Bandwidth refers to the frequency range covered by a specific technology. When it comes to data traffic and communications technologies, adding more frequencies means adding more information carriers, like adding more lanes to a busy highway. Internet traffic has exploded and will only continue to increase. With the support of the Marie Skłodowska-Curie Actions programme, the WON project is establishing and coordinating the activities of the Wideband Optical Networks (WON) European Training Network. It will train 14 early stage researchers in areas including photonics, digital signal processing, system modelling and network and control management, enhancing European competitiveness in this socioeconomically critical field.