I've been trying to grok the VSAT alphabet soup lately. This post on isp-satellites seems like a pretty decent summary of the different two-way VSAT flavours. Basically it sounds like SCPC and DAMA are connection-oriented protocols with call set up and dedicated bandwidth during the lifetime of the connection. Of course I'm translating into internet terminology here ;-) On the other hand, MF-TDMA, which other people call FTMDA and which is used by DVB-RCS, is more like a packet-oriented connectionless protocol. The mapping onto the cell phone networks makes sense.
Two video streamed lectures by Jun Takei also helped me understand the basics. Takei-san clearly is an expert and has lots of interesting things to say. lecture 1 is an introduction to satellite data comm. lecture 2 gets into more internet over satellite detail. His english is not fantastic but good enough. And it's a high-quality, 250Kbps stream, and you can follow along with the slides on the web. Takei has his name on a couple of RFCs as well.