Cellular Iot - A Practical Guide for Software Developers, Electrical Engineers,

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 debugger
• Cellular network basics, covering base stations, range, cell towers, tracking areas and paging, frequency and modulation, bandwidth and latency, frequency bands, and SIM cards
• Similarities and differences across CCMs, frequency, band, Radio Access Technology (RAT), protocol and data representation, selection and consequences
• Low-level communication protocols including transmission control protocol (TCP), user datagram protocol (UDP), point-to-point protocol (PPP), and custom hybrids for cellular IoT
• Full coverage, for the first time, 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 CCMs
• Entirely 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.

Table des matières

Table of Contents
Chapter 1 - Introduction
                1.1  Wireless Connectivity Alternatives
                1.2  Goals
                1.3  The Fundamental Problem
                1.4  Audience
                1.5  Recommended Reading
                1.6  Can One Size Fit All?
                1.7  Hardware History                       
                1.8  On-the-Move Connectivity Problems
                1.9  Reference Implementations
                1.10  Reference Microcontroller/OS Platform
                1.11  Reference Cellular Communication Modules (CCMs) Family
                1.12  A Few Words on Advice, Practices and Efficiency
                                1.12.1  Best Practice or Good Practice
                                1.12.2  Efficiency Is a Large Umbrella
                                                1.12.2.1  Spatial and Temporal Efficiency
                                                1.12.2.2  Data Efficiency
                1.12.2.3  Developmental Efficiency
                1.13  3G, 4G, 5G, 6G
Chapter 2 - Platforms, Tools and Debugging
                2.1  Importance of Tool-Chain Selection
                2.2  An Expanded View of the Tool Chain
                2.3  Computing/OS Platforms
                2.4  Programming Language Choices
                2.5  Running the Same Code on Development Computer and IoT Device
                2.6  Running IoT Connectivity Code in a Debugger
Chapter 3 - Cellular Network Basics
                3.1  Standards
                3.2  What do Cellular Networks do?
                3.3  Are Cellular Networks Wireless?
                3.4  What is a Cell? What is a Sector?
                3.5  Omnidirectional Cellular Coverage
                3.6  Cell Towers
                3.7  How are Cellular Networks Identified?
                3.8  How Are IoT Devices Identified
                3.9  eNodeB IDs, and Cell IDs
                3.10  Tracking Areas and Paging
                3.11  Frequency and Modulation
                                3.11.1  Modulation
                                                3.11.1.1  Radio Telegraphy
                                                3.11.1.2  Amplitude Modulation (AM Radio)
                                                3.11.1.3  Frequency Modulation (FM Radio)
                                                3.11.1.4  Phase Modulation
                3.12  Spectral Efficiency
                3.13  Error Detection
                                3.13.1  Luhn Algorithm
                3.14  Error Correction
                3.15  LTE Modulation Techniques
                                3.15.1  Binary Phase Shift Keying (BPSK)
                                3.15.2  Quadrature Phase Shift Keying (QPSK)
                                3.15.3  Quadrature Amplitude Modulation (QAM)
                3.16  Bandwidth and Latency
                3.17  Range
                3.18  Frequency Bands
                                3.18.1  Frequency Affects Range
                3.19  Radio Access Technologies (RAT) and Categories
                3.20  SIM Cards
                3.21  What Happens When a Cellular Modem Switches On?
                                3.21.1  Network Selection, Cell Selection, Camping, and Cell Reselection
                                3.21.2  Network Registration
                3.22  Handoff (also called Handover)
                                3.22.1  Maintaining Connectivity
                                3.22.2  Load Balancing
                3.23  Sharing the Air
                3.24  Timing Advance
                                3.24.1  Why is Timing Advance Useful?
                                3.24.2  How Accurate are Distance Estimates Using Timing Advance?
