Utility-Equilibrium Oriented Multi-Device Cooperation Mechanism

Nowadays, a lot of researches have been widely conducted on the background of ubiquitous computing. In the ubiquitous networks, users can access ubiquitous services in a "wherever, whatever, whenever" manner. With the rapid development of the information society, a large number of heterogeneous devices spring up in the surroundings of users, which dramatically expands the stub of the network. These devices can make up intelligent environments by inter-connection and cooperation to enhance the ability of distributed services. In ubiquitous environments, devices are heterogeneous. Thus, for an individual ubiquitous service, in order to content the user’s demands to the most, how to choose cooperative devices to form a high-performance device set in the process of service composition turns out to be a research issue. Typically, multiple users may request for the ubiquitous services simultaneously. Effective multi-device cooperation can’t just guarantee quality of one ubiquitous service with reducing the quality of others. In multi-users and multi-services circumstances, another key point to be solved is how to evaluate and ensure every user’s benefit utility.Mobile Ad hoc network, as a typical networking mode of the ubiquitous stub networks, has many unique advantages, such as dynamic topology, fixed infrastructure independent, organizing network rapidly and flexibry, distributed control, limited node computing capability and so on. With the rapid development of ubiquitous computing, mobile devices are continuously integrated into ubiquitous environments to provide more rich resources for complicated ubiquitous services, especially in MANET. Because mobile devices have limitations of small memory, weak CPU processing ability and using battery power, how to effectively and reasonably arrange limited resources while ensuring utilities of multi-users and devices becomes very essential.The main contributions of this paper are as follows:(1) To achieve the effective cooperation among heterogeneous devices and deal with the conflict problem of multi-user utilities allocation caused by the limited network resources and device capabilities, a utility-equilibrium oriented device cooperation mechanism for multi-user is proposed in this paper. Firstly, based on the equilibrium index of relative entropy, the equilibrium service quality utility function is designed, and furthermore, the model of the Multiuser-Oriented Device Composition problem is established. Then, this paper proposes to use dimensionality reduction in order to produce an Equilibrium-based Device Composition algorithm. Finally, the simulation is implemented with C++programming and MATLAB. The results show that the proposed mechanism improves the equilibrium of multi-user by0.5%-20%and proves to perform well in balancing and ensuring each user’s utility under multi-service circumstance.(2) To solve the maximization and equilibrium issue of users’and devices’utilities under the resource constraints, the energy resource is attached price attribute from the perspective of economic concepts and a utility-equilibrium device cooperation mechanism for users and the network is proposed. Firstly, a model of Utility-oriented Resource Pricing for Users and Devices is built. Then a novel Generalized Lagrange based Resource Negotiation mechanism is proposed including the solution to two kinds of sub-problem models using Generalized Lagrange multiplier technique and the strategy of multi-round resource negotiation. At last, the experimental results demonstrate that the proposed mechanism is capable of optimizing the system utility and balancing the utilities of users and devices under the constraints of budget, response delay and energy resource.