Technical Terms and Abbreviations Glossary: A
Access Point, AP, Apps, ASCII, AMR-WB
AP (abbr.): Access Point. Base Station in a wireless network (see also -> WLAN).
Apps (abbr.): Abbreviation of "Applications". Software for smart phones (see also -> Smart Phone) and hand-held computer (see also -> PDA).
ASCII (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.
AMR-WB (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 synchronization 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.
Reference/read more at: Wikipedia