Breakthrough Technology To Provide Significant
Capacity And Quality Gains On cdmaOne and CDMA2000 Systems
COSTA MESA, Calif., March 15, 2001 -- The CDMA Development
Group (CDG) (www.cdg.org) today announced significant strides
made in the development of a new and innovative voice encoder
(vocoder) for cdmaOne and CDMA2000 systems. A vocoder converts
the spoken word into digital code and vice versa. The global
standards body, 3GPP2, with support from the CDG, recently
completed the development of the Selectable Mode Vocoder (SMV)
algorithm and released it for implementation. The breakthrough
technology utilized in SMV will allow CDMA subscribers to
enjoy superior quality while allowing the service providers
to increase capacity as needed.
"SMV builds upon the heritage of
CDMA's innovation in high-quality voice coders, which includes
the 13kbps and Enhanced Variable Rate Codec solutions,"
said Perry LaForge, executive director of the CDG. "We
are extremely pleased with the progress the industry has made
in getting the new technology ready for the market."
SMV's advances come from improvements in speech encoding
technology. SMV also implements an algorithm to continually
choose optimal encoding rates based on the input speech characteristics,
thereby ensuring that the sound quality remains high. This
feature provides the SMV vocoder with a significant advantage
over other solutions, such as the newly developed GSM Adaptive
Multi Rate (AMR) vocoder (AMR slowly switches between fixed
encoding rates based on RF channel conditions, resulting in
reduced sound quality). Both SMV and AMR vocoders were compared
recently using listening tests conducted at an independent
lab. The results show clearly that SMV delivers better quality
than the AMR, even when using lower rates. This is significant
in that lower coding rates results in greater capacity on
Furthermore, SMV offers CDMA carriers the flexibility to
tradeoff small quality losses vs. large system capacity gains.
Wireless operators can gain up to 75% increase in system capacity
compared to the current CDMA vocoders by using the lower encoding
rates of SMV. Wireless operators can also provide improvements
in voice quality by using data rates similar to the current
CDMA vocoders. SMV operational mode can be controlled on a
static or dynamic basis, allowing carriers further efficiency
in service at peak loaded times.
3GPP2 started the SMV standardization process in 1Q99. This
was the first industry-wide effort to develop a vocoder that
fully exploited CDMA's ability to increase system capacity
proportional to the vocoder's reduction in average encoding
rate. SMV algorithm development was completed in Feb. 2001,
and it has been released to the 3GPP2 community for implementation.
Products based on the SMV technology are expected by the middle
of next year.