Traffic Rank Based QoS Routing in Wireless Mesh Network

Transcription

1 Trffic Rnk Bsed QoS Routing in Wireless Mesh Network Deep P Kmble #1, Sujth P Terdl *2 #1 Deprtment of Computer Science nd Engineering, Poojy Doddp App College of Engineering, Gulbrg, Krntk, Indi. *2 Deprtment of Computer Science nd Engineering, Poojy Doddp App College of Engineering, Gulbrg, Krntk, Indi. Abstrct Wireless Mesh Network (WMN) is network to provide Internet ccess to remote res. As prt of the Internet, WMN hs to support multimedi pplictions to ll its users. It is essentil to provide efficient Qulity-of-Service (QoS) support to the networks. Serching the better qulity pth with the mximum vilble utilized bndwidth is one of the fundmentl issues for supporting QoS in the WMN. Rel time pplictions such s type of medi ccess like video, udio, mil services vries from one node internet ccess to nother node internet ccess. A smll vrition of the efficient Qulity-of-Service (QoS) metrics like jitter, dely, nd throughput, hs significnt impct on the bndwidth nd link cpcity demnds of the node. In this pper we present computing of better rnk bsed pth, which cptures the vilble pth utilized bndwidth informtion is proposed. This pper lso show, tht the efficient routing protocol bsed on the new rnk bsed pth which provides the consistency. The consistency property gurntees tht ech node in the trffic mkes n pproprite pcket forwrding decision, bsed on the ssigned rnks, so tht dt pcket does trvels through the exct pth. Once the current pth fils the rerouting of the pcket is supported. The OMNeT simultion experiments lso show tht the proposed rnk bsed pth gives high-throughput pths. Keywords Wireless mesh networks, Qulity-of-Service, Bndwidth, Rnk of nodes (wireless hosts). I. INTRODUCTION A wireless mesh network is communiction network mde up of rdio nodes orgnized in mesh topology. As prt of the globl Internet, Wireless Mesh Network hs to support multimedi pplictions for ll its users. It is essentil to provide efficient Qulity-of-Service support in this type of networks [1]. Serching the new link with the better rnk is vilble to nodes in the network trffic nd lso serching the pth with the mximum vilble utilized bndwidth is lso one of the fundmentl issues for supporting QoS in the WMN [2]. The vilble pth bndwidth which is defined s the mximum dditionl rte flow cn push through sturting its pth [3]. For tht reson, if the trffic rte of new flow on pth is no greter thn the vilble bndwidth of the pth, then ccepting the new trffic will not violte the bndwidth which gurntees the existing flows. This pper focuses on the problem to identify the mximum utilized bndwidth pth from the source to the destintion, nd lso ims t developing best trnsmission solution for QoS routing in mesh network through verticl hndover where nodes in mesh network cn choose the best ccess point ner them by mesuring link qulity through throughput of independent ccess ctegory. The source nodes identify the best ccess point s pths from the source to the destintion, which is clled s verticl hndover technique. Meeting uncertin demnd nd ensuring sme throughput to ll the nodes is one of the dominnt nd importnt issues in mesh network which ffects the qulity of services. Severl protocols nd updtes in the protocols re proposed which gurntees more stble pths. But most of these protocols depends upon the instntneous vlues of the stbility fctor nd does not chnge the route if better route is vilble thn the selected route. Therefore in this work we propose trffic rnk bse mesh routing protocol which estimtes the link qulity bsed on the bndwidth nd link cpcity nd incorporte the sme in routing tble. There re severl fctors which ffects the qulity of trnsmission in mesh network. Congestion, Bndwidth, Jitter re the few of the prmeters which ffects the trnsmission qulity. But ll these prmeters re result vrition in trffic nd effective throughput. Chnge in throughput results in chnge of rte of trnsmission, dely, pcket collision. Bndwidth provides good estimtion of throughput. Therefore mesuring the bndwidth is sufficient for mesuring the link vribility. The metric lso chnges due to fctors like