Performance analysis of voip over wimax Shima Faisal Ahmed Muhi-Aldean 1, Amin Babiker 2 1,2 Department of Communications, Faculty of Engineering Al Neelain University, Khartoum,Sudan Abstract: Voice over IP (VoIP) applications are being widely used in today network such as Skype, Google Talk, and Face Time and it consider as one of most promising technologies for providing low cost voice calls to customers over the existing data networks and higher quality of service than pstn dose. in parallel WiMAX is a deployed technology that has great impact in filed of 4th generation networks. it provides high speed,throughput and cover larger area which make it appropriate to achieve quality requirements for voip service. In this paper, we use OPNET 14.5 A simulator to analyze QoS parameter for VoIP application under various voip codes. Keyword : wimax,voip,qos I. INTRODUCTION Multimedia system applications are getting much of an individual attention with the introduction of new broadband systems [3]. In recent years user wishes have turned from internet surfing around and normal email to multimedia services, such as VoIP & video recording training video and conferencing loading, etc. To handle the specific end user needs for abundant multimedia applications, the companies are looking for broadband wireless network. The IEEE 802.16 standard [1] [2] has been designed as an gain access to network to satisfy an individual needs of multi-media applications.the IP main supplies the support of advanced technology and protocols to Wimax that fulfills the mandatory Quality of Service (QoS) and security features [4]. Lately, VoIP over Wimax has been growing as an facilities to provide broadband cellular tone of voice service with cost efficiency trustworthiness and assured quality of service. However, the assisting VoIP over Wimax network encounters major challenges when compared with its counterpart cable DSL network. Which means VoIP over Wimax boosts several deployment issues regarding the network structures, system design, network capacity, qos and configurations provisioning. Quality of service (QoS) is the entire performance of the telephony or computer network, specially the performance seen by the users of the network. Quality of service is especially very important to the transport of traffic with special requirements. Specifically, much technology has been developed to permit computer networks to be as useful as cell phone networks for audio tracks conversations, as well as assisting new applications with even stricter service needs[5]. Mean Opinion Score (MOS) is a test that is used for many years in telephony networks to get the human user's view of the grade of the network. In media (audio, words telephony, or video recording) specially when codecs are being used to compress the bandwidth need, the MOS offers a numerical sign of the recognized quality from the users' point of view of received marketing after compression and/or transmitting. The MOS is portrayed as an individual number in the number 1 to 5, where 1 is most affordable perceived audio tracks quality, and 5 is the best perceived audio tracks quality way of measuring[6]. Throughput is the pace of successful note delivery more than a communication channel. The info these information participate in may be provided on the reasonable or physical website link, or it can go through a certain network node. Throughput is usually assessed in parts per second (little/s or bps), and sometimes in data packets per second (p/s or pps) or data packets per time slot machine game[7]. @IJRTER-2016, All Rights Reserved 48
II. PREVIOUS STUDY Pranita D. Joshi and S. Jangale [8] analyzed various critical QoS parameters such as throughput, jitter and average delay for VOIP technology using NS-2 simulator. They focus on the Qos parameters for Best Effort service class. Similar analysis have been conducted by I. Adhicandra [9] to examine the QoS deployment over WiMAX network and comparative the performance parameter to obtained over UGS and ertps service classes. H. Abid, H. Raja, A. Munir, J. Amjad, A. Mazhar and D. Lee [10] investigated when multimedia contents are transferred over WiMax network using Best Effort and ertps service classes. M. Vikram and N. Gupta [11] analyzed the Qos parameters for WiMAX networks, their performance analysis focuses on UGS service class. III. SIMULATION SETUP To judge the performance of VoIP on the WiMAX network, the cases were designed and in the network simulator OPNET [14.5] with the assumption that really the only traffic made in this network model is VoIP. There are just peer-to-peer voice telephone calls throughout the simulation, this means there is absolutely no speech conferencing and the customer stations (SS) are believed as fixed through the simulation operates. Fig. 1 illustrates the WiMAX network model considered in the simulations. The WiMAX network involves seven skin cells and an IP backbone. The cell radius is defined to 0.2 Kilometers. Each cell contains five Subscriber Channels (SS) and one Platform Station (BS). There's a server backbone made up of only one voice Server. The variables of Base Place (BS) and Customer Station (SS) is seen in the Fig. 2 and Fig. 3. For the given simulation set up, the following test was performed. Experiment 1: Words quality is very important to VoIP system due to users' high requirements once and for all quality tone of voice services. In these situations, we considered the utilization of varied voices codecs in the same WiMAX network to be able to research the performance of tone codecs for VoIP. G.711 (64kpbs), G.729 (16kbps) and G.723 (5.8kbps) were considered because of this experiment. Fig 1 : Network model @IJRTER-2016, All Rights Reserved 49
