Statistical Performance Analysis Routing Algorithms for Wimax - Wi-Fi Integrated Heterogeneous Network

Transcription

1 Vol.3, Issue.2, March-April pp ISSN: Statistical Performace Aalysis Routig Algorithms for Wimax - Wi-Fi Itegrated Heterogeeous Network Poulomi Das, 1 Aridam Baerjee, 2 Prof. Siladitya Se Departmet of Electroics ad Commuicatio Egieerig, Heritage Istitute of Techology, West Begal, Idia Abstact: To provide uiterrupted service to every subscribe i a wireless etwork, there is a eed to icorporate a low cost, flexible heterogeeous etwork which ca able to couple ay kid of etwork for efficiet spectrum utilizatio, hece improve system capacity. For data commuicatio Wi-Fi/ Wi-MAX itegrated etwork seems to be a ideal solutio as it is able to provide easy deploymet, high speed data rate ad wide rage coverage with high throughput, low ed to ed delay, flat ad low jitter. As Wi-Fi (IEEE ) & WiMAX (IEEE m) etwork support mobility so from real time service providig to surveillace activities for mobile users ca be supported by this itegrated etwork. The selectio of appropriate routig protocol for high speed uiterrupted applicatios is a importat parameter while desigig of scalable, flexible ad efficiet itegrated etwork. The routig protocol should take ito accout the mobility factor i the etwork ad the topology beig used. So, i this paper we have first desiged a itegrated Wi-Fi/WiMAX etwork ad the statistically aalyze the performace of the etwork for various routig algorithms. This aalysis will help to forecast the best suitable algorithm. Keywords: Itegrated etwork, Network performace, Routig algorithm, Wi-Fi (IEEE ), Wi-MAX (IEEE e) I. Itroductio Recet surveys elighte the fact that there will be a expoetial growth for mobile data demad due to massive developmet i mobile devices like smart phoes, laptop, tabs etc. It is also forecasted that demad of mobile data will be doubled from 2013 where the growth rate is 66 times i betwee 2008 to Chroologically the high speed iteret access from cable, Digital Subscriber Lie (DSL), ad other fixed broad-bad coectios are goig to replace by wireless hotspots, Wi-Fi & WiMAX services. Due to advet of portable, low cost & user friedly devices users are attracted towards wireless services. As time & users demads for uiterrupted services so the last mile wier WiMAX ca be able to cover large areas i metropolita, suburba, rural or terrie with high speed mobile broadbad iteret access called wide area etworks (WANs). Where Wi-Fi ca provide high data rate i short rage commuicatio. Providig proper etwork services to every user, from time of registratio to time to leave is the fuctio of a etwork. As both etworks support mobility so itegratio of both etworks ca be a best solutio to maitai proper QoS. It is importat that the apparet similarity betwee Wi-Fi ad WiMAX, But complemetary atures betwee them are key desigig aspects of this itegrated etwork. While Wi-Fi has a short coverage rage of about 100 meters, WiMAX offers a sigificatly greater coverage i a rage of 500 meters ad beyod; while Wi-Fi offers high raw data (up to 500 Mb/s is evisaged) capacity due to the use of ulicesed frequecy bads with poor traffic cotrol capabilities, WiMAX is capable of highly sophisticated traffic maagemet ad QoS cotrol [1] with low data rates, due to the use of licesed frequecy bads. These itegrated etworks have become more efficiet with the itroductio of mobility cocept of odes. Oe of the challegig aspects i these itegrated etworks is to fid ad develop routig protocols that ca efficietly fid routes betwee ay two odes (may be static or mobile). The routig protocol should take ito accout the mobility factor i these etworks ad the topology beig used. For this reaso, performace evaluatio of various protocols has bee carried out by differet researchers. Routig is a fuctio i the Network layer which determies the path from source to destiatio for the traffic flow. Router i the etwork eeds to be able to look at a packet s