From the ATT thread on SI - why there never will be competition - or at least for 3-5 years.
To:Cooters who wrote (3994)
From: JohnG Friday, Feb 16, 2001 5:20 PM
Respond to of 3995
AT&T's choice of GPRS for AWE appwars to be a catastrophic mistake.
GPRS brain cookers limited to two time slots or roughly 20KBps on uplink due to excessive radiation
generated exceeding SAR limits set as safe for humans. Down link may use more time slots, and achieve
higher data rates, but network congestion and cost effectiveness will be a question due to GPRS being a highly
inefficient user of spectrum.
Vidio phones are out od the question. Battery life is a severe problem. Operators may require flame retardent
gloves in the hand holding the phone in order to avoid the burn hazard.
"" NO MATTER HOW it is marketed,GPRS will not achieve the heady heights of 100Kbps plus speeds that
operators and vendors originally promised, unless there is an entire network dedicated to just one per-son.
Furthermore, the handsets that are currently available will not evolve into all singing, all-dancing units
because
of health risks associated with increased radio frequency (RF) output.
Major operators such as Germany’s T-Mobil and the UK’s BT Cellnet claim they will be able to offer
high-quality services without the need for high data rates. Both deny that the reality of GPRS has forced a
rethink of their strategies. In the early days of GPRS, speed of up to 170Kbps were touted as achievable. In
September, Finnish vendor Nokia confessed that the average maximum rate was more likely to be around
43Kbps.
The problem lies with the uplink between the handset and the server. Terminals featuring multislot downlinks
will be available, but only two slots will be permissible on the uplink, which gives a maxi-mum data rate of
around 20Kbps. This is due to specific absorption rate(SAR) guidelines, which govern the amount of RF
output
a mobile device can generate.
Steve Baker, GPRS product manager at chipset technology company TTPCom, explains: “There is a 500MW
limit on radio emissions in Europe. In Japan, Australasia and the U.S., this is even lower. The use of two
timeslots can take you over this limit.”
Achieving data rates of over 100Kbps would only be possible by using all available time slots on the handset,
the exact number of which depends on the class of phone. Operators are limited to using a maximum of five
active slots at any one time, to allow for error correction. This means that maximum data rates are likely to be
restricted to between 40Kbps and 60Kbps
BT Cellnet is already well aware of the situation but is confident its applications will provide a good user
experience without the need for excessive data speeds. The company’s GPRS service has been available to
corporate users since late June and offers average data speeds of 10Kbps via the 1-up/2-down time slot
Motorola Timeport P7389i.
“I think speeds of between 40 and 60Kbps should be comfortably achieved, and this is enough for most
applications,” says Peter Lisle, BT Cellnet’s GPRS program manager. Lisle is quick to point out that his
company “has never hyped GPRS data speeds” and says it will use data compression and optimization
techniques “to give users the feeling of speeds in excess of 60Kbps.”
The operator plans to launch consumer services this year, but deals with vendors other than Motorola have yet
to materialize. “We are talking with all the major vendors and have tested almost all the GPRS handsets that
are currently available,” Lisle says. Thus, Lisle expects the company to offer a 1-up/4-down product in the
spring.
In Germany, the situation is similar. T-Mobil launched its GPRS service just one day after BT Cellnet and to
date has yet to launch a commercial service. The company is still in what it calls its “friendly user” phase,
designed to iron out any problems before unleashing GPRS on the unsuspecting public.
T-Mobil’s service operates at around 20Kbps, with a maximum achievable rate of 40Kbps. “We have never
claimed that we will achieve rates over 40Kbps,” says T-Mobil spokesperson Andrea Vey. “Let’s face it,
anything we offer via GPRS is still faster than anything we could do at GSM 900MHz.”
Vey says the company plans to make the service commercially available 1Q01. As with BT Cellnet, the reason
for this is the availability of handsets. A much broader range of units are now available than at end-2000, the
year both operators originally penned for commercial launch.
The pair say they still believe that GPRS will bring end-user benefits when compared to GSM services. In
their
view, the “always-on” element and smoother WAP access should be enough to captivate consumers.
But “always-on” means a per-manent connection with the net-work, which will cause congestion. Rafael
Andrade, senior RF engineer at Agilent Technologies – formerly Safco Technologies – is concerned with the
effects of interference on GPRS signal quality. “GSM deals well with interference, because it only uses
certain
channels,” he says. “GPRS needs to support voice and data, raising the question of how much voice quality
you
are willing to sacrifice to offer data services.”
