We deliver full-stack fiber and copper cable installations — from trenching through certification. Scope covers long-haul and metro routes, large-scale GPON / FTTH rollouts, in-building structured cabling and long-term maintenance of deployed infrastructure.

Metro networks

We design and build metropolitan fibre routes for operators and enterprise clients:

  • Metro backbone — ring and mesh topologies in C-RAN architectures, aggregating POPs across the urban footprint.
  • Metro DWDM / CWDM — dark fibre for dense and coarse WDM systems; link budgets planned with headroom for future channel expansion.
  • L2 / L3 connectivity — Metro Ethernet, MPLS, E-Line / E-LAN / E-Tree services for operators.
  • Dark fibre IRU — long-term indefeasible right of use on dedicated fibres for enterprise and alternative operators.
  • Data centre interconnect (DCI) — direct fibre lanes between DC sites, supporting 100 / 400 GbE and coherent optics.

GPON rollout

End-to-end GPON access network deployment — from OLT through to subscriber ONT:

  • OLT deployment — installation and activation of the central optical line terminal (Huawei, Nokia, Calix, ZTE); integration with the operator’s EMS / NMS.
  • Feeder fibre — trunk route from OLT to splitter point; typically G.652.D single-mode with 20–30% headroom for upgrades.
  • Optical splitters — passive 1:32 or 1:64 splitters, usually in cascaded 1:4 + 1:8 or 1:2 + 1:16 configurations to balance the loss budget.
  • Distribution fibre — from splitter to subscriber drop point; typically 12 / 24 / 48-fibre cables in duct infrastructure or ADSS aerial.
  • Drop fibre — individual subscriber runs, G.657.A2 / B3 bend-insensitive for in-premise routing.
  • ONT activation — on-premise terminal installation, provisioning and acceptance testing.

We also support next-gen variants: XGS-PON (10 Gb/s symmetric), NG-PON2 (multi-wavelength TWDM), 25GS-PON.

Fiber-to-the-Home (FTTH) rollout

Large-scale FTTH projects — from concept design to activated subscribers:

  • GIS planning — homes-passed mapping, feeder route optimisation with GIS tooling (QGIS, Bentley OpenComms Designer).
  • Permitting & coordination — with municipal, roads, power utility and infrastructure-owner stakeholders.
  • Deployment — horizontal directional drilling (HDD), microtrenching in urban settings, ADSS aerial in suburban, microduct blowing in existing infrastructure.
  • Street cabinets — fibre distribution hubs (FDH) installation and internal splice / patch work.
  • MDU work — in-building riser splice points and vertical backbones to floor distribution boxes.
  • Subscriber activation — individual drop installs, fibre termination at home (FTAH), clean OTDR record per activated subscriber.
  • ISP handover — as-built documentation package, GIS layers, OTDR baseline, activated-subscriber lists.

Power utilities — OPGW, OPUG, ADSS

For the electricity sector (transmission and distribution operators, industrial HV sites) we build fibre communication networks along overhead power lines and inside substations. We work to the safety requirements of ESO, CEZ, EVN, “Energo-Pro” and industrial HV network operators.

OPGW (Optical Ground Wire)

Optical fibres integrated into the shield wire of overhead power lines. Standard practice for transmission grids at 110 / 220 / 400 kV.

  • Fibre count: 24 / 48 / 96 / 144 — typically G.652.D, with G.655 / G.657 variants as required.
  • Mechanical construction: aluminium tube hosting the fibre bundle plus outer steel layers for tensile strength and short-circuit current carrying capability.
  • Design: sag / tension calculation, fault current capability (short-circuit kA²·s), ice / wind loading per IEC 61089 / IEEE 1138.
  • Installation: stringing with tensioner / puller, specialised stringing blocks to protect the fibre core; helicopter stringing on long forest routes when needed.
  • Tower-to-substation transition via optical joint box — split and patch into the substation-side network.

OPUG (Optical Unit Ground wire / Wrapped Fiber Cable)

A standalone, small-diameter optical cable wrapped helically around an existing shield wire or phase conductor. Installed live-line (without taking the line out of service) using a specialised wrapping machine that rides the conductor.

