Exposure index of EU project LEXNET: principles and simulation-based computation Emmanuelle Conil 1 , Yoann Corre 2 , Nadège Varsier 1 , Abdelhamid Hadjem 1 , Günter Vermeeren 3 , Wout Joseph 3 , Sam Aerts 3 , David Plets 3 , Luc Martens 3 , Luis M. Correia 4 and Joe Wiart 1 1 Orange, Issy-les-Moulineaux, France 2 SIRADEL, Rennes, France 3 iMinds / Ghent University-INTEC, Ghent, Belgium 4 IST / INOV-INESC, University of Lisbon, Lisboa, Portugal Abstract— The EU project LEXNET is defining a new metric to evaluate the exposure induced by a wireless network communication at a whole. Exposure induced by base station antennas but also exposure induced by wireless devices are taken into account to evaluate the average global exposure of the population in a specific geographical area. The paper first explains the concept and gives the formulation of the Exposure Index (EI). Then the EI computation is illustrated, based on simulation, showing how radio-planning predictions, realistic population statistics, user traffic data and Specific Absorption Rate (SAR) calculations can be combined to assess the index. Index Terms—EMF population exposure, Exposure index, Simulation I. INTRODUCTION Exposure induced by electromagnetic fields (EMF) emitted by wireless telecommunication systems is limited by exposure limits recommended by international authorities as ICNIRP [1]. Existing metrics to evaluate EMF exposure are well adapted to check the compliance with limits but not at all to evaluate a global exposure of a population. In the context of high concern about possible health effect of EMF, the European Commission DG CONNECT (Directorate General Communications Networks, Content and Technology) asks for studying future networks minimizing the human exposure to radiofrequency electromagnetic waves. The LEXNET project is a European project that started in November, 2012 in response to this demand. The strategic goal of LEXNET is to take into account the public concern about possible health effects of electromagnetic fields and to improve the acceptability of existing and future wireless systems through low exposure systems without compromising the user’s perceived quality. One of the objectives of LEXNET is to define a new metric to evaluate the exposure of a population induced by a given wireless telecommunication network. The so-called Exposure Index (EI) is changing the exposure’s paradigm by evaluating simultaneously the contribution of the personal devices (as mobile phone) and the contribution of the infrastructures of the network (as base station antennas) to the global exposure. In section II, the concept of the Exposure Index is described. Its computation is illustrated in section III, based on radio- planning predictions, while section IV gives some conclusions. II. THE EXPOSURE INDEX (EI): CONCEPT AND FORMULATION A. Concept In the daily life, exposure is partly induced by the fixed network installations and partly induced by the use of personal devices. Both these components are strongly linked [2] [3]. The metric proposed by the project LEXNET, named Exposure Index, merges the exposure incurred by personal devices with that attributable to base stations and access points of a given wireless telecommunication network (or set of networks), without taking into account the background exposure induced by other RF sources such as FM radio or DTT transmitters. The purpose of this new metric is many- fold. First, it provides a way to fairly characterize the exposure generated by a given wireless network on a whole population. Second, this unique metric allows for the introduction of a simple EMF target in the network design optimization process. Third, it can also be integrated in the evaluation of new network topologies, technologies, equipment or management techniques, in the same way as more usual QoS (Quality of Service) or energy efficiency metrics, helping in the design of future low-EMF networks. In a nutshell, the LEXNET Exposure Index is a function transforming a highly complex set of data into a single parameter which has two key benefits: it is understandable and acceptable for all the stakeholders, from general public to regulatory bodies; and it is linked in a tangible way to the network operating parameters. The Exposure Index is the mean exposure of the people located into a given area, over a given time period (e.g. during a typical day time) and from a given set of networks (e.g. together from all 2G / 3G / 4G / WLAN networks operating in the area). It is basically the average of doses (SAR x exposure duration) experienced by all individuals present in the target area over the considered time period. In that perspective, the EI computation takes into account: