Analysis And Design Of Public Safety System In Middle Level City

China society is undertaking the rapid development period of urbanization and industrialization. At the same time, public safety and national security faces unprecedented challenges from various types of emergency incidents. Using modern technology to develop and design a public safety system with quick response capability to address these issues is a positive premise and guarantee, because most of our existing emergency handling system could not support the implementation of action plans at all levels.In this paper, the whole work of system analysis and design is deployed as following:first of all, a customer survey of existing main types of emergency systems is carried out to gather the system technical data and the city public safety problems and challenges faced; secondly, the new technology demand is analyzed by using OOAD methods; on the top of the analysis result, a general frame design of the new city public safety system is carried out with the characteristics of coordination emergency response.The general system frame design gives a clear indication to the following detail design of the emergency response command center and the subsystems related.The public safety system consists of four parts:the municipal government decision-making command center, the emergency response command center, the community integrated service command center and the backup command center, in which the emergency response command center is the core of the whole system, for it is responsible for receiving and dealing with daily alarms and handling the coordination with the other emergency response centers. Therefore, the analysis and design to the emergency response command center is the focus of this article.To emphasize on OOAD, a Domain Model of the city public safety is defined base on the relevant use cases description; After that, the the class diagram of emergency response is designed; Finally, it comes out of the sequence diagram of emergency call taking and alarm handling.Without the limitations of the old centralized system, the new public security system, which based on IP technology platform, can improve the emergency response mechanism cross different emergency handling sectors. At same time, the existing emergency response organizations will not be adjusted so much. So the newly established work flow of coordination emergency response is another important outcome of this paper.