10th January 2013. We have spotted the latest threat to the radio microphones, it is called "LTE". From 2013 all the microphones, according to European legislation must all operate only within the 470-790 MHz. But the story is a bit more complicated and il also involves DVB-T...
One of the important dates of Italian television history is July 2012, the month in which the whole tv system switched from analogue to digital terrestrial broadcasting.
In fact, to get straight to the point, just consider how digital wireless microphones operate in bands coincident or very close to those of the DTT to understand the problems that can arise - and some which have already occurred - mainly in some radio frequency densely populated areas.
Everything stems from the fact that the microphones and wireless systems are almost "universally available" in every show or television filming and operating in the same range transmission of digital TV UHF 470 MHz to 870 MHz.
The propagation of radio signals used by digital radio-microphones, so widely used in the entertainment world, may easily turn into serious headaches in some geographical regions where the shooting or the shows takes place in locations too close to the DVB-T transmitting sites. It's obvious to think that a mega TV studio production where dozens of frequencies are used simultaneously may be seriously affected by this this issue.
Companies that manufacture wireless microphones for professional use are not so many in the world and each one has attempted to solve these problems with different solutions.
Some had also proposed to find the free channels on which to operate, using a digital mapping buoyancy that is to be consulted before setting up the shooting "location". Such information would be necessary to be able to predict in advance which channels are free to operate on. Clearly this is still science fiction in Italy because the DVB-T situation is far from being in a position to afford a mapping reference.
Many international working groups have also struggled to identify what could be the best practice to operate the microphones in such a landscape, but without significant results.
A possible solution lies in the possibility of relying on the use of only very high-end equipment (cost around ten thousand euro each). But this scene proves unmanageable except by international broadcasters.
Even today, common sense would suggest the use of a wide-band scanner that can display TV signals in the chosen area and then rely only on wireless microphones that operate with a narrower band, which follows the carrier and excludes off-frequency signals.
All radio microphones at this moment operating in a discontinuous manner according to the geographical location will nevertheless need reallocation towards lower frequencies where channels are potentially still free, awaiting perhaps even a more stable reassignment of DVB-T frequencies.
Though, the overall picture is even worse, and the bad news is not over, as the ITU in Geneva in 2007 had theorized use of the band 790/870 MHz for telephone applications and now this deployment across Europe is a reality to be reckoned with.
Since the end of 2012-in fact-the frequency range from 790 MHz to 854 MHz that was previously used by radio mics and in ear monitoring is no longer available because it is assigned to the new telephony services defined by the acronym LTE (Long Term Evolution).
