## 4 A Hybrid Algorithm for Power Allocation in Macrocell/Femtocell Architecture
The video content is encoded to produce a stream including a base layer and enhancement layers. Each layer, together with all the layers, depends on a representation of the video content at a certain spatial and temporal (frame rate) and SINR quality. In our case, we used three layers, 2, 1 and 0, with the frame rate 30, 15 and 5 fps, respectively. The maximum video rate of the video sequence is 700 kbps and the average is 300 kbps. The rate adaptation occurs every time there is a change in the SINR and RSS due to the change of channel condition. ### Performance Evaluation

The working performance of our power allocation scheme is computed by combining it with and without rate control scheme for adapting the rate of video with the channel quality. We compared our solution firstly to the work proposed by [PERSON] et al. [29] as they introduced a utility function for adapting rate of the video basing their decision on estimated bandwidth, signal strength and QoS parameters for the video traffic: we denote it by \"utility\"--secondly to another solution represented by PA_utility, which refers to the combination of this solution with our solution for power allocation because the solution does not take the interference into account. Finally, denote our solution by RC_PA and No_RC_PA, which refers to the use of rate control for adaptivity with and without power allocation consecutively. Figure 3 denotes the throughput of the video in all scenarios, and it is evident that the throughput of the video in our suggested solution is higher than the other methods due to the use of power allocation for mitigating interference. Furthermore, the adaptive solution is making use of a good quality of channel, when deciding to match between video rate and channel rate. As for the utility, it shows less throughput; however, if we combine it with power allocation, it achieves a good performance. Even though, this solution is using SINR for making the decision of matching; however, it is using an expected bandwidth for matching the rate that does not give the exact throughput. Both our solutions and utility do not perform well in terms of throughput when there is no power allocation. As for the number of control messages exchanged between the device itself and the MBS, we remarked that it is higher when achieving rate control functionality and power allocation rather \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameters** & **Values** & **Parameters** & **Values** \\ \hline Macrocells & 1 & Thermal noise density & \(-\)174 dBm/Hz \\ Femtocells & 30 & Carrier frequency & 3.5 GHz \\ MUEs & 15–60 & UE noise figure & 2.5 dB \\ FUEs & 4 & Macrocell radius & 500 m \\ bandwidth & 10 MHz & FUEs average speed & 3 km/h \\ RB bandwidth & 50 & MUEs average speed & 30 km/h \\ Macro Tx power & 43 dBm & \(SINR^{target}\) & 5.7 dB \\ Femto Tx power & 23 dBm & Simulation Time & 60 s \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Simulation parameters. than its absence. This is a normal case as the measurement reports are sent so often to measure the quality of channels of FUEs and MUEs according to our algorithm. However, in the case when there is no rate control and power allocation, there will be almost no negotiation except for the conventional control messages sent by MBS (Figure 4). The percentage of satisfaction of the users is so important; in our case, it is related to the QoS guarantee for the parameter of throughput for video application. Figure 5 shows the percentage of satisfaction, which is from 70 to 90%, while using a rate adaptive algorithm with power allocation, while it is around 40-50% for the inverse case, i.e., rate control without power allocation, which is a natural result due to the interference issue. Figure 6 shows the Packet Loss Ratio (PLR) of all methods regarding the number of users. It is clear that the PLR is increasing when the number of users is increasing; however, there is no violation of QoS of video streaming of interfered users using our method.