Tech Terms | Abbreviations A–Z
AMR-WB, AP, Apple iOS, Apps, ASCII
(abbr.): Adaptive Multi-Rate Wideband is a patented wideband speech coding standard developed based on Adaptive Multi-Rate encoding, using similar methodology as Algebraic Code Excited Linear Prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS wireline quality of 300–3400 Hz.
AMR-WB was developed by Nokia and VoiceAge and it was first specified by 3GPP.
AMR-WB is codified as G.722.2, an ITU-T standard speech codec, formally known as Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). G.722.2 AMR-WB is the same codec as the 3GPP AMR-WB. The corresponding 3GPP specifications are TS 26.190 for the speech codec and TS 26.194 for the Voice Activity Detector.
AMR-WB codec has the following parameters:
Delay frame size: 20 ms
Look ahead: 5ms
Complexity: 38 WMOPS, RAM 5.3KWords
Voice activity detection, Discontinuous Transmission, Comfort Noise Generator
Fixed point: Bit-exact C
Floating point: under work.
A common file extension for AMR-WB file format is .awb. There also exists another storage format for AMR-WB that is suitable for applications with more advanced demands on the storage format, like random access or synchronisation with video. This format is the 3GPP-specified 3GP container format based on ISO base media file format. 3GP also allows use of AMR-WB bit streams for stereo sound.
(abbr.): Access Point. Base Station in a wireless network (see also WLAN).
iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that powers many of the company's mobile devices, including the iPhone and iPod Touch; it also powered the iPad until the introduction of iPadOS, a derivative of iOS, in 2019. It is the world's second-most widely installed mobile operating system, after Android. It is the basis for three other operating systems made by Apple: iPadOS, tvOS, and watchOS. It is proprietary software, although some parts of it are open source under the Apple Public Source License and other licenses.
Unveiled in 2007 for the first-generation iPhone, iOS has since been extended to support other Apple devices such as the iPod Touch (September 2007) and the iPad (January 2010). As of March 2018, Apple's App Store contains more than 2.1 million iOS applications, 1 million of which are native for iPads. These mobile apps have collectively been downloaded more than 130 billion times.
Major versions of iOS are released annually. The current stable version, iOS 14, was released to the public on September 16, 2020. It brought many user interface changes, including the ability to place widgets on the home screen, a compact UI for both Siri and phone calls, and the ability to change both the default web browser and email apps. No devices were dropped, as all devices supported by iOS 13 are able to run iOS 14.
(abbr.): Abbreviation of "Applications". Software for smart phones (see also Smartphone) and hand-held computer (see also PDA).
(abbr.): The American Standard Code for Information Interchange
(ASCII /'æski/ ASS-kee) is a character-encoding scheme originally based on the english alphabet that encodes 128 specified characters – the numbers 0-9, the letters a-z and A-Z, some basic punctuation symbols, some control codes that originated with Teletype machines, and a blank space – into the 7-bit binary integers.
ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern character-encoding schemes are based on ASCII, though they support many additional characters.