# Energy-Efficient Check-and-Spray Geocast Routing Protocol for Opportunistic Networks
## 4 Performance Evaluation  
The proposed EECSG routing protocol is evaluated using the ONE simulator [13], and its performance is compared against that of two benchmark- routing protocols: CGOPP and GSAF, for both synthetic dataset [13] and the INFOCOM 2006 real data mobility traces [14]. In CGOPP, the messages are flooded in the geocast area using a centrality-based technique, whereas in GSAF, the messages are flooded in the geocast region by using a spray and flood technique. All the studied protocols follow a ticketing-based message forwarding mechanism from source to the destination cast.  
In our simulations, the considered performance metrics are average latency, delivery ratio, number of messages forwarded, number of dead nodes, overhead ratio, and hop count, under varying parameters which are: number of nodes, buffer size and Time-to-Live (TTL).  
1. Number of dead nodes: This represents the number of nodes whose remaining energy are less than the prescribed minimum energy threshold at the end of the simulations. Initially, 5000 J  
Figure 1: Energy-Efficient Check-and-Spray Geocast Routing (EECSG) pictorial example.  
energy is given to the node. Transmit energy of a node is 0.2 J. The battery level threshold of the node is set to 600 J. When a node's energy is less than 600 J then it is considered as a dead node. node [15].
2. Delivery ratio: this is the ratio of messages successfully delivered to the destination at the end of the simulations vs. the total number of messages generated in the network.
3. Overhead ratio: this is a measure of the bandwidth efficiency, calculated as: \[\textit{relayed messages}\ -\ \textit{delivered messages}\ /\ \textit{delivered messages}.\] (4)  
The nodes belong to six different groups of moving elements, which are pedestrian, electric motor cars, vehicles, bicycles, office workers, and tram. The map-based mobility models are used for the movements of these groups. The operations of the studied routing protocols were simulated by considering the Helsinki city map with region 4500 m \(\times\) 3400 m. For evaluation purposes only, we created 16 casts on that map. We simulated our protocols using two wireless interfaces: Wi-Fi 802.11 ac with a transmission speed of 433 Mbps and a range of 20 m and Bluetooth 802.16 v4.0 with transmission speed of 2 Mbps and range of 10 m. We also used eight levels of host density (65, 130, 195, 260, 325, 390, 455, 520), 195 as default number of hosts, different sizes of device buffers (5, 10, 15, 20, 25, 30, 35, 40), where 10 Mb is the default buffer size, different message lifetimes (30, 60, 90, 120, 150, 180, 210 and 240 min) (the default being 120 min).  
All simulations ran for 16 h; and the warm-up and cool-down periods for each simulation were 2 h. Every simulation was repeated 5 times using different seeds for the synthetic mobility models. The messages were scheduled as follows: A sender and a destination cast were selected uniformly and at random from the set of nodes and the set of predefined casts. The message payload was set to 500 KB and a new message was scheduled every 25 to 35 s. The considered buffer scheduling policy were respectively random--meaning that the messages were randomly selected from the node's buffer when a node encounters another one, FIFO, LIFO, HTFO and LTFO, the default being the random scheduling policy.