# AODV-EOCW: An Energy-Optimized Combined Weighting AODV Protocol for Mobile Ad Hoc Networks
## 4 Routing Table Design  
The routing protocol proposed in this study chooses the route according to three metrics, so the routing table and control packets must be modified accordingly. The modified routing table is shown in Table 4.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Routing Hops** & **Score** \\ \hline
1–2 & 1 \\
3–4 & 0.6 \\
5–6 & 0.4 \\ \(\geq\)7 & 0.1 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Routing hops rating.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Weighting Method** & **Pros** & **Cons** \\ \hline \multirow{3}{*}{Subjective weighting method (i.e., AHP)} & Determines the weight based on experience, which can better reflect the actual situation & Weight determination has nothing to do with data and relies too much on experience \\  & The weight is determined by data and an algorithm and effectively reflects the change & Ignores the importance of experience, so data changes will cause greater \\  & in data & weight changes \\ \hline \hline \end{tabular}
\end{table}
Table 3: Comparison of different weighting methods.  
Since the hop count is already in the AODV routing table, it is only necessary to add the congestion degree and the residual energy of the node to the routing table. Additionally, the authors considered that there is only one routing path for vanilla AODV routing. Once the path fails, the process of route discovery will be repeated, which will increase the routing overhead and energy consumption. The improved routing protocol will also store other paths in the backup route and quickly start the restoration of the route after the failure of the main route.  
The RREQ route discovery packet of the improved AODV protocol has three routing factors. Nodes can discover RREQ packets through routing, tell other nodes about their three routing metrics, and calculate the score of the entire path based on this to select the best link. The modified RREQ routing request packet is shown in Table 5.  
Similar to the RREQ packet, the RREP packet also needs to be modified. It is also necessary to add the congestion degree and node residual energy to RREP. The packet format of RREP is shown in Table 6.  
\begin{table}
\begin{tabular}{c} \hline \hline
**RREP Packet Fields** \\ \hline Destination node’s IP address \\ Destination node’s serial number \\ Source node’s IP address \\ Source node’s serial number \\ Congestion degree \\ Node residual energy \\ Hop count \\ \hline \hline \end{tabular}
\end{table}
Table 6: RREP packet.  
\begin{table}
\begin{tabular}{c} \hline \hline
**Routing Table Entries** \\ \hline Destination node’s IP address \\ Valid flag of the destination node’s serial number \\ Network interface \\ lifetime \\ Destination node’s serial number \\ Next hop node \\ Precursor list \\ Hop count \\ Backup route \\ Routing flag \\ Congestion degree \\ Node residual energy \\ \hline \hline \end{tabular}
\end{table}
Table 4: Routing table.  
\begin{table}
\begin{tabular}{c} \hline \hline
**RREQ Packet Fields** \\ \hline RREQ ID \\ Destination node’s IP address \\ Destination node’s serial number \\ Source node’s IP address \\ Source node’s serial number \\ Congestion degree \\ Node residual energy \\ Hop count \\ \hline \hline \end{tabular}
\end{table}
Table 5: RREQ packet.