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

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3.1. The background of IEEE 802.11 CHAPTER THREE 3. IEEE 802.11, Wireless LAN When, IEEE published the standard 802.11Wireless Local Area Network protocol in 1997, it caused a revolution in methods of communication. People started to get rid of the constraint of wires and began to enjoy the freedom of unlimited space for getting information. It changed the way that people entertain themselves, get information, communicate and so on. IEEE 802.11 has many members in its family, and there are some of them that are widely used such as 802.11 a, 802.11b, and 802.11g. The newest incoming standard is 802.11n. The other name for 802.11 is called Wi-Fi. [01] - [03][22] The first practical standard in the 802.11 family is 802.11b and it came out in 1999. The earlier standard 802.11 was too slow. Due to its sluggish speed, users could not experience the advantages of wireless communication. However, 802.11b was still very successful. Its speed may be only 5.5 Mbps and 11 Mbps [04]-[06], but it was fast enough to satisfy the basic requirement for browsing the Internet. In the past two years, this standard has become extremely popular. As a result, a PC which can support this protocol becomes a fundamental requirement. Approximately around the same time when 802.11b came out, IEEE published another standard, 802.11a. These two standards used different operation bands and were not compatible. [07][08] 802.11a can reach the speed 54 Mbps and has more channels in its band to improve the bandwidth capacity for users. However, because of higher cost and the shorter transmission distance, this standard was only used by certain groups. [09][15] The standard 802.11g was developed based on 802.11b and combined with OFDM (Orthogonal Frequency Division Multiplexing, used in 802.11a). Theoretically, its speed could reach 54 Mbps. This standard was published in the summer of 2003.. [10][20] Compared to the previous two standards, it was faster than 802.11b and had longer transmission distance and lower cost than 802.11a. It had the advantages of 802.11a and had backward compatibility with 802.11b. [09][11][15] In the business field, rebuilding is always the last choice. 802.11b has existed in the market for a long time making it unwise to replace 802.11b with 802.11g. Therefore, the best method is to produce a device which can support both standards. Because they are compatible and operate in the same band, this is a more cost efficient option. For example Intel’s “Centrino” and “Sonoma” uses this type of production. [12] – [14] Meanwhile, the 802.11a has its unique advantages and was still used in certain areas. A device that supports a/b/g standards is also currently available. [08][09] 10
IEEE 802.11n is the newest standard of WLAN (Wireless Local Area Network) next generation. In January 2006, Hawaii, IEEE passed a draft of the 802.11n standard. However the official 802.11n universal standard is still in discussion. There are two main groups working on it, TGn Sync and WWiSE. In order to complete the standard earlier, these two groups composed a team called IPT (joint proposal team). [02] The following section is going to introduce the capabilities of IEEE 802.11a/b/g theses three standards. Table 3-1 shows the IEEE 802.11 standard family members. [01][86] Table 3-1 Family of IEEE 802.11 Protocol Release Date Op. Frequency 11 Throughput (Typ) Data Rate (Max) Legacy 1997 2.4 GHz 0.9 Mbps 2 Mbps 802.11a 1999 5 GHz 23 Mbps 54 Mbps 802.11b 1999 2.4 GHz 4.3 Mbps 11 Mbps 802.11g 2003 2.4 GHz 19 Mbps 54 Mbps 802.11j 2004 4.9 - 5 GHz 23 Mbps 54 Mbps 802.11h 2004 5,15 – 5,35 indoor 5,47 – 5,725 indoor/outdoor 23 Mbps 54 Mbps 802.11n Sept, 2008 (est.) 2.4 GHz/5 GHz 74 Mbps 248 Mbps 802.11y March, 2008 (est.) 3.7 GHz 23 Mbps 54 Mbps 3.2. Capacity As shown in the Table 3-2 [16], although the operation band of 802.11b is in 2.4 GHz, the FCC (Federal Communications Commission) is only allowing it to carry a certain level of frequency. Therefore for the U.S. the available WLAN channels are from 1 to11. This rule is also used on 802.11g. When building a WLAN, the interference is a very important factor. To avoid interference between channels in one area, the channels should not be overlapped and the interval of the frequency must be at least 25MHz. [04][05][16] That