Research Of The Monitoring Technology For PON Based On OCDM

With the continuous development of FTTx, PON technology as its supporting technology iswidely used in the access network, so PON fault monitoring is particularly important. Effectiveoptical monitoring technology can reduce maintenance costs and improve network reliability.Traditional monitoring tools such as OTDR, etc. can not meet the requirements of real-timemonitoring of PON. OCDM-based monitoring technology of PON is evolved in this case, it is ableto monitor all the branches of the PON system and can be widely applied to existing TDM-PON,WDM-PON and hybrid PON in the future.This article is based on the introduction of basic OCDM PON monitoring system on keytechnologies, the performance monitoring system for analysis and research, the main contentsinclude:1. Introduce the necessity of PON monitoring, summarize the development of PON monitoringand review its own characteristics.2. List and analyze the application over the PON monitoring requirements, as well as majormonitoring methods, such as OTDR, OCDM etc. in PON monitoring.3. Introduce the principle of OCDM-based PON monitoring monitor, analyze its system model.Introduce the proposed1D,2D coding scheme and periodic encoding scheme.4. Study how the geographical distribution of users influence the performance of monitoringsystem, focusing on the geographical distribution on SIR, Establish a uniform distribution model.5. Analyze the shortage of periodic coding scheme, put forward the improvement.Analyze theperformance of the monitoring system based on the improved pulse position coding (IPPC) scheme.Research shows that the geographic distribution of users and the pulse width have an importantimpact on the SIR of the monitoring signial，and it is able to identify the specific faulty link byanalyzing the SIR, this result plays an important role on the practical application of PONmonitoring system based on OCDM.The IPPC scheme has better correlation characteristics,imposesno coding loss,and is less bulky.IPPC provides superior performance in terms of SIR compared topreviously reported coding schemes adapted for PON monitoring,and thus is the ideal monitoringscheme.