                                3.24.3  Timing Advance Band Depth and Maximum Range
                3.25  Expressing Power
Chapter 4 - SIM Card Basics
                4.1  Mobile Virtual Network Operators (MVNOs)
                4.2  Size
                4.3  Native Versus Multi-SIMs or MNO Versus MVNO
                4.4  Home Versus Roaming Access
                4.5  SIM Factors Affecting Price and Coverage
                                4.5.1  How Much Do SIM Cards Cost?
                                4.5.2  Is there a Monthly Activation Fee?
                                4.5.3  Are There Fees for Activating and/or Deactivating SIM Cards?
                                4.5.4  How Much Does Data Cost
                                4.5.5  Is the Monthly Data FPooled"?
                                4.5.6  Are There Fees for Deactivated (but not Terminated) SIMS Cards?
                                4.5.7  Is There a Not-Yet-Activated Fee?
                4.6  Text Messages (SMS)
                4.7  Usage Limits
                4.8  Firewalls
                4.9  Replacing SIMs and/or Network Providers
                4.10  Access Point Name (APN)
Chapter 5 - Verify Cellular Connectivity
                5.1  Preparation
                                5.1.1  Adequate Power
                                5.1.2  Activated SIM Card
                                5.1.3  Base Station in Range
                                5.1.4  SIM Card Authorization
                                5.1.5  Band Configuration
                                5.1.6  RAT Configuration
                                5.1.7  Automatic Registration
                5.2  Try to Auto-Register
                5.3  What Can Go Wrong?
                                5.3.1  Operating System Interference
                                5.3.2  Communicating With Modem
                                5.3.3  Malformed AT commands
                                5.3.4  Parsing Responses to AT Commands
                                5.3.5  Timing Problems
                                5.3.6  Unset or Incorrect Access Point Name (APN)
                5.4  Modem Configuration for Auto-Registration
Chapter 6 - Let's Move Some Data
                6.1  Low-level Sockets or High Level Protocols
                6.2  Verify ServerServer is Running
                6.3  Verify EchoServer is Running
                6.4  USB or UART?
                6.5  AT Commands - a Troubled Past
                6.6  Unsolicited Response Codes (URCs)
                6.7  A Handy Modem Program
                6.8  AT Commands Manuals
                6.9  Communicating with the Cellular Modem
                6.10  Getting EchoServer Information from ServerServer
                6.11  Bouncing Data off EchoServer
                6.12  No Problems is Bad Luck
Chapter 7 - Cellular Connectivity Regions
                7.1  How Geography, Topology and Population Density Affect Connectivity
                                7.1.1  Geography and Topology
                                7.1.2  Population Density
                7.2  Region Categories
                                7.2.1  Rural
                                7.2.2  Rural Town
                                7.2.3  Flat Farmland/Flat Arid
                                7.2.4  Mountainous
                                7.2.5  Suburban
                                7.2.6  Dense City
                                7.2.7  Interstate Highway
                                7.2.8  Uninhabited
Chapter 8 - Cellular Communication Modules (CCMs)
                8.1  CCM Worldwide Market Share
                8.2  Frequency Band Usage
                8.3  Protocol Implementation
                8.4  Similarities and Differences Across CCMs
                                8.4.1  Single or Dual AT Command Channels
                                8.4.2  Different AT command Sets
                                8.4.3  Different Response Times for Similar or Identical Commands
                                8.4.4  Differing Response Formats
                                8.4.5  Differing Responses For Compound Statements
                                8.4.6  Different Timing Requirements
                                8.4.7  AT Command are not Thread-Safe
                                8.4.8  Support For Different Protocols
                8.5  Consider the Whole CCM Family
                8.6  CCM Firmware Bugs
                8.7  CCMs, Are a Lot Like Sensors: Imprecise and not Entirely Reliable
Chapter 9 - AT Commands (a New Approach)
