International Journal of Internactive Mobile Learning (iJIM) - Volume 3, Issue 4, October 2009 A STUDY OF WLAN CAMPUS IN AN EDUCATIONAL ESTABLISHMENT A Study of WLAN Campus in an Educational Establishment doi:10.3991/ijim.v3i4.866 T. Abdul-Hameed, Z. Hunaiti and E. Sedoyeka Anglia Ruskin University, Chelmsford, England Abstract—the main aim of campus network is to efficiently separate, share and access knowledge among its users. The big demand of such systems is to be able to handle advanced applications which are the end-user requirements. The main goal of this study is to assess the ability of Wireless Local Area Network (WLAN) campus in dealing with applica- tions’ requests of end users in education establishments and network achievement under different conditions of opera- tion. The study has been conducted in two stages: the first stage was accomplished by conducting a survey on the Stu- dent Village network at Anglia Ruskin University as a case study; the main aim was to determine end-use requirements, to gather information on the nature of application’s running by users and to get suggestions on the likely future applica- tions. The second stage was achieved by conducting experi- ments to evaluate the WLAN campus network performance under various different scenarios on the impact of handover from Access Point (AP) to another AP on end-user link per- formance, network performance in different usage time and network performance in different weather conditions. Index Terms—RTT, VoIP, VPN, WLAN. I. INTRODUCTION In the last decade Internet and Information Technology have become central part at the heart of modern life and industries. Education is one of those industries, which have become dependent on the use of Information and Communication Technology (ICT) to achieve its main goals. Consequently, both teachers and students need to be fully connected through the internet in order to be able to be part of their educational process. Educational estab- lishments are competing to build reinforcing networking infrastructures in their campuses and using remote access- ing means, like Virtual Privet Network (VPN) to allow both students and staff to remain connected with their institution even if they are outside the physical boundaries of their campus. This has contributed to facilitate educa- tion allowing learners to benefit from accessing educa- tional materials and obtained knowledge and qualifica- tions without the need to travel using electronic learning systems. This also helped to deliver education in a wider scale without the need for building class rooms. These developments have entered into a new phase with the re- cent advancement in wireless communication technology where academic institutions started deploying wireless networks as a replacement or to expand their wired net- works infrastructure; enabling students to benefit from accessibility to facilities everywhere across the whole campus. However, this development has been subject to the performance of wireless technology which might be fluctuating in some situations, such as changes in the weather condition, the number of the users accessing the network simultaneously and the nature of the applications running over the network. Therefore, this study has been conducted to evaluate the capabilities of WLAN campus network in handling applications demands of end users in educational establishments and network performance un- der different conditions of usage. II. BACKGROUND OF WLAN Wireless Local Area Networks (WLAN) is the re- placement and complement to wired technology which allows computer to connect with each other using radio signal without the need of wires. WLAN, based on 802.11b technology (commercially known as Wireless Fidelity (WiFi)), have become very common and wide- spread in the last few years. WiFi is a flexible data com- munication system technology used as an alternative to a wired LAN within a building or campus [1]. The past decade has witnessed significant changes in the type of communication services supplied to users, as well as in the infrastructure used to support them. These services, for example, can be applications with remote servers, video on demand, interactive multimedia, present- day telephony and Internet access (which occupies the biggest market). Basically, there is an overall demand for connectivity, mobility and performance. Wire line ser- vices can provide connectivity and performance, but not mobility together with connectivity. Wireless communica- tions are the solution to these demands [2]. As a result, and in parallel with the growth of the internet, there has been significant growth in the field of wireless communi- cations. Wireless LANs provide connectivity, lower mobility and much higher performance in terms of achievable data transfer rate; they operate using either radio or infrared techniques. Fig. 1 gives an example of a WLAN interfac- ing with a wired network; they are composed of mobile units, and a wireless bridge referred to as an access point (AP). The AP interfaces the wireless network with the wired network. Figure 1. An example of a wireless local area network iJIM – Volume 3, Issue 4, October 2009 41 