Matches in DBpedia 2014 for { <http://dbpedia.org/resource/Enhanced_Variable_Rate_Codec_B> ?p ?o. }
Showing items 1 to 12 of
12
with 100 items per page.
- Enhanced_Variable_Rate_Codec_B abstract "Enhanced Variable Rate Codec B (EVRC-B) is a speech codec used by CDMA networks. EVRC-B is an enhancement to EVRC and compresses each 20 milliseconds of 8000 Hz, 16-bit sampled speechinput into output frames of one of the four different sizes: Rate 1 - 171 bits, Rate 1/2 - 80 bits,Rate 1/4 - 40 bits, Rate 1/8 - 16 bits. In addition, there are two zero bit codec frame types: null frames and erasure frames, similar to EVRC. One significant enhancement in EVRC-B is the use of 1/4 rate frames that were not used in EVRC. This provides lower average data rates (ADRs) compared to EVRC, for a given voice quality.The new 4GV Codecs used in CDMA2000 are based on EVRC-B. 4GV is designed to allow service providers to dynamically prioritize voice capacity on their network as required.The Enhanced Variable Rate Coder (EVRC) is a speech codec used for cellular telephony in cdma2000 systems. EVRC provides excellent speech quality using variable rate coding with 3 possible rates, 8.55, 4.0 and 0.8 kbit/s. However, the Quality of Service (QoS) in cdma2000 systems can significantly benefit from a codec which allows tradeoffs between voice quality and network capacity, which cannot be achieved efficiently with the EVRC. An upgrade of the EVRC vocoder, known as EVRC-B, was recently introduced by 3GPP2. The EVRC-B speech codec is based on the 4GV concept and is the newest and most advanced speech codec for cellular applications. In addition to the Relaxed Code Excitation Linear Prediction (RCELP) used by EVRC, EVRC-B uses Prototype Pitch Period (PPP) approach for coding of stationary voice frames and Noise Excitation Linear Prediction (NELP) for efficient coding of unvoiced or noise frames. Using NELP and PPP coding at 2.0 kbit/s provides EVRC-B with superior flexibility in rate assignment, allowing it to operate at several operating points, each with a different trade-off between speech quality and system capacity. EVRC-B will replace EVRC as the main speech codec for cdma2000 and its first network commercial deployment is planned to start in 2007. A wideband extension, EVRC-WB, will provide speech quality that exceeds regular wireline telephony and its standardization process is planned to be completed at the summer of 2007.EVRC-B can be also used in 3GPP2 container file format - 3G2.".
- Enhanced_Variable_Rate_Codec_B wikiPageID "4975478".
- Enhanced_Variable_Rate_Codec_B wikiPageRevisionID "544366139".
- Enhanced_Variable_Rate_Codec_B hasPhotoCollection Enhanced_Variable_Rate_Codec_B.
- Enhanced_Variable_Rate_Codec_B subject Category:Speech_codecs.
- Enhanced_Variable_Rate_Codec_B comment "Enhanced Variable Rate Codec B (EVRC-B) is a speech codec used by CDMA networks. EVRC-B is an enhancement to EVRC and compresses each 20 milliseconds of 8000 Hz, 16-bit sampled speechinput into output frames of one of the four different sizes: Rate 1 - 171 bits, Rate 1/2 - 80 bits,Rate 1/4 - 40 bits, Rate 1/8 - 16 bits. In addition, there are two zero bit codec frame types: null frames and erasure frames, similar to EVRC.".
- Enhanced_Variable_Rate_Codec_B label "Enhanced Variable Rate Codec B".
- Enhanced_Variable_Rate_Codec_B sameAs m.0cy046.
- Enhanced_Variable_Rate_Codec_B sameAs Q5378795.
- Enhanced_Variable_Rate_Codec_B sameAs Q5378795.
- Enhanced_Variable_Rate_Codec_B wasDerivedFrom Enhanced_Variable_Rate_Codec_B?oldid=544366139.
- Enhanced_Variable_Rate_Codec_B isPrimaryTopicOf Enhanced_Variable_Rate_Codec_B.