Fiber Characterization Service Brochure (PDF, 0.20 MB)
Network Testing – Pre-Installation of Network Equipment
A network’s optical fiber cable has to be tested before installing or upgrading network equipment to ensure that the fiber can support the network traffic. Excessive loss, return loss, or dispersion prevents the network equipment from operating optimally.
- Fiber Characterization Service
- Networks with OC-192, 10GE, and DWDM require full fiber characterization, which is a suite of the following five tests:
- Bidirectional optical insertion loss (OIL) measurements using a light source and power meter
- Bidirectional optical return loss (ORL) measurements using optical continuous wave reflectometry (OCWR) technology
- Bidirectional optical time domain reflectometry (OTDR) traces
- Chromatic Dispersion (CD) measurements
- Polarization Mode Dispersion (PMD) measurements
Please refer to our Fiber Characterization Service brochure in the literature section for more detail.
- Fiber Qualification Service
- Networks with short spans (campus or metropolitan environments) or slower speeds still require fiber qualification, which consists of some or all of the following tests (actual tests depends on requirements):
- Optical time domain reflectometry (OTDR) traces on all or a sample of the fiber
- Optical insertion loss (OIL) measurements using a light source and power meter or estimating using an OTDR trace
- Optical return loss (ORL) measurements using OCWR technology or estimated based on OTDR trace
Network Testing – Post-Installation of Network Equipment
- DWDM Systems Acceptance Testing
- For DWDM, before a network system is hander over to the customer, it must undergo an acceptance test in which all critical optical parameters are measured once more for:
- Center wavelength of each channel
- Spectral stability over time and temperature
- Channel spacing and channel crosstalk
- Peak power of each channel and overall/total power
- OSNR
- Gain and noise figures
The measurements of the digital parameters are performed either end-to-end (before the transmitter and behind the receiver) or via a loop through the entire DWDM system. The following parameters should be tested:
- Pointer analysis
- Path trace
- Alarm tests
- Performance monitoring (B1 byte)
- Round trip delay (needs to be done in loop)
- Bit-error rate with pseudo random bit sequence (PRBS) for 24 – 48 hours
SONET Testing
- Mapping analysis
- Alignment of port interfaces
- Measurements with structured test signals
- Measurements on add/drop multiplexers
- Delay measurements
- Testing of automatic protections switching (APS)
- Simulation of pointer activity
- In-service SONET measurements:
- Alarm analysis
- Path trace monitoring
- Pointer analysis
- Checking the system’s built-in sensors
- Drop and insert measurements
- Checking network synchronization
- Measurements on the TMN interface
- Error performance measurement:
- Jitter and wander analysis
Ethernet Testing
- RFC 2544 suite of tests
- Throughput
- Latency
- Lost frames
- Back-to-back frames
Burn-In Testing
- Monitor traffic after turn-up to verify proper network operation
United States