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PERFORMANCE ANALYSIS OF THE HIGH DENSE WLAN NETWORK WITH MULTIPLE ACCESS POINTS USING
OPNET MODELER
Le Tran Duc,
Bonch-Bruevich Saint-Petersburg State University of Telecommunications, Saint-Petersburg, Russia,
letranduc.telecom@gmail.com Keywords: WLAN, dense, multiple
access points, performance, OPNET.
Nowadays, wireless networks are experiencing unprecedented growth and gradually becoming the dominant means by which people access the Internet. Moreover, Wi-Fi technology [1] is being used in a variety of different settings, from home, loT market and enterprise networks to city-wide wireless mesh networks (WMNs). As a result, the deployment of WLANs becomes denser. Therefore, a situation in which there are many WLANs deployed in close proximity to each other, all of them simultaneously trying to deliver as many data as possible, becomes fairly probable.
In addition to the growth of the Wi-Fi market, emerging applications such as voice and video are also placing additional demands on such wireless networks. The ability to stream high definition video at home and on-the-go while simultaneously transferring large files over the network requires an abundance of bandwidth that existing Wi-Fi networks fail to provide. In addition, the delay-sensitive nature of voice and video applications makes the delivery of such content even more challenging for such Wi-Fi networks.
In this paper, we are going to evaluate the performance of a high dense WLAN network with multiple APs using OPNET modeler in term of End-to-End Delay, Media Access Delay, Retransmission Attempts and Throughput. There are 3 cases of simulation will be performed to evaluate the influence of overlapping channels, the distance between access points, the number of access point and stations on network performance.
Information about author
Le Tran Duc, Postgraduate student of the communication
networks and data transfer department, The Bonch-Bruevich Saint-Petersburg
State University of Telecommunications, Saint-Petersburg, Russia
Для цитирования:
Ле Чан Дык. Анализ производительности высокоплотной wlan с многими точками доступа посредством моделирования в OPNET // T-Comm: Телекоммуникации и транспорт. 2017. Том 11. №3. С. 56-61.
For citation:
Le Tran Duc. (2017). Performance analysis of the high dense wlan network with multiple access points using OPNET modeler. T-Comm, vol. 11, no.3, рр. 56-61.
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1. Introduction
Most companies, campuses, shopping centers use wireless networks nowadays as it significantly increases the mobility of the office, reduces cost by eliminating the need of purchasing and installing cables. Fig. 1 |10] shows the forecast of global public Wi-Fi hotspots by 2020. Correct planning before actually deploying a network plays a key role in successful managing of the money and equipment used in wireless networks. Therefore, it is very important to model the proposed wireless network and evaluate the performance of St.
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Fig, 1, The forecast of global public Wi-Fi hotspots by 2020
For the reasons mentioned above, it is crucial to understand the outcome of increasing WLAN densities and usage on the performance of these WLANs. In this paper, we are going to evaluate the performance of dense WLAN network with multiple access points (AP) in terms of Delay, Media Acccss Delay, Retransmission Attempts and Throughput by using OPNET 14.5 modeler [2].
2. Related works
In [3], the authors have analyzed the QoS (Quality of Service) of WLAN standards 802,1 Ig and 802.1 In. They considered some parameters that affect directly QoS; data dropped because of buffer overflow, media access delays, retransmission attempts as well as traffic received by the end station. The quality of these standards is measured setting up 4 different scenarios under the same OPNET (Riverbed) project. In [41, the performance of the next generation WLAN protocol IEEE 802,1 In 2.4 GHz was analyzed by using OPNET modeler simulation tool. Media access delay and jitter, traffic received by all receiving stations, data packet loss, the total throughput of the network, total Network load and other WLAN parameters were measured for each scenario and the results were compared.
In [5], the performance optimization methods have been presented using OPNET modeler 14.0. A further effect of segmentation on delay, throughput and mobility is analyzed. Finally, a utility table is provided from calculation drawn from six different scenarios. There are also more researches, which focused on this topic such as [6-9]. However, most Of them are done with only a single AP, some other researches are performed with 2 or 3 [4| APs. But in a high dense WLAN network with multiple APs, the number of APs is greater.
