In order to maintain seamless communication and quality of service (QoS) for mobile applications, a new and flexible mechanisms are needed. The first technique is the use of vertical handover to maintain QoS through multiple interfaces. Modern architectures use handover to move connections to a better network when required. The server localisation is the second facility that can be developed to move services closer to the user as they move around. In this paper, these two options are explored in detail. In addition, a reactive network slicing concept is introduced which is used as the measured service rate in the proposed system. Using this framework, mobile users can make decisions to select whether to stay connected using the current network, do a vertical handover to a neighbouring network or request that the service be migrated closer to the user. An analytical model is presented and a decision table developed to explore these options.