15-12-2012, 01:05 PM
WiMAX TECHNOLOGY
[attachment=43889]
INTRODUCTION :-
WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobileinternet access. The technology provides up to 3 Mbit/s broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access). The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL".
WiMax is new technology in mobile computing. It is yet to be deployed on huge scale world wide unlike technologies like WiFi. WiMax is short form of Worldwide Interoperability of Microwave Access. It performs about similar to some extend like Wifi but at higher speed, at great distance and for greater number of users, WiMax operates on 802.16 standards define by IEEE, Institute of Electric and Electronic Engineering. IEEE 802.16 standard is known to be WMAN, Wireless Metropolitan Area Network.
WiMAX technology was developed in earlier 2000 and it was named by WiMax Forums. In year 2004 this technology started to groom and eventually gets into lots of talk’s and discussions around the world among major international institutes, in year 2004 advancements, enhancements were deployed to some extend. As mentioned above WiMAX has not yet deployed to its full potential and still lot and lots of room to use this technology to its potential. It is not yet put to use as commercialized technologies like Wifi, GPRS, and 3G.
HISTORY OF WI-MAX :-
The brief history of Wi MAX is an interesting study in technology development tandardization and spin control. The idea for WiMAX came about in the wake of the elecom bubble, when generating hype about what technologies could do was anathema. WiMAX is also - by name as well as by function and association - a cousin of Wi - Fi, which hasn't exactly become firmly ensconced as an indispensable technology tool in the telecom service provider quiver. When Wi-Fi's new maxed-out cousin came onto the scene, it already had that (perceived) strike against it.
So it should come as no surprise that the WiMAX powers that be - namely, the WiMAX Forum and the companies comprising it - have been very careful to control the spin, downplay the hype and shroud the technology's certification processes in a veil of mystery. Without that level of control, excitement about WiMAX's potential as a broadband access form could have continued unabated, with people within and outside of telecom making assumptions about WiMAX that ultimately could have resulted in letdowns.
But now it's beginning to feel like the WiMAX community has taken the protection of its brainchild too far. A postponement of the WiMAX Forum's product certification process earlier this year led to rampant speculation that the forum was changing direction or its position on support of certain versions of WiMAX. True or not, the conjecture - accompanied by the forum's relative silence on the issues - didn't do much for the nascent technology's still-forming reputation in service provider circles.
WI-MAX STANDARDS :-
The various 802.16 standards.
802.16a: Licensed Frequency 2 GHz to 11 GHz. The Working IEEE 802.16a operates at the MAC and PHY specification and specifies the transfer of non-visual connections (NLOS). Frequencies are important for the 3.5 GHz and 5.8 GHz licensed for royalty-free applications. The data is at a channel width of 20 MHz 75 Mbit / s. 802.16a is replaced by 802.16-2004.
Specifications of 802.16
802.16b: Licensed Exempt Frequencies, with a focus on the frequency band of between 5 GHz and 6 GHz. This group also runs under the name Wireless HUMAN (High Speed Unlicensed MAN).
802.16c: Profiles of transmission frequencies in the frequency range from 10 GHz to 66 GHz. The channel width is in the U.S. 25 MHz, 28 MHz in Europe. 802.16c is replaced by 802.16-2004.
802.16d: Profiles of transmission frequencies in the frequency range of 2 GHz to 66 GHz. Replaced by 802.16-2004. This standard provides visual and non-visual connections in the range of 2 GHz to 66 GHz.
802.16e-2005: Mobile Wireless MAN (WMAN). This working group defines a mobile access in the context of IEEE 802.16. Here are ranges of more than 10 Mbps in cells in the range of several kilometers and speeds exceeding 100 kph investigated. In addition, 16e-clients between different radio cells can switch, known as roaming. 802.16e is in conjunction with DSRC an interesting alternative for telematic and safety services in the automotive technology.
Point to point topology :
As the name implies, a point-to-point wireless network is a direct link between two distinct locations. In the diagram, point-to-point connections are represented by the red lines. These connections are commonly used in cellular backhaul (from the BTS site towards the network operations center) and for building-to-building extensions of IP and circuit-switched services (i.e. analog PBX). Fiber optics and leased copper connections are examples of "wired"point-to-pointnetworks.
Advantages of point-to-point networks include a dedicated link to a specific location and offering higher data capacities than on a shared topology like multipoint or mesh. Point-to-point networks typically include a matched pair of radios, which can be installed professionally or by a seasoned IT technician. For cellular backhaul, microwave point-to-point radios have been called into action during several natural disasters, such as wildfires, where cabled copper and fiber optics are inoperable. Most cellular operators have vehicle-mounted base stations, called a COW (cellular on wheels), which provide incremental or recovery network coverage and utilize a wireless point-to-point connection from the COW back to the network operations center.
Point to multipoint topology :
WiMAX is most often associated with the point-to-multipoint topology. Multipoint networks can be thought of as a hub and spoke combination. Multipoint networks use a base station as the "hub" and subscriber units as the connection points at the other end of the spokes connecting to the base station. In the diagram, a multipoint base station would be the red circles and the subscriber units are the black circles attached via black lines. Cellular phone networks are another example of a multipoint network, where the subscriber stations arethemobilephones.
