eCPRI

eCPRI, or enhanced Common Public Radio Interface, is a packet-based fronthaul protocol that transports baseband data between distributed radio units (RRUs) and centralized processing units (DUs or BBUs) in mobile networks. It is an evolution of the legacy CPRI standard, designed to enable fronthaul over Ethernet and IP networks rather than a fixed-rate serial link.

Operation and features: eCPRI separates the user plane, which carries digitized baseband data, from the control plane, which handles management and signaling. It defines a lightweight payload and framing scheme that can be carried inside standard Ethernet frames, supports multiple data-rate options, and enables multiplexing of several fronthaul streams over a single link. The protocol supports QoS and timing synchronization via mechanisms such as IEEE 1588 Precision Time Protocol (PTP) and related timing methods.

Relation to CPRI and impact: Compared with traditional CPRI, eCPRI is packet-based and software-friendly, allowing better scalability and utilization of general-purpose Ethernet networks. It supports flexible radio access network architectures, including centralization and disaggregation of baseband processing, and is compatible with open interface initiatives that seek multi-vendor interoperability.

Industry context: eCPRI has been standardized by the CPRI Alliance as a successor to CPRI and is widely cited in 4G and 5G fronthaul deployments. It is often referenced in discussions on fronthaul options alongside other Ethernet-based approaches and open fronthaul initiatives.