| Full title | Information technology. Generic cabling for customer premises. Part 4: Single-tenant homes |
| Publisher | ISO and IEC, prepared by ISO/IEC JTC 1/SC 25 |
| Current edition | Edition 1, November 2017, with Corrigendum 1:2018. No amendments published |
| Status | Published and current |
| Replaces | ISO/IEC 15018:2004 and its Amendment 1:2009 |
| Related standards | ISO/IEC 11801-1, ISO/IEC 11801-6, EN 50173-4, ISO/IEC 14763-2, ISO/IEC 30129 |
What it covers
ISO/IEC 11801-4 specifies generic cabling within a home. A home is defined as a physical structure used as a dwelling place. A home can contain one or more buildings, or can be within a building that contains more than one home. It is read together with ISO/IEC 11801-1, which holds the requirements common to all premises types.
The standard covers three media:
- balanced (twisted pair) cabling
- coaxial cabling
- optical fibre cabling
These serve two application groups:
- ICT: information and communications technologies, such as Ethernet and telephony
- BCT: broadcast and communications technologies, such as TV and radio distribution
It specifies the cabling structure and minimum configuration, the interfaces at the outlets, channel and link performance, implementation options, component performance and conformance. Safety and EMC requirements are outside its scope.
Cabling between homes, such as campus or backbone cabling in a block of flats, is covered by other standards such as ISO/IEC 11801-1 or IEC 60728. Building services cabling in homes, such as controls and sensors, is covered by ISO/IEC 11801-6.
Structure of home cabling
The cabling uses a star topology from a distributor out to the outlets. Bus topologies are outside the standard.
| Functional element | Role |
|---|---|
| Primary home distributor (PHD) | Main distribution point in the home. Primary home cables run from here |
| Primary home cable | Cable from the PHD to an outlet or to an SHD |
| Secondary home distributor (SHD) | Optional. Adds flexibility, for example in a home over several floors |
| Secondary home cable | Optional. Cable from an SHD to an outlet |
| Application outlet | A telecommunications outlet (TO) for ICT or a broadcast outlet (BO) for BCT |
This gives two possible subsystems: primary home cabling and, where used, secondary home cabling. The standard also defines the external network interface (ENI), where the home cabling meets an access network, and the home network interface (HNI) for distributing TV, sound and interactive services.
Classes by medium
| Medium | Channel and link classes | Typical use |
|---|---|---|
| Balanced | Class D, E, EA, F, FA | ICT, for example Ethernet |
| Balanced | Class BCT-B | BCT applications over balanced cabling |
| Coaxial | Class BCT-C | BCT, for example TV and radio |
| Optical fibre | As ISO/IEC 11801-1 | ICT and BCT |
The performance limits for these classes come from ISO/IEC 11801-1. Annex A (informative) describes the use of baluns to carry TV and radio applications over balanced cabling.
Document structure
| Clause | Title |
|---|---|
| 1 to 3 | Scope, normative references, terms and abbreviations |
| 4 | Conformance |
| 5 | Structure of the generic cabling system |
| 6 | Channel performance requirements |
| 7 | Link performance requirements |
| 8 | Reference implementations |
| 9 | Cable requirements |
| 10 | Connecting hardware requirements |
| 11 | Cords |
| Annex A | Reference implementation of TV and radio applications: use of baluns |
Conformance requires the structure in Clause 5, channel performance to Clause 6 (with an option to conform through components to Clauses 9 to 11), outlet interfaces and connecting hardware to Clause 10, and compliance with ISO/IEC 14763-2 (installation planning) and ISO/IEC 30129 (bonding).
Changes from ISO/IEC 15018
- Re-structured to hold only the requirements specific to homes, with common requirements moved to ISO/IEC 11801-1
- Channel Class CCCB and its reference implementations deleted. This type of cabling is now treated as distributed building services in ISO/IEC 11801-6
- Optical fibre added as an implementation option alongside balanced and coaxial cabling
EN 50173-4: the European counterpart
In Europe, home cabling is covered by EN 50173-4, Information technology. Generic cabling systems. Part 4: Homes. It is prepared by CLC/TC 215. In the UK it is published as BS EN 50173-4.
| Item | Detail |
|---|---|
| Base edition | EN 50173-4:2018, approved by CENELEC on 2018-03-19 |
| Supersedes | EN 50173-4:2007+A1:2010+A2:2012 |
| Amendment | A1:2023, approved by CENELEC on 2023-10-25 |
| A1 latest national implementation (dop) | 2024-10-25 |
| A1 latest withdrawal of conflicting national standards (dow) | 2026-10-25 |
EN 50173-4 follows the same model as the ISO standard: balanced, optical fibre and coaxial cabling for ICT and BCT, primary and secondary home distributors, and TOs and BOs. Its scope covers a home that is one or more buildings or part of a building. The two documents are aligned but not identical. EN 50173-4 has its own annexes, including one on audio/video networks.
The 2018 edition added Category 8.1 and 8.2 balanced cabling components to support Classes I and II, added OM5 fibre, revised the functional elements, clarified how home cabling relates to network access cabling, introduced design objectives and cable sharing requirements, and removed CCCB cabling.
Building regulations in England
In England, Approved Document R Volume 1 deals with gigabit-ready physical infrastructure and gigabit connections for new dwellings. The gigabit connection requirement is subject to a cost cap. It is statutory guidance under the Building Regulations, separate from these cabling standards. It has its own page in this library.
What it means in practice
- Plan a star layout from a primary home distributor to each outlet. Add a secondary home distributor only where the layout needs it.
- Decide which outlets are TOs (ICT) and which are BOs (BCT), and which medium serves each.
- Specify balanced channels by ISO class, for example Class EA, with limits taken from ISO/IEC 11801-1.
- For TV and radio, specify Class BCT-C coaxial cabling, or Class BCT-B balanced cabling with baluns.
- In the UK and Europe, specifications commonly call up BS EN 50173-4. Check which edition and amendment the specification calls up.
- Use ISO/IEC 11801-6 for building services cabling in the home, not this part.