                9.1  Purpose of AT Commands
                9.2  Problems of AT Commands
                                9.2.1  Maximum Response Time for an AT Command
                9.3  Traditional Solution to Executing AT Commands and Extracting Responses
                9.4  Command Independent Processing (CIP)
                                9.4.1  The Central Observation Underlying CIP
                                9.4.2 Fundamental Elements of CIP
                                                9.4.2.1  AtParams
                                                9.4.2.2  AtCommand
                                9.4.3  AT Command in CIP
                                                9.4.3.1  Step 1 - Define a Name for a Command
                                                9.4.3.2  Step 2 - Create a Set of Parameters for Each Command              
                                                9.4.3.3  Step 3 - Store the Command Name and AtParams Object in a Map
                                                9.4.3.4  Step 4 - Create a Command Object
                                                9.4.3.5  Step 5 - Pass Arguments to the Command Object (if necessary)
                                                9.4.3.6  Step 6 - Perform the Command
                                                9.4.3.7  Step 7 - Verify Success or Failure
                                                9.4.3.8  Step 8 - Extract Response Information
                                                9.4.3.9  AT Commands with Parameters
                                                9.4.3.10  Timing Out
                                9.4.4  Using CIP Across CCM Families and Across Manufacturers
Chapter 10 - CIP Design and Details
                10.1  Pseudocode Conventions
                                10.1.1  Identifier Names
                                10.1.2  Angle Brackets
                                10.1.3  Constructors
                                10.1.4  Dot Operator
                                10.1.5  Unified Modeling Language (UML)
                10.2  A Note on Objected-Orientation and Threads
                10.3  AT Command Basics
                                10.3.1  Echoing
                                10.3.2  Enable/Disable Response Codes
                                10.3.3  Short or Long Response Codes
                                10.3.4  Line Terminators
                                10.3.5  Housekeeping
                10.4  Categories of Responses to AT Commands
                                10.4.1  OK_ONLY
                                10.4.2  TEXT_OK
                                10.4.3  AFTER_COLON
                                10.4.3  OK_PLUS_AFTER_COLON
                                10.4.5  MULTI_RECEIVE
                                10.4.6  MULTI_SEND
                                10.4.7  MULTI_AFTER_COLON
                10.5  Details of Command Independent Processing (CIP)
                                10.5.1  AtStep Purpose
                                10.5.2  AtStep Attributes
                10.6  A "Factory Method" for Creating AtCommand Objects
                10.7  Performing AT Commands
                                10.7.1  Why AT Commands Fail
                                10.7.2  Timing Out
                                10.7.3  Details of the Execute Method
                                10.7.4  Response Length
                                10.7.5  Hardware Timing
                                10.7.6  Combining Parameter Settings - Method Chaining
                                10.7.7  Assessing Success, and Multiple Tries
                                10.7.8  Multi-Line AT Commands - AtStep
                                10.7.9  A Second Example With a Regular Expressions
                                10.7.10  Integrating AtStep Into the execute Methods
                10.8  AT Commands For Multiple Modems
                                10.8.1  The Simplest Case
                                10.8.2  Connectors
                                                10.13.2.1  All Connectors Are Also Threads
                                                10.13.2.2  Connectors Are Created Using a Factory Method
                                                10.13.2.3  Custom AT Commands are Added In Static Blocks of Connectors
                                                10.13.2.4  Where to Override Methods or Parts of Methods
                                10.8.3  An Asymmetrical Case - AtParamsNoOp
Chapter 11 - Geographical Coverage, Signal Strength and Quality
                11.1  Radio Technologies (RATs)
                11.2  Cellular Network Coverage Maps
                11.3  Signal Strength and Quality: RSSI, RSRP, RSRQ, SINR
                                11.3.1  RSSI and RSRP
                                11.3.2  RSRQ
                                11.3.3  SINR
                                11.3.4  Using Modem For to Report Signal Strength and Quality
                11.4  Antenna Selection and Performance
                                11.4.1  Antenna Size
                                11.4.2  Passive Versus Active Antennas
                                11.4.3  Antenna Connectors
                                11.4.4  Antenna Placement
                11.5  Antenna Testing
                11.6  Geography and Signal Strength Must Be Considered Together
Chapter 12 - Network Selection and Registration
                12.1  Network Registration
                12.2  Radio Access Technology (RAT)