  • Use case: adding optical connectivity to an existing OHL without replacing the ground wire or erecting new towers.
  • Installation rate: typically 2–5 km per day with one machine.
  • Benefit: minimal impact on line operation, no outage to downstream customers.
  • Cable families: AFL SkyWrap, Prysmian WRAPPED, Corning OPT-GW-WRAP.

ADSS (All-Dielectric Self-Supporting)

Fully dielectric (metal-free) self-supporting cables, strung between towers of overhead lines or street-light poles.

  • Fully dielectric — safe to install and operate near energised HV conductors without line outage.
  • Span lengths up to 700 m with appropriate dielectric strength grade (track-resistant sheath for >12 kV space potential).
  • Use case: 20 kV distribution networks, suburban secondary routes where OPGW isn’t cost-justified.
  • Installation: stringing with dielectric blocks, similar workflow to OPGW with lighter loadings.

OPPC (Optical Phase Conductor)

Fibre integrated directly into one of the phase conductors — for special projects where no ground wire exists or has been decommissioned. Rare topology, but supported on client specification.

Scope of work in the power sector

  • Fibre network design in parallel with the OHL design — jointly with the OHL designer or as a subcontracted design package.
  • Supply and installation of OPGW / OPUG / ADSS / OPPC per client specification.
  • Splicing in joint boxes on towers and in substations — pedestal / wall-mount cabinets suitable for HV environments.
  • Transition to fibre terminal and patch panel in the control room — integration with SCADA and teleprotection plane.
  • OTDR certification with temperature compensation (OPGW fibre operates across -40 to +85 °C).
  • Emergency restoration after cuts — including post-storm re-stringing, coordinated with the TSO operational centre.
  • Smart grid communication, telecontrol, differential current teleprotection, SCADA telemetry.

Competence and safety

  • Qualified personnel with V and IV qualification groups under the Bulgarian Regulation on Health and Safety in Electrical Installations.
  • Trained to work in induced-voltage zones (induced voltage during live-line wrapped-fibre installation).
  • Fall protection systems per EN 363; work with bucket trucks and tower climbing.
  • Coordination with the TSO / DSO dispatch centre for all operational switching.

Applicable standards for power utilities

  • IEC 60794-4 — optical cables along overhead power lines (OPGW-specific).
  • IEEE 1138 — standard for OPGW design and testing.
  • IEC 60794-4-20 — ADSS cables.
  • IEC 61089 — conductors for overhead lines.
  • BDS EN 50341-1/2-23 — overhead electrical lines exceeding 1 kV (Bulgarian national normative aspects).
  • Bulgarian Regulation No. 9 on technical operation of power stations and networks.

Copper cabling

For in-building structured cabling and legacy integration:

  • Cat 6 / 6A / 7 — permalink certification to 500 MHz (Cat 6A) / 600 MHz (Cat 7); shielded (STP / F-UTP) for EMI-heavy environments.
  • Coaxial RF — for operator HFC networks and CCTV.
  • Industrial variants — PROFINET, EtherCAT, outdoor UV-resistant cables.
  • Certification — Fluke DSX / LinkRunner report per permalink, archived in the as-built package.

Maintenance & operations

  • 24/7 emergency response — SLA-backed response windows of 4 / 8 / 24 hours.
  • OTDR baseline monitoring — periodic verification traces on critical routes; gradual deterioration caught before it becomes service-affecting.
  • Planned preventive maintenance — windows coordinated with the client NOC.
  • Splice repair — on-site response to cable cuts (rain damage, construction incidents, vandalism); typical restoration under 4 hours in urban areas.
  • Documentation upkeep — as-built updated after every intervention; GIS layers kept current.

Testing & certification

  • Bi-directional OTDR per link budget (ITU-T G.650).
  • OLTS / IL / RL per link.
  • End-face inspection per IEC 61300-3-35 for every connector.
  • Fluke DSX / EXFO MaxTester / VIAVI ONX reports.
  • Full certification package ready for operator sign-off or independent investor QA.

Standards

International: ITU-T G.984 / G.9807.1 / G.989 (PON), IEEE 802.3 (Ethernet), ISO/IEC 11801 (structured cabling), IEC 61300 / 61280 / 60793 / 60794, TIA-568, TIA-942 (data centre).

Bulgarian: BDS EN 50173, BDS EN 50174-1/2/3, BDS EN 187000.