Cell selection and resource allocation for sleep mode enabled femtocells with backhaul link constraint

Dense deployment of femtocells in urban regions has proved to be an effective solution to handle ever increasing mobile data demands. Cellular operators are now focusing on extending their network reachability in rural and remote areas by exploring the possibilities for cost effective femtocell deployments. Considering operators' perspective, capital expenditure due to the deployment of femtocells and associated backhaul links is a major concern. Additionally, operational expenditure due to energy consumption in femtocell and backhaul links is another disquiet. Hence, it is of utmost interest to minimize the capital and operational expenditure to accelerate the rural and remote femtocell deployments. In this paper, we aim to reduce the energy consumption of femtocell deployments by suggesting an energy efficient cell selection scheme complemented by a resource allocation technique. For resource allocation, we suggest a spectrum and power allocation technique based on power spreading to maximize the spectrum efficiency and minimize the transmit power. Additionally, to save energy, we suggest Load Aware Sleep Strategy (LASS) for under-utilized femtocells using Renewal Reward Process. Finally, we propose Energy Efficient Cell Selection (EECS) scheme for mobile users association to femtocells which also incorporates the mobile users' Quality of Service (QoS) and backhaul link constraints into user association criteria. Obtained results show that our proposed framework for femtocell resource allocation and cell selection can facilitate operators to provide coverage in rural and remote environment in an energy efficient manner.