OPTICAL FIBER MEASUREMENT ODP ODF ODC n ~ ODP ODP Fiber cable ONU ONU FTTH Topology (simple) Figure capture from https://www.ntt-review.jp/archive/ntttechnical.php?contents=ntr201803ra1.html Post-Construction Link Measurement Length of the fiber End to end fiber attenuation Loss, Location and reflectance each splice Optical return loss Any reflective or high loss event Test Equipment OTDR OTDR, OLS & OPM OTDR OTDR OTDR There are 2 ways to find out the power level of and attenuation of optical fibers that have been construction. 1. Measuring using OPM & OLS from ODF to ODP. ODF position in Central Office and ODP near customer. Measurements can be made in two directions (A - B) and (B-A). This method is done because there is no power from OLT. So, we are using power from OLS (Optical Laser Source) for transmit the power and OPM (Optical Power Meter) for receiver ODP ODF ODC n ~ ODP ODP Fiber cable OPM Attenuation (dB) = P in (dBm) - P out (dBm) Attenuation (dB) = 10 log2 (Pin / Pout) ---- > Pin/Pout in (mW) 2. Measuring using OPM for receive only. Assumption : Power source from OLT. OLT power has been transmitted until ODP. Measurements can be made in two directions (A - B) and (B-A). This method is done because there is no power from OLT. So, we are using power from OLS (Optical Light Source) for transmit the power and OPM (Optical Power Meter) for receiver. ODP ODF Fiber cable ODC n ~ ODP ODP In this method, we have to know the power source level. So we can check the value from OLT configuration.
