From my little understanding:
1E1=2048Kbps (or 2.048Mbps)
2E1=2x2048Mbps
=4096Mbps @ the node B.
If you can ascertain the erlang value for ur question and some basic paramenters then use any suitable Erlangs formulas to estimate the number of subscribers that can carry.
If u have some problem about it pls let me know.