Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 Optmzed Route Technque for DSR Routng Protocol n MANET Dr.K.Santh, Assocate Professor, Dept. of Computer Scence, Sr Ramakrshna College of Arts & Scence for Women, Combatore, Inda. santhcs@srcw.org Dr.G.Kalpana, Assocate Professor, Dept. Of Computer Scence, Sr Ramakrshna College of Arts & Scence for Women, Combatore, Inda. kalpanacs@srcw.org Abstract- Moble ad hoc network (MANET) s a collecton of portable devces whch communcate wth each other wthout the help of any fxed base staton or access pont. Each node n MANET experences the dynamc topology, lmted transmsson range, bandwdth and battery power whch affects routng. The crtcal ssue of routng n MANET s to select an optmal and stable route. Lnk falure causes due to hgh moblty, congeston and lmted battery power whch affects the performance of the routng protocol. Such problems make a routng protocol neffectve and unrelable. To make a routng protocol effectve and relable, ths paper proposes a Optmzed Routng Technque(ORT) usng Modfed Combned Weght Functon (MCWF) mechansm by calculatng sgnal strength, energy level, load and dstance between nodes. Then based on the MCWF, the routes are arranged such that routes wth mnmum length, traffc load, maxmum energy level and sgnal strength are lsted frst n the route table. The path s establshed wth route whch has maxmum MCWF. The beneft of ths mechansm s to select the stable and optmal path to reach the destnaton. It s mplemented usng NS-2 whch mnmzes the end-to-end delay, overhead and energy consumpton and maxmzes the packet delvery rato. Keywords: DSR, MANET, Modfed Combned Weght Functon, stable route, lnk falure. I. INTRODUCTION Moble ad hoc network s a collecton of wreless portable nodes formng a temporary/shortlved network, wthout any fxed nfrastructure, where all nodes are lberated to move randomly and confgure themselves. In MANET, each node wll act as both router and as well as host. The premse of formng a MANET s to provde wreless communcaton between varous devces, anytme - anywhere- any devce-any (A4). MANET s sutable for the applcaton whch needs quck setup and mplementaton such as Mltary and dsaster areas. Due to nodal moblty, the network topology may change rapdly and unpredctably over tme whch affects the propagaton of packets from one node to another. So MANET requres a stable and effcent routng method whch should have a long lfe to transmt the data.thus Routng s a major problem n a decentralzed envronment. Fundamentally two types of routngs are used n Ad hoc network they are Proactve and Reactve. Proactve routng protocols mantan consstent, upto-date routng nformaton between source and destnaton nodes n the network by propagatng the routng nformaton n a perodcal manner. These protocols are sometmes referred to as table drven routng protocol because each and every node n Avalable onlne@www.jcta.com 773
Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 the network mantans the routng nformaton n the table and updates ts nformaton perodcally. In On-demand routng protocol, when a source node wants to send data to the destnaton, frst t checks ts route table whether t has an exstng route. If no route exsts, then t performs a route dscovery procedure to fnd the path to the destnaton. Hence route dscovery becomes ondemand. A Stable route s route whch asssts for a long tme transmsson wthout lnk breakage. II. RELATED WORK A moble ad hoc network s an emergng technology. Due to ts dynamc topology t has to face many challenges and ssues lke lnk falure[9][10]. To overcome ths problem t has to select the stable route for the data transmsson between source and destnaton. Varous methods have been proposed to acheve the stable route. Ntn Manjh & Nlesh Patel[3] has proposed a method SSAODV( Sgnal Strength Adhoc On Demand Routng Vector ), n whch sgnal strength s measured between nodes and compare wth the RSSI threshold value. If the sgnal strength s greater than the threshold value then t s accepted for further transmsson else t s dscarded. Ths scheme s used for selectng the stable route between source and destnaton. It maxmzes packet