ITU home networking standards bring coax and phoneline up to fibre speed
The latest amendments to ITU G.hn family of standards enable home networks to achieve speeds up to 10 Gbit/s over coaxial cable and 5 Gbit/s over phoneline.
The G.hn family was developed to solve home networking challenges over any type of wiring available in a residential environment, typically powerline, coaxial cable and phoneline.
Industry was quick to adopt G.hn as a solution for broadband access. It was particularly attractive in scenarios were homes were already connected by legacy phonelines and where installing new optical fibre was prohibitively expensive.
The early version of G.hn used in broadband access applications achieved throughput up to 1.7 Gbit/s over coaxial cable or phoneline.
This throughput was comparable to the throughput of the fibre access systems of the time, but fibre technologies have advanced considerably since.
The higher speeds enabled by the amendments will maintain G.hn’s position in the market as a competitive fibre-extension technology.
Features of the new physical layer
Achieving this level of G.hn performance called for the development of a new physical layer. The new layer inherits the main features of the existing physical layer, but adds compelling new features:
- Higher transmission speeds: Using broader bandwidth (sometimes greater than 1 GHz), the new system enables home networks to achieve speeds up to 10 Gbit/s over coax and 5 Gbit/s over phoneline.
- Radiofrequency capabilities: The new system allows the coexistence with current coax technologies such as DOCSIS by moving the operating spectrum to higher frequencies.
- Use of Multi Level Coding (MLC): This coding scheme significantly reduces the complexity of the systems at such high speeds.
- New physical framing: The new framing provides for full-duplex behaviour in anticipation of the MAC layer updates planned for future amendments to G.hn.
The G.hn family of standards is under the responsibility of ITU’s working group for ‘technologies for in-premises networking and related access applications’ (Q18/15).
The group is building on the new base achieved by these amendments with the continued development of new features to improve G.hn’s support for fibre-extension applications.
For all ITU standards under development in Q18/15, see the Q18/15 work programme.
Learn more about ITU-T Study Group 15
The international standards developed by ITU-T Study Group 15 define networks, technologies and infrastructures for transport, access and home.
For all working groups (‘Questions’), see list of Questions and Rapporteurs.
To learn more about ITU-T Study Group 15, contact tsbsg15@itu.int.
