Patent ID: 7289439

Claim:
A method for implementing various functions in a GE-PON (Gigabit Ethernet-Passive Optical Network) system, the method comprising the steps of: a) periodically transmitting, by an OLT(Optical Line Termination), synchronous signals to the ONUs (Optical Network Units) after initial drive such that each of a plurality of ONUs is synchronized with the OLT in response to one of the synchronous signals periodically transmitted; b) identifying, by the ONU synchronized with the OLT, a transmission start time of an initial registration request frame and a transmission time length included in a grant frame such that the ONU transmits the initial registration request frame to the OLT after a random delay in order to avoid collision of initial registration request frames transmitted from the ONUs at a transmission time of the initial registration request frame; c) calculating, by the OLT receiving the initial registration request frame, a difference between a predicted frame arrival time and a real frame arrival time, the predicted frame arrival time being predicted from the transmission start time of the initial registration request frame indicated in the grant frame such that the OLT calculates an RTT (Round Trip Time) with a random delay value; and d) registering, by the OLT of the ONU requesting an ONU registration, in an ONU list after calculation of the RTT such that the OLT gives a new ONU ID to the ONU, and transmits a registration response frame including the new ONU ID and the RTT to the ONU requesting the ONU registration.