One of the tradeoffs in modern state of the art VSAT modems is that you can intentionally choose more computationally 'expensive' FEC, to slightly improve your bps/Hz in a given fixed kHz/MHz amount of FDD transponder capacity, at the expense of higher latency. With the Comtech CDM-760 for instance.
This is getting better as the years go on and modem manufacturers are able to throw additional CPU and FPGA resources at FEC processing, without increasing their cost to build a modem a great deal.
This is getting better as the years go on and modem manufacturers are able to throw additional CPU and FPGA resources at FEC processing, without increasing their cost to build a modem a great deal.