Can you play PS3 games online using 3G Hotspot?

So since i moved i cant get decent Internet set up at my house in the country. I have an HTC Desire and have been trying to use the WiFi Hotspot to play online again. The PS3 picks up my phone network, but wont stay logged on to PSN. Ive tried my laptop connected to the Hotspot with the Ethernet cable running from my laptop to PS3 but dont understand the process.