## 6 Conclusions and Future Works  
This work presents a new improvement to the LOADng routing protocol in IoT scenarios when the network devices have different capacities and use different message types. The proposal was compared with the default implementation of LOADng and LOADng-SmartRREQ through simulations using COOJA. Four different metrics were studied to expose the network performance in terms of reliability, QoS, and power efficiency. For all the considered metrics, LOADng-IoT demonstrated better performance for sparse, dense, and mobile networks. These significant results were obtained due to the set of improvements provided by the proposed approach. Unlike other approaches, the proposed LOADng-IoT does not require a previous definition of gateways and, hence, it can find the most appropriated Internet node to forward messages. This feature provides a self-adaption capacity to the network nodes and reduces the necessity of human intervention in both network deployment and execution. Optionally, LOADng-IoT allows the use of a cache system dedicated to storing Internet routes, enabling the nodes to direct the route discovery to INs that anteriorly had been used as gateways. These approaches together permits LOADng-IoT to reduce the control message overhead required to find the Internet routes, contributing to the reduction of power consumption and improving the packet delivery ratio. Finally, this work proposed a new error code that makes it possible for the Internet nodes to advise the other network nodes about its temporary Internet connection loss. Thus, devices that intend to send Internet messages can find new gateways to forward messages, increasing the chances of successful delivery. It was also noted that LOADng-IoT performance was, in general, less variable when compared with the other studied proposals. This behavior is justified because LOADng-IoT requires fewer radio transmissions to perform the data packet delivery and route discovery. Thus, LOADng-IoT is less affected by the interferences and collision that commonly makes the network performance unstable. In conclusion, the authors deduce that, together, all of the proposed mechanisms that comprise LOADng-IoT provide  
Figure 9: Percentage of packets with low latency in function of number of nodes. a new significant enhancement for IoT networks, allowing them to attain better QoS, efficiency, and reliability. For future work, the authors suggest that experiments in real IoT environments should be conducted to test the results obtained using computational simulation. Moreover, the source code from the proposed solution should be improved, documented, and disseminated to the scientific community. [PERSON] collected and performed the in-depth analysis and reviewed the related literature on the topic, wrote the first draft of the document, proposed the new approach in cooperation with the second author, performed the comparison study, and identified several open research issues. [PERSON] supervised the study, consolidated the comparison analysis and open issues, and reviewed the structure and the first draft. All other authors reviewed the text carefully, verified the comparison study, and reviewed the identified open issues. All authors contributed equally to the scope definition, motivation, and focus of the paper. This work has been supported by the Brazilian National Council for Research and Development (CNPq) via Grant Nos. 201155/2015-0 and 309335/2017-5; by National Funding from the FCT--Fundacao para a Ciencia a Tecnologia through the UID/EEA/500008/2013 Project; and by Finep, with resources from Funtled, grant no. 01.14.02310.00, under the Radiocomunication Reference Center (Centro de Referencia em Radiocomunicacoes -- CRR) project of the National Institute of Telecommunications (Instituto Nacional de Telecomunicacoes -- Intel), Brazil. The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding this work through research group no. RG-1439-022. The authors declare no conflict of interest.