## 2 The Elephant in the Room: Great Diversity
### One Simple Approach to Help Harmonization
#### 2.2.6 LoWPAN  
In the realm of the Internet of Things (IoT), enhancing energy efficiency and connectivity in various environments necessitates innovative networking solutions. Devices in these networks are often interconnected in a mesh topology, leveraging an adaptation of the 802.15.4 standard through 6 LoWPAN. 6 LoWPAN, standing for IPv6 over Low-Power Wireless Personal Area Networks, is pivotal for enabling devices with constrained processing and power resources to communicate over the IPv6 protocol, thus offering notable advantages such as interoperability and flexibility. The protocol's extensive addressing structure, provided by IPv6, significantly aids in scaling IoT networks by facilitating the addressing of a virtually unlimited number of devices. Moreover, 6 LoWPAN's efficiency in bandwidth utilization is achieved through header compression mechanisms. This efficiency is crucial in reducing the size of transmitted data packets, an essential feature in wireless sensor networks where transmission capacity and battery longevity are of paramount importance. Consequently, the application of 6 LoWPAN in IoT device communication propels the interoperability, scalability, and efficiency of deployments, facilitating the establishment of comprehensive networks. The integration of 6 LoWPAN with NB-IoT represents a strategic advancement that capitalizes on the strengths of both technologies. The NB-IoT is celebrated for its exceptional coverage, power efficiency, and reliability, providing a reliable communication layer for IoT devices in scenarios where traditional connectivity options are impractical or overly power consuming. This symbiosis between 6 LoWPAN and NB-IoT enhances the seamless and efficient transmission of data from localized, star-of-stars IoT networks to the broaderInternet, effectively narrowing the divide between localized IoT networks and the expansive global Internet infrastructure. Such integration is essential for the development of IoT systems that are scalable, interoperable, and capable of efficient operation across diverse environments and protocols, marking a significant step towards the realization of fully connected and efficient IoT ecosystems [3, 25, 26]. There are at least two main types of devices expected in 6 LoWPAN networks: (i) coordinators and (ii) leaves. Our testing scenario is composed of one coordinator node and two leaves, as follows:  
The coordinator node (see Figure 2, left), centered on a BeagleBone Black, offers a robust platform for managing network communications and data processing tasks. This single-board computer's significant processing power and connectivity options make it ideal for overseeing the operations of an IoT network. The coordinator node is enabled by a 6 LoWPAN standard communication module, establishing it as the network's central hub. Notably, the BeagleBone Black implements a CoAP (Constrained Application Protocol) server, designed to handle request-based communications from the network's sensor nodes. This setup is pivotal for managing the energy-efficient protocol operations, ensuring that data are relayed efficiently from the sensor nodes to the coordinator, and then onwards as required. The 6 LoWPAN device connects to the BeagleBone via UART. This connection method is instrumental in maintaining the system's overall low power consumption and simplicity, whilst ensuring a low-data-rate, seamless stream from the capillary network. Standard/leaf nodes (see Figure 2, right) were deployed, which in the scope of this study happen to be ambient sensors, although any kind of device would be set the same way. Parameters gathered by ambient sensors are typical IoT parameters--temperature, humidity, luminosity, and motion--so they seemed to be a good choice to implement for testing. In alignment with the principles of low power consumption and efficient communication, these ambient sensors utilize a request-based CoAP.