As satellite ground segment architectures evolve to support higher bandwidths, multi-orbit networks and greater operational flexibility, traditional analog intermediate frequency (IF) distribution is becoming a constraint. Digitization enables scalable, packet-based transport of IF signals, but without common interfaces, it risks recreating proprietary lock-in within digital architectures. The Digital IF Interoperability (DIFI) standard addresses this challenge by defining vendor-agnostic interfaces for digitized IF data and associated metadata. This article provides an engineering overview of DIFI, including its protocol structure, Information Classes and packet types used to transport RF data across IP networks. Key system design considerations such as Ethernet capacity planning, timing synchronization, flow control and link establishment are examined, together with the role of interoperability testing and PlugFest validation. Practical migration strategies for hybrid analog-digital ground segment architectures are also discussed.
