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FTTx/PON Service Activation

When the network is activated and full-fledged operation begins, it is critical to conduct thorough test procedures, as it is at this stage that quality of service must be tested and monitored in order to meet service-level agreements (SLAs) with subscribers.

 

 Test Equipment
Test Type PON Power Meter PON OTDR Ethernet Tester
Optical power level x    
Link troubleshooting   x  
Service activation and commissioning     x

Service Activation

During the service-activation phase, a technician will go to the customer premises and perform the following tasks:

» Install the ONT
» Install the drop cable
» Measure all optical levels
» Power up the ONT

Test MethodeDescriptionProposed Equipment
Optical power measurement A PON power meter is optimized to simultaneously measure optical levels at specific wavelengths carried by PON networks, i.e., 1310/1490/1550 nm.

PPM-350C PON Meter

Up to three optical signals can simultaneously travel along a PON link at different wavelengths. Network operators need a simple means of detecting these signals, measuring them and verifying that they are within acceptable power ranges, according to the type of network and equipment used.

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Figure 1: Testing signal level quality with a PON power meter at the customer premises

The PON power meter can measure the power of simultaneous wavelengths when conducting PON service-activation tests at customer premises. This instrument features a patented pass-through design allowing technicians to obtain a power measurement of the upstream burst signals emitted by optical network terminals at 1310 nm and the downstream signals at 1490 and 1550 nm.

 

Link Troubleshooting

Test MethodeDescriptionProposed Equipment
Optical power measurement A PON power meter is optimized to simultaneously measure optical levels at specific wavelengths carried by PON networks, i.e., 1310/1490/1550 nm. A set of 10 thresholds can be configured to measure at different points within the network for easy troubleshooting.

PPM-350B PON Power Meter

OTDR testing Link troubleshooting with an optical time-domain reflectometer (OTDR) allows technicians to find and locate faults such as macrobends, breaks or faulty connection points.

AXS-100 Access OTDR
Handheld mini-OTDR

When a problem is diagnosed (e.g., low signal or no signal), troubleshooting must be performed to locate the source of signal disruption. A PON power meter, combined with an OTDR optimized for live testing, are the tools of choice for such applications.

 

More on Optical Power Measurements

Using a PON power meter will provide the user with a power level reading for each individual wavelength. Depending on the optical levels measured, the user will know which service can be affected. By measuring the optical levels at different locations, the defective section may be identified.

Figure 2: Live PON testing results displayed on the PPM-350C PON Power Meter’s graphical user interface.

An OTDR optimized for access networks is specifically designed for in-service PON troubleshooting. It features an optional dedicated port (for testing at 1625 nm) incorporating a filter that rejects all unwanted signals (1310, 1490 and 1550 nm) that could contaminate the OTDR measurement. The filter only lets through the 1625 nm OTDR signal, ensuring accurate OTDR measurements.

In-service OTDR troubleshooting of optical fiber does not interfere with the normal operation and expected performance of the information channels. For example, the AXS-100 Access OTDR does not interfere with the COs laser transmitters, as it uses an out-of-band wavelength, as per the ITU-T L.41 recommendation, entitled Maintenance Wavelength on Fibers Carrying Signals.

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Fig 3.: Testing live PONs with an access OTDR


Service Activation and Commissioning

When turning up services in the PON, thorough performance assessment, detailed frame analysis and accurate bit-error-rate testing provide the baseline to define and maintain competitive, customer-retaining service-level agreements (SLAs).

Test MethodeDescriptionProposed Equipment
Ethernet transmission testing A portable Ethernet tester enables you to minimize network downtime, rapidly restore failed services and efficiently manage network performance for SLAs.

FTB-8510 Packet Blazer
Ethernet Test Module

The industry has developed test methodologies to address Ethernet performance verification at Layer 2 and Layer 3 in EPON. The RFC 2544 from the Internet Engineering Task Force (IETF) specifies the procedures for testing the following characteristics:

» Performance availability (throughput)
» Transmission delays (latency)
» Link burstability (back-to-back frames)
» Service integrity (frame loss)

Tests like these are usually conducted at the end of the installation phase, and they can be performed with Ethernet testers and similar instruments.

For more information on Ethernet applications and related testing, please visit the Ethernet application page.