Energy Efficient Heterogeneous Cellular Networks

Abstract

Abstract-With the exponential increase in mobile internet traffic driven by a new generation of wireless devices, future cellular networks face a great challenge to meet this overwhelming demand of network capacity. At the same time, the demand for higher data rates and the ever-increasing number of wireless users led to rapid increases in power consumption and operating cost of cellular networks. One potential solution to address these issues is to overlay small cell networks with macrocell networks as a means to provide higher network capacity and better coverage. However, the dense and random deployment of small cells and their uncoordinated operation raise important questions about the energy efficiency implications of such multi-tier networks. Another technique to improve energy efficiency in cellular networks is to introduce active/sleep (on/off) modes in macrocell base stations. In this paper, we investigate the design and the associated tradeoffs of energy efficient cellular networks through the deployment of sleeping strategies and small cells. Using a stochastic geometry based model, we derive the success probability and energy efficiency in homogeneous macrocell (single-tier) and heterogeneous K-tier wireless networks under different sleeping policies. In addition, we formulate the power consumption minimization and energy efficiency maximization problems, and determine the optimal operating regimes for macrocell base stations. Numerical results confirm the effectiveness of switching off base stations in homogeneous macrocell networks. Nevertheless, the gains in terms of energy efficiency depend on the type of sleeping strategy used. In addition, the deployment of small cells generally leads to higher energy efficiency but this gain saturates as the density of small cells increases. In a nutshell, our proposed framework provides an essential understanding on the deployment of future green heterogeneous networks.

Interference Mitigation in CR-Enabled Heterogeneous Networks

“…Recently, stochastic geometry is applied to model crosstier interference in macro/femto two-tier networks [7], [22], [44], [65], [66] and K-tier general HetNet [67]- [70]. Please note that femto-BSs might be deployed independently by customers and thus be distributed randomly, which justifies the modeling of femto-BSs by PPP, whereby each point is distributed independently and uniformly at random.…”

Resource Allocation for Energy Efficiency in 5G Wireless Networks

“…With the increasing demand for green networking, recently research has been focused on approaches that reduce energy consumption [16,51,55]. It is critical to meet the required quality of service (QoS) for all users in the network [53] while managing the amount of utilized energy.…”

“…In fact, wireless cellular communications may face a significant challenge to satisfy the demand of higher data-rate communications at reduced greenhouse emission [16]. Hence, the energy efficiency (EE) performance is one of the major topics and will be attached to green communications in the deployment of 5G technology [16,32,51]. Nevertheless, the EE maximization problem usually results in a nonconvex program [5].…”

Optimal design of wireless networks for broadband access with minimum power consumption

“…In general, there are two different approaches for improving EE, namely, small-cell networks [7], [8] and large-scale or massive multiple-input multiple-output (MIMO) systems [9]- [12]. Both technologies can improve the area throughput and reduce the radiated power, but at the cost of deploying more hardware infrastructure.…”

“…A more practical problem formulation is to design a network that can provide a certain service performance with minimal power consumption. In this context, the work [8] minimizes the power consumption for different AP sleeping techniques in heterogeneous networks. In [15], a comparison between micro and macro cells with distributed and co-located antennas is done in terms of energy consumption.…”