Fiber testing

Description

Importance of Fiber testing in networks

Networks are constantly evolving and to do so, they need ongoing maintenance and upgrades. The accelerated pace of technology evolution and the growing sophistication of networks – which are now transitioning to 5G – makes supporting network evolution even more challenging.

Use of standardized protocols is necessary to verify and maintain optical signal integrity within these increasingly complex networks and across all optical paths. That is why EXFO has developed a full suite of fiber optic test solutions to ensure network integrity.

The automation of easy-to-use, field-optimized test solutions coupled with instantly interpreted results delivers accelerated outcomes by making scarce expertise available to everyone, at any skill level. Using EXFO’s intelligent handheld test equipment takes the guesswork out of set-up, execution and analysis, leading to high-quality networks, delivered on time and able to address any foreseeable service requirements.

Testing fiber optic cables

Maintaining quality of signal – measuring optical loss

Light sources and power meters

As optical signals traverse the network, many variables can affect the quality of transmission. This is an important factor for network performance. Low signal strength that fails to meet the transceiver threshold translates to no connectivity and difficulty to scale capacity in future.

The light signal naturally reduces in power as it progresses so, to test the signal, technicians use an optical light source and power meter to inject light into one end and measure the signal at the end point. Low power could indicate there is a fiber defect impeding the signal, such as a macrobend or a bad connector, or a fiber break. Additional testing would be required to identify and locate the fault.

Optical loss test sets

EXFO’s optical loss test sets (OLTSs) provide insertion loss (IL), optical return loss (ORL), and fiber length measurements at two wavelengths in five seconds via fully automated bidirectional analysis. EXFO’s OLTs include a step-by-step reference wizard and intelligent fault diagnosis and are available in dedicated handheld instruments and platform-based modules to suit various network architectures and test requirements.

Field testing fiber optic cables - measuring performance

Fiber inspection

Dirty and/or damaged fiber connectors are one of the most common causes of optical network problems. This is a critical issue given the need for faster fiber deployments and increased OPEX pressure. A variety of fiber inspection solutions from EXFO help technicians and engineers assess and rectify issues.

Live fiber detection

EXFO’s handheld live fiber detectors enable efficient, accurate and reliable data collection without disrupting traffic or damaging/over-stressing fibers. Technicians can detect live and dark fibers and avoid unnecessary manipulations, saving time and eliminating guesswork.

Optical fiber multimeters (OFM)

An OFM is an essential handheld tool for fiber optic technicians similar to well-known multimeters used for electrical circuits. OFMs do quick measurements of multiple key optical parameters such as loss (dB), optical return loss (dB), length (meters), and power (dBm). This empowers technicians -- without additional training -- to verify fiber optic link health and troubleshoot potential issues while on-site, maximizing their time and minimizing additional truck rolls.

OTDRs and iOLM

EXFO’s industry-acclaimed OTDRs provide highly accurate measurements to easily characterize and validate fiber links. These devices are critical to characterize, troubleshoot and monitor fiber links throughout construction, activation, and turn-up phases.

OTDRs are compact, rugged and simple to use in the field. iOLM, or intelligent optical link mapper, analyzes and interprets multiple complex OTDR traces while simplifying the diagnostics for the link under test. At the push of a single button, any technician can now become a testing expert. It’s easy to see why these devices are critical to ensuring fiber link performance, providing a valuable tool for field technicians.

Fiber monitoring solution

Not only can OTDRs be used for on-site testing; they can also be remotely triggered from a centralized unit via the cloud. With centralized OTDR systems (Remote Fiber Test system), technicians can access OTDR capabilities directly from the field.

A centralized solution can help operators reduce mean time to repair (MTTR), meet service level agreements (SLA’s), and improve customer experience. EXFO’s centralized NOVA system enables testing from the Central Office to the optical network terminal (ONT). This is particularly useful in Fiber to the Home (FTTH) applications.

Dispersion analysis

Chromatic dispersion (CD) and polarization mode dispersion (PMD) can be responsible for transmission errors, as the different wavelengths and the different states of polarization supported within the fiber can travel at diverse speeds and cause pulse broadening. The higher the speed of the signal, the higher the chances of bit error rates caused by CD and PMD. EXFO provides a variety of analyzers that can detect dispersion and ensure signal integrity to avoid service degradation.

Spectral testing

EXFO’s in-band, Pol-Mux optical signal to noise ratio (OSNR) and in-service Pol-Mux OSNR methods are the answer to the question of how to accurately measure optical OSNR on a per-channel basis in reconfigurable optical add-drop multiplexer (ROADM) and 100 Gbps -- and higher -- networks.