TVBDs: Everything you need to know


Are you working with a wireless microphone? Therefore, you need to know what TVBDs are and their importance. It can push cordless microphones from ultra-high frequency whitespaces. How? We will equip you with everything you need to know about TVBDs.

Table of Contents

What is a TV Band Device/White Space Device?

A white space device or TV Band Device is an intelligent, static, or mobile radio. Moreover, it receives and transmits data on unutilized portions of the Television band of about 55-700 MHz. Besides, this is the same operating frequency range used on cordless microphones. 

Additionally, a TV band uses a database to check which frequencies it can occupy safely. Nonetheless, there is no specific device that is a TV band device. But, today’s technologies must receive certificates to convert television white space into TVBDs.

Moreover, TVBDs come in two types: portable and fixed. For instance, portable TVBD includes smartphones and laptops, but others. They use the spectrum to connect. Therefore, they do not use a gateway or a central antenna. On the other hand, fixed TVBDs work as super Wi-Fi routers. Additionally, they diverge wireless networks to many people over a larger area than a standard 2.4 GHz Wi-Fi router.

TVBDs  Wi-Fi router

Wi-Fi router

Fixed TV bands produce 4 watts of power or 1 watt of equally radiated power. Besides, portable TV bands emit 40 megawatts or 100 Megawatts (2 times the maximum power a microphone needs) when operating on a channel close to a TV channel in use. 

 Additionally, fixed TV bands can transmit both ultra-high frequency and very high-frequency portions of the transmission band. Therefore, this is either 470-700 MHz, 175-215 MHz, 75-90 MHz, or 55-60 MHz. However,  channels next to an active channel have over 512 MHz. 

Additionally, mobile/personal TV bands operate on 512-670 MHz, apart from the reserved channel (channel 37) for radio astronomy. Besides, these channels are set aside for cordless mics. Moreover, they are also excluded from the two channels below and over channel 37.

Do TV Band Devices Interfere With Wireless Microphones?

I would say yes. Therefore, a TV band device detrimentally interferes with an unregistered cordless microphone. Nonetheless, this is a different case with registered cordless microphones.

TVBDs Wireless microphone

Wireless microphone

Usually, TV bands should identify all incumbent users and block them. However, a report from  2008 research shows that TV bands can sense microphones. However, they are unreliable, especially if the center frequency is close to an active TV channel. Besides, noise from close TV channels is complex since wireless microphone signals are weak and interrupt real signal levels.

A study by the federal communication commission (FCC) in the year 2008 on cordless microphone interference. Contrary, the study gives a general understanding of cordless microphone interference. However, it does not offer answers to all questions on audio interference. Also, the regulatory requirements that TV bands try to identify and avoid cordless microphones are no longer applicable. Nevertheless, the same commission idea is to set aside one channel below and above channel 37 as reserve channels.

Additionally, unregistered microphones can now get protection from interference. Besides, most technology companies are interested in whitespaces. TV bands are the most speedy and reliable devices that offer mobile connectivity.

But How Could the FCC Make this Decision?

 Firstly, unregistered cordless microphones belong to part 15 of Low Power Secondary gadgets. Therefore, they must receive any interference. Additionally, they should not cause any destructive interference to approved services. However, this is a slogan on every microphone. Besides, are TV bands not unlicensed gadgets? Yes, however, this is from page 24 of the 2nd memorandum.

Moreover, unregistered devices work on a non-interference foundation. Additionally, they should accept all interferences, including unregistered gadgets such as TV bands. However, having TV bands devices to recognize low-power secondary stations such as cordless microphones is the best option. Besides, this provides interference protection to many unregistered devices. Unfortunately, there is no method to recognize a feature of a TVBDS device. Also,  there is no way to differentiate registered devices from unregistered ones.

Secondly, using cordless microphones run by trained operators can register cordless microphones. However, this should be as per parts 15 and 74 on a database that guides them from interference from TV bands. Therefore, it challenges having cordless microphones cut out when in the hands of influential people such as the president. 

Unfortunately, this protects only 1% of cordless microphone users who cannot register for the database. Besides, anyone using more than 30 channels of cordless can apply for TV band interference protection.

Lastly, two channels below and above channel 37 are set aside as the domains of cordless microphones. Also, TV bands cannot convey in the very high-frequency range. 

Additionally, several protestations from cordless audio companies include “very high frequency is a garbage and are no longer in use” and “two channels are not adequate.” However, discussions on these topics are still ongoing. Besides, regulations can change, and the use of TV bands is a few years away. 

Bottom line

TV bands play a significant role in wireless systems. We provide the best cable assemblies to support your system. You can contact us for more help.