 fs4 fc0 sc0 ls19 ws41">determining an <span class="ff2 ls22 ws8d">initiative I</span><span class="ls29 wsc1"> defined as follows: </span></div><div class="t m0 x17 hc ya1 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x9 hc ya2 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x28 h12 ya3 ff4 fs6 fc0 sc0 ls0 ws3">otherwise</div><div class="t m0 x1e h12 ya4 ff4 fs6 fc0 sc0 ls0 ws3">if</div><div class="t m0 x29 h13 ya5 ff7 fs7 fc0 sc0 ls0 ws3">min</div><div class="t m0 x2a h13 ya6 ff7 fs7 fc0 sc0 ls0 ws3">max</div><div class="t m0 x2b h14 ya7 ff4 fs7 fc0 sc0 ls0 ws3">rem<span class="_ _c"></span>rem</div><div class="t m0 x2c h14 ya8 ff4 fs7 fc0 sc0 ls0 ws3">Th</div><div class="t m0 x2c h14 ya9 ff4 fs7 fc0 sc0 ls0 ws3">relay<span class="_ _d"></span>relay</div><div class="t m0 x2d h14 yaa ff4 fs7 fc0 sc0 ls0 ws3">Th<span class="_ _e"></span>RTS</div><div class="t m0 x2e h15 yab ff4 fs8 fc0 sc0 ls0 ws3">E<span class="_ _f"></span>E</div><div class="t m0 x2f h15 yac ff4 fs8 fc0 sc0 ls0 ws3"><span class="fc2 sc0">d</span></div><div class="t m0 x30 h16 yab ff6 fs8 fc0 sc0 ls0 ws3">≥</div><div class="t m0 x31 h16 yad ff6 fs8 fc0 sc0 ls0 ws3">≤</div><div class="t m0 x30 h16 yae ff6 fs8 fc0 sc0 ls0 ws3">≤</div><div class="t m0 x32 h16 yac ff6 fs8 fc0 sc0 ls0 ws3">≥</div><div class="t m2 x33 h17 yaf ff6 fs9 fc0 sc0 ls0 ws3">β<span class="_ _10"></span>β</div><div class="t m2 x2e h17 yb0 ff6 fs9 fc0 sc0 ls0 ws3">λ<span class="_ _11"></span>λ</div><div class="t m2 x2c h17 yb1 ff6 fs9 fc0 sc0 ls0 ws3">ξ<span class="_ _12"></span>ξ</div><div class="t m0 x24 hc yb2 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc yb3 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x34 ha yb4 ff1 fs4 fc0 sc0 ls19 ws41">(1) </div><div class="t m0 x35 h18 yb5 ff6 fs6 fc0 sc0 ls0 ws3"> <span class="_ _13"></span>1,</div><div class="t m0 x24 hc yb6 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x4 h19 yb7 ff4 fs4 fc0 sc0 ls0 ws3">I<span class="ff7 ls23">= </span></div><div class="t m0 x24 hc yb8 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x24 hc yb9 ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hc yba ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x36 h18 ya3 ff7 fs6 fc0 sc0 ls0 ws3">,<span class="_ _14"></span>0</div><div class="t m0 x17 hc ybb ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hc ybc ff7 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x17 hb ybd ff2 fs4 fc0 sc0 ls2b ws3"> </div><div class="t m0 x17 hb ybe ff2 fs4 fc0 sc0 ls0 ws3"> </div><div class="t m0 x21 hd y73 ff2 fs5 fc0 sc0 ls27 ws4f">International Workshop on Verification and Eval<span class="ls31 ws93">uation of Computer and Co<span class="_ _0"></span>mmunication Systems </span></div><div class="t m0 x22 he y74 ff1 fs5 fc0 sc0 ls26 ws93"> VECoS 2008 </div><div class="t m0 x23 hc y75 ff7 fs4 fc0 sc0 ls0 ws3">3</div></div><div class="pi" data-data='{"ctm":[1.611639,0.000000,0.000000,1.611639,0.000000,0.000000]}'></div></div>
