The development and implementation of a single-line intelligent digital telephone answering unit on a personal computer

ThesisCommercial telephone answering machines are limited to some extent by one or more of the following factors: • limited facilities • difficult to upgrade • nonstandard telephone interfacing • expensive • lack of user-friendliness • lack of dialogue and intelligence The purpose of this study is to design an intelligent digital telephone system which will overcome as many of the above-mentioned problems as possible. The following features are proposed and will be discussed: The use of a commonly available, but powerful, personal computer processor and memory instead of the elementary and rigid processor and magnetic tape storage units of the commercial telephone answering machine . This allows the quick storage and retrieval of digitized messages, each with its individual name, time and date stamp. Using the personal computer's hardware and not duplicating the processor and memory units allows a more cost-effective system upgrade. Upgrades mainly consist of software changes and minor hardware changes. This means that an upgrade does not implicate a total hardware redesign. Standards as prescribed by the local switching network standards and the Department of Post and Telecommunications, apply to this design and are applicable for licensing of the product. It is evident that the cost of this project and design is kept minimal by not duplicating expensive components like the microprocessor and the memory units, although these are used in the design. In this respect upgrades are software orientated to further limit the costs. The personal computer is equipped with a display which allows the user to make easy selections in order to execute the required instructions or to obtain information by using the help functions. This real-time help function eliminates the need for a user manual. Dialogue between user and personal computer over the telephone network offers a simple method of delivering information without the need for any extra equipment such as modems, keyboards or display units. The software used on the personal computer is designed in such a way that the system is intelligent and capable of decision making. Communication from the public telephone network is possible by using the telephone keypad and Dual Tone Multifrequency (DTMF) signalling