(Nikkei BP Group)
(No.1 High-Tech News Site in Japanese)
| Japan's TU-KA Cellular Group to Beef Up Voice Quality
March 15, 1999 (TOKYO) -- The TU-KA group's three member companies will
beef up voice quality improvement efforts for their cellular phones,
a group spokesman said.
|As a first step, the mobile phone companies will equip its new technology
Noise Suppressor as standard with the cellular phone models they will
release in and after April. A user of the new models can communicate
more clearly with another party than before in a noisy environment by
eliminating surrounding noises with the new technology.
The Noise Suppressor will perceive signals with features different than
human voices as noises, and eliminate such signals prior to compression.
The new models can transmit more voice information than existing models,
because noises are eliminated beforehand, enhancing regeneration of
voices. The new technology will also allow the other party to hear voices
With a cellular phone, voice signals are usually compressed before being
transmitted to the other party, and then get decompressed when they
get to the other party's cellular phone. However, decompressed voice
signals cannot fully recover their original quality, because some information
is abandoned from the original signals when compressed.
The quality of regenerated voices largely depends on how much information
is abandoned and which information is abandoned.
TU-KA Cellular Tokyo Inc. and TU-KA Cellular Tokai Inc. will introduce
the Noise Suppressor technology to their cellular phone networks as
well as their cellular phones terminals. This will allow users to hear
voices more clearly on the cellular phone. The two companies will improve
their networks by the end of March to be ready for the release of the
TU-KA Phone Kansai Inc., the remaining firm of the three, is also considering
introduction of the technology to its cellular phone networks.
The three firms are also currently negotiating with other cellular phone
companies on CODEC-through technology. CODEC-through technology omits
decompression and compression processing at the base station controller
and instead decompress and compress voice signals only between two cellular
phones. The technology can help improve the voice quality by preventing
it from being deteriorated after voice signals are through several decompressions and compressions.
When a user transmits voice signals from a cellular phone to the other
cellular phone, voice signals compressed at a cellular phone are usually
decompressed at the base station controller. Thereafter, the signals
are compressed again at the base station controller of the other party
and decompressed again at the other party's cellular phone.
TU-KA Cellular Tokyo and TU-KA Cellular Tokai have already enabled for
the CODEC-through technology within their respective networks and combined
network. TU-KA Phone Kansai also plans to follow suit no later than
the summer of 1999.
The TU-KA group has set to improvement of the voice quality because more
users are as strongly interested in voice quality as in telephone charges,
size, weight and service area offered by each cellular phone company.
In addition, the three companies are seen threatened by the release of
cdmaOne, a cellular phone service slated to be launched in April nationwide,
with a catch-phrase of "the best voice quality ever." This accelerated
their improvement efforts for voice quality.
<Visit News Center for more Asian news.>