ISDN services began in April 1988 and along with expectations for the development of more advanced telecommunication services, there is greater need for assuring their interconnectivity.

In order to realize advanced and diverse interconnective telecommunication services which make use of the advantages of advanced telecommunication networks such as ISDN, it has become increasingly important to proceed while incorporating the following factors: understanding user needs, realizing more advanced networks, developing new terminals, establishing technological standards, assuring interconnectivity of communication systems to name a few.

With this understanding, the Ministry of Public Management, Home Affairs, Posts and Telecommunications established the HATS Conference in August 1988 with the objective of users, manufacturers and telecommunications carriers working together to gain an understanding of the problems surrounding the above mentioned issues, as well as to provide a setting for the exchange of information and to promote the smooth dissemination of advanced telecommunication services such as ISDN.