POMELO: A 4G Prototype Testbed to Demonstrate Scalable and Bandwidth Efficient Broadcast of GNSS Corrections

The precise positioning for mass-market optimal data dissemination demonstrator (POMELO) is the outcome of a collaboration led by GMV with Telespazio France (TPZ-F), GEOFLEX and Thales Alenia Space France (TAS-F) under a NAVISP EL1 programme funded by the European Space Agency (ESA). The project objective was to explore the feasibility of delivering broadcast real-time kinematic (RTK) and precise point positioning (PPP) corrections using communication protocols aligned with the third-generation partnership project (3GPP) standards to make high-accuracy positioning services accessible to massmarket users of the fourth and fifth generation networks (4G/5G). These positioning techniques are usually adopted by professional users and even though the global navigation satellite system (GNSS) industry has embarked on the path to high-precision GNSS at low costs and low power consumption, the currently available dissemination techniques are still not affordable on a large scale, requiring either high-cost equipment and large investments or significant challenges especially when there is the need to extend the service to a very large amount of users. A possible way forward would be to allow the use of terrestrial wireless networks to broadcast multi-GNSS augmentation services in real-time at a low cost. This would require the mobile network operators to transfer data based on a ‘Send-To-All’ type of dissemination. The main achievement of the POMELO project is the implementation of the first testbed able to demonstrate that it is possible to exploit a part of the wireless network resources available to host high-accuracy GNSS assistance data and broadcast it through cellular signals. Although some limitations still need to be addressed, this achievement represents a significant step forward in making precise GNSS data accessible to a broader range of users through existing communication infrastructures and protocols. The implementation of this service potentially enables any users to adopt high-accuracy positioning techniques through an affordable service.