In this work, the B-TA(Broadband Terminal Adaptor) for telephone is designed and implemented which performes the AAL type 1 protocol. This device is intended to be attached to B-NT2 and the information is exchanged in a form of 53 byte long ATM cell. The implementation has been done on IBM PC with the operating system of MS-DOS. The hardware of the system consists of subscriber loop interface module, PCM codec module, and receiver and transmitter stage. The receiver and transmitter have two separate buffers for voice and signalling data. The trasmitter takes voice samples from the voice buffer and signalling data from the signalling buffer and then transmits them. The receiver is always ready to receive the cells which are delivered through the B-NT2. The software consists of three routines. They are initialization routine, handset interrupt routine which begins when the handset state is changed, and receiver interrupt routine which starts when the receiver has received a signalling cell. The software has been designed for a simple end-to-end call control because it is assumed that there exists a permanent virtual circuit between the transmitter and receiver and that there are no intermediate network node such as B-NT2.
