87 Protocol Decision Frameworks

Visual Decision Trees and Reference Matrices for Protocol Selection

87.1 Decision Framework Reference

Learning Objectives

By studying these decision frameworks, you will be able to:

Navigate decision trees to quickly identify suitable protocols based on range and power needs
Map use cases to protocols using scenario-based selection guides
Understand protocol trade-offs through visual power/range matrices
Apply quick decision rules for common IoT deployment scenarios

87.2 Prerequisites

Before using these frameworks, you should understand:

Protocol Selector Overview: Introduction to protocol selection concepts
IoT Protocols Overview: Basic understanding of IoT protocol categories

87.3 Quick Decision Guide

Quick Decision Guide

Use this flowchart when you need a quick protocol decision:

If you need…	And also need…	Consider…
Long range (km)	Battery (years)	LoRaWAN, Sigfox, NB-IoT
Long range (km)	Low latency	LTE-M, 5G
Short range (m)	High bandwidth	Wi-Fi
Short range (m)	Battery life	BLE, Zigbee, Thread
Mesh networking	Low power	Zigbee, Thread
Mesh networking	IP-native	Thread
Touch range	Instant	NFC
No battery	Tracking	UHF RFID

87.4 Protocol Decision Flowchart

%%{init: {'theme': 'base', 'themeVariables': {'primaryColor': '#E8F4F8', 'primaryTextColor': '#2C3E50', 'primaryBorderColor': '#16A085', 'lineColor': '#16A085', 'secondaryColor': '#FEF5E7', 'tertiaryColor': '#FDEBD0'}}}%%
flowchart TD
    Start([Start]) --> Range{Range needed?}

    Range -->|< 10m| Touch{Touch required?}
    Range -->|10-100m| Building{Power source?}
    Range -->|100m-1km| Campus{Licensed spectrum?}
    Range -->|> 1km| Wide{Mobility needed?}

    Touch -->|Yes| NFC[NFC]
    Touch -->|No| BLE1[BLE]

    Building -->|Battery| Mesh{Mesh needed?}
    Building -->|Mains| BW{High bandwidth?}

    Mesh -->|Yes| ZT[Zigbee/Thread]
    Mesh -->|No| BLE2[BLE]

    BW -->|Yes| Wi-Fi[Wi-Fi]
    BW -->|No| ZT2[Zigbee/Thread]

    Campus -->|No| LoRa[LoRaWAN]
    Campus -->|Yes| NBIoT[NB-IoT]

    Wide -->|Yes| LTEM[LTE-M]
    Wide -->|No| LPWAN{Budget?}

    LPWAN -->|Low| Sigfox[Sigfox]
    LPWAN -->|Flexible| LoRa2[LoRaWAN]

    style Start fill:#2C3E50,stroke:#16A085,color:#fff
    style NFC fill:#16A085,stroke:#2C3E50,color:#fff
    style BLE1 fill:#16A085,stroke:#2C3E50,color:#fff
    style BLE2 fill:#16A085,stroke:#2C3E50,color:#fff
    style ZT fill:#16A085,stroke:#2C3E50,color:#fff
    style ZT2 fill:#16A085,stroke:#2C3E50,color:#fff
    style Wi-Fi fill:#E67E22,stroke:#2C3E50,color:#fff
    style LoRa fill:#2C3E50,stroke:#16A085,color:#fff
    style LoRa2 fill:#2C3E50,stroke:#16A085,color:#fff
    style NBIoT fill:#E67E22,stroke:#2C3E50,color:#fff
    style LTEM fill:#E67E22,stroke:#2C3E50,color:#fff
    style Sigfox fill:#2C3E50,stroke:#16A085,color:#fff

Figure 87.1: Protocol selection decision flowchart: Start with range requirements, then consider power, mesh needs, bandwidth, and mobility to arrive at the optimal protocol choice.

