As we know, Industrial Internet of Things (IIoT) refers to the ecosystem of connected devices in industrial fields: manufacturing, health care, building automation, machine-to-machine communications and others. After thousands of devices have been already deployed, one important question remains: How can we safely modify and update?

In industrial environments, it is not feasible to update remote devices using the traditional method, which involves connecting each embedded device to a PC with a cable. If not updated, the devices can miss out on critical security improvements and bug fixes. Nowadays, there is a technology called OTA. An over-the-air (OTA) update is a mechanism for remotely updating internet-connected hardware with new settings, software, and/or firmware.

OTA Update Framework for IIoT

There are different methods for OTA updates, but the most common are as follows:

• Edge-to-cloud: a microcontroller on the edge device connected to the internet directly receives new firmware images from a remote server. In this scenario, the Cloud performs the role of a dispatcher that transmits the firmware to the edge/gateway or IoT devices that need to be upgraded.
• Gateway-to-cloud: a set of local edge devices are connected to a gateway that manages these devices. The gateway receives updates from a remote server. This update allows updating the gateway firmware, the host’s environment.
• Edge-to-gateway-to-cloud: the gateway connected to the internet receives updates from the remote server and distributes this update to the local edge devices. Here the edge gateway is a dispatcher that downloads the firmware from the server, and then dispatches to another edge/gateway or IoT device that is under the dispatcher and needs to be upgraded.

As the choice of an OTA update method depends on the project and system requirements, updates with cloud gateways can be a safer and more secure option.

The Role of IoT Gateway in the OTA Update

A gateway is a bridge between edge devices and cloud; it manages traffic between networks that use different protocols. A cloud gateway performs protocol translation tasks. It also acts as a proxy server for devices on the field that do not feature wireless communication capabilities. The IoT gateway receives data from those devices and packages the information for transmission over TCP/IP.

Some applications require using gateway because the remote devices do not have wireless capabilities, for example, industrial equipment and Bluetooth devices. Devices that don’t have electrical power to perform network transmission or don’t have processing capability of TLS are also required to be connected to the gateway for updates.

Advantages of Gateway in OTA Framework

• Reduces loading of the Cloud.
• IoT devices upgraded in the LAN are supposed to be more secure than WAN.
• Can schedule a dispatch to balance the working devices and upgrading devices while OTA is processing.

Summary

In industrial IoT applications, many systems are safety-critical and require continuous updating to meet high technical requirements to quality, security and efficiency of industry safety standards. A system that deploys gateways for an OTA update is reliable and secure. The IoT gateway plays an important role in the process of managing remote devices. Choose the right device wisely for your application.