Stable Task Assignment For Mobile Crowdsensing With Budget Constraint

With the continuous development of mobile smart devices and their sensing capabilities,mobile crowdsensing has received considerable attention.In mobile crowdsensing,it is a challenge to assign tasks to appropriate mobile users.Existing task allocation mechanisms mainly aim at optimizing the global system performance,while ignoring the personal preferences of individual crowdsensing tasks and mobile users.Nevertheless,in an open crowdsensing system,a task assignment is prone to be unstable if mobile users or tasks have incentives to deviate from the global assignment,and seek for alternative choices to improve their own utilities.Besides that,in order to improve the competitiveness of task matching,the rational mobile users might choose to dynamically adjust their payments,and even change their service quality for tasks,which however,brings new challenges in achieving the stability.To address these issues,this thesis carries out a study on task matching in mobile crowdsensing,so as to ensure the stability of task allocation and improve system performance while optimizing task utility.The main work and research results of this thesis are as follows:1.Considering the budget constraints of tasks,this thesis constructs a distributed many-tomany matching model,and designs a task assignment based on stable matching.Mobile users can dynamically adjust their payment according to the matching results.It is proved that the designed algorithm achieves several desirable properties including stability and convergency.It is also proved that the designed scheme achieves at least half of the optimal system efficiency when each smartphone provides homogeneous service quality.Finally,simulation results confirm the effectiveness of the designed scheme.2.On the basis of the above model,this thesis designs a service quality and payment mixture adjustable algorithm to allocate the tasks to the users.This algorithm not only allows the mobile users to adjust the price of the task adaptively,but also allows the mobile users to change their service quality in the process of task assignment,so that mobile users can improve the success rate of matching.It can be proved that the designed assignment algorithm can converge in finite time and produce a stable matching result.At the same time,this thesis explores how mobile users can determine the amount of service quality increase and the amount of price increase to improve competitiveness.Finally,simulation results show the effectiveness of the designed scheme.