WiMax (Worldwide Interoperability for Microwave Access) is a wireless broadband technology, which supports point to multi-point (PMP) broadband wireless access over a coverage area of 3 – 5 miles. WiMax is another name for the 802.16 IEEE wireless broadband standard. The wireless broadband technology, referred to as WiMax, can support access rates up to 2+ Mbps. WiMax can solve a problem called the “last-mile” problem, by connecting individual homes and business office’s communications.

The WiMax standard has a range of up to 30 miles, and can deliver broadband at around 75 megabits per second. This is theoretically, 20 times faster than a commercially available wireless broadband. WiMax can be termed partially a successor to the Wi-Fi protocol, which is measured in feet, and works, over shorter distances.

Let us take a peek into the background of this much talked about technology, which is taking the wireless world by storm. Read More…

It is a fact that WiMax was a precursor to the original 802.16 standard published in December 2001. The WiMax forum was formed in April 2001, an advocacy group, founded by a coalition of companies such as Intel, Nokia and Proxim. The promoters of the WiMax technology expect it to make networks with multimedia applications connect within a range of 30 miles.

This extension provides for non-line of sight access in low frequency bands like 2 – 11 GHz. These bands are sometimes unlicensed. This also boosts the maximum distance from 31 to 50 miles and supports PMP (point to multipoint) and mesh technologies. Interestingly, these standards (PMP and mesh technologies) went unnoticed until the WiMax forum was formed.

WiMax is the new shorthand term for IEEE Standard 802.16, which was designed to support the European standards. 802.16’s predecessors were not very accommodative of the European standards, per se. 802.11a wasn’t lucky enough to be compatible and hence lost on a global adoption.

WiMax can be used for wireless networking like the popular WiFi. WiMax, a second-generation protocol, allows higher data rates over longer distances, efficient use of bandwidth, and avoids interference almost to a minimum. WiMax operates on licensed and unlicensed frequencies, provides a regulated environment and gives a feasible economic model for the users. Let’s take a peek into the technology called the fixed wireless. This, fixed wireless, is also the base concept for the metropolitan area networking (MAN), given in the 802.16 standard.

WiMax changes the last mile problem for broadband in the same way as WiFi has changed the last one hundred feet of networking. 802.16 can give users high capacity links on both the uplink and the downlink of up to 75 Mbits per second (Mbps) data-transfer rates on a single channel, compared with 802.11b's theoretical 11 Mbps.

Generally speaking, WiMAX has a range of up to 31 miles, which can be used to provide both campus-level network connectivity and a wireless last-mile approach that can bring high-speed networking and Internet service directly to customers. Metropolitan-Area Networks (MAN) connections to home and business office, especially in those areas that were not served by cable or DSL or in areas where the local telephone company may need a long time to deploy broadband service. The WiMAX-based wireless solution makes it possible for the service provider to scale-up or scale-down service levels in short times with the client request.

802.16 MAC - An Overview
The MAC uses a protocol data unit of variable length, which increases the standards efficiency. Multiple MAC protocol data unit can be sent as a single PHY stream to save overload. Also, multiple Service data units (SDU) can be sent together to save on MAC header overhead. By fragmenting, you can send large volumes of data (SDUs) across frame boundaries and can guarantee a QoS (Quality of Service) of competing services. The MAC uses a self-correcting bandwidth request scheme to avoid overhead and acknowledgement delays.

This also allows better QoS handling than the traditional acknowledged schemes. The terminals have a variety of options to request for bandwidth depending on the QoS and other parameters. The signal requirement can be polled or a request can be piggybacked. More to come…

Conclusion
The operators, rooting for the WiMax cookie, are in for a surprise. WiMax would prove to be a double-edged sword. The initial WiMax products would operate between the frequencies of 2.5 GHz and 5.8GHz. This range includes both the licensed and unlicensed spectrum. Under the licensed spectrum, the operators can apply for franchisees for providing fixed wireless broadband. The unlicensed spectrum would have to make do with independent backhaul services for hotspots, which would create a wireless network across the nation.
The operators might be well off trying to offer parallel, integrated services for WiMax, similar to WiFi offerings. This guarantees a swifter ROI on low upfront investment. The margins would definitely be lower than cellular rates. WiMax may very well be the happening technology of the future, but the community is keeping its fingers crossed!