                12.3  Network Frequency Band Selection
                12.4  PLMN Selection
                                12.4.1  Manual PLMN Selection
                                12.4.2  Automatic PLMN Selection
                12.5  How to Create Your Own User Preference List
                                12.5.1  Reading the UPL and OPL
                                12.5.2  Modifying the UPL
                12.6  Once a PLMN is Auto-Selected, Is it Always Selected?
                12.7  Forcing the CCM Back to the PLMN Preference List
                12.8  A Mysterious PLMN Selection Behavior
                12.9  Troubleshooting Registration Problems
                                12.9.1  New Modem, Never Registered
                                12.9.2  Old Modem, Previously Registered
                12.10  Anomalous Behavior
Chapter 13 - Communication Protocols: TCP, UDP, PPP and Hybrids
                13.1  Internet Protocol (IP)
                13.2 Transmission Control Protocol (TCP)
                13.3  Considering Data Consumption
                13.4  User Datagram Protocol (UDP)
                13.5  TCP Pros and Cons
                13.6  Point-to-Point Protocol (PPP)
                13.7  AT Commands for Data Transfer are Completely Unstandardized
                13.8  PPP on Linux
                                13.8.1  Debugging PPP
                13.9  Alternatives to PPP
Chapter 14 - Thin Air
                14.1  A Most Dramatic Case
                                14.1.1  Watching the Server
                                14.1.2  Packets Not Getting to the Server
                14.2  What Was Going On? Thin Air
                14.3  Why Did Thin Air Persist Over Hundreds of Miles?
                14.4  How to Detect Thin Air
                14.5  What to Do About Thin Air
                14.6  Minimizing the Size of a Thin Air Region
                14.7  A Hybrid UDP Protocol For Detecting Thin Air
                14.8  Reducing (or Eliminating) Thin Air by PLMN or Band Selection
                                14.8.1  The Most Direct Approach
                14.9  Putting the Hybrid Protocol to a Second Use
Chapter 15 - Time and Location (GNSS)
                15.1  Clarifying Terminology
                15.2  Time
                15.3  Location
                15.4  Obtaining Time information
                                15.4.1  Real-Time Clock (RTC)
                                15.4.2  Cellular Modem
                                                15.4.2.1  Additional Configuration
                                                15.4.2.2  Local Time or UTC
                                                15.4.2.3  Daylight Saving Time
                                                15.4.2.4  Using Modem to Read the Clock
                                15.4.3  Get Time From a GNSS Receiver
                                15.4.4  Get Time From a Server
                15.5  Sources of Location Information
                15.6  Pros and Cons of CCM's GNSS Receiver Versus Stand-Alone GNSS Receiver
                15.7  Cold Start, Warm Start, Hot Start
                15.8  Assisted GPS (A-GPS)
                15.9  GNSS Antenna Selection        
                15.10  GNSS Receiver Placement
                15.11  GNSS Accuracy and Precision
                                15.11.1  Improving Accuracy
                15.12  NMEA Sentences
                                15.12.1  Using Modem to Read GNSS Sentences
                15.13  Three Ways to Obtain Location Information
                15.13.1  Simple AT Command Request for Location
                15.13.2  Read Streaming Data From gpsd Daemon
                15.13.2.1  For a Stand-Alone GNSS Receiver
                15.13.2.2  For a CCM's GNSS Receiver
                15.13.3  Read Streaming Data Directly From CCM's GNSS receiver
                15.14  Understanding gpsd JSON Output
                15.15  Writing Software To Capture and Process gpsd Output
                15.16  GNSS Data Streamed From a CCM
                15.17  NMEA 0183
                                15.17.1  Talker Sentence Format
                                                15.17.1.2  RMC Sentence Format
                                                15.17.1.3  GSV Sentence Format
                                15.17.2  NMEA Checksums
                                15.17.3  CCM GNSS Receivers Only Stream Some NMEA Sentences
                15.18  Some Additional gpsd Utilities
                15.19  Setting System Time From Cellular Network, GNSS Time, or Server
Chapter 16 - Establishing and  Maintaining a Cellular Connection
                16.1  Modem Selection
                16.2  Foundational Tasks
                                16.2.1  State 1 - Detecting CCM
                                                16.2.1.1  Using Modem to Detect a CCM
                                16.2.2  State 2a - Initializing CMM
                                                16.2.2.1  Viewing Modem's Initializations
                                16.2.3  State 2b - Waiting to Retry
                                16.2.4  State 3 - Set MNO
                                16.2.5  State 4 - Checking Registration Status
                                                16.2.5.1  Using Modem to Check Registration Status
                                16.2.6  State 5 - Connecting
                                16.2.7  State 6 - Manage Connection
Chapter 17 - Sending and Receiving Text Messages (SMS)
