Bart Lannoo

Dynamic Resource Provisioning for Energy Efficiency in Wireless Access Networks: A Survey and an Outlook

Traditionally, energy efficiency aspects have been included in the wireless access network design space only in the context of power control aimed at interference mitigation and for the increase of the terminal battery lifetime. Energy consumption of network components has also, for a long time, not been considered an issue, neither in equipment design nor in network planning and management. However, in recent years, with the user demand increasing at nearly exponential pace and margins rapidly shrinking, concerns about energy efficiency have been raised, with the objective of reducing network operational costs (not to mention the environmental issues). Installing more energy-efficient hardware does not seem to fully solve the problem, since wireless access networks are almost invariably (over)provisioned with respect to the peak user demand. This means that efficient resource management schemes, which are capable of controlling how much of the network infrastructure is actually needed and which parts can be temporarily powered off to save energy, can be extremely effective and provide quite large cost reductions. Considering that most of the energy in wireless access networks is consumed in the radio part, dynamic provisioning of wireless access network resources is crucial to achieving energy-efficient operation. The consensus on this approach in the research community has been wide in the last few years, and a large number of solutions have been proposed. In this paper, we survey the most important proposals, considering the two most common wireless access technologies, namely, cellular and WLAN. The main features of the proposed solutions are analyzed and compared, with an outlook on their applicability in typical network scenarios that also include cooperation between both access technologies. Moreover, we provide an overview of the practical implementation aspects that must be addressed to achieve truly energy-efficient wireless access networks, including current standardization work, and trends in the development of energy-efficient hardware.

Parking sensor network: Economic feasibility study of parking sensors in a city environment is well

Wireless sensor networks (WSNs) have a variety of purposes. They are mainly used for monitoring environmental factors, like CO2 concentrations, temperature and humidity. Other applications of sensor networks focus on detecting traffic parameters, e.g. passenger flows, damaged roads and traffic lights. This paper extends the current research with an economic feasibility of a real case, deploying a wireless parking sensor network in a city environment. After modeling the service adoption, the costs and revenues of the project are estimated. The static Net Present Value (NPV) case is already highly profitable. However, like most network projects, WSNs offer many flexibility options. A business case is extended with a Real Option Analysis (ROA), in order to quantify the value of the learning possibilities. We show that the built-in flexibility in the original project raises the attractiveness of the project.