Research And Implementation Of Incentive Tree Mechanism For Nobile Crowd Sensing

As a new sensing means in Internet of Things,mobile crowd sensing has been widely focused in both academia and industry by using a large number of ordinary users' mobile devices to achieve large-scale data collection.It is critical to design effective incentive mechanisms to achieve required performance for mobile crowd sensing applications which require extensive user engagement.Most of the existing incentive mechanisms assume that users already know the sensing task.In contrast,incentive tree mechanisms not only motivate users to participate in sensing tasks,but also encourage users to diffuse task messages and solicit other users to join in,so that they are applicable to many scenarios where users do not know the sensing tasks.However,the existing incentive tree mechanisms have many problems such as lack of budget constraint,being vulnerable to sybil attack,single incentive strategy and lack of actual scene verification.In order to address the above problems,this paper focuses on the incentive tree mechanism under the budget constraint,improves and expands the classical single-beneficiary pachira tree based incentive mechanism.Firstly,we improve the root node adjustment strategy of the pachira tree to solve the budget inconsistency issue.Secondly,we propose some strategies to expand the number of beneficiaries to break out the limitation of the single-beneficiary mode,and analyze how to choose an appropriate number of beneficiaries in different application scenarios.Meanwhile,we theoretically proved that our proposed extensive pachira tree based incentive mechanism can satisfy six important properties,including continuing contribution incentive,continuing solicitation incentive,reward proportional to contribution,unprofitable solicitor bypassing,unprofitable sybil attack,and budget consistency,so as to ensure that the incentive mechanism is fair,honest and reasonable.Finally,a simulation platform and a real application system based on treasure hunting game are designed and implemented respectively.By analyzing the different incentive strategies of the extensive pachira tree based incentive mechanism,we verify their performance in different scenarios and provide important theoretical guidance for the practical application of incentive tree mechanisms.