http://dx.doi.org/10.3991/ijim.v3i4.866� A STUDY OF WLAN CAMPUS IN AN EDUCATIONAL ESTABLISHMENT The most widely used WLAN (Wi-Fi) application util- ises radio waves at a frequency band of 2.4 GHZ, which is also known as the Industrial, Scientific, and Medical (ISM) band. The advantage of radio waves is that they can supply connectivity for non-line-of-sight situations and it is license free, while the disadvantages are [2]: • The electromagnetic broadcast may cause interfer- ence with equipment working in the same frequency; • Security may be a problem, because radio waves propagate through walls. WLAN has quickly become greatly popular. Defined by IEEE 802.11 series of standards, WLAN has quickly be- come popular as more users avoid the expenses and delays that come with wired networks [3]. The original 802.11 standard is the fundament of WLAN products evolved in 1997 by the Institute of Elec- trical and Electronics Engineers (IEEE). That base stan- dard continues to be enhanced through documents addi- tions such as 802.11b, 802.11a, or 802.11g. These en- hancements get developments in data rate and functional- ity guiding to fast progression of the WLAN market [4]; • IEEE 802.11b is a technical specification issued by the Institute of Electrical and Electronic Engineers (IEEE) that defines the operation of 2.4 GHz, 11Mbps, Direct Spread Spectrum Wireless Local Area Networks (WLAN). • IEEE 802.11a standard was designed for higher bandwidth applications than 802.11b and includes data rates of 6, 9, 12.18, 24, 36, 48,54Mbps. • IEEE 802.11g standard was designed for data rates faster than 20Mbps. • IEEE 802.11n is a proposed amendment that im- proves the previous 802.11 standards. III. WLAN AS CAMPUS NETWORK The demand for mobility on campus by students and staff is increasing. A momentous number of education Institutes are having comprehensive mix of cabled Ethernet connections and they are increasingly proposing on-campus wireless services using WLAN / WiFi (802.11) technology with access to both internal applica- tions and services and to the Internet [5]. (WLANs) are becoming increasingly popular, particu- larly on University and corporate campus. Previous Re- search [6], [7] found that nearly all plan to install a wire- less network, about half already have a limited deploy- ment, and few of them (7%) have a “comprehensive” de- ployment. WLAN (Wi-Fi) will change the teaching and learning methods from passive to interactive, from one- way communication to collaboration. This feature has been installed and deployed in many Universities over the world [8]. The demand of this feature is to be capable to handle the future desire of user applications. Previous research [9], [10] found that “In fact a recent survey (2007) re- vealed that as high as 10% of all Internet traffic is estab- lished from just a single extremely popular video website alone”. This attitude shows that we should anticipate more users in the next few years to rely on their WLAN for video applications. Voice over IP (VoIP) calls is another WLAN applica- tion gaining popularity [9]. VoIP is a technology that al- lows telephone calls to be made over computer networks like the Internet. It converts analog voice signals into digi- tal data packets and support real-time, two-way transmis- sion of conversations using Internet protocol (IP) [11]. IV. CASE STUDY Wireless Broadband Network in the Student Village at Anglia Ruskin University’s (WLAN) has been used as a site for the case study in this research project. In a per- sonal interview with the Network Administrator at the IT Department in Anglia Ruskin University, the administra- tor pointed out that the network consisted of 40 Netgear abg Access points, distributed around the campus. There are between 250 and 370 students connected throughout the day, with 370 users connected at peak times (rush hour) between 1600hrs and 2300hrs. The maximum theo- retical speed of the network is 54 Mbps. The backbone of the network is a gigabit fibre link to the data centre, and this connects to a Bluesocket Controller, which in turn connects to a Cisco 6509, all at gigabit speed. The WAN link via JaNet is 10 gigabit, as shown in Fig. 2. To accom- plish this study, two types of research methods have been used, survey and experiments. Figure 2. Anglia Ruskin University Network Architecture. V. METHODOLOGY A. Survey A Questionnaires targeting students was distributed to 120 students and was returned by 91 of them (47 female and 44 male) in the case study. The response rate was 75% of the total number of users. The questionnaires were designed to achieve the following objectives: • Evaluate and determine end-users satisfactions. • Obtain good information on the nature applications running by users. • Explore students’ opinion on the likely future appli- cations, like VoIP and video applications. B. Experiments Experiments were conducted to evaluate the WLAN campus network performance under various different sce- narios: • Network performance in different usage time. The tool that was chosen for this research was the RTT test. This test provides reports for delay, packet loss, download, Upload bandwidth speeds and other key performance