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  • 1. Nisha, Mr. Anil Sangwan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 4, July-August 2012, pp.980-983 A Novel Approach to perform Reliable Packet Dilievery in High Speed Network Nisha * and Mr. Anil Sangwan** *Student,University Institute of Engineering & Technology, Maharshi Dayanand University, Rohtak **Assistant Professor , University Institute of Engineering & Technology, Maharshi Dayanand University, RohtakAbstract: A Wimax network is once of most delivery last mile broadband access as a substituteappealing network that covers most of needs of to conventional cable and DSL lines.a business network. A network that requires WiMAX MAC layer is responsible for QoS.security at high data speed is fulfilled by WiMAX MAC layer support real time, non real timeWimax. Although this as the data is transferred and best effort data traffic and its high data rate, subat very high speed a small delay in channelization, and flexible scheduling improve thecommunication or any decision making process QoS. WiMAX architecture is very flexible. It canwill result the data loss over the network. Such support point to point and point to multipointkind of problem occur in a hierarical network connection according to its requirements. It alsowhere multiple users transfer data to other supports IP-based architecture that is easilynetwork, In such case the connecting node to converge with other networks and takes advantagethese two network suffers the problem of of application development from the existing IPbottleneck problem. As in case of bottleneck based application.there is a tight end for the outsidecommunication and it results the data loss. Theproposed work is the implementation of OFDMto resolve this bottleneck problem. TheProposed work is the better utilization ofnetwork bandwidth to get the reliable solution.The bandwidth is shared by connecting nodesrespective to the variable length data request.The system will first observe the number ofrequest being transferring and the size of datacommunication made by each request and on Figure 1: Wimax Information Base Architecturethis basis the bandwidth will be assigned to eachnetwork. WiMAX support both time division duplex andKeywords: Wimax, OFDM, bottleneck, hierarical, frequency division duplex which helps in spectrumbandwidth. management, transceiver design and low costI Introduction system development.WiMAX offer optimized With the introduction of WiMAX network handover which support full mobility applicationas IEEE 802.16 the complete architecture of such as voice over internet protocol (VOIP). It hascomputer network is changed. Now the also the power saving mechanism which increasesexpectations of a user increased in terms of speed the battery life of handheld devices. WiMAXand accuracy. Wimax provide a network without support extensible security feature for reliable dataany restriction. It can work with any kind of exchange. It use Advanced Encryption Standardnetwork either the local or the global. It works for (AES) encryption for secure transmission and forcomputers as well as the mobile network. It gives a data integrity, it use data authentication mechanism.better enhancement over the wired network andrepresents the wireless more reliable, efficient and Figure 1: Wimax Information Base Architectureeasy configured network. The Wimax The above figure 1 shows the managementtechnology offers around 72 Mega Bits per second reference model for BWA (Broadband Wirelesswithout any need for the cable Access) networks. This consists of a Networkinfrastructure. Wimax technology is actually based Management System (NMS), some nodes, and aon the standards that making the possibility to database. BS and SS managed nodes collect and store the managed objects in an 802.16 MIB 980 | P a g e
