P1AP

P1AP, short for P1 Application Protocol, is a protocol defined within O-RAN Alliance specifications for the P1 interface in modern radio access networks. The P1 interface connects non-Real-Time RICs (non-RT RIC) with Near-Real-Time RICs (near-RT RICs) and their associated RAN components, enabling policy-based closed-loop control across the RAN. P1AP provides the application-layer messaging used to configure, monitor, and enforce policies, as well as to convey events and actions between the non-RT RIC and near-RT RICs.

Typical functions of P1AP include establishing and maintaining P1 sessions, managing subscriptions to policy data and events, delivering policy decisions, reporting events, and issuing or acknowledging actions. The protocol supports asynchronous messaging and reliable delivery to support scalable management of RAN behavior. Security and integrity protections are provided by the transport layer defined for the P1 interface in the O-RAN specifications.

Standardization and usage: P1AP is part of the O-RAN Alliance specifications and is implemented by many vendors in RAN Intelligent Controller (RIC) deployments. It functions in concert with other O-RAN interfaces (such as A1 and E2) to enable policy-driven, closed-loop control across the RAN, contributing to dynamic resource management, QoS assurance, and network optimization in open, multi-vendor environments.

See also: O-RAN Alliance, P1 interface, Non-Real-Time RIC, Near-Real-Time RIC, A1 interface, E2 interface.