Mesh topology :
A more recent wireless network topology that has been implemented for municipal Wi-Fi networks is mesh networking. Mesh offers a combination of point-to-point and point-to-multipoint capability by having each of the subscriber nodes able to communicate directly with other nodes. This obviates the base station element in the network, though one or more of the nodes are designated "off ramps" to connect themeshwiththe-Internet.
The most successful implementations of mesh have been when a single entity has access to the nodes (i.e. an operator in a municipal network). Early mesh vendors discovered that providing broadband wireless access over mesh nodes were challenging because one user taking down his node would impact the performance and operation of other nodes relying on that device for connectivity. Opponents to mesh topologies point out that latency (in the form of signal delay) can become pronounced over multiple hops to an "offramp", making video and audio streaming application performance unreliable
WI-MAX NETWORK :-
WiMAX technology works little different than WiFi technology. In wifi computers can be connected through wireless LAN card to near by access point, wireless router or any Hotspot, it does not works this way when we talk about connectivity in WiMAX. WiMAX network connectivity constitutes of two parts, one can define as WiMAX tower or WiMAX booster, it is known as WiMAX Base station, whereas the other portion is WiMax receiver. Let’s talk about them in little details for better understanding the working.
WI-MAX EQUIPMENTS :-
As WiMAX standards evolve and drive towards consistent profiles, operators must consider business models and other factors when selecting equipment and solutions from vendors.
In his keynote presentation at the WiMAX Forum Global Congress event held in Amsterdam last month, Barry West, who now heads up the international interests of Clearwire, said one of his priorities in the coming months was to persuade operators toadopt-WiMAXProfile.
At first glance, the need to do so might seem strange. Why would any operator not want to choose Profile C, which stipulates an open and non-proprietary interface standard (R6) between the BTS and the ASN Gateway? As Profile C operators are not tied into one vendor for BTS and ASN Gateway equipment, they can force prices down through playing off different suppliers against each other. They can also choose the suppliers that can best support the functionality and services they want to offer over their network rather than being tied.
But, as West implies, the case for Profile C is not clear cut; if it were, he would not need to campaign for its adoption. Despite the apparent advantages of Profile C, some 'turnkey' vendors are still successfully tempting operators with the two other Profiles available between the BTS and ASN Gateway: Profile A and Profile B. As both Profiles can create vendor lock-ins, they stand in the way of WiMAX interoperability..
[attachment=43889]
INTRODUCTION :-
WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobileinternet access. The technology provides up to 3 Mbit/s broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access). The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL".
WiMax is new technology in mobile computing. It is yet to be deployed on huge scale world wide unlike technologies like WiFi. WiMax is short form of Worldwide Interoperability of Microwave Access. It performs about similar to some extend like Wifi but at higher speed, at great distance and for greater number of users, WiMax operates on 802.16 standards define by IEEE, Institute of Electric and Electronic Engineering. IEEE 802.16 standard is known to be WMAN, Wireless Metropolitan Area Network.
WiMAX technology was developed in earlier 2000 and it was named by WiMax Forums. In year 2004 this technology started to groom and eventually gets into lots of talk’s and discussions around the world among major international institutes, in year 2004 advancements, enhancements were deployed to some extend. As mentioned above WiMAX has not yet deployed to its full potential and still lot and lots of room to use this technology to its potential. It is not yet put to use as commercialized technologies like Wifi, GPRS, and 3G.
HISTORY OF WI-MAX :-
The brief history of Wi MAX is an interesting study in technology development tandardization and spin control. The idea for WiMAX came about in the wake of the elecom bubble, when generating hype about what technologies could do was anathema. WiMAX is also - by name as well as by function and association - a cousin of Wi - Fi, which hasn't exactly become firmly ensconced as an indispensable technology tool in the telecom service provider quiver. When Wi-Fi's new maxed-out cousin came onto the scene, it already had that (perceived) strike against it.
So it should come as no surprise that the WiMAX powers that be - namely, the WiMAX Forum and the companies comprising it - have been very careful to control the spin, downplay the hype and shroud the technology's certification processes in a veil of mystery. Without that level of control, excitement about WiMAX's potential as a broadband access form could have continued unabated, with people within and outside of telecom making assumptions about WiMAX that ultimately could have resulted in letdowns.
But now it's beginning to feel like the WiMAX community has taken the protection of its brainchild too far. A postponement of the WiMAX Forum's product certification process earlier this year led to rampant speculation that the forum was changing direction or its position on support of certain versions of WiMAX. True or not, the conjecture - accompanied by the forum's relative silence on the issues - didn't do much for the nascent technology's still-forming reputation in service provider circles.
WI-MAX STANDARDS :-
The various 802.16 standards.
