Energy- and Time-Efficient Tasks Offloading and Dynamic Resource Allocation in Smart City

With the rapid development of information society, people urgently need to develop the traditional city model into a highly information and intelligent city model to meet the needs of users and the development of sociality. Therefore, people put forward a new concept called smart city. Correspondingly, as a concept of multiple intelligence, smart city has also got an excellent opportunity for development in terms of service performance with the emergence of mobile cloud computing, mobile edge computing and some new technologies. Specifically, based on the concept of mobile edge computing, there are many edge servers are installed close to users in smart city, and users can offload tasks to these edge servers to obtain better services by computation offloading. However, in the further development process of this new concept, smart city still need to face some problems in terms of energy consumption, latency, resource utilization and even in privacy security. These issues will affect the service quality of smart city seriously. In view of this, the optimization problem of smart city is studied in this paper. Considering the diversity and large number of users, the tasks generated are defined as a series of complex tasks composed of time-constrained workflows and concurrent constrained workflows, and an energy- and time-efficient method with privacy preservation is proposed, which can optimize the energy consumption, time consumption and the resource of the system jointly. Experimental results have shown that the proposed method can reduce the energy consumption and improve resource utilization for the system effectively.