The Internet is expected to see a rapid growth in multimedia services in the next few years. Network traffic will increase dramatically for many different services, so it will be necessary to have high-speed broadband backbone networks capable of supporting wide-area coverage. Such networks are expected to be built on ATM technology. This paper describes the next-generation ATM switching node architecture for multimedia communications, the enhancement of system capability and functions, and improved system maintainability. The goal is an ATM switching system for Multimedia Communications switching systems; we call it a Multimedia Handling Node for ATM (MHN-A). MHN-A is based on the concept of a unified architecture for circuit switching, packet switching, and ATM switching. Various functions are provided as options that can be economically added or deleted according to customers' requirements.