Eben Alberto Zavala, student at Universidade Wutive.

TV White Spaces (TVWS) and Cognitive Radios (CR)

A small word in technology can take us to a huge amount of information that most of the times are

not necessary. To avoid get unnecessary information will better to refine this topic into a small

brief and give a slight explanation about it. So, the goal here is just to aim directly on TV white

Spaces and Cognitive Radios definitions, advantages and so on.

TV White Spaces

What is white Spaces?

When radio communication started growing up some years ago and overpopulate every kind of

communication, many radio planning engineers and designers started being concerned about this

fast growth in the latest years, because it imposes the existence of a crowded spectrum.

Nevertheless, a solution came up. This solution came from the under-utilized spectrum. In fact, in

some regions, at certain periods, a large amount of frequency is not being utilized at all. This gives

rise to the so-called white spaces spectrum.

White spaces is needed to reduce the request for radio frequency spectrum growth.

The reuse of these spaces comes with several social and economic advantages, it means for

example that can be used to improve the signal on a rural areas, reduce of infrastructure services

cost, etc.

TV White Spaces is the unused TV Channels between the Very High Frequency (VHF) and Ultra

High Frequency (UHF) spectrum. These channels are called buffer channels. It has since been

researched and proven that this unused spectrum can be used to provide broadband Internet access

while operating harmoniously with surrounding TV channels.

TV white space application

These technology can be used in so many ways and places to provide some of the listed solutions

bellow:

Better Coverage than Wi-Fi;

Non-Line-of-Sight (NLOS) Performance;

A New Broadband Possibility Connecting More People;

Beyond Broadband Connecting More Things.

This technology will be the key to Internet of Things (IoT) because all device connected to internet

will need a flexible signal to provide better functionality on data transference.

One of the zones of spectrum, where holes are easily identified, is the old analog television band,

which most of the time is completely free, taking into account the geo-location of a specific device.

This happens because TV broadcasting technology is changing, with analog TV transmissions

gradually being shut down and being replaced by their digital counterparts almost all over the

world.

Cognitive Radios

What is Cognitive Radios?

In order to consolidate the knowledge of TVWS, now we are going to explain a topic that comes

before that, it is called Cognitive Radios. It is the basis of white space device.

CR is a solution that optimize wireless network transmission and frequencies sharing using the

empty bands or subtilized bands, without causing interference on the original signal. The way it

works is: first, the transceivers analyses the transmissions already on progress than detects

available channels in wireless spectrum and find a way to transmit its signal without interfere on

the other transmission. In most of the existing applications, the transceivers identify white spaces

on the radio frequency spectrum to be able to accommodate telecommunications services, making

better rational spectrum usage. The CR follows the new standard IEEE 802.22

The fusion of CR and TVWS is the future of our lives, so its really important to work hard to

make sure that these dream comes true to our country.

References:

http://idgnow.com.br/blog/circuito/2012/10/10/o-radio-cognitivo-e-o-futuro-da-internet/

http://searchnetworking.techtarget.com/definition/cognitive-radio

http://www.carlsonwireless.com/tv-white-space/

B. Nuno, C. Alessandro, G. G. Roberto, White Space Communication Technologies, United

Kingdom: Cambridge University Press 2015.