87.4.1 How to Use This Flowchart

Start with Range: Your communication distance is typically the strongest constraint
Consider Power: Battery-powered devices eliminate high-power protocols
Evaluate Topology: Mesh networks offer flexibility but add complexity
Check Bandwidth: Video and audio require high-bandwidth protocols
Factor Mobility: Moving devices need handoff-capable protocols

87.5 Scenario-Based Protocol Mapping

%%{init: {'theme': 'base', 'themeVariables': {'primaryColor': '#2C3E50', 'primaryTextColor': '#fff', 'primaryBorderColor': '#16A085', 'lineColor': '#7F8C8D', 'secondaryColor': '#E67E22', 'tertiaryColor': '#16A085'}}}%%
flowchart LR
    subgraph SCENARIO["Common IoT Scenarios"]
        direction TB
        S1["Smart Home"]
        S2["Industrial Monitoring"]
        S3["Asset Tracking"]
        S4["Smart Agriculture"]
        S5["Wearables"]
        S6["Video Surveillance"]
    end

    subgraph PRIMARY["Primary Protocol Choice"]
        direction TB
        P1["Thread/Zigbee"]
        P2["Wi-Fi/Ethernet"]
        P3["LTE-M/LoRaWAN"]
        P4["LoRaWAN/NB-IoT"]
        P5["BLE"]
        P6["Wi-Fi/5G"]
    end

    subgraph FALLBACK["Fallback Options"]
        direction TB
        F1["BLE, Wi-Fi"]
        F2["5G, NB-IoT"]
        F3["Sigfox, NB-IoT"]
        F4["Sigfox, LTE-M"]
        F5["NFC, Thread"]
        F6["LTE-M, Ethernet"]
    end

    S1 --> P1 --> F1
    S2 --> P2 --> F2
    S3 --> P3 --> F3
    S4 --> P4 --> F4
    S5 --> P5 --> F5
    S6 --> P6 --> F6

    style SCENARIO fill:#2C3E50,stroke:#16A085,stroke-width:2px,color:#fff
    style PRIMARY fill:#16A085,stroke:#2C3E50,stroke-width:2px,color:#fff
    style FALLBACK fill:#E67E22,stroke:#2C3E50,stroke-width:2px,color:#fff
    style S1 fill:#7F8C8D,stroke:#2C3E50,color:#fff
    style S2 fill:#7F8C8D,stroke:#2C3E50,color:#fff
    style S3 fill:#7F8C8D,stroke:#2C3E50,color:#fff
    style S4 fill:#7F8C8D,stroke:#2C3E50,color:#fff
    style S5 fill:#7F8C8D,stroke:#2C3E50,color:#fff
    style S6 fill:#7F8C8D,stroke:#2C3E50,color:#fff

Figure 87.2: Scenario-based protocol mapping - This alternative view maps common IoT use cases directly to recommended protocols. Rather than navigating a decision tree, engineers can find their scenario (navy column) and immediately see the primary protocol choice (teal column) along with fallback options (orange column). Smart Home maps to Thread/Zigbee with BLE/Wi-Fi fallbacks. Industrial Monitoring uses Wi-Fi/Ethernet primarily with 5G/NB-IoT alternatives. Asset Tracking favors LTE-M/LoRaWAN with Sigfox/NB-IoT backups. Smart Agriculture uses LoRaWAN/NB-IoT with Sigfox/LTE-M options. Wearables rely on BLE with NFC/Thread alternatives. Video Surveillance requires Wi-Fi/5G with LTE-M/Ethernet fallbacks. {fig-alt=“Scenario-based protocol selection diagram with three columns. Left column (navy, Common IoT Scenarios): Smart Home, Industrial Monitoring, Asset Tracking, Smart Agriculture, Wearables, Video Surveillance. Middle column (teal, Primary Protocol Choice): Thread/Zigbee, Wi-Fi/Ethernet, LTE-M/LoRaWAN, LoRaWAN/NB-IoT, BLE, Wi-Fi/5G. Right column (orange, Fallback Options): BLE and Wi-Fi, 5G and NB-IoT, Sigfox and NB-IoT, Sigfox and LTE-M, NFC and Thread, LTE-M and Ethernet. Arrows connect each scenario to its primary choice and then to fallback options.”}

