## 2 Methods
### Dose Calculations
To take into account the different positions of the mobile phone during data traffic compared to those during calls (holding the mobile phone in the hand instead of close to the ear) we used the ranges delivered in the SEAWIND report for different distances between the device and the respective tissue [20]. The SAR decreased on average by a factor of 1000 by having the device approximately 20 cm away from the body compared to a device touching the body. [PERSON] _et al._ found that the exposure for a mobile phone in \begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Near-Field Predictor**} & \multicolumn{2}{c}{**Brain SAR**} & \multicolumn{2}{c}{**Whole-Body SAR**} & \multicolumn{1}{c}{**References**} \\ \cline{2-5}  & **(mW/kg)** & **Derivation** & **(mW/kg)** & **Derivation** & \\ \hline GSM 1 mobile phone calls without headset & 3.198 & – & 0.411 & – & [18] \\ GSM 1 mobile phone calls with headset & \(3.198\times 10^{-3}\) & \(3.198\times 0.001\) & 0.411 & 0.411 \(\times\) 1 & [18,20] \\ UMTS mobile phone calls without headset & 0.023 & – & 0.003 & – & [18] \\ UMTS mobile phone calls with headset & \(0.023\times 10^{-3}\) & \(0.023\times 0.001\) & 0.003 & 0.003 \(\times\) 1 & [18,20] \\ DECT phone calls without eco mode & 0.373 & – & 0.051 & – & [18] \\ DECT phone calls with eco mode & 0.0373 & 0.373 \(\times\) 0.1 & 0.0051 & 0.051 \(\times\) 0.1 & [18,20] \\ mobile phone data traffic with mobile internet connection & \(0.092\times 10^{-3}\) & \(0.023\times 4\times 0.001\) & 0.012 & 0.003 \(\times\) 4 \(\times\) 1 & [18,20, 21, 22, 23, 24] \\ mobile phone close to body (passive mobile phone data traffic) & \(0.092\times 10^{-3}\) & \(0.023\times 4\times 0.001\) & 0.012 & 0.003 \(\times\) 4 \(\times\) 1 & [18,20, 21, 22, 23, 24] \\ mobile phone data traffic with WLAN & \(0.092\times 10^{-3}\) & \(0.023\times 4\times 0.001\) & 0.012 & 0.003 \(\times\) 4 \(\times\) 1 & [18,20, 21, 22, 23, 24] \\ computer, laptop and tablet use with WLAN & \(0.092\times 10^{-3}\) & \(0.023\times 4\times 0.001\) & 0.012 & 0.003 \(\times\) 4 \(\times\) 1 & [18,20, 21, 22, 23, 24] \\ \hline \hline \end{tabular}  
* For calls with the mobile phone on the GSM network the mean of the SARs for the GSM900 and the GSM1800 network was used because there was no differentiation between GSM900 and GSM1800 network in the mobile phone operator data.  
\end{table} 
Table 2: Near-field _brain_ and _whole-body_ SARs, corresponding derivation and references for the near-field predictors. watching-like position at 10 cm distance is about ten times below the exposure in voice position. At 40 cm distance it appeared that the exposure was about 1000 times lower [22]. These findings are comparable with the SAR ranges presented in the SEAWIND report for UMTS voice and UMTS data [20]. These considerations led us to use a brain SAR of 0.092 \(\times\) 10\({}^{-3}\) mW/kg for data traffic on the mobile phone via mobile internet connection. For the whole-body SAR we assumed that the mobile phone is held approximately at the same distance from the body for data traffic as for voice calls resulting in a whole-body SAR of 0.012 mW/kg for data traffic on the mobile phone via mobile internet connection. Considering an approximately equal exposure for transmission of a fixed size data packet using UMTS or WLAN (SEAWIND report, page 3 [20]) we decided to use the same SAR for data traffic via WLAN as for data traffic via mobile internet connection for both the brain and the whole-body SAR. For using a computer, laptop or tablet connected to the internet via WLAN we used the same SAR as for data traffic on the mobile phone using WLAN assuming approximately the same distance between the device and the brain and the body, respectively.