single wireless connection

Hi,

I am just wondering if any of you can help, I have 2 flats, one of
them is on the 15th floor of a tall "building A" and the other is on
the 3rd floor of another short "building B". The distance between the
2 buildings is just under than quarter of a mile. From the 15th floor
of "building A" I can see the roof of "building B". I have DSL
broadband access in "Building A" and I want to share the connection
with flat in "Building B". I can get a cable going from the roof to
the flat in "building B". So all I want is a wireless dsl connection
from the balcony of 15th floor and the roof of "building B". Please
can you suggest any specific hardware that would be perfect for this
setup or even another setup that would work well with this situation?

Thanks,
James