A Novel Technique for Low-Cost Embedded Non-intrusive Fiber Monitoring of P2MP Optical Access Networks

Abstract

Abstract:A low cost embedded OTDR method is presented for monitoring the fiber plant of TDM optical networks without extra optical components nor performance penalty. It localizes abrupt changes in link attenuation without disturbing network operation.

Optical layer monitoring in Passive Optical Networks (PONs): A review

“…The idea behind this solution is to measure the backreflected and backscattered echoes caused by the light signal transmitted upstream from already existing laser located inside ONU/ONT [20], [21]. Thus, the wavelength used for the monitoring is the same as for normal upstream data transmission and the need of connecting separate test equipments to the network is eliminated.…”

Cost efficient non-service interrupting monitoring of optical fiber links in FTTH / FTTB networks

“…This can e.g. be done by measuring the optical power backscattered from the optical upstream data bursts [6]. However, due to varying burst lengths this requires additional information from the Media Access Control (MAC) layer of the network to enable converting the backscattered power traces into the impulse response hfiber(t) of the fiber link.…”

Dual-band OLT transmitter using self-locked RSOA for next generation WDM-PON

“…Therefore, the WDM-PON service architectures require a number of tunable wavelength transmitters at optical line terminal (OLT) site. Furthermore, a tunable Optical Time Domain Reflectormeter (T-OTDR) is required at OLT for in-service line monitoring of WDM-PON [4][5]. Conventionally, the burden of inventory problem on WDM sources and the additional requirement of line monitoring technology are the obstacles against the pervasive of WDM-PON in optical access networks.…”

“…Recently, a number of configurations based on Reflective Semiconductor Optical Amplifier (RSOA) have been successfully demonstrated as low cost solutions for implementation of WDM-PON [3][4]. Also, all public future WDM-PON architectures are inclined to have line monitoring system integrated into the main transceiver module for simplicity [4][5]. Such solutions include the embedded OTDR in a small form factor (SFP) transceiver for in-service monitoring was demonstrated [5].…”