What is FOTA? How does it work? (Updated)

how fota works

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Wondering How FOTA Works? FOTA Android? First, let us understand what it is! FOTA (Firmware Over The Air) is a technology which helps manufacturers to update their devices once sold. The technology enables the device makers to deliver the wireless update for their devices. FOTA can be used with all the devices connected virtually.

The need for FOTA:

Device manufacturers or network operators need to fix the bugs present in the software. They also need to give the refresh to the operating system installed in the device when available for the years on their policy. Sometimes they have to give some new software features because of the market trends as well. That’s why FOTA is needed.

FOTA Architecture:

how fota works

How FOTA Works?

The word FOTA is self-explanatory. FOTA updates devices ‘over the air’. But it does work in two ways. 

Binary Replacement

Binary Replacement is the least complex refresh method utilized for firmware refreshes over the air and in addition, wired. To play out a refresh utilizing twofold substitution, the firmware double document must be downloaded totally first. In the middle of the downloading and refresh process, a few inquiries show up. The first is the place to store the new firmware and the second which mode the firmware is running amid download.

Following regularly utilized ideas are set up to address these inquiries:

The firmware update is put away in an explicit piece of the unstable blaze, amid the download ordinary task mode can be kept. When the firmware download is finished the activity mode is changed to refresh mode, which is regularly part of the bootloader. This mode requires the most memory assets on the refreshed gadget because of the way that no less than twofold of the memory space must be given. In the event that a rollback instrument is required no less than multiple times space is required – 1x running application, 1x new firmware, 1x rollback firmware. The preferred standpoint on the opposite side is that such gadget is difficult to block by a flawed firmware refresh or even by an intrusion amid the over the air refresh.


The device is running in a specific update mode (ordinarily in the bootloader) and updates the firmware on the fly. This is the most perilous ideas because of the reality, that each issue amid the update procedure can prompt a bricked device. The hazard for this state can be limited having a rollback alternative set up, somewhere around one with least usefulness yet the likelihood for another firmware update shot.

The device is running in a device refresh mode and composes the information amid the download to a non-unpredictable memory first. When all information is downloaded it will supplant the old firmware. This technique isn’t that sensitive to unforeseen resets like the past one however can, in any case, lead to a bricked device.

Binary Patching

Binary Patching is a strategy to lessen the information which must be transmitted amid the over the RF interface – in this manner “over the air”. For this system, the information of the right now introduced firmware adaptation is required. Together with this data a fix is made on the refresh server and send to the gadget. A fix contains just the contrasts between two adaptations and the position where they are situated in the present firmware. Amid the download of the fix, the gadget can remain operable and change to refresh mode when the download is finished. Because of the reality, that the firmware is controlled straightforwardly there is as yet a high hazard to have a bricked device in the event of a surprising reset, which must be taken care of legitimately.

Is FOTA Safe?

Selecting the FOTA partner is mostly an important thing if you have to get a one. If the FOTA partner is not trustworthy, it may install some adware or spyware over the air. And that can be a huge risk. 

If you are a manufacturer then you should have at least a firmware signature and signature checking mechanism. Thus, this is How FOTA Works. Any questions? Let us know in the comments.

Also Read: What is Industry 4.0?