Here in Ireland they "boosted" the sginal to find a missing boy even after the mobile battery had died.
I didn't know this was possible.

Sorry if this upsets anybody

"Officers had worked with the mobile phone company O2 to boost the signal from Robert’s Nokia mobile phone, which went dead shortly after he disappeared. This allowed them to narrow down the search to the area around Inch Strand. An enormous mobile phone mast overlooked the site where Robert’s body was eventually discovered"

http://www.breakingnews.ie/archives/...#ixzz0oGYTL0A6