scope:

This Technical Report describes exposure evaluation concepts and techniques for the overall exposure level in spatial regions and occupants caused by the simultaneous exposure to multiple narrowband electromagnetic (EM) sources. Throughout this Technical Report, it is assumed that the exposure evaluation occurs under static conditions, i.e., the source position and transmit-mode characteristics (e.g. emitted power, modulation scheme, etc.) of the device(s) under test do not vary significantly over the time required to carry out the evaluation using the chosen evaluation technique (e.g., field measurements). The vast majority of wireless communication systems worldwide employ signalling schemes featuring narrowband waveforms, hereinafter defined as signal waveforms occupying a frequency band not broader than 10 % of its central frequency (justification of this threshold is provided below). For information, Annex A presents the operating system bands and channel bandwidths of several common wireless services. Wide-band communication systems, e.g., ultra-wideband (UWB) systems employing impulsive waveforms with fractional bandwidth well in excess of 10 %, are relatively new to the marketplace, have experienced limited deployment so far, and are not typically regarded as significant contributors to EM exposure levels due to low transmit power levels.