mobility nd power losses. But ccurtely mesuring power nd used bndwidth gives good estimtion of this vribility. Hence the objective is to estimte the bndwidth vribility nd power in the link s well s the vritions in the rte nd incorporte the stbility vlue in the routing nd existing route cche. The min work is to ensure QoS in the mesh network. The technique cn be used to obtin better pcket rte nd throughput. The work cn lso be used to improve the vribility in trnsmission or Jitter. It cn be used to obtin the stble routes which cn be used for Multimedi trnsmission. The technique is well suited for single rdio mesh network where every link hs fixed mximum bndwidth. In such single rdio chnnel, Bndwidth nd power losses does not vry bsed on rdio interfce. Thus is well suited for proposed system. In this work, we study how to perform better QoS routing in Wireless Mesh Networks nd mke the following contributions. ISSN: Pge 2899

2 1. Here we propose new pth rnk tht cptures the ide of vilble utilized bndwidth. We give the system to ccess the medi services; vries from one node internet ccess to nother node internet ccess. Hence bndwidth nd link cpcity demnd of the nodes vries. The proposed mesh router nd ccess points must lso ble to ctegories the link qulity nd demnds, which is essentilly importnt to offer best services. We officilly prove tht the proposed pth rnk is good for the trffic bsed QoS routing. 2. Then we illustrte how to construct the rnks for nodes in network nd routing tble, nd develop pcket forwrding scheme. And we formlly show tht the routing protocol stisfies the consistency nd optimlity requirements. 3. Lstly, we implement the routing protocol bsed on the AODV (Ad hoc On-demnd Distnce Vector) protocol in the OMNeT simultor. The generl simultions experiments demonstrte tht the routing protocol outperforms the present routing protocols for demnds discover the mximum vilble bndwidth pths. The rest of the pper is orgnized s follows: In Section II Relted work is described; then in section III, we explin System Design. Section IV describes Simultion Description nd in Section V the Simultion Results nd Performnce mesurement re shown. Finlly we conclude our pper in Section VI. II. RELATED WORK Wireless Mesh Networks is hot topic in network reserch [4] in recent yers. But very little reserch hs been done in designing trffic rnk bsed QoS routing for WMNs. One of the more populr solutions is AODV, every node in the network trffic ct s mesh router nd rely. In this section we describe in brief how the rective routing is well suited for this works. The WMR (Wireless mesh routing) protocol is bsed on AODV nd includes the following spects: Topology Discovery: This is the procedure tht mintins neighborhood informtion for ech node by locl informtion exchnge. This is done by sending out periodic becons (Airfrme pckets). Route Discovery: This lgorithm uses the topology informtion to obtin the route to destintion. The routes re discovered on-demnd. For internl trffic, the route is obtined from the source to the destintion while for externl trffic the route is obtined to the nerest node tht provides externl connectivity. Agin, Route Discovery consists of two phses, Route Rnk Explortion when the route is discovered, nd Link cpcity when with the receipt of the first dt pcket to ll resources links for tht flow re ctivted. Admission Control: This is the module tht helps decide whether flow with the given QoS constrints will be ccepted or rejected. AODV uses the following methodology for clculting the Bndwidth consumed t ech node: Bndwidth Mesurement techniques; For providing best QOS technique, ccurte bndwidth estimtion is very importnt. Generlly bndwidth mesurement technique concentrte towrds estimting used bndwidth between ll neighboring links of node. But in cse of Burst trffic it is eqully importnt tht we tke into considertion of self generted trffic by node. B x B i.. (1) cons in self (1) Gives the bndwidth consumption t ny node where B self i is the self trffic generted t Node. We ssume tht the chnnel cpcity in network is C (chnnel cpcity here is ssumed s the Idel vilble bndwidth in idel time t ny node). For