WiMax: It's Here To Stay

DQC News Bureau
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First there was Wi-Fi. Now there's WiMax, which stands for Worldwide

Interoperability for Microwave Access. This technology allows laptop users to be

connected to a wireless, high-speed broadband connectivity with a radius of 10



Filling the gap between wireless LANs and wide area networks (WANs), WiMax-compliant

systems will provide a cost-effective fixed wireless alternative to conventional

wire-line DSL and cable in areas where those technologies are readily available.

What Wi-Fi did for the LAN, the longer-range WiMax could do for metropolitan

areas and last-mile access.

It will initially use the IEEE 802.16d specification and support connections

to fixed locations at typical speeds from 300K to 2M bit/sec, over a range of as

much as 30 miles. A later version, based on the 802.16e standard, is being

designed to support mobility.


WiMax Forum, an industry group working to promote 802.16 adoptions, plans to

begin certifying interoperable products by 2005. According to the forum, the

world's first WiMax Forum certified products would be available by year-end.


Potential of WiMax

A wireless Metropolitan Area Network (MAN) based on the WiMax air interface

standard is configured on the lines of a traditional cellular network with

strategically located base stations. The latter use a point-to-multipoint

architecture to deliver services over a radius up to several kilometers,

depending on the frequency, transmit power and receiver sensitivity.

Although WiMax has great potential, a key decision with regard to spectrum

choice is whether to use licensed or unlicensed spectrum. The use of licensed

spectrum has the obvious advantage of providing protection against interference

from other wireless operators. The disadvantage is dealing with the licensing

process. The use of unlicensed spectrum gives the wireless operator the

advantage of being able to deploy immediately but runs the risk of interference.

With a large number of countries tightly controlling the Wireless spectrum,

WiMax needs all the encouragement that the industry can provide to it. Two

primary bands are under consideration — the licensed 3.5GHz band, the

unlicensed UNII band (but licensed in India) 5.8 GHz bands of frequencies. Of

these the 3.5GHz seems to offer more promise, given the fact that the 5GHz

spectrum is fast approaching its limits in most technologies and countries where

such has been used.


Optimizing on existing technologies

Many technologies currently available for fixed broadband wireless can only

provide line of sight (LOS) coverage. However, the technology behind WiMax has

been optimized to provide both, excellent LOS and non-LOS coverage. WiMax's

advanced technology provides the best of both worlds — large coverage

distances of up to 50 kilometers under LOS conditions and typical cell radii of

up to 5-mile/8 km under NLOS conditions.



Although both LOS and NLOS coverage conditions are governed by the

propagation characteristics of their environment, path loss, and radio link

budget, NLOS technology helps reduces installation expenses by making

under-the-eaves CPE installation a reality and easing the difficulty of locating

adequate CPE mounting locations.


The technology also reduces the need for pre-installation site surveys and

improves the accuracy of NLOS planning tools. This forms the primary advantage

of WiMax over other forms of broadband wireless access. 

Viable market segments

WiMax if implemented offer great opportunities for various business segments.

Residential and SOHO: In many cities, there are pockets of residential

customers, who are often cut off from the world. The reach for these customers

may be provided with the help of WiMax. For instance, the e-choupal concept of

Indian Tobacco Company can be improved with the concept of Wi-MAX.


Rural villages: With a majority of India's population present in the

rural areas, there is a need to connect them to the knowledge base outside their

proximity. This could help them connect to the Internet to propel online

education, information dissemination and even banking.

The deployment of an exchange to provide analog connectivity would take years

and lots of money in terms of laying cables. With WiMax, ISP's can provide

point-to-point connectivity over large distances and with a huge bandwidth to

address the needs of this marker.

Mobile users: As WiMax provides constant access to the Internet using

large antennas (about the size of a laptop), mobile users can always be

connected within the radius of coverage.


Cellular backhaul: WiMax can play a major role in enabling mobile

operators to cost-effectively increase backhaul capacity using WiMax as an

overlay network. This will help them add the capacity required to support the

wide range of new mobile services that they offer, without the risk of

disrupting existing services.

Public safety services and private networks: Since WiMax offers

coverage in a metropolitan area, it can become a handy tool for law enforcement

agencies during medical emergencies. Public safety organizations can also

leverage on it to maintain critical communications during calamities or distress


Setting up a WiMax network

A business case for this technology includes core and edge networking

equipment in addition to WiMax-specific equipment. In any area-rural or urban-it

is desirable to install a sufficient number of base stations to cover an

addressable market large enough to recover the fixed infrastructure costs. When

expansion is being considered, WiMax capacity can be increased by simply adding

additional channels to all or to selected base stations as required.


Given the potential that WiMax provides, countries like the US have been

going for even pre-standard Wi-MAX. When I was interacting with one of my

customers about this technology, he said, "I can get WiMax for $500 per

month. This is a bit more than the cost of the SDSL service but much less than a

T-1 rate. And my office gets 1M bit/sec in each direction".

Even industry vendors are taking cognizance about this technology and its

benefits. Intel, for one, will soon integrate WiMax into its Centrino wireless

chip set along with Wi-Fi beginning in late 2006, with a wider rollout in 2007.

In a closely-guarded project telecom major Reliance Infocom and MNC chipmaker

Intel are said to have tested a technology to deliver entertainment on demand,

video on demand, IP telephony and broadband Internet access to home. In a

sparsely populated region of rural Rajasthan, Intel is reportedly conducting a

similar experiment along with NGO Drishti. WiMax has another big backer in Nokia,

which plans to launch WiMax-compatible phones by end-2005.

So if you want to be in the know, better get yourself acquainted with WiMax

and educate your customers about it. This way, when the WiMax spectrum is

unleashed and compatible products launched, you will have the first mover

advantage in it.

Sudhir Sarma is MD, Network Solutions Ltd.