destiatio address ad the determies which of the output port is the best choice to get the packet to that address. I this paper, first we have desiged Wi-Fi/ WiMAX itegrated etwork ad proposed a survey o routig algorithms used i this itegrated etworks for both uplik ad dowlik traffic usig QualNet simulator. Also this paper will elighte best suitable routig algorithm for a itegrated heterogeeous etwork to maitai proper QoS all applicatios. II. Theoritical Overview of Wi-Fi (IEEE ) ad Wimax (IEEE e) Techologies 2.1. Wi-Fi (IEEE ) Techology: I 1997, the Istitute of Electrical ad Electroics Egieers (IEEE) created the first WLAN stadard. They called it after the ame of the group formed to oversee its developmet. Ufortuately, oly supported a maximum etwork badwidth of 2 Mbps - too slow for most applicatios. For this reaso, ordiary wireless products are o loger maufactured. The ew geeratio of IEEE based Wi-Fi techology is expected to pick up sigificat market mometum i The curretly available draft techology ca comfortably cover a typical house with sufficiet badwidth to support video, gamig, data ad voice applicatios. I the eterprise eviromet, is expected to support missio-critical applicatios with the throughput, QoS ad security capabilities comparable to Etheret. The developig IEEE stadard is based o MIMO (multiple-iput multiple-output) air iterface techology. MIMO is a sigificat iovatio ad a techology that is beig adapted for use by several o wireless data commuicatios stadards, icludig 4G cellular is a amedmet which improves upo the previous stadards by addig 1032 Page

2 Vol.3, Issue.2, March-April pp ISSN: multiple-iput multiple-output ateas (MIMO) operates o both the 2.4 GHz ad the lesser used 5 GHz bads. It operates at a maximum et data rate from 54 Mbits/s to 600 Mbits/s. The IEEE has approved the amedmet ad it was published i October 2009 Table 1: Features of Advace Wi-Fi Protocols IEEE IEEE802.11ac Frequecy Bad 2.4GHz & 5GHz 5GHz oly Chael Widths 20,40MHz 20, 40, 80MHz & optioal 160MHz Spatial Streams 1 to 4 1 to 8 total up to 4 per cliet Multi User MIMO No Yes Sigal Stream [1x1] Multi Cliet 150Mbps 450Mbps Data Rate Three Stream [3x3] Multi Cliet Data Rate 450Mbps 1.3Gbps 2.2. WiMAX (IEEE e) Techology: The IEEE Stadard, first published i 2001, defies a meas for wireless broadbad access as a replacemet for curret cable ad DSL "last mile" services to home ad busiess. The adoptio of this stadard is curretly i progress through the use of WiMAX Forum certified etworkig equipmet ad wide & spread adoptio should appear over the ext few years. This paper provides a overview of the stadard i regards to frequecy bads, the physical layer specificatio, security sub-layer, MAC commo part sub-layer, ad service specific covergece sub-layer. The IEEE e air iterface stadard exteds its fixed wireless access predecessor, IEEE , to support mobile broadbad wireless access systems [2, 3]. I additio to ehacig several advaced orthogoal frequecy divisio multiple access (OFDMA) techology features, IEEE e icorporates the fuctioality eeded to support user mobility. I particular, techologies such as hybrid automatic repeat request (HARQ), space time codig (STC), advaced atea systems (AAS), multiple iput multiple output (MIMO), ad space divisio multiple access (SDMA) have bee ehaced to support mobile eviromets ad to improve the broadbad access speed. some of these ehacemets are similar i cocept to those icorporated i third geeratio cellular stadards such as CDMA2000 high rate packet data (HRPD) or the high speed dowlik packet access (HSDPA) feature withi the Uiversal Mobile Telecommuicatios System (UMTS) stadard [4], they have bee specifically tailored to a OFDMA air iterface. Additioal sub-chaelizatio optios have bee added i IEEE e to improve recourse maagemet flexibility ad achieve better system performace uder a wide rage of operatig coditios. IEEE e also adds ew medium access cotrol (MAC) procedures related to hadover support. Multiple carrier