Due to the restrict of the single frequency technical structure, the Satellite Based Augmentation System (SBAS) do not meet the requirements of the CAT-I. To satisfy the requirements of aviation users for accuracy, integrity, continuity and availability, all of the SBASs are transmitting from single frequency single constellation to dual-frequency multi-constellation (DFMC). All the SBAS service providers create a working group to make the definition document and the interface control document of the DFMC SBAS. Meanwhile, all of the SBASs are also preparing the upgrades of the ground stations, and plan to provide the DFMC SBAS service around 2020. In order to promote the internationalization process of the BeiDou Satellite Based Augmentation System, the international coordination of GEO frequencies and international standard setting have already been started.