WiMax Technology

WiMax (Worldwide interoperability for Microwave Access) is the latest technology which enables  high speed and reliable internet access anywhere and everywhere. It is seen as the alternative to DSL, Cable modem, T1, T3 lines Wi-Fi, and dial up connection.  To understand more about it lets discuss:

Why is it important to have a WiMax?

• It overcomes the problem of small coverage area and high cost associated with Wi-Fi and broadband. It comes with high speed of broadband, ‘Wirelessness’ of Wi-Fi and broad coverage area like a cell phone network.
• Keeping in mind the increasing demand and use of high bandwidth application, WiMax is seen as the only solution that is 3-5 times faster and 5 times more cost effective than present 3G technologies.

• WiMax is going to make ‘Internet on the go’ a reality, a scenario where you can just connect a device, connectable to internet and enabled with WiMax(Like Wi-Fi), anywhere. You can experience connectivity to its max, which is going to become on of the basic necessities in near future (very similar to mobile phones today).

How WiMax works?

The operation of WiMax is quite similar to Wi-Fi but at a higher speed and encompassing a large coverage area.

A WiMax system is composed of two parts:

1. A WiMax tower: Providing a coverage area of around 3000 sq. miles ( 8000 km²)
2. A WiMax receiver: The receiver and antenna can be a PCMCIA card small box, a laptop or any device built-in with WiMax.

A WiMax tower and receiver communicate via radio signals and a device equipped with WiMax would receive encrypted data keys to prevent any unauthorized access. This communication is done in two ways:

1. The Non-line-of-sight way: Using this we can connect an antenna on a computer directly to the transmitting tower but it uses a lower frequency range of 2 GHz to 11 GHz.
2. The line-of-sight service: A dish antenna from a rooftop or pole points and connects straight to WiMax tower. This uses a higher frequency of around 66 GHz with very less interference and more bandwidth.

Orthogonal Frequency Division Multiple Access (OFDMA) provides efficient support for many users using the service simultaneously.

To support a huge data traffic WiMax uses multiple, Multiple Input/Multiple Output(MIMO) smart antenna.

This 4G wireless technology, built on IEEE 802.16e-2005 air interface standard, provides:

• high data transfer rates
• Low cost
• Based on all-IP network architecture, it is more scalable and efficient network for video, voice and data (This is called Quality of Service).
• Reduced Network complexity
• Backward compatibility with existing 2G and 3G cellular network deployment, making it easier to deploy WiMax.
• Holds equally good for fixed environment very similar to DSL or cable modem service.

With Giants like Intel and service provider, Clear coming into play, it is definitely going to revolutionize the broadband access like cell phones did it for phone access.

4G Technology

Under the Mobile Technology domain G is said to be the Generation and it covers the major advances in the range of 20-30 years. 1G technology involved the first widely available mobile phones. 2G technology, which started in the early 1990s, switched to a digital format and introduced text messaging. 3G technology improved the efficiency of how data is carried, making it possible to carry enhanced information services such as websites in their original format. The latest iPhone is the best known example of 3G technology. Meanwhile, just to mention, that iPhone 4 is Not a 4G phone !

Currently 3G networks still send there data digitally over a single channel, OFDM is designed to send data over hundreds of parallel streams, thus increasing the amount of information that can be sent at a time over traditional CDMA networks.

4G mobile is not yet established as an agreed set of standards, so its features are currently simply goals rather than requirements. As well as drastically increasing data transfer speeds, 4G mobile should use enhanced security measures. Another goal is to reduce blips in transmission when a device moves between areas covered by different networks. 4G mobile networks should also use a network based on the IP address system used for the internet.

Within the United States, there are two major systems offering 4G mobile technology. One is known as WiMax and is backed by Clearwire, a firm whose majority owner is Sprint Nextel. It began testing services in Baltimore in 2008 and was set to expand this into major new markets in 2009. Sprint intended to have 80 cities covered by the end of 2010.

The rival system, Long Term Evolution or LTE, is backed mainly by Verizon. It was expected to be ready for testing in 2010 but not available for widespread use until 2012. LTE’s backers hoped to overcome this disadvantage by offering faster speeds and producing cheaper equipment.

Unlike previous generations of mobile technology, 4G mobile will be widely used for internet access on computers as well as carrying cell phone communications. Customers in areas which have strong 4G coverage will be able to use it for a home broadband connection which doesn’t require any cabling to their household. It can also be used for accessing the internet on the move without having to be in a wireless hotspot such as those offered by some coffee shops, airports and libraries.

The 4G technology will be able to support Interactive services like Video Conferencing (with more than 2 sites simultaneously), Wireless Internet,etc. The bandwidth would be much wider (100 MHz) and data would be transferred at much higher rates. The cost of the data transfer would be comparatively very less and global mobility would be possible. The networks will be all IP networks based on IPv6. The antennas will be much smarter and improved access technologies like OFDM and MC-CDMA (Multi Carrier CDMA) will be used. Also the security features will be much better.

The WiMax lobby and the people who are working with the WiMax technology are trying to push WiMax as the 4G wireless technology. At present there is no consensus among people to refer to this as the 4G wireless technology. WiMax can deliver upto 70 Mbps over a 50Km radius. As mentioned above, with 4G wireless technology people would like to acheive upto 1Gbps (indoors).

WiMax does not satisfy the criteria completely. Also WiMax technology (802.16d) does not support mobility very well. To overcome the mobility problem, 802.16e or Mobile WiMax is being standardised.

The important thing to remember here is that all the researches for 4G technology is based around OFDM (Orthogonal frequency-division multiplexing).

WiMax is also based on OFDM. This gives more credibility to the WiMax lobby who would like to term WiMax as a 4G technology. Since there is no consensus for the time being, we have to wait and see who would be the winner.

More Gs are awaiting as we progress in the path of connectivity… keep evolving !