Energy-Efficient Inter-Frequency Small Cell Discovery Techniques for LTE-Advanced Heterogeneous Network Deployments

Heterogeneous network, or HetNet, deployments are one of the key enablers in providing ubiquitous coverage and capacity enhancements for LTE-Advanced networks. They play an important role in achieving high data rate and quality of service requirements defined for next generation wireless networks. In this article we evaluate various cell discovery techniques tailored for energy-efficient detection of small cells deployed in a carrier other than the serving macrocell. The presented schemes are evaluated using extensive system simulations conducted in a 3GPP LTE-Advanced HetNet scenario. Shortcomings of the currently standardized mechanism are analyzed, and advantages of the evaluated schemes are presented. Both the offloading opportunity utilization and savings in UE battery power consumption are analyzed. The results show that using the considered flexible, adaptive, and intelligent schemes for small cell discovery, significant UE power savings can be achieved with small loss in offloading - giving benefits both on system level as well as in user experience.