## 3 Research Design
### Performance Metrics  
The performance of a Wi-Fi-based VANET system is evaluated by considering both external and internal measurements. External measurements assess the effectiveness of the protocol and include metrics such as delay, debit, acquisition time, and the percentage of segments received out of sequence [36]. Internal measurements focus on the protocol's internal efficiency and include metrics such as the average number of transmitted/received data bits, control bits, packets, and data [36].  
The packet delivery ratio is a crucial metric for evaluating routing in any network. It can be calculated by dividing the total number of received packets by the total number of packets sent. This can be represented mathematically using the following equation:  
\[\frac{\Sigma\,\text{Numberofpackets}\text{receive}}{\Sigma\,\text{Numberofpackets }\text{sent}} \tag{1}\]  
The end-to-end packet delay is measured as the time taken for a packet to be transmitted across a network from source to destination. It can be written as  
\[\text{d}_{\text{end-end}}=\text{N}\big{[}\text{d}_{\text{trans}}+\text{d}_{ \text{prop}}+\text{d}_{\text{proc}}\big{]} \tag{2}\]  
where \(\text{d}_{\text{end-end}}\) = end-to-end delay, \(\text{d}_{\text{trans}}\) = transmission delay, \(\text{d}_{\text{prop}}\) = propagation delay, \(\text{d}_{\text{proc}}\) = processing delay, and N = number of links (number of routers + 1).  
Packet losses occur when one or more packets across a network fail to reach their destination. These can be written as  
\[\text{PL}=\frac{\text{nSentPackets}-\text{nReceivedPackets}}{\text{nSentPackets}} \tag{3}\]  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Researcher** & **Main Contribution** & **Year** & **Key Concept/Description** \\ \hline [PERSON] et al. [27] & Investigated V2V communication. & 2022 & \begin{tabular}{c} Analyzes the emergency alert system in case of \\ vehicle collision. \\ \end{tabular} \\ \hline [PERSON] et al. [28] & Wi-Fi/WiMAX for VANETs & 2020 & Surveys WiMAX and WiFi for VANETs. \\ \hline [PERSON] et al. [29] & \begin{tabular}{c} VoIP performance in a IEEE \\ 802.11p VANET \\ \end{tabular} & 2012 & \begin{tabular}{c} VoIP performance in IEEE 802.11p-based VANET \\ with on-the-field measurements. \\ \end{tabular} \\ \hline [PERSON] and [PERSON] [30] & VANET using ZigBee & 2012 & Uses AODV simulation evaluation. \\ \hline [PERSON] et al. [31] & VANET performance & 2012 & Analyzes protocol performance in a VANET. \\ \hline [PERSON] et al. [21] & \
\begin{tabular}{c} Assessing VANETs under \\ different traffic mobility \\ \end{tabular} & 2010 &
\begin{tabular}{c} Analyzes and formulates the “storage capability” \\ of VMesh (one-way and highway). \\ \end{tabular} \\ \hline [PERSON] [32] & VANET data dissemination & 2010 & 802.11g, Bluetooth, ZigBee, and WAVE. \\ \hline [PERSON] [4] & VANET clustering & 2010 & GPS localization in VANET clustering. \\ \hline [PERSON] et al. [20] & VANET simulation & 2009 & GPS receivers, communications, and radars. \\ \hline [PERSON] et al. [33] & VANET Vehicle Warning & 2009 & Developed a system prototype. \\ \hline [PERSON] et al. [10] & Wi-Fi-based VANETs & 2008 & Feasibility of Wi-Fi based VANETs. \\ \hline [PERSON] [22] & Vehicular applications & 2008 & 802.11p for roadside communication. \\ \hline [PERSON] [34] & Vehicular ad hoc network & 2008 & Propagation models used in VANET. \\ \hline [PERSON] and [PERSON] [35] & Secure VANETs & 2008 & Proposes a secure framework for VANETs. \\ \hline \hline \end{tabular}
\end{table}
Table 3: Key researchers and their main contributions to Wi-Fi-based VANETs.  
where nReceivedPackets = number of received packets, and nSentPackets = number of sent packets.  
Throughput is measured as the number of transactions per second an application can handle. Throughput depends on various factors such as type of test, computer specifications, network card speed, and software support. The network throughput can be written as  
\[\text{Throughput(Mbps)}=\frac{\text{DataSize(MB)}}{\text{TransmissionTime(s)}} \tag{4}\]