The 5G-driven public transport system had its first run crossing the Spanish-Portuguese border.
The Spanish government is offering an extra €116 million euros in funding for new R&D projects.
The companies have also agreed to share their findings with the GSMA and the wider industry.
Aircraft manufacturer Airbus says it will deploy its 5G private network in UK and Spain in the coming months.
Spain has announced plans to fund 5G infrastructure in areas with poor mobile data coverage.
The mobile operator says it successfully tested a surveillance system that included the use of drones in the Spanish port.
A new forecast based on data from the analyst firm Omdia uses operator coverage data to predict this growth in subscribers.
The operator aims to provide services in many villages, a move which it says will tackle the digital divide.
Spain’s Ministry of Economic Affairs and Digital Transformation (MINECO) says making this band available will serve as a national “stimulus for the implementation and development of 5G technology”.
Yoigo, which is operated by Masmovil, says its 5G network now reaches a total of 686 municipalities.