# Over-the-Air Update  ## Metadata - Author: [[wikipedia.org]] - Full Title: Over-the-Air Update - Category: #articles - Summary: An over-the-air update (OTA update) allows devices like smartphones and cars to receive software updates wirelessly through networks like Wi-Fi or cellular. This process makes it easier to fix bugs, add features, and improve security without needing physical access to the device. However, OTA updates can also pose security risks if not properly protected against hacking. - URL: https://en.wikipedia.org/wiki/Over-the-air_update ## Highlights - The term *over-the-air update* applies specifically to [embedded systems](https://en.wikipedia.org/wiki/Embedded_system),[[4]](https://en.wikipedia.org/wiki/Over-the-air_update/#cite_note-:0-4) rather than non-embedded systems like computers. Before OTA updates, embedded devices could only be [flashed](https://en.wikipedia.org/wiki/Firmware#Flashing) through direct physical access (with a [JTAG](https://en.wikipedia.org/wiki/JTAG)) or wired connections (usually through [USB](https://en.wikipedia.org/wiki/USB) or a [serial port](https://en.wikipedia.org/wiki/Serial_port)). ([View Highlight](https://read.readwise.io/read/01jwm82pxpmqa0pxybctd3ccj2)) - 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](https://en.wikipedia.org/wiki/Delta_encoding) of the old and new firmware is produced through a process called [diffing](https://en.wikipedia.org/wiki/Data_differencing); then, the delta file is distributed to the end-device, which uses the delta file to update itself.[[8]](https://en.wikipedia.org/wiki/Over-the-air_update/#cite_note-8) ([View Highlight](https://read.readwise.io/read/01jwm8aq7c9gqqr0jmx49699gj)) - Cars can support OTA updates to their [in-car entertainment](https://en.wikipedia.org/wiki/In-car_entertainment) system, navigation map, [telematic control unit](https://en.wikipedia.org/wiki/Telematic_control_unit), or their [electronic control units](https://en.wikipedia.org/wiki/Electronic_control_unit) (the onboard computers responsible for most of the car's operation). ([View Highlight](https://read.readwise.io/read/01jwm8bhd0tt8myfd04hg1txht)) - Cars cannot be driven while an OTA update is being installed. ([View Highlight](https://read.readwise.io/read/01jwm8ba8s4wmn9qft1apvhj0e)) - OTA updates provide several benefits. In the past, Volkswagen had to recall 11 million vehicles to fix an issue with its cars' emissions control software, and other manufacturers have instituted recalls due to software bugs affecting the brakes, or the airbags, requiring all affected customers to travel to dealership to receive updates. OTA updates would have removed the need to go through dealerships, leading to lower warranty costs for manufacturers and lower downtime for customers ([View Highlight](https://read.readwise.io/read/01jwm8c5whz2xtbrwrhxsmk1s8))