Green Wireless Networking


The requirement of a huge improvement in capacity of next generation mobile communication systems due to the increasing volume of mobile data traffic leads to sustainability issues in terms of monetary costs and ecological footprint.
Network deployment and running costs are steadily rising due to the high energy consumption requirements of higher-capacity network equipment. This issue is becoming even more prominent due to the recent trend of increasing price of energy. Moreover, such a huge improvement in capacity is one of the main reasons behind the 10% yearly increase of ICT industry in greenhouse gases (GHG) emissions. Some projections indicate that next-generation Internet applications will require electricity in amounts that can’t be generated or transported to major metropolitan areas.

Energy saving is consequently a key issue to be addressed to have low-cost and eco-friendly next generation mobile networks.

It is recognized that most of the energy consumption of a mobile network comes from the wireless access (i.e. from base stations (BSs)). Our interest is then focused on the wireless access part of the system. The reference scenario is the Heterogeneous Network (HetNet), which intrinsically provide low energy consumption and reduced deployment costs, due to the low emitted power and the small form factor of the small BSs.

Proposed scenario: HetNets powered by renewable energy

Our proposal: HetNets powered by renewable energy

Our research activities are mainly devoted to:

Energy Efficiency

Network optimization for minimizing the power consumption of its elements. In particular, our research is focusing on:

  • analysis of the energy savings due to traffic offloading to small cells
  • design of (self-organizing) sleep mode enablers in BSs to save energy, while at the same time maintaining the required QoS
  • design of protocols and algorithms to decrease the power consumption of a BS when it is in sleep mode

Energy Sustainability

In our vision energy sustainability is the set of procedures, protocols, and algorithms aiming at sustaining traffic demands and meeting the quality of service requirements of mobile users by using only the amount of harvested energy by the network elements. In particular, our research is focusing on:

  • off-grid Radio Access Networks
  • feasibility study of a HetNet powered with renewable energy sources (RES)
  • modelling a BS powered by RES
  • radio resource management in a HetNet with RES

In order to properly integrate RES in mobile networks, we developed a methodology and a tool called SolarStat for modeling photovoltaic sources through stochastic Markov processes. The main outcomes of this work have been included in a technical report. The tool is an open source Matlab based code aimed at deriving simple but yet accurate stochastic Markov processes for the description of the energy scavenged by outdoor solar sources. It has been developed in collaboration with the Department of Information Engineering (DEI), University of Padova.