The IoT is more than simply the data from a sensor. We must first understand and architect the transport of moving sensor data from the remotest places on Earth to the cloud. There are a significant number of technologies and data paths to move data, and a bulk of the material in this book will investigate the aspects, constraints, and comparisons of communication choices for the architect.

We begin the WAN discussion with a review of wireless RF signals and the contributing factors that impact signal quality, limitations, interference, models, bandwidth, and range. There are many WAN communication protocols to choose from in different bands, and the architect must understand the pros and cons of choosing one radio spectrum over the other. 

The following graphic helps delineate the various range and data rates for wireless protocols we will cover in later chapters. WPAN is often used with other near-range communication acronyms such as wireless Field Area Network (FAN), Wireless Local Area Network (WLAN), wireless Home Area Network (HAN), wireless Neighborhood Area Network (NAN), and Wireless Body Area Network (WBAN):  

This chapter will provide foundational models and theory on communication systems, frequency spaces, and information theory. Communication constraints and comparison models will be provided to allow the architect to understand how and why certain types of data communication work, and where they won't work.

Next, we start with communication theory as it plays a fundamental part in choosing the correct mix of wireless technologies to deploy an IoT solution.