# An Improved Opportunistic Routing Protocol Based on Context Information of Mobile Nodes
## 3 Performance Analysis
As shown in Figure 8, the delivery ratios of all three protocols increase as the message generation interval increases, since the number of generated message decreases as the message generation interval increases, and thus, the number of removed message decreases for a fixed buffer size. The proposed protocol has larger delivery ratio than PRoPHET and RPC for a fixed value of message generation interval. As shown in Figure 9, the overhead ratios of all three protocols increase as message generation interval increases, since the number of delivered messages decreases as message generation interval increases. The proposed protocol has smaller overhead ratio than both PRoPHET and RPC, since it has higher delivery probability and it efficiently limits the number of forwarding by comparing the average distance and average time, as well as delivery predictability. The delivery latencies of all three protocols increase as message generation interval increases, as shown in Figure 10, since the number of messages dropped at the buffer decreases since the number of messages decreases, and thus, more time is needed for forwarding to another node during short contact duration. The proposed protocol has smaller delivery latency than both PRoPHET and RPC,  
Figure 8: Delivery ratio for different message intervals. Figure 9: Overhead ratio for different message intervals. since it efficiently limits the number of forwarding by comparing average distance and average time as well as delivery predictability. Figures 11-13 show the delivery ratio, overhead ratio, and delivery latency of the proposed protocol, PRoPHET, and RPC, by varying the number of nodes. As shown in Figure 11, the delivery ratios of PRoPHET and RPC protocol does not increase as the number of nodes increases since more nodes generate more message copies and thus the number of delivered message decreases due to more message removal at the buffer. The delivery ratio of the proposed protocol increases as the number of node increases since the proposed protocol efficiently selects forwarding node out of more number of possible forwarding nodes. The proposed protocol has larger delivery ratio than both PRoPHET and RPC. As shown in Figure 12, the overhead ratios of all three protocols increase as the number of nodes increase. In both PRoPHET and RPC, the overhead ratio increases due to more relayed messages and decreased number of delivered messages in Equation (9). The overhead ratio of the proposed protocol also increases, since the effect of increased relayed messages due to more number of nodes is more dominant that the effect of more delivered messages. The proposed protocol has smaller overhead ratio than both PRoPHET and RPC. Figure 11: Delivery ratio for different number of nodes. Figure 10: Delivery latency for different message intervals. As shown in Figure 13, the delivery latencies of all three protocols decrease as the number of nodes increases, since more contacts are possible when the number of nodes is higher and messages can be delivered more quickly. The proposed protocol has smaller delivery latency than both PRoPHET and RPC.