87.5.1 Scenario Details

Scenario	Why Primary	When to Use Fallback
Smart Home	Thread/Zigbee offer mesh reliability and Matter compatibility	BLE for wearable integration, Wi-Fi for cameras
Industrial Monitoring	Wi-Fi/Ethernet provide bandwidth and reliability for factory floors	5G for mobile robots, NB-IoT for remote sites
Asset Tracking	LTE-M offers mobility support; LoRaWAN for fixed assets	Sigfox for simple telemetry, NB-IoT for indoor coverage
Smart Agriculture	LoRaWAN reaches across large farms without infrastructure	NB-IoT where cellular exists, Sigfox for simple sensors
Wearables	BLE is optimized for smartphone connectivity and low power	NFC for payments, Thread for smart home integration
Video Surveillance	Wi-Fi/5G handle bandwidth requirements	LTE-M for mobile cameras, Ethernet for permanent installations

87.6 Power and Range Matrix

%%{init: {'theme': 'base', 'themeVariables': {'primaryColor': '#2C3E50', 'primaryTextColor': '#fff', 'primaryBorderColor': '#16A085', 'lineColor': '#16A085', 'secondaryColor': '#E67E22', 'tertiaryColor': '#7F8C8D'}}}%%
graph TB
    subgraph LOW_POWER["Ultra-Low Power (Years on Battery)"]
        direction LR
        LP1["NFC<br/>Touch range"]
        LP2["BLE<br/>10-100m"]
        LP3["LoRaWAN<br/>2-15 km"]
        LP4["Sigfox<br/>3-50 km"]
    end

    subgraph MED_POWER["Low-Medium Power (Months on Battery)"]
        direction LR
        MP1["Zigbee<br/>10-100m mesh"]
        MP2["Thread<br/>10-100m mesh"]
        MP3["NB-IoT<br/>1-35 km"]
        MP4["LTE-M<br/>1-35 km"]
    end

    subgraph HIGH_POWER["High Power (Mains/Frequent Charge)"]
        direction LR
        HP1["Wi-Fi<br/>10-100m"]
        HP2["5G<br/>100m-10 km"]
        HP3["Ethernet<br/>100m wired"]
    end

    SHORT["Short Range<br/>(< 100m)"]
    LONG["Long Range<br/>(> 1 km)"]

    LP1 --> SHORT
    LP2 --> SHORT
    MP1 --> SHORT
    MP2 --> SHORT
    HP1 --> SHORT
    HP3 --> SHORT

    LP3 --> LONG
    LP4 --> LONG
    MP3 --> LONG
    MP4 --> LONG
    HP2 --> LONG

    style LOW_POWER fill:#16A085,stroke:#2C3E50,stroke-width:2px,color:#fff
    style MED_POWER fill:#E67E22,stroke:#2C3E50,stroke-width:2px,color:#fff
    style HIGH_POWER fill:#2C3E50,stroke:#16A085,stroke-width:2px,color:#fff
    style SHORT fill:#7F8C8D,stroke:#2C3E50,stroke-width:2px,color:#fff
    style LONG fill:#7F8C8D,stroke:#2C3E50,stroke-width:2px,color:#fff

Figure 87.3: Alternative view: Protocol Matrix by Power and Range - Instead of a decision tree, this diagram organizes protocols by two key dimensions: power consumption (rows) and range (connections). Ultra-low power protocols (teal, years on battery) include NFC, BLE, LoRaWAN, and Sigfox. Low-medium power protocols (orange, months on battery) include Zigbee, Thread, NB-IoT, and LTE-M. High power protocols (navy, mains/frequent charging) include Wi-Fi, 5G, and Ethernet. The connections show which protocols serve short range (< 100m) vs. long range (> 1km). This matrix view helps engineers quickly narrow down options based on their two most critical constraints. {fig-alt=“Protocol matrix diagram organized by power consumption and range. Ultra-Low Power row (teal, years on battery): NFC at touch range, BLE at 10-100m, LoRaWAN at 2-15 km, Sigfox at 3-50 km. Low-Medium Power row (orange, months on battery): Zigbee at 10-100m mesh, Thread at 10-100m mesh, NB-IoT at 1-35 km, LTE-M at 1-35 km. High Power row (navy, mains or frequent charge): Wi-Fi at 10-100m, 5G at 100m-10 km, Ethernet at 100m wired. Lines connect each protocol to either Short Range (less than 100m) or Long Range (greater than 1km) categories at the bottom.”}

87.6.1 Understanding the Matrix

Ultra-Low Power (Teal): These protocols enable 5-10 year battery life through aggressive duty cycling and minimal transmit power.

