Here it comes...

In article , Woody
wrote:



Following the logical path of DIA I would have thought CIA was Communal
Installation with Amplifier?

I am often puzzled by how 'they' get to the power ratings fo a site.
Allowing for about 2dB difference between EIRP and ERP that makes the
base station around 800W radiated power. What is the point of having
that much power when the other end of the 'path' - even if a mobile -
is unlikely to be more than 10W erp and if it is class 4 then it will
be less than a watt (or +30dBm for the uninitiated.) The object of the
exercise is reciprocity or slightly better, not total overkill.

No, the situation is far from reciprocal, except in the most trivial sense.

Firstly, the base may be handling *many* links 'symultaenously'. So needs a
given amount of power per downlink. The mobile device only needs one uplink
channel.

Secondly, the amounts of data are asymmetric. The assumption is that users
will 'consume data' downlinked. e.g. watch TV, etc rather more than
broadcast it.

And of course much more of the EIRP of the base comes from its
directionality than the mobile, which needs to be fairly near to omni and
has a crappy antenna.


Is it that a site may be putting out a number of carriers close together
and it is the sum of the powers of the individual carriers that comes to
800W?

The powers allowed are specified as a power spectral density. e.g. 61 dBm
per 5MHz channel. Each such channel will, of course, handle many 'carriers'
and downlinks. And there are a number of such channels nominally per base.


I have that deep down feeling - and a depth of cynicism from 40+ years
in mobile radio - that this is another load of hype designed to feed a
dying TV and aerial trade to get people to buy what they don't need at
exorbitant prices. Yes there may be some issues with poor quality
masthead and/or distribution amps but my gut feeling is that only a
very small fraction of a percentage of viewers will have any problems
at all.

1 percent of the population is still well over half a million people. So
you need to note that "small" may be a misleading term here.

The root problem here seems to me, quite simply, that no-one knows how many
problems there will be. But we have companies who have paid their cash and
expect to roll out their systems.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , tony sayer

wrote:


An Ofcom field officer told that that was the total power permitted and
often they didn't use all of it.. But he wasn't 100% sure tho...

Yes. The values given are AIUI all 'max permitted' or some equivalent
limiting qualifier. So if allowed, say, 61dBm / 5MHz then they can use
less.

I did a look at the local bases, in particular at the one 400 m away along
much the same line of sight as Angus. Its a Vodafone mast allowed about
500W ERP at 2.1GHz. There is also a farm of antennas on the hill behind
Morrisons in a very different direction.

Can someone remind me: Which operators were awarded which of the 4G
channels? This may make a big difference to where the channel closest to
Ch60 comes from!

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Thu, 11 Apr 2013 09:30:38 +0100, Jim Lesurf
wrote:

In article , Bill Wright
wrote:
Jim Lesurf wrote:

I have asked that. They have so far declined to specify. Make of that
what you will. But I'll keep poking...

Have you got a pointed stick?

I'm using the sticks sold as supports for tall flowers. My head is pointed,
though. Hopefully, that'll do the job... :-)

If they can't give the details without a *technically* plausible reason
(ditto for the details of the protocols, etc) then they should become aware
that the only logical conclusion people can draw is that the 'pilot' was
really just a basis for a PR exercise. Not defensible in engineering terms
if it can't be independently checked.

However I'll see how I get on. If I can't get details I'll have to estimate
on the basis of the relevant physics, etc, involved. Not rocket science. If
they think my conclusions are then wrong then they'd have to release the
details I'm asking for as their evidential basis for showing where and how
I got it wrong.

What you are doing is of great interest to us anoraks, but as far as
the phone companies are concerned what we think is irrelevant.
They will just plough on regardless and see what happens.

In article ,
wrote:
On Thu, 11 Apr 2013 09:30:38 +0100, Jim Lesurf
wrote:

In article , Bill Wright
wrote:
Jim Lesurf wrote:

What you are doing is of great interest to us anoraks, but as far as the
phone companies are concerned what we think is irrelevant. They will
just plough on regardless and see what happens.

