Green Cellular Networks: A Survey, Some Research Issues and Challenges

Energy efficiency in cellular networks is a growing concern for cellular operators to not only maintain profitability, but also to reduce the overall environment effects. This emerging trend of achieving energy efficiency in cellular networks is motivating the standardization authorities and network operators to continuously explore future technologies in order to bring improvements in the entire network infrastructure. In this article, we present a brief survey of methods to improve the power efficiency of cellular networks, explore some research issues and challenges and suggest some techniques to enable an energy efficient or "green" cellular network. Since base stations consume a maximum portion of the total energy used in a cellular system, we will first provide a comprehensive survey on techniques to obtain energy savings in base stations. Next, we discuss how heterogeneous network deployment based on micro, pico and femto-cells can be used to achieve this goal. Since cognitive radio and cooperative relaying are undisputed future technologies in this regard, we propose a research vision to make these technologies more energy efficient. Lastly, we explore some broader perspectives in realizing a "green" cellular network technologyComment: 16 pages, 5 figures, 2 table

A link-quality-aware graph model for cognitive radio network routing topology management

Wireless communications is one of the fastest growing fields in the world; however this creates a problem since all wireless signals are fighting for the same limited amount spectrum in any given space. The underutilization of licensed spectrum has created a need for a new way to use it. Cognitive Radio Networks and Dynamic Spectrum Access are a solution to this problem. By opportunistically using spectrum, devices can gain access to more wireless bandwidth while not violating FCC regulations. The concepts of Cognitive Radio Networks and Dynamic Spectrum Access are very new topics and have yet to be fully explored. One of the current goals in this area is adapting existing concepts in networking algorithms to be aware of and to take advantage of a Dynamic Spectrum Access environment. Awareness and using cross-layer design enables opportunistic use of the spectrum and allows devices to take full advantage of the nature of the Dynamic Spectrum Access environment. This thesis explores some existing solutions to the Dynamic Spectrum Access problem, and uses them as inspiration to create a Link-quality-aware Graph Model for Cognitive Radio Network Routing Topology Management