WARP-5 explained for the Interested Reader

For non-scientists this project page may raise different questions about WARP-5. In a try to answer them without scientific and technical terminology, the following sections address the most important questions that may have been raised by the interested reader. In case your interest did not get satisfied, feel free to contact the principal investigator for further information.

Why Broadband and how does it enable “Quintuple-Play”?

First of all, what is broadband? It is some kind of buzzword everyone hears and sees in advertisements. The term “broadband” refers in principle to a concept that allows us to squeeze a large number of communication links over a single physical channel. Imagine that you have a road with a single lane so that just one car can move, without any possibility for overtaking. This would be the case of a narrowband channel, which is limited in its throughput. Now, broadband would simply means that this road is widened to a highway, which as such can handle many cars to drive in parallel in a more flexible way, including also the possibility to have different “classes” of traffic, e.g. slower busses or lorries and faster cars, without being restricted too much by each other.
In the ICT world, DSL is a good example for broadband transmission over a narrow communication channel, namely the telephone wire. Here, one uses a sophisticated data imprinting scheme to transmit bit rates of 10 Mb/s or more over a spectrally narrow channel with a bandwidth of around 3-4 kHz. In photonics research, we go one step farther and speak about data rates of 1 Gb/s or more when referring to broadband access networks. WARP-5 investigates therefore how to migrate from nowadays rather slow DSL data rates of 10 Mb/s towards a sustainable bandwidth of up to 10 Gb/s – without sharing this rather high throughput with other users. This 1000-fold improvement will enable the deployment of novel quintuple-play services, including telephony, internet, 3D high definition video-on-demand, mobile broadband services and services related to smart houses such as remote control or tele-medicine, in a trusted and secure network infrastructure. As a representative example: The high data rate enables the content provider to "send" an entire DVD in just a few seconds.
Although people do no often see the necessity for such high data rates, the past has shown that the rollout of new ICT technology has not only fulfilled the increasing demands of current applications, but it has also enabled the creation of new services, especially related with multimedia applications. Broadband penetration is especially important in rural areas that still lag behind when it comes to a modern ICT infrastructure. By bridging this “digital divide” between urban and rural territories, even the outermost areas are stimulated by providing new business opportunities and novel services for the inhabitants.

Why Optics?

…simply because optics provide a better performance than electronics. An important fact is that the particles of light, the so-called photons, are much more “robust” for communications than their electrical counterparts, the electrons. It is possible to transmit ~10.000-times more data over a single optical fibre compared to an electrical cable. At the moment, it is possible to transmit more then 100 Tb/s over a fibre as thin as a human hair. At the same time, it allows us to operate networks over much longer distances, e.g. more than 10.000 kilometers, and with much higher energy efficiency.
Photonic networks have already replaced traditional electronic networks since many years. However, up to now optics have not effectively penetrated “last mile” networks in Europe, where many internet users still rely on copper-based DSL connections. It is expected that during the next years optical fibre will be deployed either till the houses or close to them, so that higher throughputs in the Gb/s range can be delivered to all households. While the connection to the end-user equipment (such as computers, TV-sets, or other devices in a “smart” house) is still made via electrical cabling, the link to the rest of the world (i.e. the “cloud”) is then established via a single optical fibre. The image below shows an optical transceiver under the microscope. It takes local electrical data to transmit it to the outside world via a thin optical fibre. At the same time, it receives photons, in this case at the red wavelength, carrying a high-speed data signal to forward it electrically to other electronic ICT equipment.

What are the goals of WARP-5 and how does its outcome look like?

The goal is to provide the scientific background for an economically and ecologically viable solution for a next-generation “internet modem”. As such, a household will gain access to the global network with a 10 Gb/s connection, meaning that novel services such as 3D television on-demand will become reality. Further, a “true” broadband connection of the 21st century provides new business opportunities to enterprises located in rural areas.
At the same time, WARP-5 will extend the reach where data communication can be established. In case of copper-based DSL for example, broadband coverage is only given for a short radius (e.g. a few kilometers) around the next point-of-presence of the telecom operator. Through the advantageous use of photonics, this reach will be increased to more than 100 kilometers, which not only results in a better coverage of rural territories but also allows to centralize field equipment to a single site, e.g. amplifiers and transponders are moved out of every smaller city to be effectively concentrated at centralised sites, e.g. in the capitals of a country’s provinces. For the given case of Vienna, this would mean that Lower Austria could be entirely operated from the city without active electrical equipment in the field.
To reach all these objectives, WARP-5 applies the concept of coherent optical communications, which allows to access the properties of transmitted lightwaves in a much better way than in conventional schemes. Note that recent progress in photonics research has already provided confidence that complex electronic and also optical subsystems can be integrated into a single optoelectronic chip. This means that the future internet modem will come as miniaturized chip, which will not be larger than a fingernail.