Fibre Optic Testing Specialists (UK & Europe)
TNS Communications provides professional fibre optic testing services across the UK and Europe, supporting telecom infrastructure providers, altnets, and service operators with reliable testing, certification, commissioning and fault analysis. From new-build FTTH deployment and metro networks to long-haul fibre routes and high-capacity optical transport, we help clients verify performance, protect optical budgets, and reduce future faults.
Our engineers deliver a practical, standards-aligned approach to fibre testing. That means clear test methodologies, dependable results, and handover documentation that stands up to acceptance criteria and audit requirements. It’s also why clients trust us for critical communications infrastructure: professional workmanship, disciplined testing processes, and proven experience across live telecom environments.
If you need responsive support for commissioning, assurance, or remediation, our teams can mobilise quickly and work safely and efficiently as part of wider delivery programmes.
Fibre optic testing services for telecom networks
Fibre networks are designed around an optical loss budget. When networks underperform, the cause is often something small but costly: a poor splice, a contaminated connector end-face, an unverified link budget, or an undetected bend introduced during installation. In telecoms, where scale is large and service expectations are high, these issues can lead to repeat faults, delays to customer activation, and increased operational cost.
Our fibre optic testing services help network owners and delivery partners to:
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confirm installed fibre links meet design specifications and optical budgets
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verify performance prior to activation and handover
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identify defects early, reducing rework and repeat visits
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produce reliable commissioning evidence for acceptance and future troubleshooting
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maintain network quality during upgrades, repairs and expansions
We support testing for a wide range of telecom environments, including FTTH aggregation and distribution, metro rings, backbone routes, data centre interconnects, and WDM transport networks
Why fibre testing is critical to network performance and reliability
Fibre carries data as light. This enables high bandwidth and long-distance transmission, but it also means the network is sensitive to installation quality and cleanliness. Small losses or reflections can accumulate across long routes with many events (splices, connectors, splitters and joints), reducing margin and increasing the risk of instability.
Professional fibre testing reduces that risk by validating the network in a structured way:
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Tier 1 testing confirms overall link loss against the budget
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Tier 2 testing identifies and measures events along the route
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End-face inspection ensures connectors aren’t introducing avoidable loss or reflectance
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Fibre characterisation confirms the route is suitable for high-capacity optical transport systems
In short: good testing supports reliable service today and prevents expensive fault-finding tomorrow.
Standards and compliance (UK & Europe)
Telecom operators and infrastructure providers require testing that is consistent, repeatable and auditable. Depending on project scope and specification, our work can align with widely recognised standards and guidance including:
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EN 50173 and ISO/IEC 11801 structured cabling frameworks (where applicable)
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IEC 61280-4-1 installed cabling plant attenuation measurement methodologies
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IEC 60793-2-50 and IEC 60793-2-10 fibre specifications and measurement methods
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IEC 61300-3-35 (Edition 2 and Edition 3) connector end-face inspection criteria
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ITU-T G.650.3 guidance on fibre and cable measurement techniques for advanced optical networks
These frameworks help ensure measurement methods and acceptance evidence are consistent across suppliers, geographies and equipment ecosystems.
Tier 1 fibre testing and certification (insertion loss, length and continuity)
Tier 1 testing verifies the fundamental performance of the fibre link and is typically used to confirm that installed fibre meets the design optical budget prior to activation. It provides a clear pass/fail certification against the required specification and is a core part of commissioning and assurance on new builds and remediation programmes.
Tier 1 certification commonly validates:
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insertion loss (attenuation) across the link
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fibre length
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continuity and basic link performance
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polarity (where applicable)
Tier 1 test equipment we use
To deliver accurate, repeatable Tier 1 results across telecom networks, we use proven industry platforms including:
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Fluke Networks
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Softing
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EXFO
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Viavi
This allows us to support a range of environments and client requirements while maintaining reliable testing outcomes and consistent reporting.
Tier 2 OTDR testing and fault analysis (bi-directional testing)
Tier 2 testing uses an Optical Time Domain Reflectometer (OTDR) to analyse the fibre route in detail. OTDR testing is essential for identifying where loss occurs and for locating faults quickly—particularly on long runs and complex routes.
