Abstract: Public officials have the responsibility of giving public directions and issuing warnings in the event of an emergency. Traditionally, siren systems, radio and television have been used as the primary means for issuing public alerts. Recently, there has been increased interest in evaluating the Internet's suitability for issuing public alerts during times of emergency. This paper presents a Canadian experience with the design and trials of an Internet-based emergency public alerting system (IPAS). We discuss a proposed set of requirements and system architecture. We also include a discussion of the challenges to be overcome in developing such systems and report on experiments and field trials using the IPAS system developed during this project. Our objective is to provide motivation for future research and industry work in this area.