# An Effective and Efficient Adaptive Probability Data Dissemination Protocol in VANET
## 4 Performance Assessment
### Impact of Road Segments in the Reliability of Data Dissemination  
In this part, the impact of road segments (slots) in relation to the packet delivery ratio, redundancy ratio, end-to-end delay and relaying vehicles achieved was examined when deployment of EEAPD protocol to a networking environment. The adaptability of EEAPD protocol safety application requirement according to how a number of road segments parameter can be examined through Figures 9-12. Figure 9 demonstrates the relationship between redundancy ratio according to the road segments. It shows clearly that the redundancy ratio decreases better with the increase of road segments in EEAPD from road segments is 300, the redundancy ratio decreases to 20% and improves to 5% at road segments equal to 450, which is close approximately to a 0% redundancy ratio (no more redundancy ratio in data dissemination). However, using SEAD, S1 PD, Delay-Based and AddP protocols, the redundancy ratio decreases and reaches a constant state when the road segments increase from 360 to 450 (refer to Table 3). Figure 11: Number of road segments vs. relaying vehicles. Figure 10: Number of road segments vs. packet delivery ratio. Figure 9: Number of road segments vs. redundancy ratio. This means that a larger number of segments generate a smaller number of vehicles in single slot consider that each slot is far apart to each other enough to hold relaying nodes. This increase rebroadcast probability when the number of vehicles decreases in increasing road segment in the last slot, it clearly notices that the redundancy ratio decrease better in EEAPD compares to other protocols, and vice versa. Moreover, Figure 10 shows an important result of EEAPD compares to other protocols. It shows clearly that when the road segment increases to 450, the message delivered by EEAPD is around 9.8 (98%) which approximates to 1 (100%) of the packet delivery ratio. When S1 PD, SEAD, delay-based and AddP at road segments increase from 360 to 450, the packet delivery ratio starts moves to steady state (Refer Table 3). This show that EEAPD is a suitable choice for the reliability of data dissemination. This helps to minimize the broad storm problem. Figure 11 presents the comparison among our proposed protocol EEAPD and other approaches such as SEAD, S1 PD, delay-based and AddP in how a number of road segments determine the relaying vehicles. In this case, we discuss two points of view, namely the comparison between EEAP and (SEAD and S1 PD), and the comparison between EEAPD and (delay-based and AddP). EEAPD versus (SEAD and S1 PD): it is clearly seen from Figure 11 that EEAPD perform better than (SEAD and S1 PD) for all road segments. It is interesting that the percentage of relaying vehicles is directly proportional to road segments. The percentage of EEAPD relaying vehicles increases better with an increasing number of road segments. EEAPD receives almost 70% of relaying vehicles to compare to other protocols. When road segments (slots) decrease also the percentage of the relaying node decreases for both protocols, but it is observed that the percentage of EEAPD relaying vehicles deviates better than SEAD and S1 PD considering the number of the road segment is 150. This means that the proposed framework has a higher percentage of reducing the number of relaying vehicles when the number of road segments increases compare to SEAD and S1 PD protocols. This observation  
Figure 12: Number of road segments vs. end-to-end delay. \begin{table}
\begin{tabular}{c c c c c} \hline \hline _PROTOCOL_ & **Rr (\%)** & **PDr (\%)** & **Rv (\%)** & **E2E (ms) at 450 Segments** \\ \hline S1 PD & 32 & 70 & 40 & 70 \\ SEAD & 30 & 65 & 50 & 64 \\ Delayed-Based & 37 & 65 & 50 & 64 \\ AddP & 28 & 68 & 50 & 56 \\
**EEAPD** & **5** & **98** & **70** & **50** \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Protocols comparison based on number of road segments. shows that the road segment will consider the best choice of relaying node for message rebroadcast at the cost of dissemination delay.