Impact of VoIP services on the level of head exposure to radiation from 3G smartphones

Subscribers of 3G cellular systems are becoming increasingly attracted to the use of packetized voice services on their data-enabled wireless devices. Voice over IP (VoIP) cellular radio connections are characterized by a set of air interface parameters that may be quite different from those used by conventional, circuit-switched speech connections. This work is aimed at quantifying the impact of such differences on the level of non-ionizing radiation on the head of voice users. It follows a line of research that looks at the statistics of head exposure levels from a system perspective, that is, considering the cellular device not as an isolated piece of equipment but as a part of a cellular network. The study focuses on smartphones, and considers two types of packetized speech services, namely, VoIP using standard protocols and the proprietary system known as Skype^®. The methodology employs Monte Carlo simulations of the radio uplink of a R´99 W-CDMA system, in combination with experimental radio emissions data from a group of popular devices. Results indicate that, as a general rule, VoIP connections always bring in an increase in key statistics of the level of emissions absorbed by the head of voice users, as compared to circuit-switched connections. Specifically, under a certain set of typical conditions, the increase in average radiation levels may be as high as 60%. As a result, a number of recommendations aimed at mitigating the rise in radio emissions associated to the use of VoIP instead of conventional voice services are formulated.