delvery rato, throughput and mnmzes end-to-end delay and routng overhead. B.R Sujatha, & M V Satyanarayana[4] proposed a PDSR (Preemptve Dynamc Source Routng) whch mprove the data connectvty n the network by selectng an alternate path as soon as sgnal strength reduces below the threshold value and also consderng the age of the path whch exceeds the predefned threshold. The performance depends on the preemptve rato and t s consderably mproved. header part n the RREQ to fnd out the destnaton. The best path s found out by usng ts sgnal strength. Source node frst checks the vsblty of the adjacent nodes and those nodes further checks for the vsblty of ther adjacent nodes. Subsequent to that the source node fnds out the average path. The path wth the maxmum average value s selected as the fnal path. Second hypothess s based on the hop count smlar to that of the AODV protocol. The path wth mnmum hop count s consdered as the fnal path. Thrd assumpton s based upon the sequence number. Ths helps to mprove the performance of the enhanced AODV. P.Srnvasan & K.Kamalakkannan[6] proposed a novel SEA-DSR (Sgnal strength and Energy Aware Routng DSR) protocol consder the sgnal strength and resdual battery capacty of nodes for the route selecton through the cross layer approach. In ths approach ntermedate nodes update the relablty count n the RREQ feld based on the strength of the sgnal and energy. Relablty factor s calculated for the receved path. The path wth hghest relablty count s selected and the RREP s send n that path for data transmsson to take place. Ths mnmzes the energy consumpton n a great manner. Pryadsrn, T.M. Navaman and Venkatesh Mahadevan[7] proposes algorthms to estmate the stablty of the path by consderng the energy dran and rate of moblty of the node. Ths algorthm s mplemented n the AODV and ths was evaluated aganst the orgnal AODV. The proposed work mproves the network performance and mnmzes the computaton overhead by avodng route dscovery process by selectng stable path wth long lfe. So t maxmzes packet delvery rato and reduced routng overhead. Deept Bansal & Megha Vj[5] enhanced the exstng AODV routng protocol by addng the Avalable onlne@www.jcta.com 774
Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 III. PROPOSED WORK Ad hoc networks requre hghly adaptve routng protocols to deal wth the frequent changes n topology. DSR s a dynamc routng protocol, dscovers the path only when t requres. Due to ts moblty characterstc the lnk between source and destnaton node s broken quckly whch makes protocol as neffcent. The effcency of the DSR routng protocol s upgraded by selectng the stable route for data transmsson n order to avod the lnk falure. The ORT selects the routes whch have more stablty. The stablty of the route s measured by calculatng the modfed combned weght functon usng the followng characterstcs Sgnal Strength-specfes the receved sgnal strength Energy-Specfes the resdual battery energy for the route Length- dstance between nodes and Traffc load-specfes the traffc load across the route Frst the receved sgnal strength s calculated n order to determne whether the node s wthn the transmsson range or not. There are three man rado propagaton models. They are free space modal, two-ray ground reflecton model and shadowng model. The ORT adopted the two-ray ground reflecton model [2] whch gves more accurate predcton over a long dstance than a free space model PtGtGrh (d)= d L Pr 4 t 2 h r 2 - (1) d s the dstance between transmtter and recever. h t and h r are the heghts of the transmt and receve antennas respectvely. The length of the route between two nodes S(x m, y m ) and D(x n, y n ) s calculated usng the Eucldean dstance [8] among the nodes s = 2 2 (x -x )(x n m 2 2 -y ) n m Len -- (2) Determne the multple paths between the nodes and choose the path whch has mnmum dstance between them. If the dstance s less than the transmsson range then they are consder as neghbors. Energy Energy res () = N Energy ntal ----- (3) Where N s the number of nodes n the route, Energy ntal s the energy assgned to the node n the begnnng of smulaton (whch s set to the same value for all nodes) Energy res () s the sum of the remanng energy n the nodes of route. The traffc load also plays a vtal role n the lnk falure. A route wth a mnmum traffc has a hgher prorty n the routng process than route wth maxmum traffc. Traffc of each node s related to the number of routes through t. TL whch ndcates total traffc of route s: Where P t s the transmtted sgnal power. G t and G r are the antenna gans of the transmtter TL = N NH n R1 k n + R2 n n=1 k=1 NH C max ---- (4) and the recever correspondngly L s the system loss, Avalable onlne@www.jcta.com 775
Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 Where R1 n s the number of routes through node n and N s the number of nodes n route. Packet delay s not only caused due to traffc load at the current node, but can also be caused by the traffc load at neghborng nodes. NH n s the number of neghbors for node n, R2 k n s the number of routes through k th neghbor of node n., NH s the number of neghbors of nodes n route whch has N n nodes (repettve neghbor s also taken nto account once), Cmax s the maxmum connecton whch a node can establsh n a network (whch s set to the same value for all nodes) Fnally the Modfed Combned Weght Functon s calculated usng the formula (1), (2), (3) and (4) MCWF = (Energy (Len + P R + TL ----- (5) STEPS INVOLVED IN THE ORT ALGORITHM ARE SUMMARIZED BELOW: ) ) NS2 s used for smulaton n whch the channel capacty of moble hosts s set to the value of 2 Mbps. DCF of IEEE 802.11 for wreless LANs as the MAC layer protocol. It has the functonalty to report the network layer about the lnk breakage. In ths smulaton, moble nodes of sze 10, 20, 30, 40 and 50 moves n a rectangular regon of 1500 meter x 300 meter moves randomly wth the mnmal speed of 5 m /s to the maxmal speed of 20 m /s. It uses Random Way Pont moblty model wth the packet sze of 512 bytes. Intally, each node s ntalzed wth the energy of 5.1 joules. The tme taken for the smulaton s 100 seconds. All nodes have the same transmsson range of 250 meters. The smulated traffc used s Constant Bt Rate (CBR). The node transmts the data at a constant rate. Smulaton settngs and parameters are gven below: If Source node A wants to transmt data to destnaton node B Usng Route Dscovery phase all possble routes for a path are dscovered Add all routes R n route table Where =1 n For each route R n the route table Calculate sgnal strength, resdual energy, load and dstance between nodes Calculate Modfed combned weght functon for each route End for Set Fxed threshold value Routes R n the route table are arranged n the descendng order based on MCWF Route R wth maxmum MCWF s selected If sgnal strength of R >= fxed threshold value Establsh a route through R and data transmtted through R Else Drop/Dscard the route from the route table Select the alternate path from the route table and transmt the data through that path End f At tme perod T Route table s refreshed by nvokng routng algorthm If New routes found, t can be added n to table based on ts MCWF value IV. SIMULATION RESULTS Checks each route n the route table by recalculatng MCWF If MCWF < mnmum threshold value Drop/Dscard the route from the route table End f End f Avalable onlne@www.jcta.com A. Smulaton Parameters No. of Nodes 10,20,30,40 and 50 Area Sze 1500 X 300 Mac 802.11 Rado Range 250m Smulaton Tme 100 sec Traffc Source CBR Packet Sze 512 Moblty Model Random Way Pont Rxpower 0.395 Txpower 0.660 dlepower 0.035 Intal energy 5.1 Joules Speed 5m/s to 20m/s Pause tme 10, 20, 30, 40 and 50 776
Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 B. Performance Metrcs The ORT s compared wth the RECM. The performance of ORT s evaluated usng the followng metrcs by varyng the number of nodes and pause tme. Control overhead: The control overhead s defned as the total number of routng control packets normalzed by the total number of receved data packets. Average end-to-end delay: The end-toend-delay s averaged over all survvng data packets from the sources to the destnatons. Average Packet Delvery Rato: Packet delvery rato s measured by dvdng the number of packets receved by the destnaton to the total number of