LLU = local loop unbundling which is what enables companies like Talk Talk, Sky etc run ADSL services from the exchanges.
I thought you might not be lucky enough to get Sky BB as they have only rolled out a certain number of exchanges so far. Do you know what other ADSL suppliers are operating out of your exchange?
http://www.samknows.com/broadband/search.php
or
http://www.samknows.com/broadband/checker2.php
may help