Fiber Ring Encoder for PON Fault Monitoring

This paper proposes a novel periodic optical encoder forcentralized fault monitoring of fiber-to-the home (FTTH)passive optical networks (PONs). The encoder exploits afiber ring to produce a periodic code. This reduces thecost of monitoring system while maintains goodperformance and high capacity. We evaluate theperformance of this encoding system in terms of signal tonoise ratio (SNR). We obtain an SNR of 12.5 dB for a 32customers network in one shot measurement. We alsoshow that capacity of 64, 128 and 256 could beaccommodated in expense of larger but acceptablemeasurement time.