 (ENGLISH) ZyXEL Hardware (16:1600/665)  HARDWARE.ZYX 
 Msg  : #18 [34]                                                                
 From : Manfred Recla                       16:500/112      Thu 30 Jun 94 21:30 
 To   : All                                                 Wed 20 Jul 94 23:44 
 Subj : ITU-T Newsletter V.34                                                   

.MSGID: 16:500/112@zyxnet.ftn 2e133994
.PID: GE 1+
ITU/94-16  9 June 1994
ORIGINAL: English

Milestone in modem technology: the V.34 standard is agreed
by ITU-T and put under ballot for adoption
Study Group 14 of the International Telecommunication Union -
Telecommunication Standardization Sector, ITU-T (formerly known as
CCITT), has been meeting in Geneva, Switzerland for the last week to
decide on the approval of the long-awaited standard for future high-
speed modems. The meeting was chaired by Mr K. Kern (Germany). The
work of Study Group 14 covers modems and transmission techniques for
data, telegraph and telematic services.
The adoption of the standard will give a go-ahead signal to the
industry to offer new products using high performance data transfer
technology. Work on the drafting of the standard started some three
years ago  Termed by industry experts V.fast in its development
stage, V.34 as it will now be called, will surpass the current
technology used in data transfer via traditional telephone lines.
V.34 future modems will transfer data at speeds twice the current
technology, thus the nickname V.fast. By increasing transmission
speed, they will drastically cut down the time needed by computers
and faxes and in turn lower user phone bills. These new modems will
have variable data transmission capacity ranging from 2 400
bits/second all the way up to 28 800 bits/second. The new modems will
use a feature called line probing that will allow modems to identify
the capacities and quality of the phone line and adjust themselves to
allow, for each individual connection, for maximum throughput using
the highest possible data transmission rate. In addition the standard
will support a half-duplex mode of operation for fax applications and
will support automoding to existing V-series modems.
Other important features of the new technology include an optional
auxiliary channel with a synchronous date signalling rate of 200
bits/second.  Data conveyed on this channel would be independent of
the primary channel (2 400 - 28 800 bit/second) and would consist
mostly of modem control data. Multi-dimensional trellis coding will
be used to gain higher immunity to noise and other phone line
impairments thus improving throughput. V.34 modems will also be the
first modems to identify themselves to telephone network equipment
(handshaking). Most important to the industry, V.34 will not only
foster world-wide connectivity due to its adaptive capabilities, but
will enlarge the market opportunities in areas which face poor
telephone line quality.
V.34 technology has been long in coming and has had to overcome many
obstacles.  One year ago, members of the modem manufacturing industry
had become so impatient, they suggested that an interim standard for
modems be approved. This interim standard, however, only made speed
improvements.
The proliferation of high-speed non-V.fast modem production led many
market analysts to become sceptical of the interoperability such non-
V.fast technology-oriented products. The adoption of V.34 is
therefore very opportune. "V.34 modems will be transmission devices
that will be faster, more reliable and cheaper to use," said Mr Kern
at the outcome of the meeting.  Given its half-duplex mode of
operation, the use of V.34 will also help reduce costs of fax
transmissions and make feasible the use of colour fax. "The fax
market is in sharp increase on a global basis, thus providing a new
market outlet for modem manufacturers," Mr Kern added. The approved
standard should be applicable within a period of 16 weeks maximum.
"One of the main issues for the future will be to make it possible
for V.34 modems to adapt their speed while transmitting data to
adjust with changes occurring on the lines such as noise
impairments," concluded Mr Kern.


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