ATM technology can integrate not only new multimedia services but also existing services such as plain old telephone services (POTS) and narrow-band ISDN (N-ISDN) services. We developed ATM subscriber line interface circuits (ATM-SLIC), which can accommodate POTS or N-ISDN subscribers, and a trial ATM access switching system using the ATM-SLICs. This paper proposes embedded trunk functions, a message-type signaling transfer method, an economical ATM interface structure, and a cell-based system control method. Moreover, it shows the main characteristics and efficiency of these proposals in terms of experimental data.