Dynamic user preference based group vertical handoffs in heterogeneous wireless networks: a non-cooperative game approach

When a group of Mobile Users (MUs) equipped with multi-mode or multi-home terminals, like passengers on board a bus or a train or a car, moves from one wireless network (WN) to another WN within a heterogeneous wireless network (HWN) environment, request vertical handoffs simultaneously, a group vertical handoff (GVHO) occurs. In literature, the prevailing research work is mainly concerned for forced GVHO with network aspects like signal strength and bandwidth etc. while in reality the user initiated GVHO with the user aspects like price, power consumption and velocity etc. along with their respective user preferences is more important for performing vertical handoffs in HWNs. In user initiated GVHO, selection of the mutually best WN-MU pair which can maximise network revenue of constituent WN as well as user satisfaction of MU in a group while minimising the simultaneous selection of a WN by multiple MU of the group is a challenging problem. This paper proposes a GVHO decision model based on non-cooperative game which utilizes multiple handoff decision attributes and their respective user preferences calculated dynamically on real-time basis as the game strategies to select the best available WNs by group MUs at NASH equilibrium for vertical handoffs. The performance of the proposed model is evaluated in terms of number of GVHOs, price of anarchy and price of stability for both group of MUs and WNs. The simulation results show that the proposed model results in minimum number of GVHOs as compared to existing GVHO models and maximisation of user satisfaction and network revenue.