What is TV White Space?

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Editorial Team - everything RF

Jun 10, 2020

It is no secret that wireless communication has been growing rapidly over the years. With the introduction of 4G, 5G, IoT and a whole plethora of devices and services, the frequency spectrum above 800 MHz has been becoming more and more crowded. 

However, there this is not the case for the sub-800 MHz spectrum. Large amounts of lower band spectrum which was originally blocked for TV broadcasting is unused. TV White Space or TVWS refers to the unused frequencies or gaps in the VHF and UHF spectrum, between 470 and 790 MHz to be precise (This pertains to the United States). This unused frequency can be used to provide wireless internet services.

These gaps or white spaces are present because in the past, active TV channels placed buffers in between them to prevent interference. Back then spectrum was not such a precious commodity. Wireless communication and TV broadcasting have come a long way now and research has proven that these gaps can be used to provide broadband internet access while operating hand-in-hand with TV channels operating in surrounding bands.

What is the need?

Although internet access has expanded exponentially over the last years, approximately 3.9 billion people still don’t have a fixed broadband connection. Both developed and developing countries contribute to this number. TVWS is a solution to provide more people with internet access where traditional methods fail to be efficient.

In rural areas, providing a wired broadband connection can be costly and inefficient. One of the biggest problems in rural areas is that houses are separated by long distances and it's very difficult to connect them using cable and fiber otpic lines.

How is TVWS (TV White Space) better than traditional technologies?

There are multiple reasons why TVWS stands out. It operates over a lower frequency as compared to other services which allow it to propagate over long distances with minimal interference. It is a rule that as the frequency of Electromagnetic Wave increases, their propagation and penetration power, resilience to interference and range reduce. 

For instance, the signal from an indoor Wi-Fi router can penetrate through 2-3 walls while the TVWS waves can penetrate through buildings, trees, withstand natural interference and have a range of up to 10 km or longer. There is also potential to increase the bandwidth with speeds of up-to 100 Mbps offered. This technology is also called “Super Wi-Fi” because of the mammoth range and high bandwidth.

TV White Space also outperforms Microwave links because they require LOS (Line of Sight) for efficient and error free communication, which is not the case with TVWS. As mentioned before, TVWS waves can penetrate through obstacles, uneven ground planes, buildings etc. without requiring any additional infrastructure, thanks to its lower frequency.

Where and how is TVWS being used?

The Internet has become an integral part of our lives and we rely on it for communication, information, health, business, entertainment etc. It is difficult to imagine our daily lives without constantly and reliably connected to the internet. Yet, due to various reasons, areas with low population density often don’t have a decent broadband connection. This is due to the fact that it becomes difficult to justify the cost of laying fiber to connect rural areas.

TVWS is being implemented in the US and UK along with many African countries. The availability of TVWS channels and frequency bands varies depending on the country and location within a country. Since TVWS technology uses unlicensed bands, it is a great way to provide free or low cost wireless internet services in rural areas.

If you want to use TVWS (TV White Space) with your existing laptop, you would need a separate device which received the TV White Space Signal and then converts it to a signal that can be fed in to a regular Wi-Fi router which can then be connected to from any regular Wi-Fi device.

Click here to learn more about TV White Space.