Hi, and welcome to the IoT communications and networks MOOC. This MOOC is dedicated to the media layers of the Internet of Things, or IoT. I am Georgios Papadopoulos, an Associate Professor at IMT Atlantic and the Coordinator of this MOOC. I will be guiding you in this introductory week. The IOT is transforming our world. It comprises billions of sophisticated objects, such as sensors, actuators, and meters that are connected to the Internet. These objects, things, or devices have often limited capacity in terms of memory storage, computational power, and energy. They can be deployed nearly everywhere in homes, hospitals, factories, cities, and they can even be attached to or implanted in human bodies. A given network of objects must be carefully designed for its target application. Among these IoT based applications, the industrial IoT is an emerging domain aiming to improve factory automation and reduce its management cost. Efficient automation and cost reduction can be achieved, in particular, by potentially replacing the existing cables with wireless links. However, wireless communications is usually less reliable than a wired links. This is due to many factors, such as external interference, obstacles, or distance between the devices. It is thus challenging to use wireless communication in an industrial network because an industrial network must be robust in terms of network reliability and timely delivery of the transmitted information. Let's take an example, rail transport. Multiple trains share the same infrastructure while serving different stations, moving at different speeds, and yet they manage to avoid collisions and arrive usually on time. All of this is possible, thanks to a precise schedule which defines which tracks will use which railway at what time. How can we set up a wireless communication and networking in IoT? Well, this is what we are going to see in these MOOC together. To start, in this introductory week, we will present the main network topologies that we could have in IoT. The star topology, where the devices communicate directly with a gateway, and the mesh or multi-hop topology, where some of the devices operate as relays for others, we felt direct communication with the gateway. In order for two devices to communicate, we can schedule collision-free communications based on a time synchronization and frequency hopping technique, which is called TSCH. In the Week 1, we will explain the fundamental methods to access the channel and we will go through the specifics of the TSCH protocol. Next in the Week 2, we have the six top protocol, or 6P, which enables distributed scheduling in wireless IoT mesh networks by enabling the negotiation of cells between neighboring nodes. Then, the minimum scheduling function, or MSF, allows the devices to reserve resources to transmit data packets. Finally, this Week 2, we will describe how a new device may join an existing IoT network. Connecting a device to the Internet in a future proof way requires that it supports IPv6. Again, it is important to keep in mind that objects have limited networking as well as processing capacity. Thus, the sizes of the exchange messages in the network should be as low as possible. It follows that some adaptation mechanism will also be required to support IPv6. These are the compression mechanism which reduces the size of the packets and the fragmentation mechanism, which splits the larger IPv6 packets into smaller ones called fragments. All of these mechanisms will be presented in Week 3. Finally, to build and manage an industrial network, we have the routing protocol, names RPL pronounced ripple. It allows the devices belonging to a network to learn the paths towards a given destination. It is based on IPv6, and it belongs to the family of distance vector routing protocols. Different network metrics, such as the link quality, latency, or throughput, may be used to select a neighboring device to forward a packet. In our final Week 4, we will see the specifics of a RPL, routing protocol. For each week in addition to the text, videos, and assessments, you will use a well-known IoT based simulator to configure different parameters of each study protocol and to run simulations over different network topologies. Thanks for participating and we hope you enjoy the course.
