**1. Introduction**

The Internet of Things (IoT) is based on the connection of multiple devices to the Internet and data sharing between them. Data is first sent to the cloud where it is processed using analytics, and then sent back to other devices. This process depends completely on a centralized architecture. A Wireless Sensor Network (WSN) is considered the most critical element of the IoT model. In the context of IoT, these wireless networks play an essential role in increasing the ubiquity of networks [1] since wireless technology is the fundamental way in which "intelligent objects" communicate with each other and the Internet. In this sense, WSNs allow IoT scalability and provide enough functionality to support its integration with the current Internet architecture. Moreover, it is essential to study the scalability and the adaptation methods of the network in the face of packet transmission failures and topology changes [2].

IoT provides smarter services by the interconnection of various objects. Providing intelligent services requires data to be collected from different places, areas, and devices. Hence, in these kinds of applications, energy consumption is a key factor; sensors can be in remote zones and they can be challenging to access, so it is not possible to replace their batteries continuously. Due to the limitations of battery life, the nodes are designed to save as much energy as possible and most of the time they are in sleep mode (low power consumption mode). It is thus essential to know the factors that have an impact on battery life [3]. Regarding the wireless medium, aspects that contribute to the deterioration of the information transmission must be taken into account as the channel parameters depend directly on the characteristics of the transmission medium. These characteristics affect the medium and the duration of the useful life of the batteries because there might be connections and disconnections of some nodes in the network. The conditions of the medium also influence the packet retransmission and listen attempts to the channel. This causes the routing protocol to increase its control messages and deteriorate its overhead [4].

WSNs are multi-functional, low-cost, and low-power networks that rely on communications among nodes or from sensor nodes to one or more sink nodes. Sink nodes, sometimes called coordinator nodes or root nodes, may be more robust and have larger processing capacity than other kinds of nodes. Sensor networks can be widely used in various environments even the hostile ones. Some of the many applications of WSNs are in the medical field, agriculture, monitoring, and detection, automation, and data mining. The key element of the IoT is that different devices are connected within the same environment being able to transmit and receive information about their immediate environment and interaction with users. The accuracy of the location allows interactions and data sharing between devices that automate and simplify tasks that generate comfort and facilitate daily work practices. Continuing developing technologies that combine IoT and location will lead to the development of better services for automation and support of daily life tasks.

Adaptive methods for wireless networks have been studied because of the introduction of many technologies for using different technical standards [5]. The concepts of coexistence and cooperation are currently booming in the literature. Both have to do with how the nodes relate to each other and to the network itself. A balanced network seeks to match the load of information traffic and routes, adapting the rules of routing protocol by means of control packages. Coexistence and cooperation offer an idea on how the device puts its functions at the service of the network regardless of the technologies or protocols in use. One of the challenges when analyzing these concepts is interference. There are different metrics that indicate the quality of links in wireless networks.

To analyze the terms that describe the relationship of the devices among them and with the network, it is important to define the degree of intelligence that these nodes possess, a term that is included in technological convergence. When talking about heterogeneous environments, we can mention different network topologies so that the devices exist in an environment that has different characteristics.


The main disadvantage of cooperative networks lies in the shared management and interdependence of networks that are in an environment with common conditions. Cognitive networks have an agile cognitive process with which they can determine the current conditions of the network, in order to plan, decide, and act. The network can learn from these adaptations to make future decisions taking into account the final objectives: to develop communication protocols.