simplicity we consider one wy link here. We express bndwidth t ny node i is C B i.. (2) N Where N is the number of nodes tht shres the chnnel nd C is termed s chnnel utiliztion rte. It is quite obvious tht s number of nodes in n re increses( node density) chnnel will be shred by tht much more number of nodes or in other terms utiliztion per node will decrese. Hence we cn device theory tht α Node_Density. We choose =Node_Density by optimizing the proportionlity constnt to 1 s it will not hve direct effect on the performnce. Bsed on this we cn sy tht bndwidth t ny node i is C 1 Bi x Ui. (3) ni Where n i is the totl neighbours of i nd U i is the used bndwidth by node i. This bndwidth mesurement is very significnt s node only need to know bout its neighbours nd cn still estimte the vilble bndwidth. From (1) nd (2) we cn device new bndwidth estimtion (Bndwidth consumed t node). C Bcons Bself i... (4) in From (4) nd (3), Totl vilble bndwidth cn be clculted by. C 1 B x x B i Ux n x in self... (5) Where B (x) is the totl vilble bndwidth t node x. from 5 it is very cler tht if trffic genertion t ech node is controlled by the node, QOS cn be provided to overll network. Since AODV nd QOS re very identicl protocols, in the rest of this pper we use the term AODV for describing the semntics of AODV i.e., on demnd route request nd QOS to void confusion in providing better qulity service. With ll these mechnisms in plce, AODV seems to be good rective routing protocol tht gurntees efficient routing with QoS gurntees.mesh routing protocols re used in environments where there is not necessrily well-controlled infrstructure network but where there is common routing policy. There re two min ctegories of routing: proctive nd rective. ISSN: Pge 2900

3 Proctive routing protocols re bsed on the norml routing protocols used in wired networks, such s tody s internet. Algorithms bsed on distnce vector nd link stte re common. Distnce vector often uses the number of hops s metric to minimise when selecting the best route, but cn lso go beyond this to consider more prmeters, for exmple link bndwidth nd dely. This is used to construct route tble, which is shred with other routers. Link stte opertion is more complex nd requires ech router to build its own mp of the network. Thus, in proctive protocols, there is n ttempt to build loclly, t ech node, picture of roots within the network before they re required for use. The routing tbles re usully built periodiclly through the norml opertion of the protocol exchnging routing updte pckets. In norml opertion, this hs dvntge tht the routes re lredy pre-computed nd so pcket forwrding cn tke plce s soon s pcket for prticulr destintion ppers t node. The drwbck is tht routes my be clculted nd reclculted (for e.g. due to node mobility) when they re ctully not required for dt. This wstes bndwidth nd, for mobile nodes, lso wstes bttery power vi the sending nd receiving of unnecessry routing updtes. Rective routing tkes n lterntive pproch by building routes only upon demnd. It my lso cche route informtion ccording to some short time-out or stle-ness policy. Cched routes cn be used s required, but if route is not known then it hs to be discovered. This hs dvntge tht routes re only evluted when needed, lthough this pproch dds ltency to pcket forwrding when routes re not lredy known. Generlly, the rective routing pproch is the one tht hs received most ttention in the d hoc networking community.all these optimiztions pplied to AODV results in WMESH, our routing protocol for Wireless Mesh Networks. III. SYSTEM DESIGN Systems design is the process of defining the rchitecture, components, modules, interfces, nd dt flow for system to stisfy specified requirements. System design is clssified into two designs they re logicl design nd physicl design. Logicl Design: The logicl design of system pertins to n bstrct representtion of the dt flows, inputs nd outputs of the system. Physicl Design: The physicl design reltes to the ctul input nd output processes of the system. A Dt Flow Digrm (DFD) is grphicl representtion of the flow of dt throughput the system. Dt Flow models re used to show how dt flows