Research Assignment Communication & Networks Student No: CN2681 0420345 Page 1 of 13 R R e e s s e e a a r r c c h h A A s s s s i i g g n n m m e e n n t t Contents Abstract ............................................................................................................................... 2 Introduction to IEEE 802.16 ............................................................................................... 2 What is WiMAX? ........................................................................................................... 2 The 802.11 Standard ....................................................................................................... 2 Current Technology ............................................................................................................ 4 Limitations of Current Internet Options ......................................................................... 4 WiMAX is Coming: Isn’t Wi-Fi enough? ...................................................................... 5 Wi-Fi, Wimax, Whats The Difference? .......................................................................... 6 WiMAX is the Future… ..................................................................................................... 7 How WiMAX technology will work .............................................................................. 7 Future plans for WiMAX implementation and applicability .......................................... 9 Beyond WiMAX… ......................................................................................................... 9 Conclusion .......................................................................................................................... 9 Glossary ............................................................................................................................ 10 References ......................................................................................................................... 12 Bibliography ..................................................................................................................... 13 Appendix 1 - Weiss, A. (2004). ‘Trends for 2005’. netWorker (Volume 8, Number 4)
Transcript
Research Assignment Communication & Networks Student No: CN2681 0420345
What is WiMAX? ........................................................................................................... 2 The 802.11 Standard ....................................................................................................... 2
Current Technology ............................................................................................................ 4 Limitations of Current Internet Options ......................................................................... 4 WiMAX is Coming: Isn’t Wi-Fi enough? ...................................................................... 5 Wi-Fi, Wimax, Whats The Difference?.......................................................................... 6
WiMAX is the Future… ..................................................................................................... 7 How WiMAX technology will work .............................................................................. 7 Future plans for WiMAX implementation and applicability .......................................... 9 Beyond WiMAX…......................................................................................................... 9
Appendix 1 - Weiss, A. (2004). ‘Trends for 2005’. netWorker (Volume 8, Number 4)
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Abstract This assignment comprises of a technical report on the new “WiMAX” technology. It will explain about the origins of WiMAX, what the current state of the technology is and what it will have to offer in the future in regards to connectivity and applicability.
Introduction to IEEE 802.16
What is WiMAX?
WiMAX, also known as “WirelessMAN”, is an acronym that that stands for Worldwide Interoperability for Microwave Access and is considered a next generation descendent of the current omnipresent Wi-Fi (802.11) technology, designed to provide broadband wireless access (BWA) over great distances [1, 2, 3] .
The Institute of Electrical and Electronics Engineers (IEEE), a company responsible for setting LAN standards (project 802), assigned the working group number 16 to the WiMAX Standard. As a result of this, WiMAX is often referred to as IEEE 802.16 (Figure 1) [1].
Figure 1
The IEEE 802.16 Logo.
Source: www.ieee.org
The 802.11 Standard
Approved in 1997 by IEEE, the network standard 802.11 was developed for wireless LAN’s. This standard defined a method of allowing a device to communicate via spread-spectrum radio waves rather than the conventional method of using a cable. The 802.11 standard could communicate over a distance of approximately 150 feet with a bandwidth of up to 2 Mbps.
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Shortly after the 802.11 standard was approved, IEEE began to work on improving the WLAN technology in order to achieve a higher transfer rate. By the middle of 1998 an extended version of the 802.11 standard was developed and approved as IEEE 802.11b. This new extended standard supported a maximum range of up to 300 feet with data rates of up to 11 Mbps. This was soon to be followed by the 802.11a standard and finally by 802.11g (Figure 2). [4, 5]
All wireless devices that conform to the extended versions of the 802.11 standard are known as “Wi-Fi” Certified. This ensures compatibility between wireless networking devices manufactured by different vendors. [5]
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Current Technology
Limitations of Current Internet Options
With over 957 Million users at present [6], the ever-increasing internet is becoming a big part of many lives with usage ranging from personal e-mails, to multinational business communications. The constant need for faster more efficient methods of internet connectivity is becoming crucial for the worldwide economy to grow. At present, there are three main options on how to access the internet, including; Dial-up access, Broadband access and Wi-Fi access. [7]
According to Aaron Weiss (2004) in the ACM article “Trends for 2005”, “As of October 2004, about 51 percent of active Internet users in the United States enjoyed broadband connections”, however the speed of these connections ranges from 200 Kbps to 3 Mbps provided to consumers via DSL and Cable lines. The article also states how South Korea’s broadband usage is over 90 percent with speeds reaching up to 40 Mbps. [2]
Figure 3
A diagram showing the potential security risk to users on a cable network.
