Level 2 specification
NR/L2/TEL/31200
Design of High-Capacity Fibre Cable Systems
Issue 1, 04 December 2021 · Fibre design
Clause map — what each clause deals with
| 1 | Purpose | What the standard is for: principles for building, extending or maintaining NR's high-capacity (ribbon) fibre network |
| 2 | Scope | What it covers: HCFC cabling parameters and configuration |
| 3 | Roles and responsibilities | Who is accountable for competent design and survey |
| 4 | Definitions and Abbreviations | Abbreviations and definitions (DISAF, S-ODF, N-ODF, ribbon and so on) |
| 5.1 | Fibre Architecture | How HCFC sits alongside the 24-fibre FTN architecture |
| 5.2 | Ribbon Fibre Cables | What ribbon fibre cable is and why it is used |
| 5.3 | Segmentation ODFs (S-ODFs) | Segmentation ODFs — how they split the cable into sections for flexibility |
| 5.4 | Continuity Ribbons, Utility Ribbons, and Nodal-ODFs | Continuity and utility ribbons and nodal ODFs — managing connector loss along the path |
| 6.1 | Minimising Optical Loss Through Maximising Straight Joint Spacing | Why straight joints are spaced as far apart as possible |
| 6.2 | Information Needed to Assist Design Decisions | What information the designer needs to size the cable for future demand |
| 7.1 | High Capacity Fibre Cables | How HCFC differs from the loose-tube cables of FTN/FTNx |
| 7.3.1 | Introduction | Choosing the HCFC size from demand information |
| 7.3.2 | Urban and Rural Weighting Guidance | Weighting fibre demand for urban, town and rural areas |
| 7.4 | The HCFC Network | Where an N-ODF is required when sheaths meet |
| 8.1 | General Surveying Requirements | What the HCFC survey has to establish |
| 8.2 | Centre to Centre Cable Lengths | Measuring centre-to-centre lengths and maximising joint spacing |
| 8.3 | Straight Joint locations | Choosing straight joint locations |
| 8.4 | Sheath gaps | Recording sheath gaps; points to 30162 |
| 8.5.1 | General | The HCFC cable variants the surveyor records |
| 8.5.2 | PE sheathed steel tape armoured HCFC | PE-sheathed armoured HCFC — the default, and the limit on how far it may run into a building before ZHLS |
| 8.5.3 | ZHLS sheathed steel tape armoured cables | ZHLS (low smoke) HCFC — subsurface stations, long tunnels, and buildings where the internal run from entry to termination is long |
| 8.5.5 | Choice of cable type | The environment-to-cable-type table for HCFC |
| 9 | Resilience | Resilience considerations for the HCFC network |
| 10 | Fibre Records | Where fibre records go and which records standard applies |