through sequence of processing steps. The dt is trnsformed t ech step before moving on to the next stge. These processing steps or trnsformtions re progrm functions where s dt flow digrms re used to document softwre design. The Dt Flow Digrm (DFD) for ssigning rnk of node nd rnk updting is shown in fig.1. Source Rnk Updte Fig. 1 Dt Flow Digrm of ssigning rnk of node. The rnk of node, Rnk (node), determines its priority in ssigning chnnels to the links emnting from it [5]. The rnk encompsses the dynmics of chnnel ssignment nd is computed on the bsis of three fctors: The ggregte trffic t node bsed on the offered lod of the mesh network s computed in [7] The distnce of the node, mesured s the minimum number of hops from the gtewy node The number of rdio interfces vilble on node The gtewy node is ssigned the highest rnk s it is expected to crry the most trffic. The rnk for the remining nodes is given by: Rnk (node) = Aggregte Trffic t the Node (node) Min hops from the gtewy (node) Clerly, the ggregte trffic flowing through mesh node hs n impct on the chnnel ssignment strtegy. The rtionle behind this observtion stems from the fct tht if node relys more trffic, ssigning it chnnel of lest interference will increse the network throughput. Thus, ggregte trffic increses the rnk of node with its trffic. The ggregte trffic (totl trffic trversing node) is key fctor in computing the rnk of the node. Once the rnk of ech node hs been computed, the lgorithm trverses the mesh network in decresing order of Rnk (node). ALGORITHM: Route Cche Let trffic rte be P pckets/second for fixed trffic nd e x where x is rndom Gussin distribution with probbility density function 0.5. (We hve selected Gussin distribution for our trffic genertion, becuse of its burst nture). Let L= 2 P is the queue length t ny node. Totl Avilble bndwidth C= 11.2 MBPS Totl re of simultion be A m 2 Let totl Number of Nodes be N = A N Trnsmission, Access Percentge Updting Link (RANK) Interm edite Node Rnk (node) ISSN: Pge 2901

4 Let P be totl Number of sessions selected nd S= {s1, s2...sp} be the set of source node nd D= {d1, d2 dp} be the set of destintion node For ech source in S Generte RREQ do At every node I tht hs received RREQ Clculte vilble bndwidth t i. If (B i < L) Drop RREQ Till i=destintion //Now we hve QOS pth, formed bsed on CBR (Constnt Bit Rte) trffic pttern. For every pth p in P Select trffic pttern For every node I in p do If (B i <L) // B i mesured by MAC lyer nd informtion is pssed to ppliction lyer. Store L trffic in queue Restrict self trffic so tht i L B is minimum // in by ppliction lyer Till i=destintion of p Throughput, dely nd control overhed re estimted t every trnsmission. Here we define dely s summtion of ltency nd witing time of the trffic in node. self IV. SIMULATION DESCRIPTION The OMNeT relesed on Thursdy, 17 November :12. The OMNeT Integrted Development Environment is bsed on the Eclipse pltform, nd extends it with new editors, views, wizrds, nd dditionl functionlity. OMNeT++ dds functionlity for creting nd configuring models (NED nd ini files), performing btch executions, nd nlyzing simultion results, while Eclipse provides C++ editing, SVN/GIT integrtion, nd other optionl fetures (UML modeling, bug trcker integrtion, dtbse ccess, etc.) vi vrious open-source nd commercil plug-ins. OMNeT++ is n object-oriented modulr discrete event network simultion frmework. It hs generic rchitecture, so it cn be (nd hs been) used in vrious problem domins: modeling of wired nd wireless communiction networks protocol modeling modeling of queuing networks modeling of multiprocessors nd other distributed hrdwre systems vlidting of hrdwre rchitectures evluting performnce spects of complex softwre systems In generl, modeling nd simultion of ny system where the discrete event pproch is suitble, nd cn be conveniently mpped into entities communicting by exchnging messges. OMNeT++ simultions cn be run under vrious user interfces. Grphicl, nimting user interfces re highly useful for demonstrtion nd debugging purposes, nd commnd-line user interfces re best for btch execution. The simultor s well s user interfces nd tools re highly portble. They