VSAT Links

hi guys!

i would like to know how to optimize this VSAT link
for maximum data throughput. You are allowed to change all technical parameters,including modulation, protocols knowing that your VSAT link between Station A and B Transponder bandwidth is limited to the same
as a QPSK modem at 4096 kb/s needs.

Our measured bit error rate (BER)
is 5x10E-6.
Analyze the effective (real) transfer rate in kb/s if we use:
a. Stop-and Wait ARQ (for each IP packet)
b. Go-Back-N ARQ
c. Selective-Reject ARQ

any ideas from whre to start and get those results in order to represent i in bar graph for purposes of demostration

thanks alot for your time