## 4 Results and Discussions  
This section provides an examination of the long-term throughput, delay, and fairness of the system when using the proposed algorithm, as well as how they compare with the same characteristics when the baseline algorithm is used.  
For these purposes, we assume an urban macro-cell environment for which the radius is equal to 1 km, and in which two adjacent CCs in the 2 GHz (gigahertz) frequency band are aggregated within the BS for packet transmissions. The underlying path-loss model selected for this study is the COST 231 (Cooperation in Science and Technology) model [31; 32]; this model is widely used for making predictions of the path-loss for mobile wireless systems. The function (in dB)  
\[L_{\text{path\_loss}}=69.55+26.16\text{log}_{10}f-13.82\text{log}_{10}h_{ \text{b}}-\varphi(h_{\text{d}})+(44.9-6.55\text{log}_{10}h_{\text{b}})\text{ log}_{10}d \tag{4}\]  
is used to express the COST 231 path-loss model for an urban macro-cell operating at the frequency \(f\) equal to 2000 MHz (megahertz). In Equation (4), \(d\) denotes the distance between the BS and the user terminal (in km), \(h_{\text{b}}\) denotes the effective BS antenna height (in m), \(h_{\text{d}}\) denotes the user-terminal antenna height (in m), and \(\varphi(h_{\text{d}})\) is a correction factor for the user-terminal antenna height, which is given by  
\[\varphi(h_{\text{d}})=3.2\text{log}_{10}(11.75h_{\text{d}})^{2}-4.97 \tag{5}\]  
In addition, we also assume independent Rayleigh slow-fading channels are employed [29], with those channels being corrupted by additive white Gaussian noises. Related to this, the speed of the fading variation is assumed to be slower than the packet transmission speed.  
For each CC, the bandwidth is set at 5 MHz, with each CC also containing 512 subcarriers. The fast Fourier transform size is set at 512. Values of 100 and 1 m are set for \(h_{\text{b}}\) and \(h_{\text{d}}\), respectively. The setting for \(\eta\) is equal to 1/2, while that for \(w\) is equal to 1/6. A value of 5 msec is set for \(t_{\text{OFDMA}}\), with 48 OFDMA symbols, while a simulation time of \(10^{8}\) OFDMA frames is also set. For the considered cell, it is assumed that there are eight RT users and eight NRT users, and that the distribution of all of these different users generated is uniform. Additionally, the speed at which every RT user moves is assumed to be equal to 3 km/h, while they are further assumed to move in random directions with a uniform distribution. For the NRT users, meanwhile, it is assumed that they mostly access the network from fixed locations. Values of 3 and 20 rounds are set for \(t_{\text{th}}\) and \(\delta_{\text{RT}}\), respectively.  
Meanwhile, in order to generate traffic sources for both the RT and NRT packets, the ON-OFF Poisson traffic model [33] is used. More specifically, all of the users' traffic is generated independently according to this ON-OFF model in order to provide simulation results. For the RT and NRT packets, the OFF durations have exponential distributions with means of 0.03 and 0.05 s, respectively, while the ON durations for the RT and NRT packets also have exponential distributions, with respective means of 0.01 and 0.1 s. Under the ON condition, packet sizes with means of 100 and 300 bytes, respectively, and with truncated geometric distributions are generated for the RT and NRT packets. Furthermore, it should be noted that if the size of a generated packet is larger than 1500 bytes, then the packet size will be regenerated.  
For the purpose of demonstration, the packet generation rate is allowed to vary. To facilitate later description, the ratio of the total packet arrival rate to the maximum system service rate is used as the definition of the system load. For the considered case, the maximum system service rate, after averaging the service rates under different fading conditions, was about 14.8 Mbps (megabits per second). It should be noted that in this context, the system load is dependent upon the change in the packet generation rate.