Wifi on the train

I went to visit LBV Telelvision and on the GNER train on the way up I noticed that they have wireless - you have to pay a couple of quid but I thought in the interests of research(!) I'd give it a go. It did work but the through-put was very variable. At times I'd guess I was getting a megabit per sec and at other times it felt like a 9600Kbit modem from the early nineties. I was able to maintain a VPN connection into the office but Outlook was so sluggish as to be unusable (so only slightly worse than normal!) - I imagined they used a satellite service (but maintaining a proper lock on a moving train must be hard) but the literature suggests they use multiple connections - maybe they've got a heads-up on WiMAX?