Dynamic multicast group management and service wavelength allocation method for communication-broadcasting convergence service in WDM-PON

A method of dynamically allocating multicast service wavelength for communication-broadcasting convergence based on IGMP snooping-based in a WDM-PON having an OLT and a plurality of ONTs, comprising:

• a wavelength allocation step of allowing the OLT to allocate individual data wavelengths λc and a shared broadcasting wavelength λb to the respective ONTs;
• a first data transmission step of allowing the OLT to transmit data for broadcasting through the shared broadcasting wavelength λb and data for control through the individual data wavelengths λc;
• a determination step of determining whether the bandwidth of the shared broadcasting wavelength λb is exceeded;
• a second data transmission step of, if the bandwidth of the shared broadcasting wavelength λb is not exceeded, continuing to transmit the data for broadcasting through the shared broadcasting wavelength λb , and if the bandwidth of the shared broadcasting wavelength λb is exceeded, transmitting data for broadcasting and data for control, which are formed subsequently, through the individual data wavelength λc;
• a share index ascertainment step of allowing the OLT to periodically ascertain share indices of wavelengths of multicast groups that employ the shared broadcasting wavelength and the data wavelengths;
• and
• a wavelength allocation change step of, if the share index of the wavelength of the multicast group that employs the broadcasting wavelength is smaller than the share index of the wavelength of the multicast group that employs the data wavelength, changing allocation of the wavelength of the multicast group so that the share index of the wavelength of the multicast group employing the broadcasting wavelength is maximized.