L.110 Lightweight Optical Cable Could Cut Rural FTTH Broadband Rollout Costs

The International Telecommunication Union (ITU-T) has granted first-stage approval (‘consent‘) to a new standard called L.110, which specifies a lightweight optical cable that could make it easier and cheaper for communities to roll-out their own FTTH/P ultrafast broadband networks.

At present a lot of the fibre optic cables that network operators deploy tend to require heavy machinery and highly skilled labour, although some UK community schemes like B4RN have already proven that you don’t need highly skilled labour for the entire build. Nevertheless the costs of optical cable installation can in certain cases rise to 70% to 80% of the entire CAPEX of the network.

On top of that this challenge is made even greater by the low densities of rural communities, where fibre deployments demand a disproportionate level of initial capital investment relative to the potential return on such investment. So anything that can bring the price tag down is helpful.

In keeping with that the ITU-T’s Study Group 15 has been designing a new international standard (L.110 – “Optical Fibre Cables for Direct Surface Application“), which is developed within the framework of Recommendation ITU-T L.1700 and “defines the shape of low-cost, terabit-capable optical cable that can be deployed on the ground’s surface with minimal expense and environmental impact.”

ITU-T L.1700 Description

This Supplement identifies a low cost sustainable optical cable solution for potential users of broadband digital services in remote or rural areas who are unlikely to gain such services. The solution would quickly and inclusively close the digital divide which is the key target of ITU Connect 2020 Agenda.

Matured and proven technologies are best integrated into affordable and reliable solutions suitable for non-skilled local people to install, operate, maintain and repair so that the system will become part of the community thus leading to better system maintenance and quicker damage recovery.

Best practice examples use lightweight, thin and robust optical cables and commodity-type media converters. The results of field trials are presented. The cost of such cables with their simple construction are estimated to be down to one tenth of the solution using conventional optical cables.

Apparently the design of the optical cable specified in L.110 “builds on lightweight submarine-cable technology, technology with its first deployments targeted towards lakes and wetlands and other submarine environments less hostile than our oceans“. Cables like this already exist and so we’d question the impact it will have, although telecoms operators certainly do prefer to use cables that follow a solid standard.

The new cable will of course still be waterproof, rodent-proof, highly durable against lateral pressure and fire resistant to a certain extent. The ITU-T envisages that it will enable local communities (i.e. non-skilled local labour) to take part in system deployment (e.g. shallow direct burying, aerial wiring, long-length suspension and even submerged application for changeable terrain), daily operations/maintenance and service provisioning.

The ITU believes that the new cable will be so light that that, as well as making it easier to deploy “shallowly by using hand spades and pickaxes” (depends how you define shallow, too shallow and you leave the cable exposed to damage), you might even be able to use helicopters: “Where cable laying through the ground is difficult, cable laying using a helicopter may be considered as a last resort,” said the ITU-T.

Some examples of the potential cost differences are included in the L.1700 framework, although take note that the full context for these case studies is not provided (every country has different rules, labour costs etc.).