Sep
17
2012
The PON network is having different distances between OLT and ONTs due its physical location. This results into different times required for signal to reach its destination. For successful time delay avoidance, ITU-T Recommendation G.983.1 introduces concept called ranging. Ranging protocol allows adjust the timing between ONT and the OLT on distance up to 20 km, giving flexibility in equipment installation. The OLT is sending specific grand to activate ranging and opens up a window to receive response from ONT. The ONT is sending a ranging call back to OLT, after receiving the grant. OLT is assigning an equalization delay to specific ONT, based on the elapsed time between sending ranging grant and receiving response.