# Comparing New Wireless Sensor Network Protocols through Simulation and Data Analysis +
## 4 Results and Analysis
### End-to-End Delay  
During the transmission phase of WLAN, the data (packets) are sent from the submitting nodes (senders) to the recipient nodes (receivers). The recipient nodes receive these data at their MAC layer, and they are then sent to higher levels. When we talk about end-to-end delay, we are referring to the amount of time it takes for an entire packet to be received at the WLAN MAC layer by all the nodes in the network and then transmitted to a higher layer. This encompasses the individual reception of all fragments and frames, \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Environment size & 1000 \(\times\) 1000 m \\ Number of nodes & 25 and 50 \\ Traffic type & Constant bit rate \\ Nodes type & Fixed \\ Packet rate & 4 Packets/s \\ Packet size & 512 byte \\ Number of Flows & 25 and 50 \\ Simulation time & 3600 s \\ Number of submission hosts & 25 and 50 \\ Number of receivers & One \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Parameter vs. Value for 1 st case. transmission of frames through access point delay if enabled, and medium access delay at the source MAC. Following the dissemination of this information, the proactive nature of the path toward every node ensures that it is always prepared, resulting in the lowest and most consistent delay. This indicates that there is no route discovery process in OLSR that is pre-computed, which guarantees the lowest possible latency, as Figure 3.  
This is also demonstrated by the fact that the scenario with 50 nodes yields the same results for delay as the case with 25 nodes. This indicates that it performs well in vast networks, and the reason is, once again, the predetermined routing table entries for all of the nodes in the network. The amount of time needed to calculate the shortest path is not required, but the number of control messages will increase in large networks. In the instance of 50 nodes, not only did its rate drop to half of what it was at the beginning of the experiment, but it also took significantly more time to sustain a rate that was only marginally unstable. This suggests that the amount of time required for routing to reach all of the nodes and route maintenance will increase proportionally with the number of nodes in the network. When looking at the node failure scenario for both 25 and 50 nodes, the 25-node scenario showed that the performance of DSR lowers from 50,000 bit/s to 20,000 bit/s, and in the 50-node scenario, it dropped significantly with a bigger ratio, from 100,000 bits/s to 40,000. This again suggests that the occurrence of random node failure will have a significantly more negative impact on densely populated networks in comparison to smaller networks. The reason for this is that when there are failed nodes present in a large network, it becomes extremely difficult to find a path from the source to the destination due to the consumption of resources (memory and energy), as well as the complexity of the overhead processes. On the other hand, if we take a look at the behavior of OLSR, we can see that it has a proactive routing nature, which results in the consistent nature of the routing overhead. This indicates that the paths to all of the nodes have already been calculated and established. The periodic updates of routing information are the sole overhead that is created at the network level, and their frequency is rather minimal. Even though the size of the network will have an impact on the routing overhead, it will still be reliable and consistent. In both cases, the input parameters that were used were the same as those indicated in Table 2, with the exception of the number of nodes that were used. The outcomes of each statistic are depicted in Figures 4-6 with regard to the various situations below. Figure 3: (**a**) Fixed nodes without failure. (**b**) Fixed nodes with failure. Figure 4: (a) Fixed nodes without failure. (b) Fixed nodes with failure. Figure 5: (a) Fixed nodes without failure. (b) Fixed nodes with failure.