Network state motivated traffic offloading scheme in heterogeneous networks

Due to the severe traffic overload in wireless networks, offloading traffic to other networks is envisioned as a promising solution. However, since networks are dynamic, they can not accurately determine when and how much traffic to offload. To address the problem, this paper proposes a practical network state motivated traffic offloading scheme for two-tier heterogeneous networks, where users connect to the base station with the highest biased received signal strength. We derive the congestion probability of macro base station (MBS) in closed-form and introduce the Traffic Offloading Region (TOR). According to the location of network state in TOR, network can get the appropriate time to offload and the amount of offloaded traffic of MBS. To guide practical traffic offloading, our scheme obtains the association bias that can offload desired amount of traffic when base stations follow Poisson point process. Finally, simulation results are provided to validate our scheme.