measures. These measurements were 42 http://www.i-jim.org A STUDY OF WLAN CAMPUS IN AN EDUCATIONAL ESTABLISHMENT made during different times of the day, morning, midday and evening, to cover different usage time. • Impact of handover from Access Point (AP) to an- other AP on the end-user link performance. The measurement environment was the AP and a Fujitsu Siemens Laptop as a mobile station. Distances of up to 60m were measured. • Network performance in different weather condi- tions. Taking weather conditions into account, two different conditions were chosen when the experi- ments were conducted, good weather and rainy or windy weather. RTT test was conducted by using command Ping (Packet Internet Groper). Ping is a utility associated with UNIX, the Internet, and TCP/IP networks. This method of measurement was chosen because of its simplicity and the availability of the Ping tool on all machines. It does, how- ever, have certain limitations. Ping uses ICMP (Internet Control Message Protocol); ICMP packets can be given lower priority on some routers, or they can be blocked by firewalls. Despite these limitations, Ping data still pro- vides good insight into the performance of a network. Each Ping received by a source host contains a value for the round trip delay between that host and the destination host. If a Ping is not returned to the source host within a specified timeout period, then it is assumed the packet has been “lost” either on the outbound or return path. The percentage of packets lost and the round trip delay are important indicators of how well certain applications will perform. By retaining data on all the Pings we are able to calculate a variety of statistics; for example, mean, me- dium, minimum, and maximum values. These calculations can be performed over any aggregated set of data. VI. SURVEY RESULT From the data collected from the questionnaires that were distributed in the Student Village at Anglia Ruskin University, the analysis showed that: • The survey showed that most of the students consider the quality of the Wireless Internet connection to be average as shown in Fig 3. • On the question of what are the applications being used by students; the result was that most of them run Email activity as shown in Fig. 4. • The survey showed that most of the students think that making phone calls over the internet is either very important or important as shown in Fig. 5. Tele- phone calls made over an Internet connection are predicted to be the next revolution in telecommunica- tion, because of the cheaper broadband costs due to the number of competing companies offering these products. • When the students were asked how important it is to be able to conduct video chat, the survey showed that most of them see it this as fairly important, as shown in Fig. 6. How do you regard the quality of the Wireless Internet connection you use? 34% 37% 15% 11% 3% Good Average Poor Very good Very poor Figure 3. Student perception about the Wireless Internet connection Activities Mostly Perfomed on The Internet 0 10 20 30 40 50 60 70 80 90 E-mail Surfing the Internet Corporate intranet Online forums Education and research Social networks Chat Online news Listening to music Internet calls Updates Watching movies, music , video clips Online gaming Video conference A ct iv iti ti es Percentage of Participants Figure 4. Nature applications running by users How important to you to be able to make Internet calls? 22% 12% 20% 20% 26% Less important Slightly important Fairly important Important Very important Figure 5. Requirements of voice applications How important to you to be able to conduct video conferences? 16% 24% 27% 12% 21% Less important Slightly important Fairly important Important Very important Figure 6. Requirements of live video applications iJIM – Volume 3, Issue 4, October 2009 43 A STUDY OF WLAN CAMPUS IN AN EDUCATIONAL ESTABLISHMENT VII. EXPERIMENT RESULTS A. Differnet Period Time Results measurement in different period time: Latency: refers to the amount of time it takes a bit to transmit from source to destination. It is usually measured in millisecond (ms) and is one of the most important fac- tors to be considered when developing wireless real time applications. Round Trip Time (RTT) shows the delay that the message takes to get to the destination receiver and return back to the sender; during the latency experiment the RTT test was used. The RTT test used the command Ping, by using a Fujitsu Siemens Laptop from the com- mand line in a Disk Operating System (DOS) window under Windows XP. The results were the measurement of the Ping test from a laptop to the www.rightclicktz.com site. The results in Fig. 7 show the average round trip la- tency, which is achieved at midday when the number of students who are using the network is limited. Fig. 8 shows the results when Ping was used while downloading a file size of 9.53MB from the server ftp://rightclicktz.com to the laptop in different time peri- ods. We can see that the average round trip latency is 80 ms, when measured at midday when the number of stu- dents is less and when there was no congestion. Fig. 9 shows the results when Ping is used while up- loading a