A separated random linear network coding (SRLNC) technique that separately transmits a coding coefficient (CC) and a coded packet (CP) in different frames is proposed based on cooperative control frames in distributed relay networks. SRLNC technique can improve retransmission performance by reducing retransmission overhead, because either the CC or CP is retransmitted, whereas conventional RLNC retransmits the CC and CP simultaneously. The throughput performance is also analyzed to investigate the impact of additional cooperative control frames, because SRLNC requires little additional cooperative control frames. The simulation results show that the proposed scheme outperforms the conventional RLNC in distributed relay networks.