re tested on the most common operting systems (Linux, Mc OS/, Windows), nd they cn be compiled out of the box or fter trivil modifictions on most Unix-like operting systems. OMNeT++ is free only for cdemic nd non-profit use; for commercil purposes, one needs to obtin OMNEST licenses from Simulcrft Inc. A. Simultion Prmeters The simultion focuses on some of the network properties such s: i. Jitter ii. Dely iii. Throughput iv. SNIR The throughput is nlyzed with time. The other prmeters re nlyzed with vrious numbers of nodes. B. Simultion Experimentl Setup Chnnel Type Wireless Chnnel Hosts Wireless Hosts, Adhoc Hosts No. of nodes N no. of nodes Routing protocol AODV Time of simultion strt Time of simultion end 1000s Simultion Type OMNeT Tble. 1 Simultion Settings C. Network Simultion Scenrios Fig. 2 Bsic Model ISSN: Pge 2902

5 Fig. 3Inter-Access point1 communictes with Access point2 by sending Airfrme pckets. hndle jitter. The types of jitter re rndom jitter nd deterministic jitter. Jitter is defined s vrition in the dely of received pckets. The jitter occurs becuse of trffic, interference etc. Also while sending more dt in the routing pth the dt pcket overhed is occurred. As shown in Fig. 6, the Mc jitter is compred with existing speed, whenever speed increses the proposed jitter is decresed hence from 4mps to 6mps period of time is the optimiztion time, which shows tht the jitter is less for the proposed system. Fig. 4 Node Probe pckets to ll Neighbours Fig. 5 Performnce mesurement t ech node upon receiving Pckets. The simultion experiment settings which re listed in Tble1 re implemented in OMNeT simultion. The simultion network consists of 8 wireless hosts nd 3 mesh ccess points one mesh router nd one mesh gtewy shown in fig. 2. In fig.3 inter ccess communiction is shown. The fig. 4 bove gives node probe pckets to ll neighbours. In this setup five nodes re chosen s source nd one node is chosen s destintion. First, the distnce is clculted bsed on utilized bndwidth from ll the nodes to the destintion. Bsed on this, pth rnk selection is done from source to destintion; there my be one or more pths. Avilble Bndwidth is set s 11.2Mbps. Then ech links bndwidth is estimted which is the pth rnk, lso the mximum vilble utilized bndwidth pth is found nd hop by hop routing is done. Pcket forwrding is performed successfully to provide the qos consistency. The routing tble is constructed nd lso the routes re updted. Once the route fils then rerouting is lso supported. Fig. 5 shows performnce mesurement. V. RESULTS & PERFORMANCE EVALUATION SIMULATION RESULTS i. Jitter In voice over IP (VoIP), jitter is the vrition in the time between pckets rriving, cused by network congestion, timing drift, or route chnges. A jitter buffer cn be used to Fig. 6 Speed versus Jitter ii. Dely -to-end dely refers to the time tken for pcket to be trnsmitted cross network from source to destintion. to dely versus speed is plotted in Fig. 7. The different delys re queuing dely, propgtion dely, processing dely, processing time. The dely is clculted for different number of nodes. As shown in Fig. 7, the end to end dely is compred with existing speed, which shows tht the dely is less for the proposed system. The optimized result is got t the 4mps. Fig. 7 Speed versus Dely iii. Throughput Throughput is the verge rte of successful messge delivery over communiction chnnel. This dt my be delivered over link, or pss through certin network node. In Fig. 8, the speed versus throughput comprison is plotted. It is crried out with different evlution time. As observed in the grph throughput of the network increses in both existing speed nd proposed Bndwidth method. Due to the mximum vilble bndwidth pth routing, throughput is significntly incresed in proposed method. This is becuse the delivery rtio is extremely high nd pcket drop is comprtively less. Optimizing result got t period 6mps. ISSN: Pge 2903

