A comparison of wi-fi and wimax with case studies - Florida State ...

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CHAPTER SIX 6. Conclusion Wireless communications have been available for more than ten years. Today, 3G, Wi-Fi and WiMax are the most popular and widely discussed standards. Telecommunication industries hope that 3G can bring them new fortune, because 3G has improved enough to support e-mail and small data download. Therefore telecommunication industries want to occupy more of the market share of wireless Internet access by using 3G technology. But compared to Wi-Fi and WiMax, it is still too slow. Moreover, with the new coming Wi-Fi standard, IEEE 802.11n, WLAN becomes more powerful than before and can overcome many past limitations, such as coverage, stability and speed. It is slowly catching up with the capacities of wired networks. A Wired network’s advantage is its reliability, but its biggest disadvantage is path design. In a city, to wire a line to a house or a building is easy; however in remote or rural areas it is a huge issue. Thus WiMax is emerging as a possible solution. Parameters Table 6-1 3G, Wi-Fi and WiMax Overall Comparison Standard 3G Wi-Fi WiMax Coverage (a single tower) 2 (< 1 km) 3 1 (1 ~ 5 km) Data Rate 3 (< 300 kbps) 1 (~ 25Mbps) 2 Throughput 3 2 1 Mobility and hand-off 1 3 (WiFly) 2 (WiBro) 1: Very good, 2: Good, 3: Bad Table 6-1 is a comprehensive result of Table 5-11 and 5-12. 3G, Wi-Fi and WiMax. They have individual and unique fundamental technologies, but their capacities are partially overlapped. 3G can be a way to access the Internet and Wi-Fi and WiMax can provide VoIP service as an alternative for the traditional phone-call. However in Table 6-1, it can be found that for Internet service, 3G is too slow for real-time service, such as downloading larger files or watching online-TV. For phone-call service, VoIP’s quality is not as good as 3G; it is because of the design issue. 3G is telecommunication technology and Wi-Fi and WiMax are Internet technologies. They were designed for different purposes. Even though these technologies are overlapped in the application field, it is impossible for them to replace each other at this point. The overlap can be treated simply as a backup. It is better to let a cell-phone just be a cell-phone. 98
WiFly used Wi-Fi to cover 60% of the city including all metropolitan areas. It takes 4200 APs to do it. If it is replaced by WiMax, it will not take that much. And for FSU campus, if WiMax is applied, just one or two base stations are enough to cover the whole campus. However, two towers are not enough to take care of the daily usage. Moreover, it is always difficult to receive a signal from the outside in a concrete building. Therefore it needs a bridge or a gateway to direct a signal into a building. Wi-Fi may have low coverage, but it can be fixed by using more APs in a hotspot. The advantage is that it can not only extend the coverage but also reduce the flow rate for each AP. To build a city-wide wireless network is going to be a trend and it is feasible, but if a network only uses Wi-Fi or WiMax, it would suffer cost, coverage, signal and mobility issues. The best way would be for them to be used in combination with each other. So far there is no single technology can feed all different needs. In local area Wi-Fi has strong capability and WiMax is designed as the extension of ADSL or cable. The combination of these two standards can form a most efficient wireless network. Therefore the future of the wireless technologies should be created with the cooperation and integration of these technologies. There is a new standard IEEE 802.11u is based on this idea. It tries to make Wi-Fi interwork with other different types of networks. [154] The IEEE 802.11u allows devices to interwork with external networks. For this purpose, interworking refers to MAC layer enhancements. It allows the higher layer functionality to provide the overall end to end solution. Instead of telling it what to do, the IEEE 802.11u only helps upper layers to establish an end to end connection with external networks. It provides a “virtual point of presence” for many different networks via a single AP. IEEE 802.11u assists the advertising and connection to remote service beyond the DS and provides information to the STA about the external network prior to association. In fact, the IEEE 802.11u is an amendment to the IEEE 802.11 standard. The final approval of IEEE 802.11u is expected to be September 2009. [154] the Figure 6-1 shows the possible implementation of the future network. 99
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THE FLORIDA STATE UNIVERSITY COLLEG
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TABLE OF CONTENTS List of Tables…
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5. Case study…………………
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LIST OF FIGURES Figure 2-1 The Evol
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LIST OF ABBREVIATIONS Abbreviation
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PSS Portable Subscriber Station 89
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CHAPTER ONE 1. Introduction The cel
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Table 1-1 Cont. 802.3an 2006 10GBAS
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2.1. Introduction CHAPTER TWO 2. 3G
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2.3. Development 3G has been in dev
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2.5. Conclusion WAP (Wireless Appli
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IEEE 802.11n is the newest standard
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Table 3-3 Cont. 10 2.457 X Y Y Y Y
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3.3.1.2. PLCP and PMD The physical
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Noise Codes). The most powerful con
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Figure 3-5 CCK Modulation HR-DSSS P
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other problem is inter-carrier inte
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Tab ble 3-5 OFDDM Modulaation and D
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and contains DSSS, CCK, PBCC (Packe
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3.3.2. MAC Layer 3.3.2.1. Introduct
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Virtual channel sensing he other me
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SIFS (Short InterFrame Spacing) Fig
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Figure 3-20 WEP Frame and Operation
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3.4.2. MIMO (Multiple-Input/Multipl
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4.1. The background of IEEE 802.16
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The working groups of WiMax Forum a
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Table 4-1 Thee Basic Datta of IEEE
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Figure 4-1 The Layer Structure of I
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codes ( (CTC) and low densityy pari
Page 59 and 60: 4.3.1.2.2. AAS (Advanced Antenna Sy
Page 61 and 62: Best-effort service (BE) This schem
Page 63 and 64: Encryption Figure 4-4 PKM Protocol
Page 65 and 66: 4.3.2. IEEE 802.16e-2005, the newes
Page 67 and 68: transmiission, the aadjacent cellls
Page 69 and 70: the uplink bandwidth periodically f
Page 71 and 72: Figure 4-7 Coverage and Capacity fo
Page 73 and 74: CHAPTER FIVE 5. Case study This cha
Page 75 and 76: increased bandwidth, fixed connecti
Page 77 and 78: Figure 5-3 Landis Green Figure 5-4
Page 79 and 80: Table 5-2 Xirrus XS-3700 AP Technol
Page 81 and 82: • Automatic Tx power selection
Page 83 and 84: Table 5-4 Cont. 71
Page 85 and 86: 5.1.3. Analysis The FSU wireless ne
Page 87 and 88: since the January 2006. The populat
Page 89 and 90: Table 5-5 Parameters of WLAN and Me
Page 91 and 92: Table 5-6 Features of Nortel Wirele
Page 93 and 94: • -101 dBm typical @ 1 Mbps Recei
Page 95 and 96: Operating environment specification
Page 97 and 98: uilding density, high population de
Page 99 and 100: epeater r is developping and it wil
Page 101 and 102: Figure 5-17 WiBro Features The data
Page 103 and 104: Figure 5-19 U-RAS Premium Figure 5-
Page 105 and 106: In KT’s recent report, 60% of sub
Page 107 and 108: Figure 5-21 An Example Application
Page 109: Name Parameters Standard Table 5-10
Page 113 and 114: BIBLIOGRAPHY [01]. IEEE 802.11 offi
Page 115 and 116: [37]. Sun, Y.; "Bandwidth-efficient
Page 117 and 118: [88]. Mineno T.; Babji T.,"Issues a
Page 119 and 120: [117]. Yun Z.; Yuguang F., "Securit
Page 121 and 122: Network Operations and Management S
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