Bandwidth
Theoretical maximum speeds
of up to 171.2 kilobits per second (kbps) are achievable
with GPRS using all eight timeslots at the same time.
This is about three times as fast as the data transmission
speeds possible over today’s fixed telecommunications
networks and ten times as fast as current Circuit
Switched Data services on GSM networks. By allowing
information to be transmitted more quickly, immediately
and efficiently across the mobile network, GPRS may
well be a relatively less costly mobile data service
compared to SMS and Circuit Switched Data.
Immediacy
GPRS facilitates instant connections whereby information
can be sent or received immediately as the need arises,
subject to radio coverage. No dial-up modem connection
is necessary. This is why GPRS users are sometimes
referred to be as being “always connected”.
Immediacy is one of the advantages of GPRS (and SMS)
when compared to Circuit Switched Data.
Applications
GPRS facilitates several new
applications that have not previously been available
over GSM networks due to the limitations in speed
of Circuit Switched Data (9.6 kbps) and message length
of the Short Message Service (160 characters). GPRS
will fully enable the Internet applications you are
used to on your desktop from web browsing to chat
over the mobile network. Other applications for GPRS
include file transfer, email and terminal services
to other browser based applications for corporate
information.
Bluetooth is available for connecting to Laptops via
USB, PC-cards or CF-cards in addition to cards for
PDAs such as those offered by PALM. Older Compaq IPAQs
will require an expansion jacket but newer Pocket
PC devices usually include a suitable expansion port.
Current
Limitations
Current
GPRS terminals are limited to supporting up to three
timeslots. As such, the theoretical maximum GPRS speeds
should be checked against the reality of constraints
in the networks and terminals. The reality is that
mobile networks are always likely to have lower data
transmission speeds than fixed networks. Relatively
high mobile data speeds may not be available to individual
mobile users until Enhanced Data rates for GSM Evolution
(EDGE) or Universal Mobile Telephone System (UMTS)
are introduced.
Bandwidth
utilisation drops significantly when the user is not
stationary eg on a train.
Battery
life will be reduced when using GPRS.
Limited
roaming capability across many countries with GPRS,
operators are still negotiating to set up roaming
agreements.
Costs
GPRS works in a totally different
way to other mobile services, so you also pay for
the service in a different way. Instead of paying
for the time you spend connected to the service, you
pay for the amount of information you send or receive.
This means that thinking and reading time is free
- giving better value than traditional WAP access.
But remember that you pay for the GPRS service in
addition to your usual voice call price plan.
