In this paper, we embody KS-MAC protocol based on Korea national standard (KS X 4600-1) Class A protocol with NS-2 simulator and verify its performance. Also, we develop optimized high speed MAC in medium-voltage and propose efficient topology. Compared with experiment results and simulated results are quite analogous. With help of this simulation, when construct network with multi-node, we easily calculate bandwidth and delay of the individual node for more efficient way of utilizing When high speed PLC network is constructed, this simulation expects PLC technology to develop in response to various conditions and results.