OTDR testing helps to identify and quantify:
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splice events and splice losses
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connector events, loss and reflectance
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bends and stress points
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breaks, macro-bends and severe faults
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overall attenuation behaviour along the route
Tier 2 OTDR equipment we use
For Tier 2 OTDR testing, we use advanced OTDR platforms from:
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EXFO
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Viavi
Why complete bi-directional OTDR testing matters
OTDR event measurements can vary depending on fibre characteristics and launch direction. For telecom acceptance and accurate splice assessment, we carry out complete bi-directional OTDR testing to reduce measurement bias and improve confidence in event-level results.
This is particularly important when verifying splice performance and when producing commissioning packs that must meet strict acceptance criteria.
Fibre splicing services and why 0.1 dB splice loss matters
Splicing quality is one of the biggest factors influencing long-term fibre performance. Each splice introduces a small loss. On long routes with many joints, those losses accumulate and can erode optical margin.
On critical telecom networks, targeting 0.1 dB splice loss (or better where specified) supports:
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stronger optical budgets and improved reach
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more reliable service as networks age or are modified
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reduced risk of marginal links falling out of tolerance
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better performance for high-capacity transport and WDM environments
Professional workmanship matters here. Achieving consistently low splice loss is not just about the splicer—it’s about preparation, cleanliness, correct fibre handling, and verification through appropriate testing methodology.
Characterisation equipment we use (Viavi ONA-800)
We perform CD/PMD and attenuation profile testing using the Viavi ONA-800 long-haul system, designed for long-distance telecom routes and advanced optical network acceptance requirements.
Why we test to ITU-T G.650.3
Testing to ITU-T G.650.3 supports recognised measurement techniques for fibre and cable characteristics used in advanced optical networks. This helps ensure results are consistent and trusted across operator and vendor ecosystems—especially important for long-haul and WDM deployments where margins and performance requirements are tighter.
Fibre characterisation for long-haul and WDM networks (CD/PMD and attenuation profile)
As networks move towards higher-capacity optical transport and WDM systems, advanced testing is required to confirm that fibre routes meet the performance requirements of modern transmission.
TNS provides fibre characterisation services across the UK and Europe, including:
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Chromatic Dispersion (CD) testing
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Polarisation Mode Dispersion (PMD) testing
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Attenuation profile measurements
Connector end-face inspection to IEC 61300-3-35 (Edition 2 and Edition 3)
Connector contamination is one of the most common avoidable causes of loss and reflectance issues in fibre networks. Even microscopic debris can degrade performance and cause intermittent faults, especially in live environments and during migrations.
End-face inspection equipment we use
Our engineers use specialist inspection equipment including:
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Viavi INX-760 for end-face inspection
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EXFO FIP-435B inspection probes
This supports inspection against IEC 61300-3-35 Edition 2 and Edition 3 criteria (as required by the specification) and helps prevent avoidable performance issues during commissioning and maintenance.
To minimise this risk, inspection and cleanliness practices are often aligned to IEC 61300-3-35.
Quality, safety and environmental standards
Telecom delivery requires consistent quality, safe working practices and responsible operations. TNS Communications operates with internationally recognised management systems:
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ISO 9001 (Quality Management)
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ISO 14001 (Environmental Management)
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ISO 45001 (Occupational Health & Safety)
These standards support robust processes, consistent documentation, safe delivery in challenging environments, and continuous improvement across multi-site programmes.
Supporting altnets and major service providers across the UK and Europe
The UK and European fibre markets continue to expand rapidly. We support a wide range of delivery models—from fast-paced altnet rollouts to complex programmes for established service providers—bringing a consistent focus on quality and acceptance-ready reporting.
Our teams support:
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FTTH network commissioning and assurance
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metro network upgrades and remediation
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long-haul route verification and fault localisation
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data centre interconnect validation
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WDM and optical transport network testing and characterisation
For an example of our delivery in a high-capacity transport environment, read our case study: Successful WDM rollout project
Fibre Optic Testing FAQ
Why Choose TNS Comms?
We combine technical capability with professional delivery. Our work is built on disciplined testing practice, experienced engineers and clear documentation — so network owners can make confident decisions based on reliable results.
They value our:
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telecom industry experience across UK and European projects
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end-to-end capability (Tier 1, Tier 2, characterisation, inspection and remediation)
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bi-directional OTDR testing approach for accurate event-level results
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commitment to quality workmanship and low-loss splicing
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standards-aligned testing and inspection with acceptance-focused reporting
If you need fibre optic testing, commissioning support, or advanced fibre characterisation, speak to our team.
