Sammendrag
While it is generally known that multi-frequency GNSS implies the coexistence of the satellite navigation signals with other users of the spectrum, the extent to which some of the signals may be impacted by shared spectrum allocations might be underappreciated. This paper presents top level observations from a multi-year international radio frequency interference (RFI) monitoring project covering all L-band signals with specific focus on the challenges facing the E6 band. The context of discussion of the RFI challenges to E6 and their potential mitigations is based on the assumption that most users will be non-authorized and have access to only the open data bearing signal component. In virtually all locations where the Advanced RFI Detection, Analysis and Alerting System (ARFIDAAS) monitoring stations were deployed, frequent disruption of the E6 band from systems such as RADARS or other authorized users of the spectrum was observed. In the presented paper, an effort is made to put the observations in the context of the expected use cases of the E6 signal, as well as the motivations of the other users of the spectrum and the options for coexistence from the point of view of the GNSS receiver.