## 7 Protocol Comparisons
### Measurement Comparisons  
First of all, we want to emphasize that all works found in the literature provide only measurements taken from simulations, not from real deployments nor from controlled testbeds. Table 4 gives the type of measurements provided by several papers in the literature. Some of them are focused on measuring parameters related with the cluster size and the number of clusters. Due to cluster-based networks are mostly used for energy saving, most of them simulate energy issues. Taking into account that the more message transmissions, the more energy dissipation, only CBRP [6] and CLACR [38] (and may be CLTC [41], depending on the number of messages transmitted using GPS) will consume less energy than our proposal. \begin{table}
\begin{tabular}{|p{142.3 pt}|p{142.3 pt}|} \hline
**Reference** & **Type of measurements** & **Purpose** \\ \hline
[34] & It gives the simulations of the average cluster size and the number of clusters versus the degree of the nodes. & Parameters related with the cluster size and the number of clusters \\ \hline
[40] & It gives the average number of cluster heads versus the number of nodes and the cluster size versus the number of nodes. & The number of clusters \\ \hline
[42] & It gives the average number of clusters versus the transmission range or the maximum displacements & The number of clusters \\ \hline
[13] & It provides the energy consumption versus the distance to the nodes and the number of nodes, the number of alive nodes versus the round and the energy consumed versus the number of rounds. & Energy issues \\ \hline
[19] & It shows the energy consumption versus the number of L-sensors, average number of working nodes versus the number of sensors and the energy consumption versus the average desired coverage degree. & The number of clusters \\ \hline
[32] & It gives the number of nodes alive versus the time, the energy dissipation versus the percentage of nodes that are cluster heads, and the energy dissipation versus the network diameter. & Energy issues \\ \hline
[37] & It compares several cluster-based protocols versus the number of rounds, number of messages received versus the energy dissipation and energy consumed and the number of nodes alive as a function of network area. & The number of nodes \\ \hline
[43] & It shows the measurements of the number of alive nodes versus the time, the energy dissipation versus the time and the energy dissipation in the setup phase. & The energy dissipation versus the time and the energy dissipation in the setup phase. \\ \hline
[44] & It shows the percentage of energy consumed versus the cluster radius, the average cluster head residual energy versus the cluster radius and the cluster energy dissipated versus the number of nodes. & The number of nodes \\ \hline \end{tabular}
\end{table} 
Table 4: Type of measurements provided by other authors. Taking into account the measurements provided in this paper, we will compare our measurements with some measurements provided in other authors in their works. We are not going to implement the same test bench, we will just take their measurements and compare them with our measurements in some particular cases. Studying the results presented by [PERSON] _et al._ in [35], taking into account the same keepalive interval (30 seconds), we obtained an average value of 17.41 packets per second for a topology of three hops, while they obtained higher values (between 50 and 100 packets per second) in a random topology with 15 nodes. In terms of overhead (packets per second), it gives us an improvement of more than 65.2 % compared the best case of their protocol. [PERSON] presented in [45] several graphs that show the packet delivery ratio versus the number of nodes in the cluster network. Close to 1 packet delivery ratio (0.99 packet delivery ratio) was shown for 25 nodes, while we can see that it agrees our measurements. Once our network has converged (after the setup phase), we obtain 15.9 packets/s for 16 nodes. It gives us almost the same packet delivery ration.