Bluskis
The thread in ATC Issues, started by Bookworm:
http://www.pprune.org/forums/showthr...threadid=73769
Has a lot of info in it.
I particularly liked this quote (referring to the ground installations):
"Have taken some 'expert' advice on this now.
Mode 'S' will not appear anytime soon in UK. Although its essentially a software upgrade for the ATC radars the main UK radars require to be replaced (not only for mode 'S'). NATS had a 10 year plan to replace them all, but the cost is now £150million and with the HUGE debt NATS has the interest repayments have crippled that size of investment."
Another thing, your (GA) Mode S squawk will be "filtered", so no-one on the ground sees it in busy airspace - a bit like the filtering of 7000 today in some TMAs.