That may well be true. However others do have some interest and can
sometimes use findings to keep dragging any 'issues' sic into the light.

I'm just doing it out of interest and a wish that others can become
informed if they so prefer. This may matter to those who encounter problems
and might otherwise feel isolated.

OTOH investigation may show that the problems aren't serious. If so, also
useful to know.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 11/04/2013 09:44, Jim Lesurf wrote:

Can someone remind me: Which operators were awarded which of the 4G
channels? This may make a big difference to where the channel closest to
Ch60 comes from!

Try
http://stakeholders.ofcom.org.uk/bin...al-results.pdf

--
Andy

Jim Lesurf wrote:

Which operators were awarded which of the 4G
channels? This may make a big difference to where the channel closest to
Ch60 comes from!

Three got the lowest slot ...

|791-796|796-801|801--------811|811--------821|
|==H3G==|==EE===|===VODAFONE===|======O2======|
|832-837|837-842|842--------852|852--------862|


|821--------832|
|==DUPLEX GAP==|

In article , Andy Wade
wrote:
On 11/04/2013 09:44, Jim Lesurf wrote:

Can someone remind me: Which operators were awarded which of the 4G
channels? This may make a big difference to where the channel closest
to Ch60 comes from!

Try
http://stakeholders.ofcom.org.uk/bin...al-results.pdf

Ta! :-)

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
Andy Burns wrote:
Jim Lesurf wrote:

Which operators were awarded which of the 4G
channels? This may make a big difference to where the channel closest to
Ch60 comes from!

Three got the lowest slot ...

|791-796|796-801|801--------811|811--------821|
|==H3G==|==EE===|===VODAFONE===|======O2======|
|832-837|837-842|842--------852|852--------862|


|821--------832|
|==DUPLEX GAP==|

Thanks. So Hutchinson 3G are "3" in their ads?

I assume the bigger companies avoided the lowest slots as they are the ones
most likely to be get flak for causing jamming.

Update: So far all AT800 will say is that details like field levels and the
pilot 4G bands used are things they won't release. When asked for
*specific* reasons all I've had so far is generalisations. So I may have to
work on the basis of what I've got and can deduce. But I'll see if I can
get details by other routes. Pleased to see that ukfree have a 'leaked'
antenna pattern for Brierly Hill at least... :-)

The problem with trying to model field levels is that to do better than
square law you need local details and measurements against which to fit
parameters. But if I knew the field levels I wouldn't need to model. Catch
22. :-)

Am I correct in thinking that FOI doesn't apply to such companies? I
suspect I've got as far as I can by simply asking for info.

So far my feeling is that Brierly was really a 'dry run' to get their
methods sorted before they got on to really more significant and complex
cases. Hence it will be interesting to see what happens in London... and if
we ever manage to get the data rather than what the companies want to
present as 'conclusions'.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 09/04/2013 20:02, Bill Wright wrote:
Bill Taylor wrote:

I'm wondering why, just 21km from a main TX, it has Brierly Hill.
Does SC
fire away from it? Topology? Or have I got the wrong end of the stick?

Slainte,

Jim

Hills in the Dudley area. There seems to be a hole in the SC coverage
NW of Brierely Hill which the Brierly Hill transmitter fills in. The
map on www.ukfree.tv shows it nicely.

Yes, I've only done three or four jobs using Brierley Hill, but I
vaguely remember that SC was hopeless. Actually am I remembering right?
These jobs were on the Merry Hill Centre.

Bill


Bill, You mean Merry Hell...... :-)

Jim Lesurf wrote:

Thanks. So Hutchinson 3G are "3" in their ads?

Yes.

I assume the bigger companies avoided the lowest slots as they are the ones
most likely to be get flak for causing jamming.

The slot O2 won has the highest frequencies, due to the coverage
obligations it carries.

Vodafone paid extra for the next slot down, 3 and EE didn't bid extra
for specific slots.