I didn't know that A5/1 is a must nowadays..
It's always been a must for the MS to support it. The network doesn't have to, but the phone does.
Then I have to search for othr ways ..
Have your own BTS (like nanoBTS, or openBTS, see http://www.ebay.com/itm/220863984566 ) or BTS simulator (like a racal 6103e)
Cheers,
Sylvain