The cause of the failure-where is the problem with the industrial ONU?

1. Industrial-grade ONU with time slot drift

This kind of failure is usually caused by the aging of the laser and the time slot drift of the ONU's upstream data transmission. It may also be the number of bandwidth maps sent by the downstream OLT

Industrial ONU

An error in the data causes an error in the ONU's transmission time slot. This kind of faulty ONU is difficult to detect. Generally, the OLT needs to monitor the upstream data of the industrial-grade ONU in real time. Determine whether it sends data in the time slot allocated by the OLT. For such abnormally luminous ONUs, because they mainly affect two adjacent industrial-grade ONUs, in addition to isolation, the protection bandwidth between time slots can also be increased to alleviate its impact on other ONUs.

2. Long luminous industrial grade ONU

This failure is caused by the ONU's laser for a long time. As a result, the ONUs under the entire PON port cannot communicate normally. If the ONU emits strong light, the abnormal light emission of the ONU can be determined by testing the optical power at the optical splitter during troubleshooting. However, if it is a weakly emitting ONU, the judgment will be more difficult and the abnormal light emission of the ONU cannot be measured at the optical splitter. Only through the intervention of the OLT and the use of specific detection algorithms can the abnormal ONU be judged. Usually, the business under the entire PON port will be affected, but because of its failure phenomenon has always existed, it has brought convenience to the troubleshooting to a certain extent.

3. Intermittent glow

The judgment of this kind of failure is difficult and irregular. It is also the fault of the abnormal light-emitting ONU in the current network. It is not only impossible to measure the abnormal light emission of ONU at the beam splitter. In addition, it is necessary to observe and monitor faulty PON ports for a long time, which brings great challenges to network maintenance.

There are many fault phenomena in the network of abnormally luminous ONUs. There is no complete mechanism and process in the industry to solve this fault. Other operators have no controllable experience. In the operation of the actual network. The author summarized a set of procedures and experience for troubleshooting abnormal light-emitting ONUs. It can effectively solve most of the existing network faults.

cause of issue

1. Long light emission problem: The photoelectric converter is connected to the branch fiber by mistake, and the photoelectric converter emits light for a long time; the industrial-grade ONU optical module has an abnormal shutdown signal, and the ONU is not turned off during the shutdown, which causes the ONU to emit light for a long time; industrial ONU software The crash will also cause the ONU to emit light for a long time.

2. Coverage interference problem: For some reasons (such as insufficient extinction ratio), individual industrial-grade ONUs emit light in unlicensed time slots, which affects the normal services of other ONUs.

3. Overlapping interference problem: Inconsistent parameters of different industrial-grade ONU optical modules cause partial overlap of upstream optical signals, which affects each other's services.