Lehman Brothers analysts also suggest that network congestion will be a major problem, but not one that is
insurmountable. In a re-port on wireless equipment, the in-vestment house suggests: “Transmitting bursty data
and voice traffic together would require more specific configuration of radio base stations and probably
greater
numbers of base stations as well.”
David Kaye, senior manager of product strategy for Australian operator Telstra’s OnAir division, is skeptical
about the hype surrounding GPRS. The danger, in his view, is akin to delivering a Ford to someone who has
been sold a Rolls Royce. “To use the term ‘instant always-on access’ is to be economical with the facts,” he
says. “Apart from battery life improvements and potentially faster access for some applications, GPRS is
totally dependent on pricing and billing for its value proposition, from a customer perspective.”
Hong Kong operator SmarTone backs GPRS, but concedes that the early hype overestimated the possibilities
presented by the technology. The company’s senior manager of PR and corporate affairs, Anita Tsui, says,
“We
have taken a cautious approach to GPRS, due to speed and form factor limitations.”
This, according to Tsui, accounts for why SmarTone’s GPRS service was only launched “to around 100
corporate customers” when introduced last September. Further-more, the operator does not plan to roll out
commercial service any time soon, claiming a shortage of available handsets.
Unlike its European competitors, though, SmarTone appears bullish that GPRS will deliver on its promises.
“We foresee that the 2.5G band-width will not be fully utilized until two to three years down the road. GPRS
or
3G only provides a bearer with sufficient bandwidth to support innovative applications/service delivery,”
Tsui
told 3G MD.
This is because SmarTone does not believe that the RF will have an adverse effect on the user. Studies that
suggest a correlation between mobile usage and increased incidences of brain and eye melanoma have been
rolling in thick and fast lately. To date, though, no conclusive evidence has surfaced to support this link.
It is this, along with the belief that GPRS handsets will act as a wireless modem, that makes SmarTone
confident it will be able to offer its customers the maximum possible data rates without risking their health.
Tsui says: “If the device is used as a wireless modem, it will not be held next to the head. Therefore, we do
not
envisage any issue with ‘frying people’s brains.’ ”
As with WAP, it is the applications and usability of GPRS that will make or break the service. BT Cellnet,
T-Mobil and SmarTone each claim that the experience of their respective corporate trials will benefit them
when it comes to rolling out consumer services.
So far, the three operators have focused on providing services like wireless access to corporate servers.
T-Mobil’s Vey says the operator’s corporate customers “have appreciated the speed with which we have
delivered applications in trials. We are confident, therefore, that consumers will also benefit from higher data
rates.”
BT Cellnet is much more specific about the applications it can and will offer. “Applications will start with
messaging and information retrieval, so early services are likely to include e-mail and Internet access via
WAP,” says Lisle. “In the coming years, we expect to start breaking into more specific fields, such as music,
games and even gambling.”
The operator has established an application developers forum and is using it to source potential partners. Late
last week, it announced that wireless Internet solutions developer Digital Mobility is set to offer
pharmaceutical news to healthcare professionals like GPs and clinicians over its GPRS network. The GPRS
handset will be supplied as part of a package, along with a Casio Pocket PC.
But operator resistance to releasing details of early user experience suggests there is still a long way to go
before a meaningful and reliable service can be provided.
This point was driven home by journalists’ tests of GPRS services in Finland and Sweden late last year. The
tests used the same Motorola Timeport handset that BT Cellnet and T-Mobil employ, and users were
disappointed to find that when connection to the network was finally established, the data speeds were slow.
One journalist, who experienced continued log-in problems, eventually resorted to connecting via his laptop
computer. “I’m not sure if it was any better than surfing via GSM,” he said.
All may not be lost, though, according to independent consultant Stuart Sharrock. While he acknowledges that
there is an RF power issue with the use of multiple time slots, he also points out that most high-bandwidth
services, with the exception of videophone services, are highly asymmetric. “This means the multiple time
slots
are needed on the downlink, not the uplink,” Sharrock says.
Therefore, devices like Ericsson’s R580 and the Trium Mondo should be capable of supporting most
applications, because they offer a greater number of downward time slots.
At present, GPRS is really only good for making WAP a more pleasant experience. Few in the wireless
industry doubt that GPRS is getting there, but like the experi-ence of early users, it is doing so slowly and
intermittently |
