200 research outputs found
Comparison of uplink SAR values in train environment for different wireless technologies
A comparison of uplink Specific Absorption Rate (SAR) values in a train environment for different wireless technologies using macrocells or femtocells is presented. The comparison is based on both simulations and real-life experiments. Compared to a typical GSM900 macrocell scenario, the largest SAR reduction is observed when using a UMTS femtocell base station, which leads to uplink SAR reductions by a factor 358,820
Assessment and comparison of total RF-EMF exposure in femtocell and macrocell base station scenarios
The indoor coverage of a mobile service can be drastically improved by deployment of an indoor femtocell base station (FBS). However, the impact of its proximity on the total exposure of the human body to radio-frequency (RF) electromagnetic fields (EMFs) is unknown. Using a framework designed for the combination of near-field and far-field exposure, the authors assessed and compared the RF-EMF exposure of a mobile-phone (MP) user that is either connected to an FBS or a conventional macrocell base station while in an office environment. It is found that, in average macrocell coverage and MP use-time conditions and for Universal Mobile Telecommunications System technology, the total exposure can be reduced by a factor of 20-40 by using an FBS, mostly due to the significant decrease in the output power of the MP. In general, the framework presented in this study can be used for any exposure scenario, featuring any number of technologies, base stations and/or access points, users and duration
Prediction and comparison of downlink electric-field and uplink localised SAR values for realistic indoor wireless planning
In this paper, for the first time a heuristic network calculator for both whole-body exposure due to indoor base station antennas or access points (downlink exposure) and localised exposure due to the mobile device (uplink exposure) in indoor wireless networks is presented. As an application, three phone call scenarios are investigated (Universal Mobile Telecommunications System (UMTS) macrocell, UMTS femtocell andWiFi voice-over-IP) and compared with respect to the electric-field strength and localised specific absorption rate (SAR) distribution. Prediction models are created and successfully validated with an accuracy of 3 dB. The benefits of the UMTS power control mechanisms are demonstrated. However, dependent on the macrocell connection quality and on the user's average phone call connection time, also the macrocell solution might be preferential from an exposure point of view for the considered scenario
Assessment of contribution of other users to own total whole-body RF absorption in train environment
- …