INTRODUCTION RESULTS & CONCLUSION OUTDOOR EXPOSURE TO RF- RADIATION OF WIFI FOR WIRELESS CITY APPLICATIONS G. Decat, G. Meynen, D. Wilczek and L. Deckx VITO - Integrated Environmental studies - Boeretang 200 – BE-2400 - Mol – Belgium gilbert.decat@vito.be The 23rd PIERS 2008 in Hangzhou China March 24-28, 2008 (in Grand Metropark Hotel, which is located in the city's commercial and financial center. 5-10 minutes walk to the famous West Lake, INTRODUCTION City services via the wireless interaction between wall fixed outdoor wifi access points (AP’s) and PDA’s become more and more popular in every city. In order to assess the magnitude and the possible risks of the RF-field generated by the AP’s when activated by the PDA, VITO measured the spatial distribution of the E-field in the city of Hasselt and evaluated the risk respective to the Belgian exposure standard (10 MHz – 10 GHz)(2005) from which the basic restriction SAR value is four times lower than the 0.08 W/kg of ICNIRP(1998). METHOD The E-field of 28 AP’s (fig.1) was measured in 28 different streets by means of the Fieldcop and Narda SRM 3000 spectrometers. Figure 2 shows the spectrum in which the field was measured whereas figures 3 and 4 show that measurements were performed in a vertical (0.1, 1, 1.75 m) and a 3 directional horizontal plane. The AP’s were activated by watching the video streaming on the PDA while it was placed below the AP (fig. 3) and behind the spectrometer (fig. 4) respectively. In each point the rms of the E-field was averaged over 6 min.. RESULTS & CONCLUSION The table below shows the maximum E-field measured at a height of 1.75 m (PBS) and the sample (n = 28) median of the 6’ averaged rms E-field obtained at a height of 1 m in the 3 horizontal directions for the 2 activation conditions. The conclusion is that all 6’ averaged rms values and even the maximum E-veld of the 3528 sample values are far below the reference level (30.7 V/m) of the Belgian standard and within the interpretation of this standard no health risks are to be expected by the outdoor wifi-applications Figure 2 Figure 3: PBA-condition Figure 4: PBS-condition 2405-2420MHz Figure 1 MAXIMUM E-FIELD (mV/m) AT 1.75 cm HEIGH (PBS) DISTANCE FROM AP MEDIAN OF 6’ AVERAGED RMS E-FIELD (mV/m) Direction 1 Direction 2 Direction 3 PBA PBS 2132 - 441 1483 1 368 460 300 313 239 332 792 2 268 362 160 151 376 487 4 154 312 109 237 114 316 392 8 119 274 80 247 257 16 89 259 58 255 63 291 32 250 53 216 52 279