Detailed, practical guidance for implementing IoT cellular network connectivity solutions for software developers and electrical engineers, and project managers. Focusing exclusively on using cellular connectivity for IoT devices, Cellular IoT presents a flexible approach, using algorithms and software designs, to drastically reduce the complexity of interacting with a wide variety of Cellular Communication Modules (CCMs) which lie at the heart of cellular modems. Written in an accessible style, this book is one of the first to cover all practical aspects of cellular network connectivity, from network and SIM selection through to custom algorithms for detecting and recovering from a wide variety of connectivity problems, and an innovative approach to reliably manage AT commands in modern cellular modems. This book explains the factors related to establishing and maintaining cellular connectivity including geography and topology, population density, SIM card (and connectivity provider) selection, antenna choice and placement, and CCM selection. The book also provides detailed examples and troubleshooting advice, showing how to transfer data using low-level sockets and also using a high-level protocol (HTTP), creating a brief, temporary connection for a primitive IoT device to send a small amount of data, and also establishing and maintaining a continuous cellular connection with full Internet access on powerful IoT devices running Linux. Written by an author with considerable professional expertise and experience with cellular connectivity, Cellular IoT includes information on: Platforms, tools, and debugging, covering tool-chain selection, computing/OS platforms, programming language choices, and running IoT connectivity code in a debuggerCellular network basics, covering base stations, range, cell towers, tracking areas and paging, frequency and modulation, bandwidth and latency, frequency bands, and SIM cardsSimilarities and differences across CCMs, frequency, band, Radio Access Technology (RAT), protocol and data representation, selection and consequencesLow-level communication protocols including transmission control protocol (TCP), user datagram protocol (UDP), point-to-point protocol (PPP), and custom hybrids for cellular IoTFull coverage of SMS, GNSS (available in most CCMs), obtaining precise time, and utilizing the power saving functionality of Extended Discontinuous Reception (eDRX) and Power Saving Mode (PSM) available in NB-IoT, LTE Cat M and LTE Cat 1 bis CCMsEntirely new and innovative software approach, Command Independent Processing (CIP), to systematically manage and execute AT commands across families of CCMs and integrating standardized (3GPP) AT commands with vendor specific ones to achieve greater software portability across CCMs Cellular IoT is an essential resource for software developers, hardware engineers, and project managers seeking to avoid connectivity pitfalls and be better able to diagnose and resolve newly encountered challenges in the field while drastically reducing the time required to produce reliable, IoT connectivity solutions.