  • 2. Nisha, Mr. Anil Sangwan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 4, July-August 2012, pp.980-983format. Managed objects are made available to of carriers that are spaced apart at preciseNMS using the Simple Network Management frequencies. This spacing provides theProtocol (SNMP). "orthogonally" in this technique which prevents theWhen a customer subscribes to the WiMAX demodulators from seeing frequencies other thanservice, the service provider asks the customer for their own. The benefits of OFDM are high spectralthe service flow information. This would include efficiency, resiliency to RF interference, and lowernumber of UL / DL connections with the data rates multi-path distortion. This is useful because in aand QoS parameters. The customer also needs to typical terrestrial broadcasting scenario there aretell the kind of applications that he proposes to run. multipath-channels (i.e. the transmitted signalThe complete Wimax network is designed as the arrives at the receiver using various paths ofcommunication n between different length). Since multiple versions of the1. Wimax Base Station signal interfere with each other (inter symbol2. Wimax Transceiver interference (ISI)) it becomes very hard to extractWiMAX base station is similar to a cellular the original information.network base station which consists of a WiMAXtower and indoor electronics. Base station performs II LITERATURE SURVEYthe MAC and PHY features. It also handles the Since WLAN OFDM Transceiver on bothsignaling and user scheduling. It is also responsible IEEE 802.11a and IEEE 802.11b is the most usablefor uplink and downlink bandwidth management technique to achieve a high performanceon a real time basis and frequency reuse. WiMAX communication, by means of some modificationsuses fiber optic cable or microwave link to connect evaluate an IEEE 802.11g Transceiver behaviorhigh speed point to point link. Point to multipoint against some link impairments as frequency offset,connectivity is uses in mesh network but usually it Inter-carrier interference, phase noise, etc. Thisuses point to point antennas to connect different paper focuses on the analysis of simulation resultsbase stations and customer premises sites across a of a link impairments applied on a WLAN OFDMlong distance. Modulation. More specifically, it uses the power ofDepending on the frequency range WiMAX can ADS 1 2005A simulation techniques to evaluateprovide two types of Wireless services, Line of phase noise and Frequency Offsets Effects on ansight (LOS) and Non line of sight (NLOS). LOS OFDM 802.11 g transreceiver [1]. It is consideredoperates in higher frequencies between 10-66 GHz. carrier frequency offset (CFO) estimation for singleThis frequency range is called millimeter bands. carrier and single-user transmission over aSince line of sight uses higher frequencies, it can frequency-selective channel. When training isprovide higher bandwidth with less interference. solely devoted to frequency synchronization, it isIt’s coverage area also huge. Theoretically it is 30 important to design the training to optimize CFOmile radius. For LOS there should be direct contact estimation performance. In this paper it exhibits thebetween the WiMAX tower and the dish antenna training sequence that minimizes the Cramer-Raofrom the customer sight which could be placed in bound associated with the carrier frequency offsetthe rooftop or a pole. In this way subscriber can get and averaged over the channel statistics following agreat data capacity. NLOS uses lower frequencies correlated Ricean fading channel model.between 2 GHz to 11 GHz. This lower frequency Simulations show significant improvementsrange is called centimeter band. The advantage of compared to the standard pseudorandom whitethese lower frequencies is, it can bend or distract training sequence [2].around obstacles. This advantage helps the The concepts of Wi-Max technology,multipoint communication, so more customers can which employs microwave for the transfer of dataget the services from a single tower which reduces wirelessly, and it also present its comparison withthe service cost also. In this way WiMAX enabled Wi-Fi, and 3G technologies. Wi-Max is deliveringcomputers can get full speed internet services broadband wireless access to the masses andwithin the coverage area but the coverage is lower represents alter native to digital subscriber linesthan the line of sight communication. Usually it is (DSL) and cable broadband access. Wi-Max is4 to 6 mi radius which is similar to a cell phone based on IEEE 802.16 standard and is scalable. Itcoverage area. stands for wireless (WI) microwave access (MAX).Frequency division multiplexing (FDM) is a Wi-Max will provide anywhere, anytimetechnology that transmits multiple signals connectivity. Features of Wi-Max are OFDM i.e.simultaneously over a single transmission path, Orthogonal Frequency Division Multiplexing, Subsuch as a cable or wireless system. Each signal Channelization, Directional Antennas and Adaptivetravels within its own unique frequency range Modulation, which make Wi-Max as the(carrier), which is modulated by the data (text, technology of today. The Benefit of Wi-Maxvoice, video, etc.). technology is that the signals can be run very closeOrthogonal FDMs (OFDM) spread spectrum to each other on wireless channels. Super narrowtechnique distributes the data over a large number lanes can put a lot of traffic over them without 981 | P a g e