Source: The River Internet Access Co
Even with speeds as great as 40 Mbps, each broadband technology has its disadvantages. A DSL line requires a phone line in order to connect to an ISP, the service is not available in some areas and the speed varies depending on the distance between the DSL modem and the central office of the ISP. Unlike DSL, Cable connections do not require the use of a phone line as they make use of the connection supplied with cable T.V. Data is transmitted over a fibre optic line allowing a much faster connection than DSL with no degradation of speed, regardless of the distance. However, a performance decrease can
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be noticed when the network is busy as the bandwidth is shared between different users in the neighbourhood. This can also present a security risk when connecting to the internet as other neighbours using the same cable can use software known as a “packet sniffer” to obtain data going between the cable company and other users on the same network (Figure 3). [8, 9, 10]
Wi-Fi is the newest method for accessing the internet. By making use of wireless networking, it is possible to easily connect any Wi-Fi certified laptop or computer to a wireless access point or “hotspot” in range. These “hotspots” are connected to a broadband router enabling all connected devices to receive an existing wired broadband connection. There are many Wi-Fi hotspots now available in public places like restaurants, hotels, libraries and airports. Many new laptops, such as any Intel Centrino (Figure 4) already come with a Wi-Fi card built in. [11, 12]
Figure 4
A Sony Vaio PCG-Z1SP, displaying the Centrino logo.
Source: PC Lab.pl
WiMAX is coming: Isn’t Wi-Fi enough?
Wi-Fi technology so far, has been very successful in supplying wireless internet access to consumers over short-range local networks. However, it still has many problems to overcome. Firstly, many “hot spots” at present are still using wired internet connections to access the internet. These “last-mile” connections still have the same speed and
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availability restrictions of the broadband technology that connect them to the ISP. Other disadvantages of the Wi-Fi technology are as follows:
The 802.11b and 802.11g versions of Wi-Fi use the 2.4 GHz spectrum, which is crowded with other equipment such as Bluetooth devices, microwave ovens, cordless phones, video sender devices plus many others which may cause degradation in performance. [12,13]
Closed access points can interfere with properly configured open access points on the same frequency, preventing use of open access points by others. [12]
Compared to other standards, power consumption is fairly high making battery life and heat a concern. [12, 13]
Rogue access points could be used to steal information transmitted from Wi-Fi users. [13]
Wi-Fi networks have limited range. A typical Wi-Fi home router using 802.11b or 802.11g might have a range of 150 ft (46 m) indoors and 300 ft (92 m) outdoors. [13]
Wi-Fi hot spots are very small, so coverage is sparse. [7]
The currently under development, WiMAX technology, plans to overcome these problems. The need for a newer technology that can produce a “high speed” broadband service is vast. WiMAX promises to offer completely wireless internet access, rather than “last-mile” wired access, enabling it to overcome many problems with existing limitations and also making it much cheaper than cable or DSL and much easier to extend to suburban and rural areas where phone and cable companies have not yet run the necessary wires. [2, 7]
Wi-Fi, WiMAX, What’s The Difference?
Although the technologies are very similar in the way they operate, they both send data via radio signals. WiMAX has the potential to transmit data at higher speeds, over greater distances and for a greater number of users [7]. In comparison, the fastest Wi-Fi connection can transmit up to 54 megabits per second under optimal conditions whereas WiMAX should be able to handle up to 70 megabits per second. The main difference between the two technologies however, is not speed but distance [2, 7]. According to Weiss, A (2004) WiMAX has a “claimed 30 Mile distance”. This outranges WiFi’s range by up to 15,000%. WiMAX has added support for the 2 to 11 GHz, known as the 802.16a standard, of which most parts are already unlicensed internationally and only very few still require domestic licenses.
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The following table provides a quick comparison of the 802.16a WiMAX technology to the 802.11b Wi-Fi technology (Figure 5). [1]
Parameters 802.16a (WiMAX) 802.11 (WLAN)
Frequency Band: 2-11GHz 2.4GHz
Range 31 miles 100 meters
Data transfer rate: 70 Mbps 11 Mbps – 55 Mbps
Number of users: Thousands Dozens Figure 5
A Comparison of WiMAX and Wi-Fi.
Source: networkdictionary.com
WiMAX is the Future… How WiMAX technology will work
A WiMAX system will consist of both a tower and receiver units. The tower, similar to a mobile phone tower, can provide coverage to an area of up to 3,000 square miles. The receiver is very much similar to a Wi-Fi receiver, in that it can be built into laptops or can take the form of a PCMCIA card, network card, or external USB device etc.
Figure 6
A diagram showing a WiMAX network connecting to various devices.