badwidths ad associated fast Fourier trasform (FFT) sizes are icluded to allow badwidth scalability. Furthermore, time divisio duplexig (TDD) ad frequecy divisio duplexig (FDD) support are available i each of these cases to allow operatio i upaired or paired spectrum allocatios respectively. III. Routig Algoritms Routig algorithms are required to build the routig tables ad hece forwardig tables. The basic problem of routig is to fid the lowest-cost path betwee ay two odes, where the cost of a path equals the sum of the costs of all the edges that make up the path. Routig is achieved i most practical etworks by ruig routig protocols amog the odes. The protocols provide a distributed, dyamic way to solve the problem of fidig the lowest-cost path i the presece of lik ad ode failures ad chagig edge costs Bellma- Ford Routig Algorithm: Bellma- Ford routig algorithm is the shortest path routig algorithm. I a etwork how a packet reached to destiatio usig available shortest path is described by this algorithm. It is popular algorithm i etworkig. The algorithm is usually amed after two of its developers, Richard Bellma ad Lester Ford, Jr., who published it i 1958 ad AODV (Ad-hoc O Demad Distace Vector Routig Protocol): This protocol is based o source-iitiated o-demad routig. This type of routig creates routes oly whe desired by the source ode. Route discovery process starts o demad by the source. This process is completed oce a route is foud or all possible routes have bee explored. It provides uicast, broadcast, ad multicast commuicatio i ad hoc mobile etworks [5]. Routes are maitaied as log as they are eeded by the source ode. AODV odes maitai a route table i which ext hop routig iformatio for destiatio odes is stored. Whe a source ode desires to sed a data to a destiatio ode ad o route iformatio is available, a path exploratio process to fid the destiatio ode takes place. It broadcasts a route request (RREQ) packet to adjacet odes, which i tur, forward the request to their adjacet odes, ad so o, util the destiatio ode is foud. Each ode maitais a sequece umber ad a broadcast ID. The broadcast ID is icremeted for each geerated RREQ. The RREQ packet cosists of the ode sequece umber, broadcast ID ad the most recet sequece umber it has for the destiatio ode. Oly those odes reply to the RREQ which have their sequece umbers greater tha or equal to that cotaied i the RREQ Page

3 Vol.3, Issue.2, March-April pp ISSN: DYMO (DYamic MANET O demad Routig Protocol) It is oe such protocol that is iteded for the use by mobile odes i wireless multihop etworks. It ca adapt to the chagig etwork topology ad determie uicast routes betwee odes withi the etwork. I O-demad protocols [6], odes compute the routes ad maitai routig iformatio oly whe it is eeded, thereby establishig routes as ad whe required by the source. This algorithm has two basic operatios- route discovery ad route maagemet [7]. I route discovery operatio, iitiatig ode seds a route request to all the odes i the etwork to fid the target ode the the target ode seds the reply, i this way proper route is discovered. I order to respod to the chages i etwork topology, odes maitai their routes ad moitor the liks over which the etwork traffic flows. DYMO ca be typically utilized i a large mobile etwork cosistig of large umber of odes where oly a part of the odes commuicate with each other OLSRv2 NIIGATA (Optimized Lik State Routig, versio 2 Routig Protocol) OLSRv2[8] retais the same basic algorithms as its predecessor (OLSR), however offers various improvemets, e.g. a modular ad flexible architecture allowig extesios, such as for security, to be developed as add-os to the basic protocol. OLSRv2 cotais three basic processes: Neighborhood Discovery, MPR Floodig ad Lik State Advertisemets. I Neighborhood Discovery process, each router discovers the routers which are i direct commuicatio rage of itself (1- hop eighbors), ad detects with which of these it ca establish bi-directioal commuicatio. I MPR