802.16a: Licensed Frequency 2 GHz to 11 GHz. The Working IEEE 802.16a operates at the MAC and PHY specification and specifies the transfer of non-visual connections (NLOS). Frequencies are important for the 3.5 GHz and 5.8 GHz licensed for royalty-free applications. The data is at a channel width of 20 MHz 75 Mbit / s. 802.16a is replaced by 802.16-2004.
Specifications of 802.16
802.16b: Licensed Exempt Frequencies, with a focus on the frequency band of between 5 GHz and 6 GHz. This group also runs under the name Wireless HUMAN (High Speed Unlicensed MAN).
802.16c: Profiles of transmission frequencies in the frequency range from 10 GHz to 66 GHz. The channel width is in the U.S. 25 MHz, 28 MHz in Europe. 802.16c is replaced by 802.16-2004.
802.16d: Profiles of transmission frequencies in the frequency range of 2 GHz to 66 GHz. Replaced by 802.16-2004. This standard provides visual and non-visual connections in the range of 2 GHz to 66 GHz.
802.16e-2005: Mobile Wireless MAN (WMAN). This working group defines a mobile access in the context of IEEE 802.16. Here are ranges of more than 10 Mbps in cells in the range of several kilometers and speeds exceeding 100 kph investigated. In addition, 16e-clients between different radio cells can switch, known as roaming. 802.16e is in conjunction with DSRC an interesting alternative for telematic and safety services in the automotive technology.
Point to point topology :
As the name implies, a point-to-point wireless network is a direct link between two distinct locations. In the diagram, point-to-point connections are represented by the red lines. These connections are commonly used in cellular backhaul (from the BTS site towards the network operations center) and for building-to-building extensions of IP and circuit-switched services (i.e. analog PBX). Fiber optics and leased copper connections are examples of "wired"point-to-pointnetworks.
Advantages of point-to-point networks include a dedicated link to a specific location and offering higher data capacities than on a shared topology like multipoint or mesh. Point-to-point networks typically include a matched pair of radios, which can be installed professionally or by a seasoned IT technician. For cellular backhaul, microwave point-to-point radios have been called into action during several natural disasters, such as wildfires, where cabled copper and fiber optics are inoperable. Most cellular operators have vehicle-mounted base stations, called a COW (cellular on wheels), which provide incremental or recovery network coverage and utilize a wireless point-to-point connection from the COW back to the network operations center.
Point to multipoint topology :
WiMAX is most often associated with the point-to-multipoint topology. Multipoint networks can be thought of as a hub and spoke combination. Multipoint networks use a base station as the "hub" and subscriber units as the connection points at the other end of the spokes connecting to the base station. In the diagram, a multipoint base station would be the red circles and the subscriber units are the black circles attached via black lines. Cellular phone networks are another example of a multipoint network, where the subscriber stations arethemobilephones.
Mesh topology :
A more recent wireless network topology that has been implemented for municipal Wi-Fi networks is mesh networking. Mesh offers a combination of point-to-point and point-to-multipoint capability by having each of the subscriber nodes able to communicate directly with other nodes. This obviates the base station element in the network, though one or more of the nodes are designated "off ramps" to connect themeshwiththe-Internet.
The most successful implementations of mesh have been when a single entity has access to the nodes (i.e. an operator in a municipal network). Early mesh vendors discovered that providing broadband wireless access over mesh nodes were challenging because one user taking down his node would impact the performance and operation of other nodes relying on that device for connectivity. Opponents to mesh topologies point out that latency (in the form of signal delay) can become pronounced over multiple hops to an "offramp", making video and audio streaming application performance unreliable
WI-MAX NETWORK :-
WiMAX technology works little different than WiFi technology. In wifi computers can be connected through wireless LAN card to near by access point, wireless router or any Hotspot, it does not works this way when we talk about connectivity in WiMAX. WiMAX network connectivity constitutes of two parts, one can define as WiMAX tower or WiMAX booster, it is known as WiMAX Base station, whereas the other portion is WiMax receiver. Let’s talk about them in little details for better understanding the working.
WI-MAX EQUIPMENTS :-
As WiMAX standards evolve and drive towards consistent profiles, operators must consider business models and other factors when selecting equipment and solutions from vendors.
In his keynote presentation at the WiMAX Forum Global Congress event held in Amsterdam last month, Barry West, who now heads up the international interests of Clearwire, said one of his priorities in the coming months was to persuade operators toadopt-WiMAXProfile.
At first glance, the need to do so might seem strange. Why would any operator not want to choose Profile C, which stipulates an open and non-proprietary interface standard (R6) between the BTS and the ASN Gateway? As Profile C operators are not tied into one vendor for BTS and ASN Gateway equipment, they can force prices down through playing off different suppliers against each other. They can also choose the suppliers that can best support the functionality and services they want to offer over their network rather than being tied.
But, as West implies, the case for Profile C is not clear cut; if it were, he would not need to campaign for its adoption. Despite the apparent advantages of Profile C, some 'turnkey' vendors are still successfully tempting operators with the two other Profiles available between the BTS and ASN Gateway: Profile A and Profile B. As both Profiles can create vendor lock-ins, they stand in the way of WiMAX interoperability..