Low-Cost PRS Receiver for Positioning and Timing Enabled by an Assistance Server
Wolfgang Kogler, Jan Wendel
Many applications require a trustworthy, spoofing-resistant navigation and timing solution like the one provided by the Galileo Public Regulated Service (PRS). However, the use of Galileo PRS signals adds complexity to a PRS receiver, making it more difficult to use for public authorities and organisations such as the police and fire brigades. This idea describes the architecture of a network-based PRS receiver that accounts for all of the security aspects of the Galileo PRS system. The system consists of a secured assistance server and user terminals. The server broadcasts historical and therefore unclassified PRN code chip sequences to the user terminals via a secure communication link, which is also used for access control. This data allows the user receiver to generate suitable replicas for correlation with the PRS signal received, which facilitates Performance Verification Test (PVT) calculation when combined with the navigation message (also provided). This concept significantly reduces the complexity of the user terminals, which do not require their own security module or PRS key handling, while fulfilling the security requirements of a secure server and a secure communication link. As a further advantage, the required communication bandwidth does not grow with the number of user terminals. This receiver will facilitate broader use of PRS in the realm of public security. This could include the police, fire brigades, and emergency rescue teams while still allowing for controlled denial of individual users and entire networks.
“Since the impressive ESNC ceremony and the surprise of being named the overall winner, we have received numerous felicitations from academia, other industry entities, and governmental organisations. Some of them have expressed interest in a future cooperation. Currently, we are developing a strategy for implementing our idea within Airbus, and we working closely with the relevant authorities to identify the next steps. In general, it has been widely recognised that the server-assisted PRS receiver architecture we presented at ESNC 2014 could enable a quick, cost-effective implementation of the PRS service within Germany and beyond.”