Internet-of-Things (IoT) environments will have a large number of nodes organized into groups to collect and to disseminate data. In this sense, one of the main challenges in IoT environments is to dynamically manage communication characteristics of IoT devices to decrease congestion, traffic collisions, and excessive data collection, as well as to balance the use of energy resources. In this paper, we introduce an energy-efficient and reliable Self Adjusting group communication of dense IoT Network, called SADIN. It configures the communication settings to ensure a dynamic control of IoT devices considering a comprehensive set of aspects, ie, traffic loss, event relevance, amount of nodes with renewable batteries, and the number of observers. Specifically, SADIN changes the communication interval, the number of data producers, the reliability level of the network. Extensive evaluation results show that SADIN improves system performance in terms of message loss, energy consumption, and reliability compared to state-of-the-art protocol.

Internet of Things (IoT) protocols provide the fundamental mechanisms to collect data from low power devices and lossy networks. IoT protocols collect data blocks from the devices in messages that have one header and a single payload, regardless the size of the payload. This paper presents a solution to collect small size data blocks from low power devices in an efficient way, carrying these data blocks in the payload of a single message. Current solutions do not offer manners to gather many small blocks of data and reduce the overhead of the communication. The proposed solution is a light-weight layer designed to operate with the standard IoT protocol stack aiming to reduce the energy consumption of the energy constrained devices without lowering the data accuracy. The proposed solution was developed in Contiki devices and the measurements conducted on a testbed showed up to 14% energy savings.