QoS-splitting for RAT Selection in Heterogeneous Networks

Today, heterogeneous network is becoming more and more crowded with a huge increment of users and their diverse requirements. These increasing requirements turn to be a big challenge to traditional Quality of Service (QoS) based resource management. Fortunately, the emergence of mobile terminals with multiple radio-access technologies (RATs) and multi-homing functionalities ensures users to feasibly access to more than one networks. Case exists when a single network cannot meet the user’s QoS requirement. To this end, we propose the concept of “QoS-splitting”. When no single channel can satisfy the QoS requirement, user can connect to another network simultaneously to share his load. Our system model is originated from the QoS satisfaction game, but with split demand. To approach the Nash Equilibrium, we propose a satisfaction-guaranteed better reply (SBR) algorithm. The convergence property of SBR is proved by using quasi-potential function. Specifically, when given a complete interference graph, preference-based matching (PM) algorithm is proposed to obtain a more stable equilibrium. In this case, users can approach a unique pure Nash equilibrium. Simulation results illustrate the efficiency of SBR and PM algorithms. Moreover, it shows that more crowded the system is, more improvement in the number of satisfied users and social welfare will be achieved.