4 ms·

I don't suppose it's any more than a few mW - Ofcom don't seem to be interested in / able to remove the many high-power pirate radio stations, often with awful

I don't suppose it's any more than a few mW - Ofcom don't seem to be interested in / able to remove the many high-power pirate radio stations, often with awful dirty signals, dotted around the UK (particularly London) so this would be a long way down their list of priorities! Even in rural Yorkshire, I get the "delights" of Phatt 100 and others every weekend. Agreed though - anything throwing unwanted noise onto the RF spectrum is a Bad Thing, however low-power it is (see powerline networking).

meaty 14y ago
TBH they're not really interested I understand as the FM broadcast band is on its way out in the UK.
- celticninja 14y ago
  pirate radio stations have a long history especially in London, they frequently try to take them down, but so do rival radio stations try to take out their competitors radio stations too. Anyway, the FM band is still in use, see the furore over iTrip or similar devices that were at a time banned in the UK as the law said you needed a license to broadcast on FM. The FM band is still in use and even when radio goes digital AFAIK the idea is that the FM band would be available for alternative use once radio stations no longer require it.
  - andyking 14y ago
    The current modus operandi of most pirate radio operators is to run as a legitimate internet radio station - remove all reference to the FM broadcast frequency from the website and promotional materials, promote yourself as "the internet's no.1 grime station" or whatever. Then, when Ofcom come calling, the FM transmission is "someone relaying our internet broadcast, we don't know who it is."
- andyking 14y ago
  This isn't true - I'm in the radio industry. High-level discussions have been taking place on the future of DAB digital radio, but there are no plans to switch off FM radio. It's FUD that's been spread over the past few years. At the very most, we will see a migration of national (and possibly large regional) stations to DAB in the next decade. FM will still remain up and running for local commercial and community radio - and an expansion of this is planned once the spectrum currently used by national broadcasters is released. The current FM and MW spectrum is of little use for new technology like mobile broadband - they are more interested in the current TV spectrum and up into the GHz bands. All this is currently under discussion, though, and nothing is confirmed. The status quo remains for now!
  - CJefferson 14y ago
    Sorry to jump in with a random reply. I've always been interested (just out of interest) to get an understanding of what the whole spectrum looks like, which bits are good (and why), and which bits are currently taken by what and could be used by other things. Is there any good place I could find such a thing that you know of?
    - andyking 14y ago
      In the UK, Ofcom provide quite a good overview of spectrum allocation here: http://spectruminfo.ofcom.org.uk/ http://spectruminfo.ofcom.org.uk/ This rather psychedelic PDF is linked from the above page: http://www.roke.co.uk/resources/datasheets/uk-frequency-allocations.pdf http://www.roke.co.uk/resources/datasheets/uk-frequency-allo... It doesn't say which allocations are good or bad - just what each slice of spectrum is used for. People like the mobile operators are only really interested in spectrum above the 800MHz area. This is where the competition for spectrum and billion-pound licence auctions come into play. Cellular companies are interested in line-of-sight frequencies in the UHF and SHF bands, where range is smaller but robustness of coverage is high. Then, they just blanket their desired area with cellular towers. VHF travels further, at the expense of robustness - it's ideal for broadcasting, but not for two-way data services. If you cleared FM and transplanted the existing 3G service onto, say, 100MHz, you'd find all sorts of interference issues. 87.5-108MHz, for instance, is used for FM broadcasting all over the world (except Japan where it's down in the 70s). The receivers will be available for the foreseeable future - certainly for my lifetime. If the band was vacated and all radio migrated to digital, the pirates would simply use it. It is of such little value - so it may as well be kept, rather than switching to digital for its own sake.
    - tomsaffell 14y ago
      In terms of 'good / bad', it's basically a trade-off between bandwidth and distance the signal can travel. A high carrier frequency allows a higher bandwidth[1], but it doesn't travel far/well. A low frequency can travel far, but doesn't support high bandwidth. So there is a sweet-spot (which is currently considered 'good') that achieves a balance of BW and distance. There's a great guide here: http://www.bbc.co.uk/rd/pubs/spectrum/bbc-the-spectrum-and-its-uses.pdf http://www.bbc.co.uk/rd/pubs/spectrum/bbc-the-spectrum-and-i... (see page 5) 1] the carrier frequency doesn't itself determine the bandwidth, it's the frequency range that does. For example, if someone says "a 100 Mhz signal", that doesn't tell you what the bandwidth is. You need to also know that the signal is actually allowed to cover 99.9 Mhz to 100.1 Mhz, so it's bandwidth is 0.2 Mhz (which could transfer ~0.2Mbps (order of magnitude accurate), depending on the encoding system used[2]). But if someone says "a 100 Mhz signal" you can guess that they don't mean the signal is allowed to cover 70 Mhz to 130 Mhz (60 Mhz of bandwidth), because: a) that's a ~2x range in frequency, which make it hard to design appropriate aerials, filters, modulators, etc; b) that isn't how spectrum is actually allocated anywhere I know of. So in practice you can normally deduce the approximate bandwidth by knowing the carrier frequency. Apologies for the long explanation - I've been nitpicked before on this.. 2] see: http://en.wikipedia.org/wiki/Nyquist_rate http://en.wikipedia.org/wiki/Nyquist_rate, http://en.wikipedia.org/wiki/Bit_rate http://en.wikipedia.org/wiki/Bit_rate
synx508 14y ago
You might be interested in this response to a FOI request on the subject of pirate radio enforcement action. http://www.whatdotheyknow.com/request/141864/response/351401/attach/2/1%20223462781.pdf http://www.whatdotheyknow.com/request/141864/response/351401...

