# MTRSRP: Joint Design of Multi-Triangular Ring and Self-Routing Protocol for BLE Networks
## 5 Network Performance
### Related Performance Discussions  
Although the proposed MTRSRP protocol does not explicitly incorporate an energy consumption model, the performance results in Figures 7 and 9 provide meaningful insights into its energy efficiency. As shown in Figure 7, MTRSRP consistently achieves a higher packet delivery ratio compared to DTC-HSR and NUPFA, even under increasing traffic loads. This improvement implies a significant reduction in retransmissions, which are typically caused by packet losses or acknowledgment failures. In BLE networks, retransmissions are a major source of energy consumption, as they involve repeated transmissions and extended listening periods. By reducing retransmission frequency, MTRSRP indirectly conserves energy across the network. In addition, Figure 9 reveals that MTRSRP maintains a lower average hop count, indicating more direct and efficient routing paths. Each hop in a BLE network consumes energy for both transmission and reception. Therefore, fewer hops translate directly into lower communication energy expenditure. This efficiency is largely attributed to the protocol's binary-label-based self-routing mechanism, which ensures deterministic and loop-free forwarding while avoiding redundant or suboptimal paths. \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Feature** & **MTRSRP** & **CORP [12]** & **BLEmesh [13]** \\ \hline Topology structure & Multi-triangular ring & Cluster-based & Flooding-based (unstructured) \\ \hline Topology formation & Hierarchical competitive leader election & Distributed cluster formation & No explicit topology formation required \\ \hline Routing method & Self-routing based on binary labeling & Reactive routing based on node roles & Flooding-based message forwarding \\ \hline Routing stability & High (predefined paths, no reconstruction) & Medium (requires rerouting) & Low (frequent redundant transmissions) \\ \hline Loop avoidance & Unidirectional labeling ensures no loops & No explicit mechanism; loops possible & None; prone to loops and duplications \\ \hline Throughput performance & High & Medium & Low to medium (degrades with congestion) \\ \hline Packet loss rate & Low (multi-path bridges) & Medium to high (congestion at cluster heads) & High (dupli-cate/collision prone) \\ \hline Delay control & Low (shortest-path self-routing) & Medium to high (delay increases under load) & High (lack of congestion control) \\ \hline Construction overhead & Medium (control packets for ring setup) & Medium to high (distributed control messages) & Low (no structural overhead) \\ \hline Scalability & Good (regular topology easily extended) & Limited (irregular structure) & High (simple broadcasting mechanism) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: MTRSRP vs. CORP and BLEmesh. Moreover, the dual-bridge design in MTRSRP enhances energy efficiency by introducing path redundancy and balancing traffic loads across the network. These features help alleviate congestion and minimize packet collisions, which in turn reduce the need for retransmissions and lower end-to-end delay. As a result, the protocol achieves better energy usage without relying on explicit power control mechanisms. In summary, the high delivery success rate, reduced hop count, and effective traffic distribution enabled by MTRSRP collectively contribute to lower energy consumption. These inherent characteristics make MTRSRP a practical and energy-conscious solution for BLE network deployments. On the other hand, scalability is another critical concern in BLE network design. To address this, we now provide analytical scalability extrapolations based on Equations (1)-(3) in Section 4.2. The hierarchical structure of MTRSRP is based on interconnected triangular rings, and the total number of nodes N scales approximately linearly with the number of rings _N_r. Through analytical estimation, we find that the average node count can be approximated by N \(\approx\) 13.5-Nr.