## 6 Key Findings  
After developing the proposed system and evaluating its basic performance, the following key findings can be provided:  
* Opportunistic communications are an emerging field that has gained relevance for scenarios with restricted connectivity. Most of the previous research cited in this article focused on more theoretical approaches such as routing optimization or protocol efficiency for different network topologies, but there are not many practical evaluations. This article compensates for this lack by presenting a new multi-layer approach that combines Bluetooth Mesh for discovery and libp2p for communications, which improves adaptability and robustness in multiple environments.
* Use of other communications technologies. The protocol proposed in this article was designed to be agnostic to the physical layer and adaptable to multiple communication technologies, thus facilitating integration with emerging networks such as 6G or already well-established technologies like 5G, Zigbee, Wi-Fi, or LoRa, which were considered as potential alternatives during the design phase and can be used in future developments to create comparisons with the results obtained in this article for Bluetooth 5.
* Use of other application-level technologies. The devised protocol can incorporate at the application level technologies like blockchain, which can improve data integrity and decentralized management through the use of smart contracts or the storage of transaction records on the blockchain for audits and traceability [45].  
Figure 23: Number of packets successfully sent and received in the six evaluated spots.  
* The results obtained during the experiments demonstrated that the protocol is robust against metallic obstacles and signal attenuation at over 100 m and maintains low latency in all scenarios, validating its suitability for industrial environments.
* Although the protocol was verified in domestic and industrial environments, it can be applied to dynamic scenarios such as vehicular networks (e.g., real-time traffic updates), natural disaster situations (e.g., drone swarms with intermittent connectivity), or smart cities (such as mobile sensor networks).
* Scalability. The performed experiments demonstrated the viability of using the system on the selected home and industrial scenarios, showing its basic functionality with a reduced minimal P2P environment with only two nodes. Such evaluations were carried out for this article to control all the variables of the experiments and thus accurately show the basic performance of the protocol, such as delivery latency and success rate, without interference from other factors. However, in real-world scenarios, Pub/Sub protocols are designed to operate in distributed networks with hundreds or thousands of nodes, so further research is still necessary in terms of scalability. Nonetheless, it is worth mentioning that some authors performed similar experiments with different protocols and technologies. For instance, in [46], the authors performed several experiments with 1000 nodes, a maximum mesh size of 12, and a round-trip time of 100 ms, achieving a 100% PDR when a Sybil attack [47] took place. Thus, the authors, by combining low latency, high resistance to attacks, and self-recovery mechanisms, were able to validate that their protocol was suitable for large-scale networks.