Do we need single-mode or multimode fibre?

Detailed answer

What this means for your project

Single-mode supports long distances and broad upgrade potential, while multimode may align with existing short-reach equipment and campus standards. The cheapest cable is not always the lowest whole-life choice because optics, patching, spares, testing and future migrations also matter. LGN confirms endpoints, distances, core counts, connector presentation, resilience and the active-equipment interface before selecting the fibre specification.

The appropriate specification and delivery method still depend on the site, programme and evidence available. LGN can review those constraints before recommending a practical next step.

Distance is only one factor

Single-mode supports long reach and broad upgrade potential, but the decision also affects optics, patch leads, test equipment and the client’s spares strategy. Multimode may be appropriate where an established short-reach standard and compatible active equipment already exist.

Questions the design should answer

• What applications and data rates must each link support now and later?
• What are the measured route lengths, not just straight-line distances?
• Are diverse routes or spare cores required for resilience?
• Which connector presentation and enclosure density suit the cabinets?
• Must the new link integrate with an existing fibre estate?

How LGN scopes the link

LGN confirms endpoints, route protection, core count, fibre construction, termination, polarity and the acceptance test regime. The recommendation is then tied to the active-equipment interface and the client’s operational standard, avoiding a cable-only decision that creates incompatibility at commissioning.