file size 9.53MB from the laptop to the server in different time periods. As we see in Fig 9, the average round trip also occurred around midday when the number of students decreased and there was no congestion. RTT in different time periods 0 20 40 60 80 100 120 140 160 1 10 19 28 37 46 55 64 73 82 91 100 ICMP R TT (m s) Morning Midday Evening Figure 7. Round trip latency for different time periods RTT in different tim e pe riods w ith dow nload se rvice 0 20 40 60 80 100 120 140 160 1 11 21 31 41 51 61 71 81 91 ICMP R T T (m s) Morning Midday Evening Figure 8. Round trip latency RTT in different tim e periods w ith upload service 0 20 40 60 80 100 120 140 160 1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 I C M P Mor ning Midday Evening Figure 9. Round trip latency. Bandwidth: refers to the transmission speed or throughput of our connection to the internet network. We cannot expect to see full nominal speed of our connection for the bandwidth measurement as there are always delays somewhere. In this experiment, the round trip time be- tween the laptop and the ‘ftp://rightclicktz.com’ server with a file 9.53MB in size being downloaded or uploaded is assessed to measure the upload and download speed between the laptop and the server. The bandwidth and transfer speed are quoted in two dif- ferent units: kilobits per second (kbps) and kilobytes per second (KB/s). The difference between the two units is the number of bits in a byte, which is 8. So, for this experi- ment, the file size 9.53MB is used, to transfer it to kb: 9.53MB*8=76.24Mb*1024= 78069.76kb. To achieve download/upload speed in kbps, the size of the file in kb should be divided by the time it takes to transfer in sec- ond. Fig. 10 shows that the download speed varies according to the download time that it takes to transfer the file from the server to the laptop, and also according to the different time periods. For example, the bandwidth measurement at midday (as shown) is much better than the bandwidth measurement in the morning and evening because the download time at midday has the lowest number of users. Fig. 11 shows that the upload speed varies according to the upload time that it takes to transfer the file from the laptop to the server, and also according to the different time periods. Rated Download speed in different time periods 0 200 400 600 800 1000 1200 1400 1600 M orning Midday Evening B an d w id th (k b p s) Figure 10. Throughput / Speed 44 http://www.i-jim.org http://www.rightclicktz.com/� ftp://rightclicktz.com/� ftp://rightclicktz.com/� A STUDY OF WLAN CAMPUS IN AN EDUCATIONAL ESTABLISHMENT Rated Upload speed in different time periods 0 200 400 600 800 1000 1200 1400 M orning Midday Evening B an d w id th (k b p s) Figure 11. Throughput / Speed Packet loss: occurs when one or more packets of data traveling across a network fail to reach their destination. It can be caused by a number of factors, including high dis- turbances, fading, and interference congestion. During the performance tests it was observed that there is no packet loss during morning, midday and evening hours. B. Impact of Distance from AP Results measurement of impact of handover from AP to another AP: RTT test method of measuring was chosen to evaluate the impact of distances from AP on end-user link performance such as Latency, Speed and packet loss. The experiment has been conducted as we were moving from the AP towards an area covered by other APs with the strongest signal strength. After choosing an AP, the mo- bile terminal associates to that AP and after finishing the re-association of the mobile terminal, the new AP informs the old AP of the re-association then the handover proce- dure is completed. We have analyzed the performance of this scenario as good and smooth because the quality re- mains the same as there is a handover to another AP from low quality to high quality [9]. Fig 12 shows that the latency is smooth for different distances from the AP when there is a handover to another AP. As we see in Fig 13 the speed is also smooth and con- stant for different distances from AP when there is a handover between APs. It was stable at 635.34kbps. C. Different weather conditions Results of the measurement in different weather condi- tions showed that the delay might occur according to the network load, interference and the weather. Latency in- creased as the number of users increased, if there was in- terference, or when the weather was rainy and windy as shown in Fig. 14. Fig. 14 shows that there is a significant difference be- tween the results in good weather and when it is rainy or windy. The average round trip time in good weather was much less than the average RTT in rainy and windy weather. As shown in Fig.15, there is packet lost only in bad weather. This occurs when we Ping ‘rightclicktz.com’ in rainy and windy weather. During the performance tests it was observed that packet loss happened only in rainy and windy weather, which is directly caused by the challenges of radio signal propagation [12], and this did not occur otherwise. RTT in different distance from AP (Handover) 0 50 100 150 200 250 300 350 400 1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 