NFC: Passive operation, power harvested from reader
BLE: Designed for coin cell batteries, excellent sleep modes
LoRaWAN: Long sleep periods, brief transmissions
Sigfox: Extreme simplicity, minimal on-air time

Low-Medium Power (Orange): These protocols balance functionality with battery life, typically supporting months of operation.

Zigbee: Router nodes need power; end devices can sleep
Thread: Similar to Zigbee but with IP overhead
NB-IoT: Cellular efficiency modes (PSM, eDRX)
LTE-M: Higher bandwidth means higher power than NB-IoT

High Power (Navy): These protocols require mains power or frequent charging but offer maximum capability.

Wi-Fi: Always-on connectivity, high throughput
5G: Maximum bandwidth and minimum latency
Ethernet: Highest reliability, often with PoE

87.7 Protocol Selection Quick Reference

Protocol Selection Quick Reference

Use this table while making protocol decisions:

Constraint	Best Protocols	Why
Years on battery	LoRaWAN, Sigfox, BLE	Ultra-low power duty cycles
Sub-10ms latency	5G, Ethernet, Wi-Fi	Low-latency by design
Tiny MCU (< 64KB)	CoAP, LwM2M	Minimal code footprint
Self-healing mesh	Zigbee, Thread, Z-Wave	Automatic route discovery
5+ km range	LoRaWAN, NB-IoT, Sigfox	LPWAN technologies
HD video streaming	Wi-Fi, 5G, Ethernet	High bandwidth capacity
Touch-based	NFC	Inherent proximity security
Passive tags	UHF RFID	No battery required

87.8 Protocol Comparison by Category

87.8.1 Short-Range Protocols (< 100m)

Protocol	Range	Data Rate	Power	Best For
BLE	10-100m	125 kbps - 2 Mbps	Ultra-low	Wearables, beacons
Wi-Fi	10-100m	11 Mbps - 1 Gbps	High	Cameras, gateways
Zigbee	10-100m	20-250 kbps	Low	Smart home, sensors
Thread	10-100m	20-250 kbps	Low	Matter devices
Z-Wave	30-100m	10-100 kbps	Low	Security, HVAC

87.8.2 Long-Range Protocols (> 1km)

Protocol	Range	Data Rate	Power	Best For
LoRaWAN	2-15 km	0.3-50 kbps	Ultra-low	Agriculture, utilities
Sigfox	3-50 km	0.1-0.6 kbps	Ultra-low	Simple telemetry
NB-IoT	1-35 km	20-250 kbps	Low	Smart meters
LTE-M	1-35 km	375 kbps - 1 Mbps	Medium	Fleet tracking
5G	100m-10 km	1 Mbps - 10 Gbps	High	Industrial, AR/VR

87.8.3 Special Purpose Protocols

Protocol	Range	Data Rate	Power	Best For
NFC	< 10cm	106-424 kbps	Ultra-low	Payments, pairing
UHF RFID	0-12m	40-640 kbps	Passive	Inventory tracking
Ethernet	100m	10 Mbps - 10 Gbps	N/A	Industrial backbone

87.9 Summary

These decision frameworks provide multiple approaches to protocol selection:

Decision Flowchart: Navigate step-by-step based on requirements
Scenario Mapping: Jump directly from use case to protocol recommendation
Power/Range Matrix: Visualize trade-offs between two key constraints
Quick Reference Tables: Fast lookup for specific requirements

Key Takeaways

Range is the primary filter - Start by eliminating protocols that cannot meet your distance requirements
Power drives battery life - Ultra-low power protocols enable years of operation
Bandwidth limits applications - Video and audio require high-bandwidth protocols
Consider fallback options - Always have a secondary protocol in mind
Match protocol to scenario - Use scenario mapping for quick decisions

87.10 What’s Next

Interactive Wizard: Get personalized protocol recommendations
Protocol Matching Game: Test your protocol selection knowledge
Protocol Selector Overview: Return to the main wizard hub
Architecture Planner: Design your complete IoT system