Abstract Passive-star Time-Wavelength Division Multiplexing (TWDM) is an attractive technology suitable for very high speed large capacity communication. One of its key issues is to find a minimum frame length with arbitrary traffic pattern and arbitrary tuning latencies. This paper presents a new algorithm named MTC for this issue. The simulation results show that MTC achieves better performance than previous scheme. It is an efficient media access protocol for TWDM networks.