Mobile: HSCSD - Bird in the hand is worth two in the bush?
Joanne Taaffe
04 June 2001
As new data services face rollout delays, older technologies get a second
look. High speed circuit switched mobile data is the latest phoenix.
If general packet radio service (GPRS) rollout had gone according to plan, high speed
circuit switched data (HSCSD) would now be heading for the annals of mobile data
history. Instead, advocates say the circuit-switched data technology could kick-start
the lagging high-speed mobile data market.
"It's definitely a transitional (technology), but it's got a longer window of opportunity
than people originally perceived," said David Gordon, of the GSM Association's high
speed data roaming interest group, and manager, International Services Partner
Communications Company, of Tel Aviv, Israel.
"The whole GPRS community will benefit from joining in," he claimed.
But critics point out that HSCSD makes much less efficient use of network capacity
than GPRS and that the services themselves can be costly for users. Whereas
GPRS networks send data packets as and when there is capacity available,
circuit-switched HSCSD networks demand that dedicated time-slots be kept open for
the duration of the data transfer.
"GPRS is much more efficient for data services," said Virtyt Kosti, senior consultant
at Ovum Ltd., of London.
So far, however, few operators in Europe have introduced GPRS services, because of
delays in handset deliveries, and many have put service rollout back until the end of
this year. HSCSD operators plan also to introduce GPRS services, but they believe
HSCSD has given them a competitive edge and better prepared them for the
introduction of data services over GPRS.
"We've been able to offer a fast mobile data transfer for almost two years," claimed
Sami Vierula, mobile data product manager at Sonera Corp., Mobile Operations, of
Helsinki. And according to the GSM Association's Gordon, HSCSD promises a
low-cost network implementation in a matter of weeks.
HSCSD not deployed everywhere
Currently, 28 members of the GSM Association offer HSCSD services. They would
like to see more GSM operators introduce the service to increase roaming coverage.
Although HSCSD users can roam between large markets such as Germany, where
E-Plus GmbH has introduced services, and the United Kingdom, where Orange plc
has a network, there are pockets of Europe - notably France - where no operator has
deployed HSCSD. Advocates hope to persuade operators that have not taken the
plunge that there is still time to introduce the data service, marketed as long ago as
1999 as an interim data technology between GSM and GPRS.
"We expect quite a few additional operators," said Gordon, including one in France.
Vierula, at Sonera, believes the introduction of HSCSD within the next six months
could still pay off financially for an operator, particularly as Nokia Oyj, of Helsinki,
later this year will launch GPRS and HSCSD dual-mode phones.
"I think (GPRS and HSCSD will) co-exist for 2-3 years, and then HSCSD (will) slowly
fade away," said Sonera's Vierula.
Analysts agree that there is still time to introduce HSCSD. "It's very complementary
to GPRS (because) it's very suitable for real-time services," said Kosti.
But another drawback to HSCSD is that whereas a voice call will block one time-slot
on a mobile phone, HSCSD needs to block four time-slots in order to provide
sufficiently high data speeds. This makes the service greedy for capacity -
unacceptable on networks that are nearing saturation point, and pricey on those that
are not.
"You really ought to be paying four times more, so it is expensive," points out
Ovum's Kosti. However, a few operators, such as Orange in the United Kingdom, are
offering HSCSD services at not much more than the cost of plain voice services.
HSCSD also has some notable selling points: For one thing it's cheap to install.
Although operators declined to give figures they described it as significantly cheaper
than GPRS, particularly as the software now comes as a feature on Nokia and
Ericsson switches.
"It's totally different in magnitude of investment to GPRS. Relative ... even to WAP,
it's a no-brainer," said Gordon. Contact the CWI editorial team at: editorial@cwi.emap.com
Information : info@tot |
