# An Adaptive Delay-Tolerant Routing Algorithm for Data Transmission in Opportunistic Social Networks
## 4 Simulation
### Simulation Setup
#### 4.1.2 Experimental Parameter Setting  
To provide a fair comparison, we give the same experimental setup to the five routing algorithms and the only difference is the method of selecting the next suitable hop. HCMM (Health Capability Maturity Model), which has been well known as a real community-based human mobile scenario, is used to test the performance of those algorithms. We allow Spray and Wait and Epidemic to implement the data transmission across node communities, because they do not rely on the node community. Opportunistic Network Environment (ONE) is regarded as a tool package to conduct this simulation. Furthermore, the other common experimental parameter setup is demonstrated in Table 3.  
It is worth noting that this experiment consists of 16 groups and each group conducts the tests 5 times. In the HCMM model, each node is assigned a community, and the nodes tend to the community they are interested in. The nodes in the same community are randomly distributed, and the communication between them is more frequent than the nodes from two different communities. Overall, HCMM simulates a real social scene in which nodes move randomly between communities. Additionally, on the basis of general performance indexes from ONE platform, this experiment mainly focuses on the following five indicators:  
1. Energy consumption: this parameter represents the total energy consumption from the network, including node mobility, data transmission, task processing, etc.
2. The remaining cache: this parameter indicates that the size of the remaining cache space of a node after it stores enough data grouping.
3. Delivery ratio: this indicator represents the ratio of the number of data packages accepted by destination to the total number of packages sent from message carriers. This indicator is calculated by DR = PA/PS, in which PA is the number of messages from all successful data transmission and PS is the number of messages sent from all mobile nodes.
4. Average end-to-end delay: this definition includes the delay from data routing, node waiting, and data transmission in a successful data transmission between a pair of mobile nodes. It is formalized as AD = TD/m, in which TD represents the total network delay and m is the number of data deliveries.
5. Network overhead: this indicator denotes the total network overhead from the whole data transmission process among all nodes in the communication area, in which routing and forwarding delay, energy consumption, and memory usage are included.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Routing Algorithm** & **Details of Implementation** \\ \hline FCNS & Mamdani fuzzy inference system for node similarity; assessment of node attributes; two-hop transmission. \\ P\&F & Two phases: prediction of meeting probabilities and forwarding of data packets; optimal stopping theory. \\ Spray and Wait & Nodes constantly exchange information copies when they meet; \\  & & limiting the number of data packets. \\ Epidemic & Flooding model: information groups are transmitted to all neighbor nodes in same communication area. \\ DTCM & Curve-trapezoid fuzzy inference system for cache and energy; node classification; two-hop transmission. \\ \hline \hline \end{tabular}
\end{table}
Table 2: The details of implementation of the compared five algorithms.