19-04-2014, 02:44 PM
Wi-MAX (Worldwide Interoperability for Microwave Access)
[attachment=61716]
ABSTRACT:
The two driving forces of modern Internet are broadband, and wireless. The WiMax standard combines the two, delivering high-speed broadband Internet access over a wireless connection. The main problems with broadband access are that it is pretty expensive and it doesn't reach all areas. The main problem with WiFi access is that hot spots are very small, so coverage is sparse. Here comes the technology of Wi-MAX, acronym for Worldwide Interoperability for Microwave Access and goes by and it also goes by the IEEE name 802.16. This technology would provide high speed of Broadband service, wireless access, and most importantly wide coverage area unlike the Wi-Fi. Because it can be used over relatively long distances, it is an effective "last mile" solution for delivering broadband to the home, and for creating wireless "hot spots" in places like airports, college campuses, and small communities.
The so-called "last mile" of broadband is the most expensive and most difficult for broadband providers and Wi-MAX provides an easy solution. Although it is a wireless technology unlike some other wireless technologies, it doesn't require a direct line of sight between the source and endpoint, and it has a service range of 50 kilometers. It provides a shared data rate of up to 70Mbps, which is enough to service up to a thousand homes with high-speed access. Ultimately, Wi-MAX may be used to provide connectivity to entire cities, and may be incorporated into laptops to give users an added measure of mobility.
This paper discusses about this revolutionary wireless technology that is challenging the present Broadband and wireless technologies. This paper deals with the working, different standards and comparison with other technologies like Wi-Fi.
INTRODUCTION:
Wi-MAX is short for Worldwide Interoperability for Microwave Access, and it also goes by the IEEE name 802.16. WiMAX has the potential to do to broadband Internet access what cell phones have done to phone access. In the same way that many people have given up their "land lines" in favor of cell phones, WiMAX could replace cable and DSL services, providing universal Internet access just about anywhere you go. Wi-MAX delivers a point-to- multipoint architecture, making it an ideal method for carriers t o deliver broadband to locations where wired connections would be difficult or costly. It may also provide a useful solution for delivering broadband to rural areas where high- speed lines have not yet become available. A WiMax connection can also be bridged or routed to a standard wired or wireless Local Area Network (LAN).
PARTS OF A WiMAX SYSTEM:
A WiMAX system has mainly two parts:
WiMAX Tower and
WiMAX Receiver.
WiMAX Tower:
It is similar in concept to cell-phone tower. It can provide coverage to a very large area -- as big as 3,000 square miles (~8,000 square km).
WiMAX Receiver:
The receiver and antenna could be a small box or they could be built into a laptop the way WiFi access is today.
WORKING:
In practical terms, WiMAX would operate similar to WiFi. A WiMAX tower station can connect directly to the Internet using a high-bandwidth, wired connection (for example, a T3 line). It can also connect to another WiMAX tower using a line-of-sight, microwave link. This connection to a second tower (often referred to as a backhaul), along with the ability of a single tower to cover up to 3,000 square miles, is what allows WiMAX to provide coverage to remote rural areas. As opposed to a traditional Internet Service Provider (ISP), which divides that bandwidth among customers via wire, it uses a microwave link to establish a connection.
This points out that WiMAX actually can provide two forms of wireless service:
1. There is the non- line-of-sight, WiFi sort of service, where a small antenna on your computer connects to the tower. In this mode, WiMAX uses a lower frequency range -- 2 GHz to 11 GHz (similar to WiFi). Lower-wavelength transmissions are not as easily disrupted by physical obstructions -- they are better able to diffract, or bend, around obstacles.
2. There is line-of-sight service, where a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole. The line-of-sight connection is stronger and more stable, so it's able to send a lot of data with fewer errors. Line-of-sight transmissions use higher frequencies, with ranges reaching a possible 66 GHz. At higher frequencies, there is less interference and lots more bandwidth.
WiFi-style access will be limited to a 4-to-6 mile radius (perhaps 25 square miles or 65 square km of coverage, which is similar in range to a cell-phone zone). Through the stronger line-of-sight antennas, the WiMAX transmitting station would send data to WiMAX-enabled computers or routers set up within the transmitter's 30-mile radius (2,800 square miles or 9,300 square km of coverage). This is what allows WiMAX to achieve its maximum range.
STANDARDS OF WiMAX:
The different standards of WiMAX as given by the IEEE are:
4.1. 802.16-2001:
This is first version of this technology approved in 2001.
4.2. 802.16a, 802.16c:
These are the later versions of the 802.16-2001 technology. These are just the amendments of the above.