ICMP R TT (m s 10m 20m 30m 50m 60m Figure 12. Round trip latency in different distance when there is a handover Rated Download speed in different distances from AP (Handover) 595 600 605 610 615 620 625 630 635 640 10m 20m 30m 40m 50m Distance (m) B an d w id th (k b p Figure 13. Throughput /Speed RTT in different weather 0 500 1000 1500 2000 2500 3000 3500 4000 1 10 19 28 37 46 55 64 73 82 91 100 ICMP R T T( m s) Rainy and windy weather Good weather Figure 14. RTT in different weather conditions Packet loss 0% 4% Good weather Rainy and windy weather Lo st p ac ke Figure 15. Packet loss for good weather vs. bad weather VIII. DISCUSSION The results from this study showed that the vast major- ity of the student participants considered the quality of Wireless Internet connection to be very good, good or average, which leads us to the conclusion that the overall student perception is that the quality of the connection (WLAN) is good. Consequently, the Student Village Wireless Network can be considered satisfactory for the students. Also, it can be seen from the results that the stu- iJIM – Volume 3, Issue 4, October 2009 45 ftp://rightclicktz.com/� A STUDY OF WLAN CAMPUS IN AN EDUCATIONAL ESTABLISHMENT dents have advanced applications requirements, as 78% of them considered making internet calls as important, 81% of them had an interest in video streaming, and 84% were interested in video conferencing or video chat. The stu- dents considered the network to be good because it is ca- pable of running advanced internet applications according to user’s requirements. It can be concluded that the off peak time for the net- work is during the midday period when most of the stu- dents are at the University and there is no congestion. Also, there was no significant difference on the speed, delay and packet loss in different usage time but there was a significant difference in different weather conditions. IX. CONCLUSION AND FURTHER WORK It can be concluded that WLAN Campus can offer good benefit to education including mobility, extending and conductivity across campus. That can be achieved with good planning of AP placement across the campus in or- der to handle changes and traffics in different time of us- ages (rush hours or peak time). However, WLAN network campus could suffer from dramatic drop in performance in bad weather conditions. In countries like the UK there- fore, it is recommended that education establishments in countries with long winter should install WLAN as a complementary network to wired network in order to minimize this limitation. In addition, educational estab- lishments should be aware of future demand on rich appli- cations like VoIP and video which might be challenging for WLAN to handle in wider scale and might have direct impact on user satisfaction. REFERENCES [1] R. Camilo, P. Mari, M. Velasco, and J. Fuertes, “Wireless Net- work Delay Estimation for time-sensitive Applications”, Research report ESAIIRR-06-12, p.1, Jul. 2006. [2] R. Prasad and L. Deneire. From WPAN to Personal Networks: Technologies and Applications. Artech House, 2006. [E-book] Available: IET e-book. [3] S. Salgar, “Emerging Technologies”, International CALIBER, New Delhi, February 2004. [Online]. Available: http://dspace.inflibnet.ac.in/bitstream/1944/354/1/04cali_46.pdf [Access Jul. 23, 2008]. 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Chan, “Technologies Delivering Multiuser Transmission for Next-Generation IEEE802.11 Wireless Network”, Nov. 5, 2007. Available: http://www.douglaschan.com/pubs/DSChan_VHT_SG_CSMA- MPR_Whitepaper.pdf [Access 24 July 2008]. [10] Ellacoya Networks Inc., “Ellacoya Data Shows Web Traffic Over- takes Peer-to-Peer (P2P) as Largest Percentage of Bandwidth on the Network,” Press release, 2006. [11] M. Bradley, “Wireless/Networking, VoIP”, Jan 5, 2009. Avail- able: http://compnetworking.about.com/?once=true& [Access 11 April 2009]. [12] A.S. Adegoke, “Mitigation of Effects of the Atmosphere on Radio Wave Propagation,” The Pacific Journal of Science and Technol- ogy, vol.9, no. 1, May-Jun. 2008. AUTHORS Taghareed Abdul Hameed (tagreedhamid@aol.com)is a postgraduate student based in Anglia Ruskin University Chelmsford in department of design and technology. Ziad Hunaiti (Ziad.Hunaiti@anglia.ac.uk)is a Lecturer at Anglia Ruskin University Chelmsford in department of design and Technology. Eliamani Sedoyeka (amani@rightclick.com) is a Re- search student based in Anglia Ruskin University Chelms- ford in department of design and technology. Submitted, December, 9, 2008. Published as resubmitted by the author(s) on June, 30, 2009. 46 http://www.i-jim.org http://dspace.inflibnet.ac.in/bitstream/1944/354/1/04cali_46.pdf� http://www.54g.org/pdf/802.11g-WP104-RDS1.pdf� http://www.heanet.ie/docs/20080605 Heanet Wireless Strategy_final-released.pdf� http://www.heanet.ie/docs/20080605 Heanet Wireless Strategy_final-released.pdf� http://www.wi-fiplanet.com/news/article.php/3710891� http://www.wi-fiplanet.com/news/article.php/3710891� http://www.douglaschan.com/pubs/DSChan_VHT_SG_CSMA-MPR_Whitepaper.pdf� http://www.douglaschan.com/pubs/DSChan_VHT_SG_CSMA-MPR_Whitepaper.pdf� http://compnetworking.about.com/?once=true&