"The present document defines low layer protocols aspects of the Open Radio equipment Interface (ORI). Low layer protocols are those terminating the ORI Link (a bi-directional interface in-between two directly-connected ORI ports@ on two ORI nodes). The Layer 1/2 protocols of CPRI Specification [1] have been used as a baseline for which further requirements for protocols up to and including the Layer 2 have been defined. See the associated specification ""Requirements for Open Radio equipment Interface"" [2] for more information on how the Low Layer protocols relate to other aspects of the ORI interface."