Tell us a little about yourself. What does your job at Telefónica involve?
I have been with Telefónica for 25 years and my professional journey has taken me through different areas of the company.
Once the fibre optic rollout is complete, it is necessary to maximise network occupancy to increase revenue and profitability. In my position, I ensure that the company’s systems are running smoothly and in line with business needs.
In today’s fast-paced, ever-changing environment, companies in our sector need to leverage quick, data-driven decision-making. BI is therefore the ‘brain’ of the company, which must be fed with sufficient, reliable data at the necessary update rate so that the business can act with agility and responsibility.
What is fibre optics?
Fibre optics is a terrestrial transmission medium in which, instead of electrical impulses travelling as in traditional copper networks, light impulses travel through a dielectric medium made of silicon glass.
Although its use in residential environments is relatively recent, fibre optic communications have been used for a long time, especially by large communications operators and for trunk links, where high capacity is required.
At the end of the 2000s, fibre began to be deployed on a massive scale in our country, in FTTH mode. Its acronym, Fibre To The Home, indicates that this type of cable is laid to the customer’s home, allowing each customer to enjoy the excellent conditions offered by this means of transmission. Other solutions, which have been discarded or are in limited use in other countries, include deployment to the building (FTTB, Building) or to the neighbourhood (FTTN, Neighbourhood).
How does it work?
In very simple terms, the end that transmits the information injects pulses of light using a laser that points to a specific area, the centre of the fibre or core. Due to the characteristics of the medium and the construction process, the light ‘bounces’ when it reaches the outermost part of the fibre, confining the energy inside.
When it reaches the other end, a receiver picks up the light pulses and decodes them, reconstructing the original information.
This makes fibre optic transmission very efficient: it has very low power loss, high speed and low latency, and is not affected by interference, as it is a passive medium with no power supply.
An interesting fact: don’t expect to see light when you look at a fibre optic cable; in fact, it’s important that you don’t. The light travelling through the cable is not in the visible spectrum and, as it is so concentrated and powerful, it can damage the retina.
What are the advantages of this technology over similar technologies?
Our FTTH network offers a number of advantages over a copper network:
- Low losses. Communication (and megabytes) can travel much further than with the old ADSL, allowing excellent performance over 20 km. This favours the reduction of headends, as each one can serve customers much further away than the old copper exchanges.
- Passive Point-to-Multipoint network, simple to deploy. A passive network is one that does not require power at any point along the route; from the moment the fibre cable leaves the exchange, there are no active elements until it reaches the customer’s home. This technology also allows the signal from a single cable leaving the headend to be split and connected to up to 64 different customers, using customer premises equipment (HGU) to decrypt only the communication intended for us. Fewer incidents. It is a more reliable and interference-resistant technology, and is easier to maintain.
- It is more efficient, has lower consumption per port and reduces the carbon footprint.
There are other intermediate technologies, such as HFC (Hybrid Fiber Coaxial), which attempted to obtain ‘the best of both worlds’ by combining the good characteristics of fibre optics with existing copper technology, in this case the coaxial cables of the already deployed television distribution networks. Although they were competitive in the early stages, difficulties in their development and the cost of maintaining both networks have led to their use being reduced in favour of pure FTTH.
Focusing on our case at Telefónica Spain, all these reasons have led to the replacement of the traditional copper network with this technology. Copper served its purpose well and was able to provide service for 100 years, and I am sure that fibre will be able to exceed this figure by far.
What are the latest innovations in fibre optics?
In the residential segment, we find two fundamental innovations:
- XGS-PON: This is an evolution of the technology used in FTTH networks, enabling symmetrical speeds of 10 Gbps. To access it, the fibre operator has to upgrade the central equipment and also the equipment in the customer’s home.
- FTTR: This is a type of fibre specifically designed for use inside the home, turning it into a ‘mini FTTH network’, which Movistar has been offering in its portfolio for two years. This means that every room can be reached at the maximum contracted speed, thus avoiding the losses that occur with WiFi access, caused by signal loss when passing through walls and the sharing of the air medium between the different connected devices.
However, the degree of adoption is still unknown. The cost model and the real need for so much bandwidth in customer applications will define the penetration curves in the coming months.
What different types of fibre optics are there? What are the pros and cons of these types?
There are many types of fibre optics to suit different uses and scenarios where they are installed. If they are to be used for long distances, single-mode fibres will be used rather than multimode fibres, which are cheaper to manufacture but offer lower performance.
The fibre coating or cover also varies depending on where it is to be installed: from fire-resistant covers when installed indoors, self-supporting when mounted on poles, to rodent-resistant or even bullet-resistant when installed in hunting areas, the combinations are numerous.
On the other hand, as we mentioned earlier, there is a new service designed to distribute fibre inside our homes. The technology here is different; this type of fibre optic is made with a plastic base instead of glass, and is called POF (Plastic Optic Fibre).
Although the operating principle is similar, this plastic base makes it ideal for this type of application, as it is very easy to install and more resistant to breakage than traditional fibre optics. Interestingly, it can be ‘deployed’ with a heat gun, similar to a silicone gun, usually along the skirting boards. Once installed, it is practically invisible.
Finally, a type of fibre that we may see in the coming years. Still in the laboratory and with limited testing in real environments, hollow core fibre is gaining momentum. By replacing the glass core with an empty space, light is propagated more quickly, with an estimated reduction in latency of around 30%. It also allows for greater power transmission, which is expected to increase the length covered between transmission equipment.
On the downside, the manufacturing process is complicated and costly. Its adoption will depend on whether economies of scale will allow costs to be reduced, but its initial use is expected to be in critical infrastructure, such as data centres, where distances are also more limited than in large-scale deployments.
Which Telefónica employees would you nominate for this interview as excellent in their work?
I would nominate Javier Tur Cano and Gabriel Requena Durán.
