LTE offloading: When 3GPP policies are just enough

We investigate the effectiveness of the 3GPP offloading policy framework, called Access Network Discovery Selection Function (ANDSF). We consider geographical areas where both LTE and WiFi are available and present a model describing multi-RAT networks as visible by the operator, as well as the offloading policy rules that apply to them. Our model captures user behavior and allows us to express any 3GPP policy in a compact and convenient way. We use the model to develop a dynamic offloading scheme, which is fully compatible with 3GPP specifications and dynamically adapts to changing traffic patterns. We analyse it in a typical two-tier 3GPP scenario, comparing its performance to those of three alternate offloading strategies. We also investigate the effectiveness for data offloading of the current and proposed features of 3GPP ANDSF.