The Common Public Radio Interface (CPRI) is an industry cooperation aimed at defining a publicly available specification for the key internal interface of radio base stations between the Radio Equipment Control (REC) and the Radio Equipment (RE). The parties cooperating to define the specification are Ericsson AB, Huawei
Technologies Co. Ltd, NEC Corporation, Nortel Networks Ltd, Alcatel Lucent and Nokia Siemens Networks
GmbH & Co. KG.
Motivation for CPRI:
The CPRI specification enables flexible and efficient product differentiation for radio base stations and independent technology evolution for Radio Equipment (RE) and Radio Equipment Control (REC).
Scope of Specification:
The necessary items for transport, connectivity and control are included in the specification. This includes
User Plane data, Control and Management Plane transport mechanisms, and means for synchronization.
A focus has been put on hardware dependent layers (layer 1 and layer 2). This ensures independent technology evolution (on both sides of the interface), with a limited need for hardware adaptation. In addition, product differentiation in terms of functionality, management, and characteristics is not limited.
With a clear focus on layer 1 and layer 2 the scope of the CPRI specification is restricted to the link interface only, which is basically a point to point interface. Such a link shall have all the features necessary to enable a simple and robust usage of any given REC/RE network topology, including a direct interconnection of multiport
REs.
Redundancy mechanisms are not described in the CPRI specification, however all the necessary features to support redundancy, especially in system architectures providing redundant physical interconnections (e.g. rings) are