We stayed at the DLH last week and it is correct that there is only wifi access in the public areas. We paid 10 Euros for 3 hours which you can use as and when you wish, not all together. I think it was 4.50 Euros for an hour.
We were using our mobile phones but they did mention if we had a laptop we could use it in our room via cable but not sure what the cost of this was.