At800 publish first "speculative model" of 4G Freeview interference
Brian Butterworth published on UK Free TV Digital Mobile Spectrum Limited (DSML) have put on line (as a PDF) of their recent introductory presentation - you can find it here: http://www.dtg.org.uk/projects/presentations/DTG_4G_Rollout.pdf.
Whilst most of the information contained within the document is already well-know, page 16 contains a graphic showing the first public version of the "speculative model of interference based on existing mast data". It is reproduced below:
The areas marked green require one type of filter (the Channel 60), those in red the other type (the Channel 59).
The model shows that proximity to a mobile phone mast is the greatest predictor of problems, even when the Freeview signals are strong. This is especially the case with multi-occupancy properties, where distribution amplifiers are very likely to have been used.
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Monday, 11 March 2013
J
Jamie8:49 PM
Would it be better sense to have 1 combined 59/60 one.
Sooner TVs in Europe restrict the higher UHF the better!
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Tuesday, 12 March 2013
M
Mike Dimmick6:36 PM
Jamie: The 'Channel 59' filter is actually a smaller cheaper one with a shallower roll-off. It only needs to pass channel 59 and below, so it can partly filter channel 60 (i.e. it can roll off across the 8 MHz of C60 plus the 1 MHz guard band). The 'Channel 60' filter has to be able to pass channel 60 and below, with a sharp cut-off (only having the 1 MHz guard band), so it's bigger and more expensive.
Given they're expecting to have to produce nearly a million of these, it's worth the extra design cost to have a cheaper version for the majority of households, in addition to the more expensive one that would work for everyone.
I suspect that Briantist has probably got the colours the wrong way round, and actually the green areas can have a 'Channel 59' filter, and only the red areas need a 'Channel 60'. The red area at the northern edge of the E postcode area is in the vicinity of the Chingford and Edmonton relays, where the BBC A multiplex broadcasts on C60. There's a small red patch near Woolwich as well.
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Friday, 15 March 2013
M
Mike Dimmick2:52 PM
Jamie: Thinking about it, it looks like you assumed that these are notch filters that filter out the specified channel.
They are not. They are low-pass filters that pass everything up to and including the specified channel, and block the 4G signals from reaching your TV/receiver/amplifier. The Channel 60 filter has to be steep so that it eliminates as much as possible of any transmission in the 4G band, which starts at 791 MHz. C60 goes up to 790 MHz.
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Sunday, 24 March 2013
It will be most interesting when Belmont's ArqB's multiplex on frequency 60 could possibly be affected in the near future,as well as the possible clearing of the entire 700MHZ-800MHZ wavebands UK wide ?
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Mark's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Tuesday, 26 March 2013
M
Matt12:41 PM
Downham Market
I can't understand all this. All i know is i've been losing stations over the last 3 days. All HD stations are totally gone and others are pixelating. For years this freeview thing has caused nothing but headaches and lots of cash. One minute it's ok the next they switch something over and then it's not ok, then you have to fork out more cash to make it ok, it's on going cycle. I finally had a new ariel set up in November 2012, everything has been perfect until 3 days ago. I'm really fed up with it all. I paid lots of money to get my TV and signal 100% perfect, then these muppets come a long and mess it all up!
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Matt's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Matt: You are at least 100 miles away from the test 4G signals - they just don't get that far!
Looking at what you have said, you might have too much signal - see Freeview signals: too much of a good thing is bad for you | Digital switchover | ukfree.tv - 10 years of independent, free digital TV advice .
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Monday, 1 April 2013
T
tony hough7:55 PM
Winter Hill is being retuned on 10th April, When will the 4g tests start in this area?
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Monday, 15 April 2013
I absolutely love your blog and find the majority of your post's to be just what I'm looking for.
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