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 mobile internet access.The technology provides up to 10 Mbps broadband speed without the need for cables. The technology is based on the IEE 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".
Main Uses
The bandwidth and range of WiMAX make it suitable for the following potential applications:
* Connecting Wi-Fi hotspots to the Internet.
* Providing a wireless alternative to cable and DSL for "last mile" broadband access.
* Providing data, telecommunications and IPTV services (triple play).
* Providing a source of Internet connectivity as part of a business continuity plan. That is, if a business has both a fixed and a wireless Internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
* Providing portable connectivity.
Wi-Max Broadband access
Companies are evaluating WiMAX for last mile connectivity. The resulting competition may bring lower pricing for both home and business customers or bring broadband access to places where it has been economically unavailable.
WiMAX access was used to assist with communications in Aceh, Indonesia, after the tsunami in December 2004. All communication infrastructure in the area, other than amateur radio, was destroyed, making the survivors unable to communicate with people outside the disaster area and vice versa. WiMAX provided broadband access that helped regenerate communication to and from Aceh.
In addition, WiMAX was donated by Intel Corporation to assist the FCC and FEMA in their communications efforts in the areas affected by Hurricane Katrina.In practice, volunteers used mainly self-healing mesh, VoIP, and a satellite uplink combined with Wi-Fi on the local link.
IPTV over WiMAX
Deploying Internet access and Voice over IP using WiMAX radio access is quite easy. In order to have a full triple-play offer, IPTV service has to be added. But it's not straight forward, since the use of IP multicast over a WiMAX radio transmission to carry the IPTV channels may be a technical challenge. Such commercial service are not yet available, but trials have been conducted or are undeway.
WiMAX Comparison with Wi-Fi
Comparisons and confusion between WiMAX and Wi-Fi are frequent because both are related to wireless connectivity and Internet access.
* WiMAX is a long range system, covering many kilometers, that uses licensed or unlicensed spectrum to deliver a point-to-point connection to the Internet.
* Different 802.16 standards provide different types of access, from portable (similar to a cordless phone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.)
* Wi-Fi uses unlicensed spectrum to provide access to a network.
* Wi-Fi is more popular in end user devices.
* WiMAX and Wi-Fi have quite different quality of service (QoS) mechanisms:
o WiMAX uses a QoS mechanism based on connections between the base station and the user device. Each connection is based on specific scheduling algorithms.
o Wi-Fi has a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. For example VoIP traffic may be given priority over web browsing.
* Wi-Fi runs on the Media Access Control's CSMA/CA protocol, which is connectionless and contention based, whereas WiMAX runs a connection-oriented MAC.
* Both 802.11 and 802.16 define Peer-to-Peer (P2P) and ad hoc networks, where an end user communicates to users or servers on another Local Area Network (LAN) using its access point or base station.
