Research On Collaborative Data Exchange And Task Execution Strategy In Mobile Ad Hoc Environment

With the continuous development of information technology,the traditional network is gradually extended to the mobile environment,in which wireless communication technology and the increase of the number of mobile devices play a key role.However,the requirements of quality of service(i.e.,delay,bandwidth and so on)become increasingly critical for the emerging network applications and mobile applications.As bringing people rich service experience,mobile network also brings new challenges.Fortunately,collaboration among mobile devices provides us a new way of solving the above problems.In this thesis,we study cooperative data exchange and cooperative task execution in mobile networks as follows:First,for cooperative data exchange model,we consider the time-critical applications.Such applications usually impose a deadline on the packet reception,i.e.,beyond which,the packet is useless or invalid.This thesis proposes a deadline-aware CDE scheme with network coding,so as to satisfy the quality of service.We first formulate the problem into an integer programming,and prove that it is NP-hard.For the case when the deadline of the packets is the same,we theoretically analyze the performance of two specific schemes with and without using linear network coding,respectively.We then design an efficient heuristic algorithm to solve the general problem,which is based on an auxiliary graph model.Next,for cooperative task execution model,we consider how to allocate data dependent tasks to mobile devices in mobile ad-hoc cloud.Generally,resources in the mobile device are limited,and data communication and task execution will consume its valuable resources.To this end,we use dynamic programming algorithm to reduce communication traffic among mobile devices,and use a bin packing algorithm to reduce the number of mobile devices participated in task execution.Finally,for above two models,simulation results show that cooperation among mobile devices plays an important role in reducing the traffic among devices and improving the quality of service.Furthermore,simulations also show the effectiveness of our proposed schemes compared with the existing algorithms.