openskills.info
Course catalog
Course Preview

IoT Connectivity Protocols

IoT connectivity protocols are the rules that let sensors, actuators, gateways, and services exchange data. A working design combines a physical link, a network path, and an application protocol that fit the device's power, range, data, and reliability limits.

itComputer architecture and hardware

IoT Connectivity Protocols

An Internet of Things device rarely uses one connectivity protocol. It uses a stack. A radio or wire carries frames. A network layer moves packets between addresses. A transport handles delivery between endpoints. An application protocol gives messages a useful interaction model.

A battery sensor might use an IEEE 802.15.4 radio, IPv6 compressed by 6LoWPAN, UDP, and CoAP. Another device might use cellular LTE-M, TCP, TLS, and MQTT. Both devices can report measurements, but they have different power budgets, failure modes, infrastructure, and security boundaries.

The central design task is therefore not "choose MQTT or Bluetooth." MQTT is an application-layer messaging protocol. Bluetooth Low Energy is a complete short-range wireless system with its own physical and link layers. They solve different parts of the path and can sometimes appear in the same system.

The path from device to application

A typical telemetry path contains five roles:

  1. The endpoint samples a sensor or controls an actuator.
  2. The access link moves data to a peer, access point, mesh neighbor, base station, or gateway.
  3. A gateway or border router connects unlike networks when the endpoint cannot reach the wider IP network directly.
  4. A transport and application protocol carries measurements, state, and commands.
  5. A service accepts requests or messages and applies device identity, authorization, storage, and processing.
sensor or actuator
        │
        ▼
radio or wire → local network → gateway or border router → IP network
                                                        │
                                                        ▼
                                             broker or resource server
                                                        │
                                                        ▼
                                                  application

Not every deployment needs every role. A Wi-Fi device can use IP directly through an access point. A Thread device uses IPv6 inside the mesh and a border router to reach adjacent IP networks. A Bluetooth Low Energy peripheral often communicates with a phone or gateway that terminates its GATT interaction and creates a separate upstream connection. A LoRaWAN end device sends frames through gateways to network infrastructure before application data reaches its destination.

Separate the layers before comparing protocols

Protocol names become easier to compare when placed at the layer where they act.

Layer or roleRepresentative choicesMain decision
Physical and linkEthernet, Wi-Fi, Bluetooth LE, IEEE 802.15.4, LoRa radio, cellular radioSpectrum, range, energy, throughput, topology, and infrastructure
Adaptation and routing6LoWPAN, IPv6, RPL, ThreadAddressing and packet movement across constrained links or meshes
Transport and securityUDP with DTLS or OSCORE; TCP with TLSConnection state, delivery behavior, overhead, and security boundary
ApplicationMQTT, CoAP, HTTP, LwM2M, Matter, Zigbee application profilesPublish and subscribe, resources, device management, or interoperable device behavior

Continue the course

This section is part of the paid course.

See pricing to subscribe, or log in if you already have access.

Where this skill leads

Relevant careers

See how this topic contributes to broader role-level skill maps.

Sources