Floodig process each router is able to, efficietly, coduct etwork-wide broadcasts. Each router desigates, from amog its bi-directioal eighbors, a subset (MPR set) such that a message trasmitted by the router ad relayed by the MPR set is received by all its 2-hop eighbors. I Lik State Advertisemet process routers are determiig which lik state iformatio to advertise through the etwork. Each router must advertise liks betwee itself ad its MPR-selector-set, i order to allow all routers to calculate shortest paths RIP (Routig Iformatio Protocol) The Routig Iformatio Protocol (RIP) is a distace-vector protocol that uses hop cout as it s metric. RIP is widely used for routig traffic i the global Iteret ad is a iterior gateway protocol (IGP), which meas that it performs routig withi a sigle autoomous system. RIP routers maitai oly the best route (the route with the lowest metric value) to a destiatio. Routers ruig RIP sed their advertisemets regularly (e.g., every 30 secods). A router also seds a update message wheever a triggered update from aother router causes it to chage its routig table OSPFv2 OSPFv2 is a IETF lik-state protocol for IPv4 etworks. A OSPFv2 router seds a special message, called a hello packet, out each OSPF-eabled iterface to discover other OSPFv2 eighbor routers. Oce a eighbor is discovered, the two routers compare iformatio i the Hello packet to determie if the routers have compatible cofiguratios. The eighbor routers try to establish adjacecy, which meas that the routers sychroize their lik-state databases to esure that they have idetical OSPFv2 routig iformatio. Adjacet routers share lik-state advertisemets (LSAs) that iclude iformatio about the operatioal state of each lik, the cost of the lik, ad ay other eighbor iformatio. The routers the flood these received LSAs out every OSPF-eabled iterface so that all OSPFv2 routers evetually have idetical lik-state databases. Whe all OSPFv2 routers have idetical lik-state databases, the etwork is coverged. Each router the uses Dijkstra s Shortest Path First (SPF) algorithm to build its route table. IV. Statistical Aalysis Wi-Fi & WiMAX systems are usig OFDM system of a block of N complex symbols are formed with each symbol modulatio oe of N subcarrier with frequecy for the N chose as orthogoal set. The complex evelope of the trasmitted OFDM sigal is represeted by x t 1 1 N j2 f t S e N 0. (1) S = Data Symbol, N= Number of Sub-Carrier, f =Represet frequecy, = bit subcarrier Let Di follows, 0 deote the expected decreases i distortio if the i th packet decoded. The overall distortio ca be writte as l DI D P D 0 i 1 i. (2) i Where D is the expected distortio whe the rate is zero P 0 i is the probability that the i th packets are received correctly & l is the umber of source packet that trasmitted choose to sed. The P i ca be writte form, 1034 Page

4 Vol.3, Issue.2, March-April pp ISSN: i j r j (3) P i = Q j1 Where Q j (r j ) is the probability that the j th of packet is received correctly whe sedig i a rate of r f.. If packets are S p trasmitted i AWGN chael the packet loss probability will be 1 {1 } m data a packet. This relatio helps to calculate throughput of the etwork. p where m is the umber of bits i Average Throughput ( ): The amout of data selected for trasmissio by a user per uit time. The value is expressed i t 1 Kbps ad calculated usig a expoetial movig average as follows *( ) 1 1t t t 1. (4) Packet Loss (ρ): The percetage of packets dropped from the queue out of all the packets that arrived i the queue. The metric idicates the percetage of packets that missed their deadlies ad is calculated as follows: m i1 j1 i Kj. (5) Where, m i is the sum of packets dropped, Kj j1 i1 is the sum of packets arrived i the queue. Both average delay ad packet loss will allow us to determie how effectively a schedulig algorithm satisfies the QoS requiremets of real-time SSs. Frame Utilizatio: The umber of symbols utilized for data out all the symbols i the uplik sub-frame. The metric reported as a percetage is calculated as follows F util i i 1 100% C. (6) Average Queuig delay (d): The time betwee the arrival of a packet i the queue to the departure of the packet from the queue. The value is reported i millisecods (ms) ad is calculated for each SS as follows d N i1 f i N a i. (7) V. System Model Figure 1: A Itegrated WiMAX & Wi-Fi Network 1035 Page