4.3. 802.16-2004:
The current 802.16 standard is IEEE Std 802.16-2004, approved in June 2004. It renders the previous versions 802.16-2001 along with its amendments 802.16a and 802.16c as obsolete.
4.4. 802.16-2005(802.16e):
IEEE STD 802.16-2004 addresses only fixed systems. An amendment is in the works which adds mobility components to the standard. This amendment comes in this new standard.
IEEE 802.16-2005, approved December, 2005, (formerly named 802.16e), the WiMAX mobility standard, is an improvement on the modulation schemes stipulated in the original WiMAX standard. It allows for fixed wireless and mobile Non Line of Sight (NLOS) applications primarily by enhancing the OFDMA (Orthogonal Frequency Division Multiplexing Access).
POTENTIAL APPLICATIONS:
WiMAX is a wireless metropolitan area network (MAN) technology that can connect IEEE 802.11 (Wi-Fi) hotspots with each other and to other parts of the Internet and provide a wireless alternative to cable and DSL for last mile (last km) broadband access.
IEEE 802.16 provides up to 50 km (31 miles) of linear service area range and allows connectivity between users without a direct line of sight. Note that this should not be taken to mean that users 50 km (31 miles) away without line of sight will have connectivity. Practical limits from real world tests seem to be around "3 to 5 miles" (5 to 8 kilometers). The technology has been claimed to provide shared data rates up to 70 Mbit/s, which, according to WiMAX proponents, is enough bandwidth to simultaneously support more than 60 businesses with T1-type connectivity and well over a thousand homes at 1Mbit/s DSL- level connectivity. Real world tests, however, show practical maximum data rates between 500kbit/s and 2 Mbit/s, depending on conditions at a given site.
CONCLUSION:
The IEEE 802.16 family of standards and its associated industry consortium, WiMax, promise to deliver high data rates over large areas to a large number of users in the near future. This exciting addition to current broadband options such as DSL, cable, and WiFi promises to rapidly provide broadband access to locations in the world's rural and developing areas where broadband is currently unavailable, as well as competing for urban market share.
The WiMAX protocol is designed to accommodate several different methods of data transmission, one of which is Voice Over Internet Protocol (VoIP). VoIP allows people to make local, long-distance and even international calls through a broadband Internet connection, bypassing phone companies entirely. If WiMAX-compatible computers become very common.
[attachment=61716]
ABSTRACT:
The two driving forces of modern Internet are broadband, and wireless. The WiMax standard combines the two, delivering high-speed broadband Internet access over a wireless connection. The main problems with broadband access are that it is pretty expensive and it doesn't reach all areas. The main problem with WiFi access is that hot spots are very small, so coverage is sparse. Here comes the technology of Wi-MAX, acronym for Worldwide Interoperability for Microwave Access and goes by and it also goes by the IEEE name 802.16. This technology would provide high speed of Broadband service, wireless access, and most importantly wide coverage area unlike the Wi-Fi. Because it can be used over relatively long distances, it is an effective "last mile" solution for delivering broadband to the home, and for creating wireless "hot spots" in places like airports, college campuses, and small communities.
The so-called "last mile" of broadband is the most expensive and most difficult for broadband providers and Wi-MAX provides an easy solution. Although it is a wireless technology unlike some other wireless technologies, it doesn't require a direct line of sight between the source and endpoint, and it has a service range of 50 kilometers. It provides a shared data rate of up to 70Mbps, which is enough to service up to a thousand homes with high-speed access. Ultimately, Wi-MAX may be used to provide connectivity to entire cities, and may be incorporated into laptops to give users an added measure of mobility.
This paper discusses about this revolutionary wireless technology that is challenging the present Broadband and wireless technologies. This paper deals with the working, different standards and comparison with other technologies like Wi-Fi.
INTRODUCTION:
Wi-MAX is short for Worldwide Interoperability for Microwave Access, and it also goes by the IEEE name 802.16. WiMAX has the potential to do to broadband Internet access what cell phones have done to phone access. In the same way that many people have given up their "land lines" in favor of cell phones, WiMAX could replace cable and DSL services, providing universal Internet access just about anywhere you go. Wi-MAX delivers a point-to- multipoint architecture, making it an ideal method for carriers t o deliver broadband to locations where wired connections would be difficult or costly. It may also provide a useful solution for delivering broadband to rural areas where high- speed lines have not yet become available. A WiMax connection can also be bridged or routed to a standard wired or wireless Local Area Network (LAN).
PARTS OF A WiMAX SYSTEM:
A WiMAX system has mainly two parts:
WiMAX Tower and
WiMAX Receiver.
