A significant portion of this book surrounds connectivity and networking. There are countless other sources that dive deep into application development, predictive analytics, and machine learning. This book too will cover those topics, but an equal amount of emphasis is given to data communications. The IoT wouldn't exist without significant technologies to move data from the remotest and most hostile environment to the largest data centers at Google, Amazon, Microsoft, and IBM. The acronym IoT contains the word internet, and because of that, we need to dive deep into networking, communications, and even signal theory. The starting point for IoT isn't sensors or the application; it's about connectivity, as we will see throughout this book. A successful architect will understand the constraints of internetworking from a sensor to a WAN and back again.

This communication and networking section starts with theory and mathematical foundations of communication and information. Preliminary tools and models are needed by a successful architect not only to understand why certain protocols are constrained, but also to design future systems that scale successfully at IoT levels. These tools include wireless radio dynamics like range and power analysis, signal-to-noise ratio, path loss, and interference. The chapter also details foundations of information theory and constraints that affect overall capacity and quality of data. The foundations of Shannon's law will be explored. The wireless spectrum is also finite and shared, as an architect deploying a massive IoT system will need to understand how the spectrum is allocated and governed. Theory and models explored in this chapter will be reused in other sections of the book.

Data communication and networking will then build up from the near-range and near-meter communication systems known as personal area networks (PANs), typically using non-internet protocol messages. The chapter on PAN will include the new Bluetooth 5 protocol and mesh, as well as Zigbee and Z-Wave in depth. These represent the plurality of all IoT wireless communication systems. Next, we explore wireless local area networks and IP-based communication systems including the vast array of IEEE 802.11 Wi-Fi systems, thread, and 6LoWPAN. The chapter also investigates new Wi-Fi standards such as 802.11p for in-vehicle communication.

The section concludes with long-range communication using cellular (4G LTE) standards, and dives deep into the understanding and infrastructure to support 4G LTE and new standards dedicated to IoT and machine to machine communication, such as Cat-1 and Cat-NB. The chapter also details the most promising features of the new 5G standard being ratified and designed to prepare the architect for future long-range transmissions where every device is connected in some capacity. A proprietary protocol like LoRaWAN and Sigfox are also explored to understand the differences between architectures.