A Little about WIMAX (Part-1)

What are the possible ways of getting Internet connectivity? – The probable answer might be something like the following:

• Dial up Connection
• BroadBand Connection (LAN, DSL, CABLE MODEM, T-1, T-2, E-1)
• Wireless Connections (WiFi, GPRS, EDGE, 1xRTT, EVDO, HSDPA etc)

Probably a few more mediums are there, but all of these do have some types of limitations. Limitations like – Bandwidth, Deployment Cost, Limited Network size, Area Coverage, protocol differences of different appliances, Security etc etc… Now let’s think of a newer way of getting connected and avoiding almost all (if not completely) the problems mentioned in the previous sentence. Think of a new technology that would provide us-

• High Speed Broadband service
• Wireless long range network which is less expensive to deploy yet creating a huge coverage area
• Bigger Network size – More user with a single node
• Secured and supports all types of Networking appliances.

Yes, I’m talking about WIMAX- Worldwide Interoperability for Microwave Access ( IEEE – 802.16)

Currently we are under some of great country wide network through which we can get connected – GPRS/EDGE/1xRTT, the data services by the wireless mobile phone and fixed phone operators. they are doing good but has a certain speed limitation. Through current GSM and CDMA technology (which are ultimately 2/2.5 G technology) we can get the network mobility through which we can move around with a live connection where ever we are under the network coverage. On the other hand, WiFi can deliver a good speed but limited to only few hot spots and we get disconnected even when we get into a new WiFi hot spot. There are some other medium like Line Of Sight (LOS), Non-Line of Sight (NLOS), Optical Fiber network and some other WAN technologies through which we can get Internet Connectivity. But WIMAX is the one which will integrate all the positive sides of all the mediums for us to get connected to the Information super Highway. WIMAX will be a painless connectivity like WiFi (Computer on – connected), will support network mobility as wireless phones’ data service, will support higher speed like Optical fiber, LOS and NLOS technologies. So it will be like all in one thing.

HOW WIMAX WORKS?

Practically, WiMAX would operate similar to WiFi but at higher speeds, over greater distances and for a greater number of users. WiMAX could potentially erase the suburban and rural blackout areas that currently have no broadband Internet access because phone and cable companies have not yet run the necessary wires or wireless network to those remote locations.

Generally a WiMAX system consists of two parts:

• A WiMAX tower, similar in concept to a cell-phone tower – A single WiMAX tower can provide coverage to a very large area — as big as 3,000 square miles (~8,000 square km).
• A WiMAX receiver – The receiver and antenna could be a small box or PCMCIA card, or they could be built into a laptop the way WiFi access is today.

A WiMAX base 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 like the current GSM and CDMA system. This connection to a second tower, 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 and even most remote areas.

WiMAX actually can provide two forms of wireless service:

• There is the non-line-of-sight (NLOS), service like WiFi, where a small antenna on your computer connects to the tower. Here, 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.
• There is line-of-sight (LOS) 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 higher 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.

Information source: howstuffworks