3. Why OPNET modeler?
In recent days, there are lots of commercial and free ware Network simulation software tools in the market. Some of the
common once are Ns2, OMNET++, OPNET, ANYLOGIC, SIMULINK and etc. Comparing to other simulation tools such as Ns-2 and Ns-3, OPNET provides a visualized platform with graphic user interface (GUI) and does not require C++ programming skills. Therefore, it is easier to develop a network model for simulations. Although OPNET has limited functionality, but it supports various servers, routers and other networking devices with different manufacturer specifications which are adequate for developing models (small scale) of real-world network scenarios, it is easier to evaluate the scalability of enterprise networks and the effects of changing server capacities and switching to a different network equipment provider. Other features of OPNET include a comprehensive library of network protocols and models, the source code for all models, and graphical presentation of simulation results.
4. Performance measurement units
To evaluate the performance of a network, some measurement units (parameters) need to be selected. In this simulation, we use following parameters to compare simulation results because they present clearly difference between a simple WLAN network and high dense WLAN network:
— Retransmission Attempts (packets): One important parameter that affects QoS in WLAN standards is retransmission attempt. According to the OPNET documentation, the total number of retransmission attempts by all WLAN MACs in the network until either packet is successfully transmitted or it is discarded as a result of reaching short or long retry limit,
— Media Access Delay (sec): it represents the global statistic for the total of queue and contention delays of the data, management frames transmitted by all WLAN MACs in the network. For each frame, this delay is calculated as the duration from the time when it is inserted into the transmission queue, which is arrival time for higher layer data packets and creation time for all other frames types, until the time when the frame is sent to the physical layer for the first time.
Delay (sec): It represents the end to end delay of all the packets received by the wireless LAN MACs of all WLAN nodes in the network and forwarded to the higher i ayer. This delay includes medium access delay at the source MAC, ecaption of all the fragments individually, and transfers of the frames via AP, if access point functionality is enabled. It is measured in fractions of seconds.
Throughput (bits/sec): It represents the total number of bits forwarded from wireless LAN layers to higher layers in all WLAN nodes of the network. It is important to figure out the total efficiency of overall WLAN environments.
5. Scenario descriptions
In this paper, we will implement the following 3 cases to study an overview of the problems encountered in a dense WLAN network with múltiple APs. It should be noted that in this study we will use OPNET modeler 14.5, which supports only IEEE 802.1 la/b/g instead of OPNET riverbed modeler 17.5, which supports IEEE 802.11 a/b/g/n. The reason is we have an only academic version of OPNET riverbed modeler 17.5 and it supports up to 80 nodes. The number of nodes is not enough for evaluating a dense WLAN network. In addition to that, the use of IEEE 802.1 lg or IEEE 802.1 In has a small meaning in the study. Therefore, in all of the scenarios we are going to use IEEE
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noted that the throughput is not only limit on what application we are running; it is also limited by the AP bandwidth and delay time. More STA joined into the network will use more bandwidth; therefore single station throughput is dropping by increase the total number of STAs in the network.
= e
-without HCF -«ill) HCF
4 6 8 10 TJie number of APs
Fig. 13. The normalized average throughput 6. Conclusion
From the simulation result, we can conclude that when the number of STAs connected to WLAN increases, a degradation of network performance will occur. And this problem becomes more serious in a dense WLAN network with multiple APs. The possibility of data packet collisions, dropping of data packets, end-to-end and media access delay will be higher when the APs and STAs connected to the WLAN are increasing and hence affect the performance of a WLAN negatively. The implementation of the polling mechanism and traffic categories of HCF prove more effective. However, it has not reduced significantly the bad influence that a dense WLAN network encountered yet. This requires new effective and appropriate solutions to support QoS for the high dense WLAN network.
References
1. IEEE Std 802.11™-2012. Part llD: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. 2012.
2. OPNET modeler 14.5. http://opnet.com.
3. Maraj, D.. Sefa. R. & Maraj. A., 2015. QoS Evaluation for different WLAN standards. 2015 23rd International Conference on Software, Telecommunications and Computer Networks (SofiCOM).
4. Eisenhofer. A. and Yohannes, D., Performance Analysis of the Next-generation WLAN Protocol (IEEE802, I In 2.4 GHz) using OPNET Modeler. Channels, 36(40), p. 44.
5. Bhatt, V.T. and Bhalt. A.. A Qos-Based Performance Evaluation of Wireless Networks using OPNET modeler. International Journal of Emerging Trends in Electrical and Electronics (IJETEE-ISSN: 23209569) Vol, 3.
6. Kulgachev. V. and Jasani, N.. 2010, October. 802.11 networks performance evaluation using Opnet. In Proceedings of the 20i 0 ACM conference on Information technology education (pp. 149-152). ACM.
