## 3 Results
### Different Signal Reception  
The reception quality and the difference between the position accuracies of the various smartphones examined depends strongly on the number, type, and quality of the satellite signals received and used to determine the GNSS position. Table 3 shows the average number of satellites that were used for position determination per constellation and the frequency bands over the entire data collection session. It is clear that four of the ten tested smartphones also used multiple frequency bands in the field to determine their positions (Xiaomi MI 8, Xiaomi MI 8 Pro, Xiaomi Mi10 light, Huawei P40). The Huawei P40 used three bands. Older smartphones, such as the Samsung S5 and the Huawei P20, only used two, and the different Samsung XCOVER 4/4s and the Samsung A7 only used three constellation/band combinations. Newer multi-frequencies models, on the other hand, used five (Xiaomi MI 8/8 Pro), seven (Xiaomi Mi 10 light), or even eight (Huawei P40) constellation/band combinations to determine the GNSS position. The benefit of applying L5/E5a/B2a code pseudoranges may be reliably verified but varies significantly between the different constellations. A careful inspection of the table allows us to conclude that the relative ratio of multi-frequency use by NAVLSTAR GPS satellites is much smaller than that of the other constellation types (BeiDou, Galileo), due to the small number of GPS satellites that provide signals on the L5 frequency band. The average number of acquired GPS satellites on L5 was much lower than that on L1 for all smartphones. The L5 frequency of the GPS NAVSTAR satellites was received by only 26% (Xiaomi Mi 10 light) to 45% (Huawei P40) of the satellites. The lower number of satellites with the L5 band can be explained by its lower availability compared to the availability of the L1 signal. With the B3a/B1l band of the BeiDou constellation, in contrast, the ratio was between 68% and 80%. In the Galileo constellation, except for Xiaomi Mi 8 pro (56%), the E5a band was used for almost every satellite for which E1 was also used. The proportions vary from 92% (Xiaomi Mi 8 pro), to 98.5% (Xiaomi Mi 10 light), to 98.6% (Huawei P40). The average number of acquired GPS satellites on L5 is much lower than that on L1 for all dual-frequency smartphones by an average from 1.6 to 3.4 satellites. Therefore, smartphones that are able to use the second or even third frequency of the BeiDou (B2a, B1) or Galileo (E5a) systems have a potential advantage to eliminate ionosphere interference using the B2a/E5a code pseudoranges, as classical dual-frequency ionosphere-free linear combinations do. \begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**GPS**} & \multicolumn{2}{c}{**GLONASS**} & \multicolumn{2}{c}{**BAIDOU**} & \multicolumn{2}{c}{**GALILEO**} & \multicolumn{2}{c}{**Sum**} \\ \cline{2-10}
**Smartphone** & **L1** & **L5** & **G1** & **B1C** & **B1I** & **B2a** & **E1** & **E5a** & **Sat’s** & **Fbands** \\ \hline Xiaomi MI 8 & 6.0 & 1.8 & & 4.0 & & & 3.8 & 3.5 & 13.8 & 19.0 \\ Xiaomi MI 8 Pro & 4.7 & 1.6 & & 3.5 & & & 3.0 & 1.7 & 11.3 & 14.6 \\ Xiaomi MI10 light & 7.5 & 3.4 & 6.4 & 5.4 & & 4.3 & 6.6 & 6.5 & 25.8 & 40.0 \\ Huawei P20 & 7.9 & & & 1.6 & & & 9.6 & 9.6 & 9.6 \\ Huawei P40 & 6.1 & 1.6 & 8.3 & 7.9 & 5.3 & 5.4 & 7.2 & 7.1 & 29.4 & 48.8 \\ Samsung A7 & 7.9 & & & 4.2 & & & 5.0 & 17.1 & 17.1 \\ Samsung S5 & 6.5 & & & 2.8 & & & & 9.2 & 9.2 \\ Samsung Xcover 4 & 7.2 & & 5.0 & 4.4 & & & 16.6 & 16.6 \\ Samsung Xcover 4s A & 7.7 & & & 4.4 & & 4.3 & 16.4 & 16.4 \\ Samsung Xcover 4s B & 7.6 & & & 4.5 & & 4.1 & 16.2 & 16.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Number of active satellites used for fixed positions per constellation and frequency bands (FBand) given as an average over the entire data collection session. It is particularly remarkable that newer, more frequently used smartphones tended to use significantly more satellites for positioning.