## 5 Evaluation
Due to the assumption concerning saturated queues at the relay nodes, it also overestimates the collision probability at each relay node, due to concurrent packet transmission and reception events. At the end of this section, we also discuss how this underestimation of a link's average throughput may also affect queueing delay. Apart from that, in the analysis presented in Section 3, a packet is not assumed to be dropped after a larger number of failed retransmissions. In the simulation parameters presented in Table 6, however, a maximum retransmit threshold equal to 3 is adopted. This suggests that, after three failed transmissions, a specific packet is dropped. This may result in lower throughput for the link over which that packet is retransmitted, but will also result in reduced interference imposed on neighbouring links. Finally, in the analysis, we have assumed that whenever a packet is transmitted, it is a packet carrying data. In the simulated scenarios, however, all nodes either perform periodic emission of routing protocol's control messages or forwarded specific topology control packets. This means that specific slots are spent carrying routing protocol's control messages, instead of data packets, resulting in our analysis overestimating the AAT observed in the simulated results. \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Topology**} & \multirow{2}{*}{\(\mathbf{\gamma}\)} & **Flow Allocation** & \multirow{2}{*}{\(\mathbf{q_{1}}\)} & \multirow{2}{*}{\(\mathbf{q_{2}}\)} & **AAT\({}_{num}\)** & **AAT\({}_{sim}\)** \\  & & & & & **Pkts/Slot** & **Pkts/Slot** \\ \hline
1 & 0.5 & TOFRA-IAN & 0.0 & 1.0 & 0.973 & 0.970 \\
1 & 0.5 & TOFRA-SIC(\(R\)) & 0.287 & 1.0 & 1.045 & 1.045 \\
1 & 0.5 & TOFRA-SIC(\(R,d\)) & 0.287 & 1.0 & 1.057 & 1.069 \\
1 & 1.0 & TOFRA-IAN & 0.0 & 1.0 & 0.946 & 0.943 \\
1 & 1.0 & TOFRA-SIC(\(R\)) & 0.227 & 1.0 & 0.920 & 0.920 \\
1 & 1.0 & TOFRA-SIC(\(R,d\)) & 0.227 & 1.0 & 0.931 & 0.951 \\
1 & 1.5 & TOFRA-IAN & 0.0 & 1.0 & 0.921 & 0.918 \\
1 & 1.5 & TOFRA-SIC(\(R\)) & 0.189 & 1.0 & 0.840 & 0.848 \\
1 & 1.5 & TOFRA-SIC(\(R,d\)) & 0.189 & 1.0 & 0.846 & 0.875 \\
1 & 2.0 & TOFRA-IAN & 0.0 & 1.0 & 0.896 & 0.891 \\
1 & 2.0 & TOFRA-SIC(\(R\)) & 0.164 & 1.0 & 0.783 & 0.802 \\
1 & 2.0 & TOFRA-SIC(\(R,d\)) & 0.164 & 1.0 & 0.783 & 0.802 \\ \hline \end{tabular}
\end{table} 
Table 3: Simulation vs. numerical results for the AAT achieved by each TOFRA variant. Topology 1. In the second part of the evaluation process, we explore the gain in terms of throughput that can be achieved by employing SIC, instead of treating interference as noise (IAN). More precisely, we explore the AAT achieved by the aforementioned flow allocation schemes, when different approaches for handling interference are followed (discussed above). Figures 3-5 present the corresponding AAT values for the three topologies summarized in Figure 2.  
Tables 3-5 show that applying SIC instead of IAN, at both receiving nodes \(R\), \(d\), proves gainful in terms of AAT, when \(\gamma\) = 0.5. For the case of the TOFRA flow allocation scheme, the gain is 10.2%, 15.2%, and 13.2%, respectively, for the three topologies considered. It \begin{table}
\begin{tabular}{l l} \hline \hline
**Parameter** & **Value** \\ \hline Max Retransmit Threshold & 3 \\ Contention Window & 5 \\ Path Loss Exponent & 3.0 \\ Packet size & 1500 bytes \\ Simulation duration & 20,000 slots \\ Transmission power & 0.1 W \\ Noise power & \(7\times 10^{-11}\) W \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Values for the network parameters that are used in the numerical and simulation results.