# On the Optimisation of Practical Wireless Indoor and Outdoor Microcells Subject to QoS Constraints
## 5 Simulation Results and Evaluation
### Wireless Outdoor Microcells  
Taking into account the outdoor environment, Table 2 provides a list of key simulation parameters for wireless outdoor microcells. Specifically, the RF at transmitter of a cell site consists of the following major components: antenna pattern is omnidirectional isotropic, transmitter frequency is 850 MHz, transmitter antenna height is 30 m, the antenna polarization is horizontal with cross polarization attenuation of 0 dB and the EIRP is set as \(-14\) dBW. The parameters at receiver units are similarly set as in Table 1 for the indoor scenario.  
Figure 8 illustrates the area that is required to be covered by wireless microcells. For the outdoors, buildings may have different heights that are represented through a colour range defined in Figure 9a, while the range of the received power at remote units are defined in Figure 9b. It is assumed that there are six positions available in the area for site installation, i.e., \(N=6\), which are marked by yellow circles. It is further presumed that 16 required coverage areas, i.e., \(M=16\), marked by red stars should be covered to guarantee that most of the areas are bounded. The maximum number of cell  
Figure 6: Heuristic site locations for indoor with multiple-input single-output (MISO) antennas.  
Figure 7: Heuristic site locations for indoor with multiple-input multiple-output (MIMO) antennas.  
sites available is also set as \(K_{\max}=6\) and the received power at the remote unit is required to be at least \(-95\) dBm, i.e., \(P(x_{e_{m}},y_{e_{m}})\geq-95\) dBm, \(\forall m=1,2,\ldots,16\). In the scenario that all the available resources are used, all the required coverage areas are shown to meet the QoS requirements, but it can also be seen in Figure 8 that there exists areas having higher received power as required. In order to save network resources, it is vital to find an optimal solution to cover the area meeting the QoS requirements with a minimum number of cell sites.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**RF Parameters at Transmitter of Cell Sites** & **Values/Description** \\ \hline Antenna pattern & omnidirectional isotropic \\ Antenna height & 30 m \\ Antenna polarization & horizontal \\ Cross polarization attenuation & 0 dB \\ Transmitter frequency & 850 MHz \\ EIRP & \(-14\) dBW \\ \hline
**RF Parameters at a Typical Receiver** & **Values/Description** \\ \hline Antenna pattern & omnidirectional isotropic \\ Antenna height & 2 m \\ Antenna polarization & horizontal \\ Cross polarization attenuation & 15 dB \\ Mobile type & cellular \\ \hline \hline \end{tabular}
\end{table}
Table 2: Simulation parameters for wireless outdoor microcells.  
Figure 8: Wireless outdoor microcells with six candidate antenna positions and required coverage areas.  
Figure 9: Colour range: (**a**) building height; (**b**) received power at remote outdoor.  
With regard to different antenna configurations, Figures 10-12 plots the optimal locations for outdoor microcells using SISO, MISO and MIMO antennas, respectively. It can be observed that only four cell sites are necessary to meet the target minimum received power, \(P(x_{en},y_{en})\geq-95\) dBm, \(\forall m=1,2,\ldots,16\), at the marked areas in Figure 8. This means that one third of the installation and maintenance costs as well as one third of the energy consumption can be saved when compared to the case of employing all six antennas, which accordingly validates the effectiveness of the proposed BSCP algorithm in reducing the waste of resources caused by overlapping coverage areas. In addition, the coverage area when employing MIMO in Figure 12 is shown to be the largest compared to the scenarios of MISO in Figure 11 and SISO in Figure 10. For instance, the radii of the areas having a received power in the range of \([-55,-40]\) dBm with the SISO, MISO and MIMO are 52.4 m, 69.75 m and 92.21 m, respectively. Again, this observation is shown to be consistent with those observed in the indoor scenario with multiple-antenna deployment.