SMV meaning in Computer and Networking ?

Answer: What is Selectable Mode Vocoder mean?

Selectable Mode Vocoder (SMV) is variable bitrate speech coding standard used in CDMA2000 networks. SMV provides multiple modes of operation that are selected based on input speech characteristics.

The SMV for Wideband CDMA is based on 4 codecs: full rate at 8.5 kbit/s, half rate at 4 kbit/s, quarter rate at 2 kbit/s, and eighth rate at 800 bit/s. The full rate and half rate are based on the CELP algorithm that is based on a combined closed-loop-open-loop-analysis (COLA). In SMV the signal frames are first classified as:

Silence/Background noiseNon-stationary unvoicedStationary unvoicedOnsetNon-stationary voicedStationary voiced

The algorithm includes voice activity detection (VAD) followed by an elaborate frame classification scheme. Silence/background noise and stationary unvoiced frames are represented by spectrum-modulated noise and coded at 1/4 or 1/8 rate. The SMV uses 4 subframes for full rate and two/three subframes for half rate. The stochastic (fixed) codebook structure is also elaborate and uses sub-codebooks each tuned for a particular type of speech. The sub-codebooks have different degrees of pulse sparseness (more sparse for noise like excitation). SMV scores a high of 3.6 MOS at full rate with clean speech.

The coder works on a frame of 160 speech samples (20 ms) and requires a look ahead of 80 samples (10 ms) if noise-suppression option B is used. An additional 24 samples of look ahead is required if noise-suppression option A is used. So the algorithmic delay for the coder is 30 ms with noise-suppression option B and 33 ms with noise-suppression option A.

The next evolution of CDMA speech codecs is VMR-WB which provides much higher speech quality with wideband while fitting to the same networks.

SMV can be also used in 3GPP2 container file format – 3G2.

reference

Full Form	Category
Squash Mosaic Virus	Academic & Science
St Moritz	Airport Code
Swivel Milling Vice	Business
Sony Music Video	Business
Sony Music Video Catalog	Community
Science Museum of Virginia	Community
Suga Music Video	Community
Selectable Mode Vocoder	Computer and Networking
Support Mp4 Video	Computing
Selectable Mode Vocoders	Computing
Smart Machine Vision	Computing
Saved Mail Video File	File Type
Streaming Mobile Video File	File Type
Smith Micro Software Videolink Mail Video File	File Type
Cadence Symbolic Model Verifier File	File Type
Standard Minivan	General
Special Mobility Vehicle	General
Special Motor Vehicle	General
Specialized Medical Vehicle	General
Stolen Motor Vehicle	General
Sell My Vehicle	General
Sport Multipurpose Vehicle	General
Standard Mint Value	General
Shiraz - Mourvedre - Viognier wine	General
Silver Medal of Valor Award	General
Sake Meter Value	General
Sexual Market Value	General
Schacht Musik Verlage	General
Sunnhordland Mek Verksted	General
St Mary's Visitation	General
Superintendencia del Mercado de Valores	General
Standard Minute Value	General
Streaming Mobile Video	General
Super Marty View	General
Santa Maria Valley	General
SigmaTel Motion Video	General
Slow Machine Verification	General
Spark Modularized View	General
Soybean mosaic virus	General
Sunset Meadow Vineyards	General
Sexual Marketplace Value	General
Stanley Marcus Victor	General
Slow Moving Vehicle	Governmental
Super Mileage Vehicle	Governmental
Smart Moving Vehicles	Governmental
SUMAOLI	Indian Railway Station
Symbolic Model Verifier	Maths
Superior Mesentric Vein	Medical
SubMentoVertex	Medical
Superior Mesenteric Vein	Medical
Space Maneuverable Vehicle	Military and Defence
Santa Maria Valley Railroad Company	Regional
St. Moritz, Switzerland	Regional
Santa Maria Valley Railroad	Regional
Southern Minnesota Volleyball	Sports
Secondary Market Value	Stock Exchange