Mobility state based flexible inter-frequency small cell discovery for heterogeneous networks

In this paper we consider the use of an energy efficient, mobility state based flexible scanning mechanism for the discovery of small cells deployed in a different carrier. The evaluated scheme considers the mobility state of the mobile terminal in a heterogeneous network scenario for determining the inter-frequency scanning rate and suspends inter-frequency measurements when the terminal is in high mobility state. The scheme is evaluated using mobility state estimation mechanisms and related enhancements, and is compared with inter-frequency cell search mechanism, currently defined for 3GPP LTE-Advanced systems. The evaluated mechanism can work autonomously within a mobile terminal or it could be implemented in a networkassisted manner. Utilization of available offloading opportunities as well as savings in terminal battery power consumption are numerically evaluated using an LTE-Advanced system setting. Results show that significant amounts of energy can be saved, while maximizing offloading potential and minimizing ping-pong connections and related signaling load.