means, when selecting a channel, the number has to be five numbers apart from each other, for example, 1, 6 and 11. Thus, for 802.11b, the maximum bandwidth capacity is 3*11 = 33Mbps and for 802.11g is 3*54 = 162 Mbps. [11][14][17] - [20] The UNII is the initial for ‘Unlicensed National Information Infrastructure’. This band is only free in certain countries, such as the U.S. and Taiwan. Table 3-3 [16] In the U.S., this band is divided into three sub-bands and then each sub-band is split up into four non-overlap channels. Therefore, the total available channels for 802.11a are twelve. Since the 5 GHz band is not commonly used, it has a lower level of interference. When using 802.11a to build a WLAN, one
Page 1 and 2: THE FLORIDA STATE UNIVERSITY COLLEG
Page 3 and 4: TABLE OF CONTENTS List of Tables…
Page 5 and 6: 5. Case study…………………
Page 7 and 8: LIST OF FIGURES Figure 2-1 The Evol
Page 9 and 10: LIST OF ABBREVIATIONS Abbreviation
Page 11 and 12: PSS Portable Subscriber Station 89
Page 13 and 14: CHAPTER ONE 1. Introduction The cel
Page 15 and 16: Table 1-1 Cont. 802.3an 2006 10GBAS
Page 17 and 18: 2.1. Introduction CHAPTER TWO 2. 3G
Page 19 and 20: 2.3. Development 3G has been in dev
Page 21: 2.5. Conclusion WAP (Wireless Appli
Page 25 and 26: Table 3-3 Cont. 10 2.457 X Y Y Y Y
Page 27 and 28: 3.3.1.2. PLCP and PMD The physical
Page 29 and 30: Noise Codes). The most powerful con
Page 31 and 32: Figure 3-5 CCK Modulation HR-DSSS P
Page 33 and 34: other problem is inter-carrier inte
Page 35 and 36: Tab ble 3-5 OFDDM Modulaation and D
Page 37 and 38: and contains DSSS, CCK, PBCC (Packe
Page 39 and 40: 3.3.2. MAC Layer 3.3.2.1. Introduct
Page 41 and 42: Virtual channel sensing he other me
Page 43 and 44: SIFS (Short InterFrame Spacing) Fig
Page 45 and 46: Figure 3-20 WEP Frame and Operation
Page 47 and 48: 3.4.2. MIMO (Multiple-Input/Multipl
Page 49 and 50: 4.1. The background of IEEE 802.16
Page 51 and 52: The working groups of WiMax Forum a
Page 53 and 54: Table 4-1 Thee Basic Datta of IEEE
Page 55 and 56: Figure 4-1 The Layer Structure of I
Page 57 and 58: 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
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CHAPTER FIVE 5. Case study This cha
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increased bandwidth, fixed connecti
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Figure 5-3 Landis Green Figure 5-4
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Table 5-2 Xirrus XS-3700 AP Technol
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• Automatic Tx power selection
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Table 5-4 Cont. 71
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5.1.3. Analysis The FSU wireless ne
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since the January 2006. The populat
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Table 5-5 Parameters of WLAN and Me
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Table 5-6 Features of Nortel Wirele
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• -101 dBm typical @ 1 Mbps Recei
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Operating environment specification
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uilding density, high population de
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epeater r is developping and it wil
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Figure 5-17 WiBro Features The data
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Figure 5-19 U-RAS Premium Figure 5-
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In KT’s recent report, 60% of sub
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Figure 5-21 An Example Application
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Name Parameters Standard Table 5-10
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WiFly used Wi-Fi to cover 60% of th
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BIBLIOGRAPHY [01]. IEEE 802.11 offi
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[37]. Sun, Y.; "Bandwidth-efficient
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[88]. Mineno T.; Babji T.,"Issues a
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[117]. Yun Z.; Yuguang F., "Securit
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Network Operations and Management S
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