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Once a WiMAX tower is operational, it will connect “directly” to the ISP using a “high-bandwidth” wired connection such as a T3 line. Alternatively, each tower will have the ability to connect to remote WiMAX towers within 3,000 square miles using a “line-of-sight, microwave link” also known as “backhaul” (Figure 6). [7]
Figure 7
A diagram showing a both LOS and NLOS connections to a house.
Source: www.howstuffworks.com
WiMAX is said to be able to provide two different forms wireless service NLOS (Non Line Of Sight) and LOS (Line Of Sight). A NLOS service is very similar to Wi-Fi, a small antenna is connected to a computer system, which in tern is connected to the tower using a low frequency range of between 2 GHz to 11 GHz. This is due to lower wavelength transmissions are not as easily disrupted by physical obstructions (Figure 7). A LOS service however is where a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole. LOS connections are much stronger, stable and produce fewer errors and use much higher frequencies up to 66 GHz. A higher frequency allows less interference and much higher bandwidth. NLOS access will be limited to 25 square miles which is similar to the range of a mobile phone zone. [7]
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Future plans for WiMAX implementation and applicability
Many companies, such as Intel are already planning to start implementing WiMAX technology into their devices. Within the next two to three years, Intel will start making their Centrino laptop processors WiMAX enabled which will greatly aid in the acceptance of implementing WiMAX networks in society. [7] Industry analysts believe the WiMAX Market will be worth anywhere from $3 billion to $5 billion by 2009 [14].
British Telecom is already testing WiMAX in Ireland and Scotland as they plan to use it in lightly populated areas where cable installation is difficult to put into service. [14]
Beyond WiMAX…
The WiMAX WMAN ability to connect an entire city is only the beginning, Grabianowski, E. et al believes “The final step in the area network scale is the global area network (GAN)… …This network would have enough bandwidth to offer Internet access comparable to cable modem service, but it would be accessible to mobile, always-connected devices like laptops or next-generation cell phones.”
Conclusion I feel that the WMAN will be a great success in transmitting broadband access to many consumers over a city. And is a great way to overcome the existing “last mile” problems of existing broadband. The fact that the Wi-Fi technology has directly influenced the creation of WiMAX, I feel shows that technology will keep improving and influencing newer and better ideas and agree with Grabianowski that eventually within the next few years the WiMAX technology will be improved upon and a GAN will be created. My main concern with WiMAX is that when transmitting using NLOS (2-11 GHz) is that the signal doesn’t interfere with other equipment operating on the same frequency. I have made this assumption based on the interference that can be caused with certain Wi-Fi systems and unlicensed devices that operate on the 2.4 GHz frequency. I feel that as the WiMAX signal is much stronger than that of other devices, there may be more chance of a WiMAX transmitter interfering with it.
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Glossary Access Point - The hub of a wireless network. Wireless clients connect to
the access point, and traffic between two clients must travel through the access point. Access points are often abbreviated to AP in industry literature, and you may also see them referred to as "wireless routers," "wireless gateways," and "base stations." We prefer to use "access point" when discussing true access points that don't also share Internet connections or bridge between wired and wireless networks.
802.11 - A family of specifications related to wireless networking.
802.16 - A standard designed for fixed broadband wireless access. It is used in WirelessMAN (Wireless Metropolitan Area Network) setups, which feature a controlling base station that connects subscriber stations not to each other but to various public networks, such as the Internet, linked to the base station.
Backhaul - Connecting Internet access to a location over long or short distances. Traditionally, wired networks have been necessary for backhaul, but with 802.16, also known as WiMAX, backhaul via wireless will become even more common than it is with Wi-Fi.
Band - Another term for spectrum used to indicate a particular set of frequencies. Wireless networking protocols work in either the 2.4 GHz or the 5 GHz bands.
Bandwidth - The amount of data that can be transmitted in a given amount of time. Throughput is commonly measured in bits per second.
Cable Modem - A device that hooks to your cable TV line to allow your computer to receive data at about 1.5 Mbps. The theoretical maximum for downstream transactions is 27 Mbps and 2.5 Mbps upstream, but the connection is usually much slower because the provider may be hooked to the Internet via a T-1 line.
Centrino - A marketing name developed and promoted by Intel for laptops that use the Pentium-M processor, an Intel Pro/Wireless mini-PCI adapter, and some of Intel's support chips. Intel also requires some compatibility testing before manufacturers can use the Centrino name.
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DSL - A common form of broadband Internet connection. DSL stands for Digital Subscriber Line.
IEEE - Institute of Electrical and Electronics Engineers, (Pronounced I-triple-ee). The organization develops standards for the computer and electronics industry, such as Wi-Fi, and WiMAX.