  • 3. Nisha, Mr. Anil Sangwan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 4, July-August 2012, pp.980-983disturbance. Many technologies currently available flexibly adjusted. The performances of thecan only provide line of sight (LOS) coverage; the proposed methods are very close to the Cramer-technology behind WI-MAX has been optimized to Rao bounds or theoretical minimum mean squareprovide excelled non-line of sight (NLOS) error[8].coverage [3]. Wi-Fi and Wi-Max, Both are cost III RESEARCH METHODOLOGYeffective. They designed, implemented anddeployed MAC- and network –layer mechanisms Wimax is one of the emerging wirelessthat to enable the low cost point-to-point and point- network technologies that provide higherto-multipoint networks using off-the-shelf Wi-Fi bandwidth and the high speed data communicationequipment. Channel-induced and Protocol-Induced over the network in a large area. Efficiency andlosses were studied on Wi-Fi Links in long distance security both are provided by Wimax networks.settings and therefore to remove this problem But when we talk about a mesh topology where theWWLDMAC, new TDMA- based MAC with nodes are arranged in a tree network, a parent nodeadaptive loss recovery mechanism was built. This has to perform the multiple inputs and the multiplehelped in improving the end-to-end throughput and outputs. This situation is called the bottleneckspectrum usage in multihop point-to-point problem, where the end from which from completebackbone links. A limitation that arises is that of network communication is handled having a heavyTopology Restriction [4]. data transmission.“Quality of Service” in WiMAX Network running 200in a distributed mesh mode configuration. TheIEEE 802.16-2004 standard and various previous packetworks were discussed related to the proposed sscheme and were reviewed. The proposed approachconsists of three main parts: admission control,bandwidth manager, and packet scheduler. Thebandwidth manager exploits the deficit round robinscheduling algorithm (DRR). The packet scheduleruses the self-clocked fair queuing schedulingscheme. Simulation scenarios using NetworkSimulator 2 were conducted in order to investigatethe efficiency and correctness of the proposedapproach. The simulation results demonstrate that 200 Packetthe proposed scheme performs better than the packets Lossprevious schemes. The results also showed thatproposed scheme is capable of ensuring Quality ofService as long as the network an satisfy the Figure 2: Bottleneck Problembandwidth[5][6].A broadcast tree-based centralized scheduling In figure 2 here we have represented amechanism for an IEEE 802.16 mesh network. network with the bottle neck problem where a nodeComparing with previous methods, the method having the maximum load to connect to some otherused here is centralized scheduling, with weighted node or the network. There is no substitution pathgraph that has better network throughput and also to move to the destination node. This bottleneckshorter scheduling length than un-weighted graph problem results in network congestion and packetapproach. Furthermore, in the limited time slots loss. Because of this we are presenting an approachsituation, our BTB mechanism can schedule more to share the network bandwidth in such way thatSSs in a frame [7]. the maximum utilization of bandwidth will beIn designing the common training signal, a training performed. This proposal is represented as thesignal structure which yields low complexity OFDM implementation in the network. The OFDMestimation methods is developed while the gives a dynamic frequency based utilization of theoptimality of the training signal is maintained. bandwidth.Frequency offset estimation is based on the best The proposed work will result betterlinear unbiased estimation principle while channel efficiency and lower packet loss over the WiMAXestimation is based on the least squares (also network. In this proposed work we are offering anmaximum likelihood) approach. The proposed approach to share the available bandwidth in such atraining signal and estimation methods can be way that it will give the better efficiency andapplied to systems with pilot-only training signals throughput without changing the infrastructure oras well as those with pilot-data multiplexed signals. the routing algorithm.The estimation range of the frequency offset can be 982 | P a g e
