Can passive repeater concept work for GSM mobile phones?

[Chris Young]

Hi,
Was searching for info, came across the below (old) mail trail.
I'm very interested in this, as my house seems to be in a mobile 
(Telstra) black spot.  This in spite of 'towers' being reasonably nearby.
So I can only speculate it's trees, terrain, maybe even beams & walls.  
Hence the "earth flattener" vs "range extender" comment is relevant.

Can such a concept work for phones - ie roof antenna, cable down into 
smaller antenna inside house?  I heard active / amplifiers break the 
law, so passive should be ok. 

I can understand if reception is improved.  But what about transmission, 
ie 'talk'.  Does it work reverse - will signal from phone find the 
antenna outside, as the path of least resistance?  Otherwise it will be 
listen-good but talk-bad.

Thanks
Chris Y.

>Hi Tony, Robert and group,
>
>Actually, Robert it right about the inverse square rule.
>
>However, "passive repeaters" do work (subject to the laws of physics).  They
>can be thought of as "earth flatteners", rather than "range extenders".
>Their best application is in cases when you can summarise the link as:  "We
>would have HEAPS of signal on this link path, if only that great big
>building | hill wasn't in the way".
>
>The best example of a passive repeater that I've seen, is on a ridgeline
>above the town of Karratha, in the Pilbara region of WA.  Two grid pack
>dishes are mounted back to back, interconnected only by a section of
>waveguide.  No electronics on site, no solar panels, no 240V.
>
>Down in the town (on the coastal plain), there's a microwave dish at the
>exchange, pointing at the passive repeater.   Over on the other side of the
>ridgeline, at a distance of about 3km (from memory) is the other end of the
>link, to service the Light Industrial Area.
>
>To get over the ridgeline would have required ridiculously tall towers at
>each end of the link.
>
>Unfortunately, I don't have any performance figures for this configuration.
>
>I have also used the passive principle to provide multi-channel VHF radio
>coverage underground over a leaky feeder system, where there was heaps of
>signal outside, and none in the underground structure.
>
>As a guide, the passive systems work best when placed as close as possible
>to one end of the circuit.  The middle of the link path is the worst-case
>scenario (that inverse square rule again!).
>
>Hope this helps,
>
>
>
>Chris vk6kch
>