IoT Gateway Architecture 101 — From Hardware and OS to Custom Application Layer

The design of an IoT gateway solution depends on the custom application and use case for which it is developed. For instance, the design of an IoT gateway for fleet management may differ from one that is used for industrial automation.

The gateway engineering team evaluates the following aspects during the design phase:

· Range of IoT sensors

· Power demands

· Performance

· Security

· Scalability

Let’s explore the basic building blocks of an IoT gateway architecture.

IoT Gateway Architecture

IoT Gateway Hardware

The hardware may comprise of a processor or microcontroller, based on the complexity of the application. A small application with limited memory requirements and processing speed can run on a microcontroller. In case the IoT gateway needs to perform complex operations, a processor is the optimum choice.

The hardware also incorporates protection circuitry and connectivity modules like Bluetooth, WiFi, Zigbee, etc.

Operating System

The IoT gateway operating system is chosen depending on the use case or type of application. For simple applications, Real Time Operating System (RTOS) is used. If there are complex operations to be performed, it is recommended to use Linux OS.

Automotive dashboard applications that require rich graphics and high-end Human Machine Interface (HMI) are usually developed on Android OS.

Hardware Abstraction Layer (HAL)

The HAL makes the software design hardware-agnostic. It supports portability and reusability of the IoT software. In case there is a need to redesign the hardware platform or migrate to a different platform, the effort and cost for the migration will be minimal.

IoT Sensors Stack

This layer consists of software stacks that are interfaces with the IoT sensor network.

Device Management and Configuration

This module is responsible for managing and configuring all the IoT devices or sensors. The configuration details of all the sensors are stored in the memory of the IoT gateway.

Security

This module ensures data security, network security and device security.

Check out our blog on IoT gateway security to learn more about this.

FOTA

Firmware Over the Air (FOTA) updates ensure that the IoT gateway software includes all the latest security patches. The gateway device regularly checks for software updates in the cloud. When the binaries are available, it fetches, authenticates and installs them.

In case there is a failure, the IoT gateway software reverts to the previous state.

Data Communication Protocols

A 2-way communication channel is present between the gateway device and the IoT cloud. The communication layer is based on UDP or TCP/IP protocol. The protocols selected also depend on the frequency and amount of data transfer.

Data Management

The IoT gateway manages the data transfer between the sensor network and the cloud. The data management module enables data streaming, filtering and storing to protect against connectivity issues with the cloud. It also minimises the delay in data transfer and ensures data accuracy.

Cloud Connectivity Manager

This module ensures seamless connectivity with the cloud and manages reconnection, heartbeat messages, device states, and gateway device authentication.

Custom Application

The custom application interacts with the functions and services of every other module in the IoT gateway architecture. It also ensures smooth sensor-gateway connectivity and gateway-cloud connectivity.

Check out our blog on architecture of IoT gateway for a deeper understanding of what we have discussed here.