Fig 2: base station configure Fig 3: workstation configure. Qos parameter In this scholarly study, we used the next four metrics to measure the performance of WiMAX in conditions of end-to-end QoS for VoIP. Mean Opinion Rating (MOS): The Mean Thoughts and opinions Score (MOS), suggested by ITU- T in 1996, is the hottest subjective way of measuring speech quality. A MOS value is generally obtained as the average judgment of quality predicated on asking visitors to grade the grade of speech signals on the five point range (Excellent =5; Good=4; Good=3; Negative=2; Bad=1) under handled conditions as lay out in the ITU-T standard p.800. Through put: its known as total number of packets/bits delivered to the end user in a network is called throughput. It is measured in terms of packets per second or bits per second. Jitter: Jitter is determined as the agreed upon maximum difference in a single way wait of the packets over a specific time interval [21]. Generally, jitter is thought as the overall value of hold off difference between decided on packets. @IJRTER-2016, All Rights Reserved 50
Simulation results and discussion Voice Quality for VoIP consider as most important require in system because of user s high demand for good quality voice services. Performance metrics of VoIP in WiMAX is compared in terms of voice codecs G.711, G.723 & G.729 to produces the following results. Fig 4: Average Mos The major observation of the experiment is the fact that G.711 has highest MOS value of 3.6. This implies that G.711 provides good talk quality when compared with the other two codecs techniques. The explanation for low MOS ideals regarding G.723 and G.729 could possibly be the jitter element in comparability to G.711 codec program. In fig 5 the negative value of jitter means that enough time difference between your packets at the vacation spot is significantly less than that at the foundation. The tone of voice jitter value for G.711 is 0ms which ultimately shows that there surely is no jitter or wait deviation between your VoIP packets. The words for G jitter.723 is nearly identical to G.711, with a value of 1ms which ultimately shows that there surely is a slight wait variant in the of VoIP packets Fig 5:average jitter In fig ( 6). The performance of Voip is analyzed for G.711, G.723 and G.729. The average throughput from the sample mean for the three networks codec is shown that codec G.711 achieves the best throughput of value and then the G.723 and in the end G.729. @IJRTER-2016, All Rights Reserved 51
Fig 6:Average Throughput IV. CONCLUSION The simulation analysis was completed to judge the performance of VoIP above the WiMAX systems. Different variables such as jitter, MOS value, and throughput were used to gauge the performance of VoIP over WiMAX. Three voice codecs i.e. G.711, G.723 and G.729 were simulated and discover the most likely tone codec for VoIP over WiMAX network. The simulation results proved that VoIP performed best under the G.711 codec when compared with the G.723 and G.729 codecs. The comprehensive research findings also show that VoIP applications can perform better under the exponential traffic distribution. REFERENCE 1. N. Scalabrino, F. D. Pelegrini, I. Chlamtac, A. Ghittino, and S. Pera, Performance evaluation of a WiMAX testbed under VoIP traffic, in Proc. First ACM International Workshop on Wireless Network Testbeds, Experimental evaluation and CHaracterization (WiNTECH), September 2006, pp. 97 98. 2. IEEE 802.16 Working Group, IEEE Standard for Local and Metropolitan Area Networks, Part 16: Air Interface for Fixed Broadband Wireless Access Systems, IEEE Std. 802.16-2004, October 2004. 3. IEEE 802.16 Working Group, Amendment to IEEE Standard for Local and Metropolitan Area Networks, Part 16: Air Interface for Fixed Broadband Wireless Access Systems Physical and Medium Access Control Layer for Combined Fixed and Mobile Operation in Licensed Bands, IEEE Std. 802.16e- 2005, December 2005. 4. Khaled Shuaib, A Performance Evaluation Study of WiMAX Using QualNet, WCE, ICWN 2009, July 1-3, London, UK. 5. https://en.wikipedia.org/wiki/quality_of_service 6. https://en.wikipedia.org/wiki/mean_opinion_score. 7. https://en.wikipedia.org/wiki/throughput. 8. D. Joshi, and S. Jangale, Analysis of VoIP traffic in WiMAX using NS2 simulator International Journal of Advanced Research in Computer Science and Electronics Engineering, Vol. 1, Issue 2, April 2012 9. I. Adhicandra, Measuring data and VoIP traffic in WiMAX networks, Arxiv Preprint arxiv: 1004.4583, 2010. 10. H. Abid, H. Raja, A. Munir, J. Amjad, A. Mazhar, D. Lee, Performance Analysis of WiMAX Best Effort and ertps Service Classes for Video Transmission, ICCSA, Issue 3, pp. 368-375, 2012. 11. M. Vikram and N. Gupta, Performance Analysis of QoS Parameters for Wimax Networks, International Journal of Engineering and Innovative Technology, Vol. 1, Issue 5, May 2012. @IJRTER-2016, All Rights Reserved 52