  • 4. Nisha, Mr. Anil Sangwan / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 4, July-August 2012, pp.980-983 To work with the available bandwidth we interference or improve spectralneed to give some kind of parallelism in the efficiency.available network. The complete work is about the  Communication technology: cognitivebetter utilization of the channel. The proposed radio can also be used to providework is here presented in the figure 3. interoperability among different communication systems by changingSpectrum sensing: Either by cooperating or not, modulation scheme etc.the cognitive radio nodes regularly monitor the RFenvironment. To improve the spectral usage REFERENCEefficiency, cognitive radio nodes should not only [1] M. Morelli and U. Mengali, “An improvedfind spectrum holes by sensing some particular frequency offset estimator for OFDMspectrum, but also monitor the whole spectral band. applications,” IEEE Communications Letters, vol. 3, pp. 75-77, Mar. 1999.Spectrum analysis: The characteristics of the [2] M. Ghogho and A. Swami,”Unified Frameworkspectral bands that are sensed through spectrum for a Class of Frequency-Offset Estimation Techniques for OFDM,” IEEE Int. Conference onsensing are estimated. The estimation results, e.g., Acoustics, Speech and Signal Processingcapacity, and reliability, will be delivered to the (ICASSP’2004), Montreal, Canada, May 2004.spectrum decision step. [3]. Ms. Shilpa Jindal (2005) Grouping Wi-Max , 3G and Wi-Fi for Wireless Broadband.Spectrum decision: According to the spectrum [4]. Mr. Bharat Singh (2010) A High Performancecharacteristics analyzed above, an appropriate Point-To-Point Rural Wi-Fi and Wi-Max Accessspectral band will be chosen for a particular Networks In Developing Regions.cognitive radio node. Then the cognitive radio [5]. Mr. Mehmet Abbak (2010) Broadband Antennadetermines new configuration parameters, e.g., data For GSM, UMTS and LTE Wi-Max Applications.rate, transmission mode, and bandwidth of the [6]. Awadh Al Shukaili , Naveen Chilamkurti andtransmission. Sherali Zeadally(2010) Enabling “Quality of Service” in IEEE802.16 Networks for Distributed Mesh Topologies. Spectrum Decision [7]. Jamal Mountassir, Horia Balta, Marius Oltean, Maria Kovaci and Alexandru Isar (2010) - A Physical Layer Simulator for WiMAX in Rayleigh Fading Channel Signal Transmission [8] H. Minn, P. Tarasak and V. K. Bhargava, ”Some Issues of Complexity and Training Symbol Design for OFM Frequency Offset Estimation Methods Based on BLUE Principle,” IEEE Spectrum Sensing VTC’03 (Spring), 1288-1292, April 2003. [9] IEEE Std 802.16-TM 2004 (Revision of IEEE Std 802.16-2001), “IEEE standard for local and metropolitan area networks – Part 16: Air Spectrum Analysis interface for fixed and mobile broadband wireless access systems,” Oct. 2004. [10] Sik Choi, Gyung-Ho Hwang, Taesoo Kwon, ”Fast Handover Scheme for Real-Time Downlink Services in IEEE 802.16e BWA System”, IEEE VTC 2005 spring, Sweden, May 2005, Vol. 3 Figure 3: Functionality of proposed model (2005), pp. 2028-2032. [11] Doo Hwan Lee, etc, “Fast Handover AlgorithmThe basic parameters that we have to analyze are for IEEE802.16e Broadband Wireless Access System”, Proceedings of 1st International  Operating frequency: cognitive radio is Symposium on Wireless Pervasive Computing, capable of changing its operating Jan 2006, pp 142-145. [12] IEEE 802.16e 2005, “IEEE Standard for Local frequency in order to avoid the PU or to and Metropolitan Area Networks - Part 16: Air share spectrum with other users. Interface for Fixed and Mobile Broadband  Modulation scheme: cognitive radio Wireless Access Systems - Amendment 2: should adaptively reconfigure the Physical and medium access control layers for modulation scheme, according to the user combined fixed and mobile operation in licensed requirements and the channel conditions. bands and corrigendum 1,” February 2006  Transmission power: Within the power [13] P. Mach and R. Bestak, “WiMAX Performance constraints, transmission power can be Evaluation” IEEE conference on Networking, ICN ’07, Apr. 2007, pp.17. reconfigured in order to mitigate 983 | P a g e