meaty 14y ago

TBH they're not really interested I understand as the FM broadcast band is on its way out in the UK.

celticninja 14y ago
pirate radio stations have a long history especially in London, they frequently try to take them down, but so do rival radio stations try to take out their competitors radio stations too. Anyway, the FM band is still in use, see the furore over iTrip or similar devices that were at a time banned in the UK as the law said you needed a license to broadcast on FM. The FM band is still in use and even when radio goes digital AFAIK the idea is that the FM band would be available for alternative use once radio stations no longer require it.
- andyking 14y ago
  The current modus operandi of most pirate radio operators is to run as a legitimate internet radio station - remove all reference to the FM broadcast frequency from the website and promotional materials, promote yourself as "the internet's no.1 grime station" or whatever. Then, when Ofcom come calling, the FM transmission is "someone relaying our internet broadcast, we don't know who it is."
andyking 14y ago
This isn't true - I'm in the radio industry. High-level discussions have been taking place on the future of DAB digital radio, but there are no plans to switch off FM radio. It's FUD that's been spread over the past few years. At the very most, we will see a migration of national (and possibly large regional) stations to DAB in the next decade. FM will still remain up and running for local commercial and community radio - and an expansion of this is planned once the spectrum currently used by national broadcasters is released. The current FM and MW spectrum is of little use for new technology like mobile broadband - they are more interested in the current TV spectrum and up into the GHz bands. All this is currently under discussion, though, and nothing is confirmed. The status quo remains for now!
- CJefferson 14y ago
  Sorry to jump in with a random reply. I've always been interested (just out of interest) to get an understanding of what the whole spectrum looks like, which bits are good (and why), and which bits are currently taken by what and could be used by other things. Is there any good place I could find such a thing that you know of?
  - andyking 14y ago
    In the UK, Ofcom provide quite a good overview of spectrum allocation here: http://spectruminfo.ofcom.org.uk/ http://spectruminfo.ofcom.org.uk/ This rather psychedelic PDF is linked from the above page: http://www.roke.co.uk/resources/datasheets/uk-frequency-allocations.pdf http://www.roke.co.uk/resources/datasheets/uk-frequency-allo... It doesn't say which allocations are good or bad - just what each slice of spectrum is used for. People like the mobile operators are only really interested in spectrum above the 800MHz area. This is where the competition for spectrum and billion-pound licence auctions come into play. Cellular companies are interested in line-of-sight frequencies in the UHF and SHF bands, where range is smaller but robustness of coverage is high. Then, they just blanket their desired area with cellular towers. VHF travels further, at the expense of robustness - it's ideal for broadcasting, but not for two-way data services. If you cleared FM and transplanted the existing 3G service onto, say, 100MHz, you'd find all sorts of interference issues. 87.5-108MHz, for instance, is used for FM broadcasting all over the world (except Japan where it's down in the 70s). The receivers will be available for the foreseeable future - certainly for my lifetime. If the band was vacated and all radio migrated to digital, the pirates would simply use it. It is of such little value - so it may as well be kept, rather than switching to digital for its own sake.
  - tomsaffell 14y ago
    In terms of 'good / bad', it's basically a trade-off between bandwidth and distance the signal can travel. A high carrier frequency allows a higher bandwidth[1], but it doesn't travel far/well. A low frequency can travel far, but doesn't support high bandwidth. So there is a sweet-spot (which is currently considered 'good') that achieves a balance of BW and distance. There's a great guide here: http://www.bbc.co.uk/rd/pubs/spectrum/bbc-the-spectrum-and-its-uses.pdf http://www.bbc.co.uk/rd/pubs/spectrum/bbc-the-spectrum-and-i... (see page 5) 1] the carrier frequency doesn't itself determine the bandwidth, it's the frequency range that does. For example, if someone says "a 100 Mhz signal", that doesn't tell you what the bandwidth is. You need to also know that the signal is actually allowed to cover 99.9 Mhz to 100.1 Mhz, so it's bandwidth is 0.2 Mhz (which could transfer ~0.2Mbps (order of magnitude accurate), depending on the encoding system used[2]). But if someone says "a 100 Mhz signal" you can guess that they don't mean the signal is allowed to cover 70 Mhz to 130 Mhz (60 Mhz of bandwidth), because: a) that's a ~2x range in frequency, which make it hard to design appropriate aerials, filters, modulators, etc; b) that isn't how spectrum is actually allocated anywhere I know of. So in practice you can normally deduce the approximate bandwidth by knowing the carrier frequency. Apologies for the long explanation - I've been nitpicked before on this.. 2] see: http://en.wikipedia.org/wiki/Nyquist_rate http://en.wikipedia.org/wiki/Nyquist_rate, http://en.wikipedia.org/wiki/Bit_rate http://en.wikipedia.org/wiki/Bit_rate

synx508 14y ago

You might be interested in this response to a FOI request on the subject of pirate radio enforcement action. http://www.whatdotheyknow.com/request/141864/response/351401/attach/2/1%20223462781.pdf http://www.whatdotheyknow.com/request/141864/response/351401...