1. Jasani, H. and Alaraje, N.. 2007, May, Evaluating the performance of IEEE 802.11 network using RTS/CTS mechanism. In 2007 IEEE International Conference on Electro/In formation Technology (pp. 616-621). IEEE.
8. Sharma. V., Singh. H. and Malhotra, J., 2012. Performance Analysis of IEEE 802.11 e (EDCF) and IEEE 802.11 (DCE) WLAN Incorporating Different Physical Layer Standards, Journal of The Institution of Engineers (India): Series B, 93(4), pp.247-253.
9. Ghaleb, A.M., Chiang, D.. Ting. A., Kwong, K.H.. Lim. K.C. and Lim. U.S., 2012, October, Throughput Analysis of 1EEE802. 1 In using OPNET. In Wireless Communications and Applications (1CWCA 2012), 1ET International Conference on (pp. 1-7). IET.
10. Cisco Systems, "Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update 2015—2020 White Paper", Tech. Rep., Feb. 2016. http://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-inde\-vni/mobile-white-paper-cl l-520862.html.
АНАЛИЗ ПРОИЗВОДИТЕЛЬНОСТИ ВЫСОКОПЛОТНОИ WLAN С МНОГИМИ ТОЧКАМИ ДОСТУПА ПОСРЕДСТВОМ МОДЕЛИРОВАНИЯ В OPNET
Ле Чан Дык, аспирант кафедры сетей связи и передачи данных, Санкт-Петербургский государственный университет телекоммуникаций им. проф. М. А. Бонч-Бруевича (СПбГУТ), Санкт-Петербург, Россия, letranduc.telecom@gmail.com
Аннотация. Оценивается производительность высокоплотной WLAN с многими точками доступа. Моделирование произведено с использованием пакета OPNET. Учитываются такие параметры как сквозная задержка, задержка доступа к среде, количество попыток повторной передачи и пропускная способность. Рассмотрены 3 случая: для оценки влияния перекрывающихся каналов, расстояния между точками доступа, количества точек доступа и станций в сети. Показано, что при увеличении количества точек доступа в высокоплотных WLAN показатели качества стремительно ухудшаются. При этом использование механизма HCF может незначительно улучшить результаты. Таким образом, для обеспечения QoS необходима разработка новых решений с учетом особенностей высокоплотных WLAN.
Ключевые слова: WLAN, высокоплотная среда, точки доступа, производительность, QoS, OPNET. Литература
1. IEEE Std 802.11™ (2012). Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.
2. OPNET modeler 14.5. http://opnet.com.
3. Maraj D., Sefa R. & Maraj A. (2015). QoS Evaluation for different WLAN standards. 23rd International Conference on Software, Telecommunications and Computer Networks (SoftCOM).
4. Eisenhofer, A. and Yohannes, D., Performance Analysis of the Next-generation WLAN Protocol (IEEE802. Iln 2.4 GHz) using OPNET Modeler. Channels, 36(40), p.44.
5. Bhatt, V.T. and Bhatt, A., A Qos-Based Performance Evaluation of Wireless Networks using OPNET modeler. International Journal of Emerging Trends in Electrical and Electronics (IJETEE-ISSN: 2320-9569), vol, 3.
6. Kulgachev V. and Jasani H. (2010), October. 802.11 networks performance evaluation using Opnet. In Proceedings of the 2010 ACM conference on Information technology education, pp. 149-152.
7. Jasani H. and Alaraje N. (2007), May. Evaluating the performance of IEEE 802.11 network using RTS/CTS mechanism. IEEE International Conference on Electro/Information Technology, pp. 616-621.
8. Sharma V., Singh H. and Malhotra J. (2012). Performance Analysis of IEEE 802.11 e (EDCF) and IEEE 802.11 (DCF) WLAN Incorporating Different Physical Layer Standards. Journal of The Institution of Engineers (India): Series B, 93(4), pp. 247-253.
9. Ghaleb A.M., Chieng D., Ting A., Kwong K.H., Lim K.C. and Lim H.S. (2012), October. Throughput Analysis of IEEE802. 11n using OPNET. Wireless Communications and Applications (ICWCA 2012), IET International Conference on, pp. 1-7.
10. Cisco Systems. Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update 2015-2020 White Paper. Tech. Rep., Feb. 2016. http://www.cisco.com/c/en/us/solu-tions/collateral/service-provider/visual-networking-index-vni/mobile-white-paper-cll-520862.html.
