Hide menu

Available internal projects

Evaluating the Energy Efficiency of Wireless Cellular Networks



The amount of wireless communications has doubled every 2.5 year, since the early 20th century. This incredible success story for wireless connectivity is expected to continue in the foreseeable future - spurred by smart phones, tablets, and new applications that haven't seen yet. To keep up with the rapidly increasing demand for wireless data, the telecommunication operators need to continuously evolve their existing network equipment and install new network infrastructure based on new technologies (e.g., 4G/LTE and the next generation: 5G).

Since the demand for wireless data traffic increases exponentially, the ambitious but necessary goal for future cellular networks is to handle a 1000x increase over the next 15 years. Whenever one observes a growth rate that is exponential, one has question whether it really can be sustained-initially from a technological and economical perspective, and in the long run from an ecological perspective. The global footprint from the information and communication technology (ICT) sector, in terms of CO2-equivalent emissions, has been estimated to be larger than that of the global aviation sector. It is thus important to greatly improve the energy efficiency of wireless networks so that 1000x more traffic can be accommodated without increasing the total energy consumption.

Problem statement

In this project, we will study the energy efficiency of future networks using the metric bit/Joule. It is computed as the area data throughput (in bit/s/km^2) divided by the area power consumption (Joule/s/km^2). We will implement a simple model of cellular networks, where the access points and user terminals are distributed randomly over a coverage area. We will use this simulation model to compute the energy efficiency of the network and study how it depends on the network characteristics; for example, density of access points, density of user terminals, transmission technology, power consumed by wireless transmissions, and power consumed by the hardware equipment. The goal is to understand the interplay between these system characteristics. We can also give quantitative results on how energy efficient different network deployments will be - is it possible to improve the energy efficiency by 1000x over today's cellular networks?


The student needs a strong background in mathematics (e.g., calculus and optimization), communication systems and good skills in Matlab programming.


[1] E. Björnson, E. Jorswieck, M. Debbah, B. Ottersten, Multi-Objective Signal Processing Optimization: The Way to Balance Conflicting Metrics in 5G Systems, IEEE Signal Processing Magazine, To Appear in Special Issue on Signal Processing for the 5G Revolution. [Online] //arxiv.org/pdf/1406.2871
[2] E. Björnson, L. Sanguinetti, J. Hoydis, M. Debbah, Optimal Design of Energy-Efficient Multi-User MIMO Systems: Is Massive MIMO the Answer?, IEEE Transactions on Wireless Communications, Submitted for publication. [Online] //arxiv.org/pdf/1403.6150
[3] G. Auer, V. Giannini, C. Desset, I. Godor, P. Skillermark, M. Olsson, M.A. Imran, D. Sabella, M.J. Gonzalez, O. Blume, and A. Fehske, How much energy is needed to run a wireless network?, IEEE Wireless Commun. Mag., vol. 18, no. 5, pp. 40–49, 2012.

Page responsible: Danyo Danev
Last updated: 2014 10 15   14:26