6 improved by incorporting other fctors tht mrks link vribility like chnnel cpcity, bndwidth, throughput or jitter. By lso incorporting vrition in received signl we cn improve the system performnce. Fig. 8 Speed versus Throughput iv. SNIR In telecommunictions, the rtio of signl to noise plus interference, or signl-to-noise-plus-interference rtio (SNIR), is defined s the rtio of signl power to the combined noise nd interference power: Psignl SNIR Pnoise Pinterference Where P is the verged power. Vlues re commonly quoted in decibels. As shown in Fig. 9, the optimized result got t 4mps, & the snir is compred with existing speed, which shows tht the snir is less for the proposed system. Fig. 9 Speed versus SNIR VI. CONCLUSION & FUTURE WORK Link qulity in WMN vries due to fctors like mobility, energy consumption, nd power losses. Vrition in link qulity results in fluctutions in pcket delivery rtio, ltency nd other performnces. So under link vritions, routes cnnot be considered s stble. Therefore incorporting link qulity nd deriving suitble technique to include the sme s cost metric in routing is essentil. There re severl techniques which estimtes the link qulity bsed on either movement or power loss. As SINR nd signl power directly or indirectly ffects ll the other prmeters, we hve considered SINR bsed link qulity metric for Link Stte routing nd verticl hndoff in WMN. Therefore in this work we mesure link stbility s consistency of dt nd control pcket rte in the links. Links with consistent rtes irrespective of high or low re considered s more stble Links. Through OLSR we find the routes tht incorporte the most stble links. Further if the current router's link fils or degrdes, the next best router is selected. Result shows tht the technique results in better QoS in terms of pcket delivery rtio, control overhed under different link vribility constrints like high mobility. The system cn be further REFERENCES [1] T.S. Strlin, D. Jsmiine Dvid, Routing Anlysis in Wireless Mesh Network with Bndwidth Alloction, proc. IJEAT, ISSN: 2249, vol. 2, issue 3, [2] Q. Zhng nd Y.-Q. Zhng, Cross-Lyer Design for QoS Support in Multihop Wireless Networks, Proc. IEEE, vol. 96, no. 1, pp , Jn [3] T. Slonidis, M. Gretto, A. Sh, nd E. Knightly, Identifying High Throughput Pths in Mesh Networks: A Model-Bsed Approch, Proc. IEEE Int l Conf. Network Protocols (ICNP 07), pp , Oct [4] Vinod Kone, Sudipto Ds University of Cliforni, Snt B7rbr, QoS Routing in Wireless Mesh Networks. [5] Hbib Sklli, IMT Lucc Institute for Advnced Studies, Smik Ghosh nd Sjl K. Ds, The University of Texs t Arlington, Lucino Lenzini, University of Pis, Mrco Conti, Itlin Ntionl Reserch Council (CNR), Chnnel Assignment Strtegies for Multirdio Wireless Mesh Networks: Issues nd Solutions, proc. IEEE, Nov [6] L. Chen nd W.B. Heinzelmn, QoS-Awre Routing Bsed on Bndwidth Estimtion for Mobile Ad Hoc Networks, IEEE J. Selected Ares in Comm., vol. 23, no. 3, pp , Mr [7] A. Rniwl, K. Gopln, nd T. Chiueh, Centrlized Chnnel Assignment nd Routing Algorithms for Multichnnel Wireless Mesh Networks, ACM Mobile Comp. nd Commun. Rev., Apr. 2004, pp [8] Q. ue nd A. Gnz, Ad Hoc QoS On-Demnd Routing (AQOR) in Mobile Ad Hoc Networks, J. Prllel nd Distributed Computing, vol. 63, pp , [9] W. Lio, Y. Tseng, nd K. Shih, A TDMA-Bsed Bndwidth Reservtion Protocol for QoS Routing in Wireless Mobile Ad Hoc Networks, Proc. IEEE Int l Conf. Comm. (ICC 02), pp , Apr [10] J.L. Sobrinho, Algebr nd Algorithms for QoS Pth Computtion nd Hop-by-Hop Routing in the Internet, Proc. IEEE INFOCOM, pp , Apr BIOGRAPHY Deep P Kmble received the B.E degree in Computer Science nd Engineering (CSE) from PDA Engineering College, Gulbrg (Krntk), Indi in Currently pursuing her mster s degree in Computer Science nd Engineering (CSE). Her re of interest includes Wireless Mesh Networks, QoS routing in Wireless Mesh Networks. Currently working on the Trffic Rnk Bsed QoS routing, towrds the progress of incresing the network throughput of wireless mesh networks. Sujth.P.Terdl is working s Associte Professor in the Computer Science nd Engineering Deprtment, P.D.A College of Engg, Gulbrg, nd Krntk. She received her M.Tech.degree from Visveshwrih Technologicl University, Belgum, Indi, in Currently, she is pursuing her reserch t Jwhrll Nehru Technicl University, Hyderbd, Indi. Her fields of interest re Mobile Ad Hoc Networks nd wireless network. ISSN: Pge 2904