Packet Sniffer - In wireless parlance, a sniffer is software or a hardware device that searches for the presence of a wireless network. Another type of sniffer is software used to analyze or intercept wired network traffic.
Spread Spectrum - A form of wireless communication in which a signal's frequency is deliberately varied. This increases bandwidth and lessens the chances of interruption or interception of the transmitted signal.
T-1, T-3 - Transmission systems commonly used in the Internet. T-1 provides a continuous, dedicated transmission rate of up to 1.5 Mbps, T-3 44.7 Mbps. T-1 and T-3 lines are expensive and generally for business or science use, not consumer use.
Wi-Fi - A certification mark managed by a trade group called the Wi-Fi Alliance. Wi-Fi certification encompasses numerous different standards, including 802.11a, 802.11b, 802.11g, WPA, and more, and equipment must pass compatibility testing to receive the Wi-Fi mark.
WiMAX - Another name for the 802.16 wireless networking specification used for long-haul and backhaul connections.
WLAN - Wireless Local Access Network, a LAN that can be connected to via a wireless connection.
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References 1. Anon. (2005) “WiMAX” [Internet]. Available from:
Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/WiMAX [Accessed 09 October 2005]
2. Weiss, A. (2004). ‘Trends for 2005’. netWorker (Volume 8, Number 4), 20-27.
3. Anon. “What is WiMAX? — WIMAX” [Internet] Available from: WiMAX http://wimax.com/education [Accessed 21 October 2005]
4. Gallo, M. and Hancock, W. (2002). “Computer Communications and Networking Technologies”. USA: Stenquist.
6. Anon. (2005). “INTERNET USAGE STATISTICS - The Big Picture” [Internet]. Available From: World Internet Usage Statistics and Population Stats http://www.internetworldstats.com/stats.htm [Accessed 23 October 2005]
7. Grabianowski, E. et al. “How WiMAX Works” [Internet] Available from: Howstuffworks http://computer.howstuffworks.com/wimax.htm/printable [Accessed 09 October 2005]
8. Curt Franklin “How DSL Works” [Internet] Available from: Howstuffworks http://computer.howstuffworks.com/dsl.htm/printable [Accessed 23 October 2005]
9. Curt Franklin “How Cable Modems Works” [Internet] Available from: Howstuffworks http://computer.howstuffworks.com/cable-modem.htm/printable [Accessed 23 October 2005]
10. Anon. (2003) “Cable Modem Security Briefing” [Internet]. Available from: May 2003 Newsletter http://info.theriver.com/members/newsletter/2003_/may.html [Accessed 24 October 2005]
11. Brain, M. “How Wi-Fi Works” [Internet]. Available from: Howstuffworks http://computer.howstuffworks.com/wireless-network.htm/printable [Accessed 09 October 2005]
12. Anon. (2005) “Wi-Fi” [Internet]. Available from: Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Wi-Fi [Accessed 24 October 2005]
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13. Anon. (2005) “Disadvantages of Wi-Fi” [Internet]. Available from: Wi-Fi-HiFi.com http://Wi-Fi-hifi.com/disadvantages.html [Accessed 24 October 2005]
14. Anon. “WiMAX - Intel in Standards” [Internet]. Available from: Intel.com http://www.intel.com/standards/case/case_wimax.htm [Accessed 24 October 2005]
Bibliography 1. Anon. (2002) “IEEE 802.16 Backgrounder” [Internet]. Available from:
2. Gruener, W. (2005) “WiMax certification process launched” [Internet]. Available from: WiMax certification process launched | TG Daily http://www.tgdaily.com/2005/07/14/wimax_certification_process_launched/index.html [Accessed 09 October 2005]
3. Anon. “WiMAX FAQ” [Internet]. Available from: WiMAX http://wimax.com/education/faq [Accessed 09 October 2005]
4. Anon. “Glossary of Wireless and Wi-Fi Terms and Definitions” [Internet] Available from: jiwire http://www.jiwire.com/glossary.htm [Accessed 09 October 2005]
5. Anon. “Glossary” [Internet]. Available from: Networking Glossary http://www.ibh.de/netglossary/glossary.htm [Accessed 09 October 2005]
6. Anon. (2005) “The WiMAX Future” [Internet]. Available from: Hotspot Finder - Behold the Wireless Future http://usatoday.jiwire.com/broadband-wireless-future-wimax-future.htm [Accessed 10 October 2005]
7. Anon. (2005) “IEEE 802.16: Broadband Wireless MAN Standard (WiMAX)” [Internet]. Available from: NetworkDictionary.com http://www.networkdictionary.com/protocols/80216.php [Accessed 24 October 2005]
8. Weiss, A. (2004). ‘Trends for 2005’. netWorker (Volume 8, Number 4), 20-27.
