The ED-54 minimum operational performance requirements (MOPR) for distance measuring equipment (DME) interrogators was published in December 1986 and is still in use in 2025. The standard does not reflect the technological evolution of equipment whose performance is higher today than the minimum required by the MOPS.

Recognizing those advances will allow the DME range data consumers, in particular Flight Management Systems (FMS), to take benefit and credit from the better DME performance. This is of particular importance in the context of widespread GNSS interference and urgent need of ensuring that DME is an adequate means to elaborate RNAV and RNP navigation solutions. Adapting the MOPS requirement to today’s capabilities will translate in better adequacy of DME navigation for more stringent navigation specifications in terms of accuracy, integrity, and continuity. This approach will support the recommendations identified in the ICAO Assembly Resolution A41-8C to reinforce CNS system resilience to GNSS interference.

The creation of WG-134 will also give the opportunity to explore options to facilitate future improvements to DME, in particular regarding spectrum efficiency, like enhanced DME (eDME) currently under study in SESAR Making I-CNSS a Reality (MIAR) project WP3.3.

Stakeholders are avionics equipment manufacturers, ground transponder manufacturers, aircraft manufacturers, aviation authorities, ATM/ANS providers.