Over-the-air update

An over-the-air update (or OTA update), also known as over-the-air programming (or OTA programming), is an update to an embedded system that is delivered through a wireless network, such as Wi-Fi or a cellular network. These embedded systems include mobile phones, tablets, set-top boxes, cars and telecommunications equipment. OTA updates for cars and internet of things devices can also be called firmware over-the-air (FOTA). Various components may be updated OTA, including the device's operating system, applications, configuration settings, or parameters like encryption keys. The term over-the-air update applies specifically to embedded systems, rather than non-embedded systems like computers. Before OTA updates, embedded devices could only be flashed through direct physical access (with a JTAG) or wired connections (usually through USB or a serial port). Over-the-air delivery may allow updates to be distributed at larger scales, reduce the cost of delivering updates, or increase the rate of adoption of these updates. The distributor of these updates can decide whether users are allowed to decline these updates, and may choose to disable certain features on end-user devices until an update is applied. Users may be unable to revert an update after it is installed. OTA updates are designed to be as small as possible in order to minimize energy consumption, network usage, and storage space. This is achieved by only transferring the differences between the old firmware and the new firmware, rather than transmitting the entire firmware. A delta of the old and new firmware is produced through a process called diffing; then, the delta file is distributed to the end-device, which uses the delta file to update itself. On smartphones, tablets, and other devices, an over-the-air update is a firmware or operating system update that is downloaded by the device over the internet. Previously, users had to connect these devices to a computer over USB to perform an update. These updates may add features, patch security vulnerabilities, or fix software bugs.