packets orgnated by the source.. Average Energy: It s the average energy consumpton of all the nodes nvolved n sendng, recevng and forwardng operatons. C. Results Fg 2: Node Vs Delay Fg 2. Shows that the average end to end delay for the ORT s mnmzed when compared to the RECM Protocol by selectng the stable route between source and destnaton () Based on Nodes The performance of the work s evaluated by varyng the number of nodes Fg 3: Node Vs Delvery Rato Fg 3. Shows the result for packet delvery rato. From the result, packet delvery rato s ncreased when compared wth the RECM algorthm snce t utlzes the robust lnks. Fg 1: Node Vs Overhead Fg 1 shows the performance over the control overhead of the protocols. Control overhead of the ORT s mnmzed by selectng the stable routes whch n turn avods floodng of route request packet. Avalable onlne@www.jcta.com 777
Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 Fg 4: Node Vs Energy From Fg 4. We can see that the energy consumpton for the proposed work ncreases when compared wth RECM () Based on Pause Tme The performance of the ORT s evaluated for 50 nodes by varyng the pause tme as 10, 20, 30, 40 and 50. Fg 6: Pause Tme Vs Delay Fg 6 shows that the end-to-end delay s reduced when compared wth RECM Fg 7: Pause Tme Vs Delvery Rato Fg 7 shows delvery rato for ORT s maxmzed when compared wth the RECM Fg 5: Pause Tme Vs Overhead Fg 5 shows that the overhead for ORT s mnmzed when compared wth RECM because the frequent route dscovery s avoded n ths technque. Fg 8: Pause Tme Vs Delvery Rato Fg 8 shows the energy consumpton for ORT s reduced when compare wth the RECM Avalable onlne@www.jcta.com 778
Dr K Santh et al, Internatonal Journal of Computer Technology & Applcatons,Vol 7(6),773-779 V. CONCLUSION In ths paper, we have developed a technque whch s used to select the stable route for data transfer. In ths technque a modfed combned weght s calculated for each route n the route cache. The route wth maxmum modfed combned weght s selected for data transmsson n order to avod the lnk breakage. So that the ORT maxmzes packet delvery rato and mnmzes the delay, energy consumpton and overhead. Algorthm, Internatonal Journal of Computer Applcaton, Vol-4, No-3, PP:11-17, July 2013. 9. K.Santh and M.Punthavall, A Relable and Effectve Cache Management Technque for DSR Protocol n Moble Ad Hoc Networks,. 3 rd Internatonal Conference on Computer Modelng And Smulaton (ICCMS 2011), Vol-2, PP:198-204, Jan 2011. 10. Nasser Al Huseen, Osman Ghazal, Suhad Hassan and Mohammed M. Kadhum, Redrect Lnk Falure Protocol Based on Dynamc Source Routng for Manet, Communcatons n Computer and Informaton Scence, Vol- 293, PP:577-591, 2012. VI. REFERENCES 1. Roht Dube, Cyntha D.ras, Kuang-Yeh Wang, Satsh K. Trpath, Sgnal Stablty-Based Adaptve Routng for Ad Hoc Moble Networks, IEEE Personal Communcatons, Feb 1997, PP:36-45. 2. Krtka Khator & Ntn Manjh, Optmze Sgnal Strength and Energy Effcent Mechansm for Lnk Falure n MANET, Internatonal Journal of Computer Networkng Wreless and Moble Communcatons, Vol-5, Issue 1, PP: 1-12, Feb 2015. 3. Ntn Manjh & Nlesh Patel, Sgnal Strength Based Route Selecton n MANETs, Internatonal Journal of Computer Scence and Telecommuncaton, Vol-3, Issue 7, PP:27-30, July 2012. 4. B.R Sujatha, & M V Satyanarayana, Improved Network Connectvty n MANETS, Internatonal Journal of Computer Networks & Communcatons, Vol.1, No.3, PP: 1-8, Oct-2009. 5. Deept Bansal & Megha Vj, Enhancement n AODV Protocol to Provde Best Path Accordng to Sgnal Strength, Internatonal Journal of Scentfc Research Publcatons, Vol-5, Issue-5, PP:1-3, May 2015. 6. P.Srnvasan & K.Kamalakkannan, Sgnal Strength and Energy Aware Relable Route Dscovery n Manet, Internatonal Journal of Communcaton Network Securty, Vol-1, Issue-4, PP:55-59, 2012. 7. S.Pryadsrn, T.M. Navaman and Venkatesh Mahadevan, An Effcent Route Dscovery n Manets wth Improved Route Lfetme, Internatonal Journal of Informaton and Electroncs Engneerng, Vol-2, N0-4, PP:493-496, July 2012. 8. Madhup Shrvastava, M.A.Rzv, A Profcent Approach to Amplfy Packet Delvery Rato Adaptng Shortest Path Avalable onlne@www.jcta.com 779