WiMAX Tower:
It is similar in concept to cell-phone tower. It can provide coverage to a very large area -- as big as 3,000 square miles (~8,000 square km).
WiMAX Receiver:
The receiver and antenna could be a small box or they could be built into a laptop the way WiFi access is today.
WORKING:
In practical terms, WiMAX would operate similar to WiFi. A WiMAX tower station can connect directly to the Internet using a high-bandwidth, wired connection (for example, a T3 line). It can also connect to another WiMAX tower using a line-of-sight, microwave link. This connection to a second tower (often referred to as a backhaul), along with the ability of a single tower to cover up to 3,000 square miles, is what allows WiMAX to provide coverage to remote rural areas. As opposed to a traditional Internet Service Provider (ISP), which divides that bandwidth among customers via wire, it uses a microwave link to establish a connection.
This points out that WiMAX actually can provide two forms of wireless service:
1. There is the non- line-of-sight, WiFi sort of service, where a small antenna on your computer connects to the tower. In this mode, WiMAX uses a lower frequency range -- 2 GHz to 11 GHz (similar to WiFi). Lower-wavelength transmissions are not as easily disrupted by physical obstructions -- they are better able to diffract, or bend, around obstacles.
2. There is line-of-sight service, where a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole. The line-of-sight connection is stronger and more stable, so it's able to send a lot of data with fewer errors. Line-of-sight transmissions use higher frequencies, with ranges reaching a possible 66 GHz. At higher frequencies, there is less interference and lots more bandwidth.
WiFi-style access will be limited to a 4-to-6 mile radius (perhaps 25 square miles or 65 square km of coverage, which is similar in range to a cell-phone zone). Through the stronger line-of-sight antennas, the WiMAX transmitting station would send data to WiMAX-enabled computers or routers set up within the transmitter's 30-mile radius (2,800 square miles or 9,300 square km of coverage). This is what allows WiMAX to achieve its maximum range.
STANDARDS OF WiMAX:
The different standards of WiMAX as given by the IEEE are:
4.1. 802.16-2001:
This is first version of this technology approved in 2001.
4.2. 802.16a, 802.16c:
These are the later versions of the 802.16-2001 technology. These are just the amendments of the above.
4.3. 802.16-2004:
The current 802.16 standard is IEEE Std 802.16-2004, approved in June 2004. It renders the previous versions 802.16-2001 along with its amendments 802.16a and 802.16c as obsolete.
4.4. 802.16-2005(802.16e):
IEEE STD 802.16-2004 addresses only fixed systems. An amendment is in the works which adds mobility components to the standard. This amendment comes in this new standard.
IEEE 802.16-2005, approved December, 2005, (formerly named 802.16e), the WiMAX mobility standard, is an improvement on the modulation schemes stipulated in the original WiMAX standard. It allows for fixed wireless and mobile Non Line of Sight (NLOS) applications primarily by enhancing the OFDMA (Orthogonal Frequency Division Multiplexing Access).
POTENTIAL APPLICATIONS:
WiMAX is a wireless metropolitan area network (MAN) technology that can connect IEEE 802.11 (Wi-Fi) hotspots with each other and to other parts of the Internet and provide a wireless alternative to cable and DSL for last mile (last km) broadband access.
IEEE 802.16 provides up to 50 km (31 miles) of linear service area range and allows connectivity between users without a direct line of sight. Note that this should not be taken to mean that users 50 km (31 miles) away without line of sight will have connectivity. Practical limits from real world tests seem to be around "3 to 5 miles" (5 to 8 kilometers). The technology has been claimed to provide shared data rates up to 70 Mbit/s, which, according to WiMAX proponents, is enough bandwidth to simultaneously support more than 60 businesses with T1-type connectivity and well over a thousand homes at 1Mbit/s DSL- level connectivity. Real world tests, however, show practical maximum data rates between 500kbit/s and 2 Mbit/s, depending on conditions at a given site.
CONCLUSION:
The IEEE 802.16 family of standards and its associated industry consortium, WiMax, promise to deliver high data rates over large areas to a large number of users in the near future. This exciting addition to current broadband options such as DSL, cable, and WiFi promises to rapidly provide broadband access to locations in the world's rural and developing areas where broadband is currently unavailable, as well as competing for urban market share.
The WiMAX protocol is designed to accommodate several different methods of data transmission, one of which is Voice Over Internet Protocol (VoIP). VoIP allows people to make local, long-distance and even international calls through a broadband Internet connection, bypassing phone companies entirely. If WiMAX-compatible computers become very common.