On December 27, 2017, the press conference for celebrating the fifth anniversary of the BDS Full Operational Capability (FOC was held in the press conference hall of the State Council Information Office. China Satellite Navigation Office released the BeiDou Navigation Satellite System Signal Interface Control Document for B1C (Version 1.0) and B2a (Version 1.0) in both Chinese and English versions of, on the basis of the early-released beta version of the documents.
