The HATS Conference (Harmonization of Advanced Telecommunication Systems) was established in 1988 by MPT, now the Ministry of Internal Affairs and Communications (MIC). Its objective is to confirm the interoperability of advanced telecommunications equipment and ICT systems connecting to telecommunication networks. Users, manufacturers and telecommunication carriers exchange information, work in cooperation to discover interoperability issues, deliberate testing methodologies, and conduct the interoperability tests with the relevant parties providing the actual equipment. This framework promotes the smooth dissemination of ICT systems and/or services and solutions.

  For each round of interoperability tests mentioned above, the HATS Conference establishes a guideline for the target equipment as well as relevant standards and recommendations. Based on this guideline, multiple manufacturers interconnect their devices and/or customer premises equipment via the network to test and confirm interoperability.

  Such HATS activities are contributing to the global community of telecommunications as well as internet societies. Through the HATS interoperability tests, ambiguous descriptions used in standards/recommendations, which was the cause of many interoperability issues, have been identified and submitted to the Telecommunication Technology Committee (TTC) in Japan which has a role of upstreming telecoummnication standards/recommendations, which in turn, provides the information as feedback to the International Telecommunication Union (ITU).

  When the HATS Conference was established, interoperability tests connected equipment via ISDN, but since then, the scope has grown to cover equipment designed for LAN and Internet connectivity, as well as multimedia terminals. Today, the scope includes equipment which connects to the Next Generation Network (NGN).