11 May 2009
Many people are concerned by the apparent uncertainty regarding the future availability of UHF frequencies for radio microphones. The first issue is the change over from Analogue TV broadcasting to Digital Terrestrial Television often referred to as DSO (Digital Switch Over). Added to this there are now pressures from European Mobile Telephone Network operators. Not all UHF radio microphone users will be affected by these changes, though many will.
N.B. Throughout the rest of this post please take the words “radio microphones” to also mean In Ear Monitors (IEM’s). It’s a long enough post without me writing both out every time, and all the issues covered apply equally to both. Thanks!
As a major global manufacturer of radio microphones it is reasonable for people, especially our customers, to look to Sennheiser for guidance in these matters, so here goes.
Sennheiser UK is actively engaged, through BEIRG, with Ofcom and many trade associations which represent radio microphone users and also other manufacturers to try and ensure a satisfactory outcome for all UK radio microphone users - or the PMSE community as they are generally referred to in official documents (Programme Making and Special Events).
To understand the changes which are expected over the next few years we must first understand the current situation. To do this we need to break down UHF radio microphone use by the type of UHF frequencies used. They fall into three categories:
Licence exempt frequencies
Channel 69 shared frequencies
Site specific “Interleaved” frequencies
Licence Exempt
At present none of the planned changes to TV broadcasting or anything else will have any direct effect on the Licence Exempt UHF frequencies used by Wireless Microphones. Just to be completely clear; the only licence exempt UHF frequencies for wireless microphones in the UK are those between 863 - 865MHz. If you are using UHF wireless microphones outside of this frequency range in the UK and you don’t have a licence then you are committing an offence under the Wireless Telegraphy Act. If all of your radio microphones are only ever used on frequencies between 863 - 865MHz then you can stop reading here, nothing is going to change that we know of at present. If you only ever use freePORTTM radio microphones this means you.
Channel 69
Frequencies from 854 - 862MHz are commonly referred to in the UK as “Channel 69“. It now looks increasingly likely that Channel 69 will be cleared to make way for new mobile broadband services - 790 to 862 MHz TV bands 61 thru 69 inclusive - have now effectively been earmarked for auction and subsequently, the deployment of these new services. However, through a process of negotiation Ofcom have committed to providing PMSE with a replacement TV band - most likely to be Channel 38 - and have agreed in principle that some form of funding scheme will need to be implemented to assist with the ‘migration’ from Channel 69 to Channel 38. At time of posting details on this are yet to be finalised.
Site specific “Interleaved” frequencies
If your radio microphones operate on UHF frequencies anywhere from 470MHz to 854MHz then you are using Interleaved frequencies (and you have, of course, therefore got a site specific Wireless Telegraphy Act licence from JFMG Ltd. for them valid for each and every occasion and location in the UK where you use them, haven’t you? Good.) Interleaved frequencies are also often referred to as “white space frequencies”. This refers to the gaps which exist in the geographical coverage from the TV transmitters. The gaps are necessary to prevent mutual interference being caused to TV reception by neighbouring TV transmitters. The gaps where there is no, or very little TV signal on a particular TV channel are the “white spaces”.
Because you have a licence you should be receiving information from JFMG and Ofcom regarding the future of your fixed site licensed frequencies.
DSO should more accurately be termed ASO, or Analogue Switch Off since it is only once the analogue transmitters stop transmitting that the so called Digital Dividend can be realised.
What should I do?
Sennheiser are committed to helping their customers deal with the future changes in the most efficient and cost effective way possible. Depending on the age and model of radio microphones (and IEM’s) that you have there may be a number of options open to you. Whilst replacing everything may be the most obvious option in most cases this will not be the only option. Some Sennheiser UHF radio microphone equipment can be re-engineered to operate on different frequencies or frequency ranges from those they were originally supplied on and in most cases this will be considerably more cost effective than complete replacement. Sennheiser have been manufacturing UHF radio microphones across the whole of the range from 470 - 960MHz for around 20 years or more now so we are extremely confident that whatever part of the UHF spectrum you need to move to in the future we will have a solution for you. As the situations become clearer we will issue further information and advice. In the mean time if you have any concerns about how the forthcoming changes will affect your use of radio microphones please get in touch, we are here to help. Above all, as the situation particularly regarding Channel 69 is still developing, don’t panic!
Further information can be found at:
www.beirg.org.uk
www.jfmg.co.uk
www.ofcom.org.uk
Related posts:
- The many flavors of wireless are all delicious
- About this blog
- Neumann KM-D Digital Mic in action
- Our bloggers
Tags: 854 - 862MHz | 863 - 865MHz | analogue | BEIRG | Channel 69 | digital | Digital Switch Over | DSO | IEM | In Ear Monitors | Interleaved | JFMG Ltd | Ofcom | PMSE | Programme Making and Special Events | radio microphones | Spectrum | UHF | UHF frequencies | Wireless Telegraphy Act
on the 4th of january 2010 there was a decision made about channel 38 being licensed for all users and licence exempt channels to become a thing of the past. will this document be updated to reflect this?