5 Vol.3, Issue.2, March-April pp ISSN: As show i above figure1, WiMAX service providers providig coectivity to Wi-Fi etworks situated i office busiess area, residetial area. The devices which are ot i apartmet ca directly coect with WiMAX etwork [4]. The Wi-Fi etwork uses a physical layer. The auto rate fallback is tured off. The data rate is always 54Mbps. The umber of APs is 16. We vary the umber of origial Wi-Fi users. The service area is a 1500x1500 m 2 square. APs are regularly placed i the service area. That is, they form a 4x4 grid. Sice a has 12 orthogoal chaels, we carefully assig the chaels amog eighborig APs such that ay AP will have differet chael from its eighbors. By doig this, we elimiate possible iter-cell iterferece amog eighborig cells. I order to elimiate the iterferece from hidde-ode collisio, we use the followig strategy. Each user radomly selects oe AP to associate with. But oce the associatio is determied, it will be placed very close to that AP. This esures a radom distributio of users, while at the same time guaratees that users belog to the same cell ca hear each other. WiMAX BS is placed at the ceter of the service area (i.e., (750, 750)). The adaptive modulatio is o by default. But the trasmissio power is large eough so that each WiMAX user ca obtai roughly the same QoS over a log period of time. The traffic source is CBR. Payload size is 1000 bytes. The rate is 16Mbps i the applicatio layer. All traffic is uplik. That is, from users to APs or BS. Roughly speakig, 2 users ca saturate a Wi-Fi etwork, ad 6 users ca saturate the WiMAX. VI. Simulatio Results Figure 2: Throughput for Differet Routig Algorithm for the etwork Figure 3: Average Jitter for for Differet Routig Algorithm for the etwork 1036 Page

6 Vol.3, Issue.2, March-April pp ISSN: Figure 4: Average Ed to Ed Delay for Differet Routig Algorithm for the etwork VII. Coclusio For this heterogeeous itegrated etwork OSPF v2 shows better performace amog all routig algorithms i terms of low jitter, Ed to Ed delay & High throughput. Such performace are helpful for implemetig such etworks for real time applicatio & for better QoS for high speed mobile users. Refereces [1] IEEE e-2005: IEEE Stadard for Local ad Metropolita Area Networks Part 16: Air Iterface for Fixed ad Mobile Broadbad Wireless Access Systems. [2] Istitute of Electrical ad Electroics Egieers, IEEE Stadard for Local ad Metropolita Area Networks Part 16: Air Iterface for Fixed Broadbad Wireless Access Systems, IEEE , Ju [3] Istitute of Electrical ad Electroics Egieers, IEEE Stadard for Local ad Metropolita Area Networks Part 16: Air Iterface for Fixed ad Mobile Broadbad Wireless Systems Amedmet 2: Physical ad Medium Access Cotrol Layers for Combied Fixed ad Mobile Operatio i Licesed Bads, ad Corrigedum 1, IEEE e-2005 ad / COR1, Feb [4] Itegratio of Wimax ad Wi-Fi services: Badwidth sharig ad chael collaboratio by Yug-Mig Li, Jhih-Hua Jhag-Li. [5] Elizabeth M. Royer ad Charles E. Perkis, A Implemetatio Study of the AODV Routig Protocol, i Proc. IEEE Wireless Commuicatios ad Networkig Coferece (WCNC 2000), Chicago, IL, September [6] Elizabeth Beldig-Royer, Ia Chakeres, David Johso, ad Charlie Perkis. DYMO dyamic MANET o-demad routig protocol. I Rebecca Buch, editor, Proceedigs of the Sixty First Iteret Egieerig Task Force, Washigto, DC, USA, November IETF [7] Ia D. Chakeres ad Charles E. Perkis. Dyamic MANET o demad (DYMO) routig protocol. Iteret-Draft Versio 06, IETF, October 2006 [8] T. Clause, C. Dearlove, P. Jaquet, I-D: The Optimized Lik State Routig Protocol versio 2 ( OLSRv2), Work i progress, Page