                17.1  Why Send/Receive Text Messages?
                                17.1.1  Need to "Push" Information to an IoT Device
                                17.1.2  Serverless IoT Devices That Interact With End-Users
                17.2  Cost of Text Messaging via Cellular Modem
                17.3  Application-to-Person (A2P) Messaging is Often Regulated
                17.4  Overview of Sending/Receiving Text Messages
                17.5  Sending Text Messages
                                17.5.1  Set the Message Format
                                17.5.2  Set Parameters for Sending
                                17.5.3  Specify the Destination Phone Number and the Text to Send
                                17.5.4  What if Sending an SM Fails?
                                17.5.5  Using Modem to Send a Text Message
                17.6  Receiving and Reading a Text Messages
                                17.6.1  Configure the CCM              
                                                17.6.1.1  Set the Message Format
                                                17.6.1.2  Configure SMS Storage
                                                                Pitfall: Don't Forget to Align Memory Blocks
                                                17.6.1.3  Check for a Received Text Messages
                                                17.6.1.4  Using Modem to List Text Messages
                                                17.6.1.5  Delete a Text Messages
                                                17.6.1.6  Using Modem to Delete a Text Message
                17.7  SMS with Constrained Devices
                                17.7.1  Set the Message Format
                                17.7.2  Set Parameters for Writing to mem-2
                                17.7.3  Specify the Destination Phone Number and Text to Store
                                17.7.4  Send a Text Message Already Stored in mem-2
                                17.7.5  Verifying a Text Message Was Sent From mem-2
                17.8  Integrating SMS into CIP
Chapter 18 - Power Saving Modes and Techniques
                18.1  What are Low-Power CCMs (LP-CCMs)
                18.2  Plenty of Power, Most of the Time
                18.3  Low-Power IoT Devices
                                18.3.1  Microcontroller Energy Consumption
                                18.3.2  Temperature Sensor Energy Consumption
                18.4   Battery Capacity
                18.5  Transmitter Power
                18.6  Legacy (GSM) Power Consumption
                18.7  Cellular Modem Energy Consumption
                                18.7.1  Additional Energy Consumption
                18.8  Network Registration States - RRC_CONNECTED and RRC_IDLE
                                18.8.1  RRC_CONNECTED (without DRX)
                                                18.8.1.1  Scenario 1 - Sending a Location Packet
                                                18.8.1.2  Scenario 2 - Fetching an Over the Air Update
                                18.8.2  RRC_IDLE (without DRX)
                                18.8.3  Discontinuous Reception (DRX)
                                                18.8.3.1  Discontinuous Reception in RRC_IDLE (iDRX)
                                                18.8.3.2  Discontinuous Reception in RRC_CONNECTED (cDRX)
                                18.8.4  Registration Characteristics Summary
                18.9  Latency
                18.10  Using Low-Power CCM - Cat M and NB-IoT and Cat 1 bis
                18.11  Power Saving Mode (PSM)
                                18.11.1  How to Enable PSM
                                                18.11.1.1  Using Modem to Enter PSM
                                18.11.2  Verifying PSM and Possible Problems or Surprises
                                                18.11.2.1  Using Modem to Check PSM Status
                                18.11.3  Actual PSM Cycle Length
                                18.11.4  Exiting PSM
                                                18.11.4.1  Using Modem to Exit PSM
                                18.11.5  Sending Data From PSM Inactive
                                18.11.6  PSM Effectiveness
                                18.11.7  Integrating PSM into CIP
                18.12  Extended Discontinuous Reception (eDRX)
                                18.12.1  How to Enable eDRX
                                                18.12.1.1  Using Modem to Enable eDRX
                                18.12.2  Verifying eDRX Cycle Length
                                                18.12.2.1  Using Modem to Check eDRX Status
                                18.12.3  Disabling eDRX
                                                18.12.3.1  Using Modem to Disable eDRX
                                18.12.4  Integrating eDRX into CIP
                18.13  When to Use PSM, eDRX or Both
                18.14  Don't Trust the Numbers
 
Appendix A - A UML Primer
                A.1  Assumptions
                A.2  UML Syntax
                A.3  Visibility (private, protected, public)
                A.4  Attribute/Parameter/Method Names and Types
                A.5  Class Attributes and Methods
   

A propos de l'auteur

Matthew A. Brenner, President, Singular IoT, VA, USA. Matt manufactures electronic equipment for vehicle tracking and a line of cellular modems and has developed specialized software and hardware tools and custom communication protocols for investigating cellular connectivity anomalies. He has vast experience teaching computer science and software engineering at every level. He offers consulting services to help companies achieve the best cellular connectivity for their IoT devices.

Détails du produit

• Auteurs: Matthew A Brenner, Matthew A. Brenner, Matthew A. (Duke University Brenner, Harvard Grad
• Edition: Wiley, John and Sons Ltd
• Langues: Anglais
• Format d'édition: Livre Relié
• Sortie: 24.11.2025
• EAN: 9781394329656
• ISBN: 978-1-394-32965-6
• Pages: 480
• Catégories: Sciences naturelles, médecine, informatique, technique > Technique > Electronique, électrotechnique, technique de l'information; TECHNOLOGY & ENGINEERING / Signals & Signal Processing, TECHNOLOGY & ENGINEERING / Mobile & Wireless Communications, Mobile phone technology, Signal Processing, Communications engineering / telecommunications, WAP (wireless) technology, Electronics & Communications Engineering