PISCATAWAY, N.J.-The Wireless Information Network Laboratory at Rutgers University is
working to set a research agenda that will facilitate deployment of General Packet Radio Service, a new wave in
wireless data communications.
GPRS is a large, complex system that merges cellular telephone radio transmission
technology and Internet information delivery protocols, according to WINLAB, which hosted a seminar on the topic
last week.
Initial implementations of GPRS, a packet data communications system, will operate within the
framework of current Global System for Mobile communications technology. However, efforts are underway to adapt
GPRS for North American Time Division Multiple Access and enhanced TDMA cellular systems, known as
EDGE.
EDGE, or Enhanced Data Rate for GSM Evolution, “has the same channelization as GSM but
supports higher peak data rates,” said Xiaoxin Qiu, a researcher with AT&T Laboratories in Red Bank,
N.J.
However, Interim Standard 136 TDMA “uses fewer frequencies than GSM so there is more frequency re-
use and poorer (transmission) quality,” said Peter Schefczik, a researcher for Lucent Technologies Inc. Global
Wireless Systems in Nurnberg, Germany.
Standardized for GSM by the European Telecommunications Standards
Institute in December 1997, GPRS products are under development by equipment vendors.
“Ericsson (Inc.)
has announced a commercial contract in Europe (for GPRS equipment), and [Nortel Networks] hopes to have base
stations available late this year, but no handsets are out yet,” said Yixin Zhu, adviser to wireless systems
engineering for Nortel Wireless Networks, Richardson, Texas.
Hakan Olofsson, senior specialist in radio network
research for Ericsson Radio Systems AB, Stockholm, said that cost-effective deployment of GPRS is a tricky
endeavor.
“You cannot over-provision the Internet by providing (separate GPRS) base stations because that
would be too expensive,” he said.
Olofsson also said, in his view, the definitions within the ETSI standards
for GSM-based GPRS “are not crystal clear, and there is room for improvement.”
Where GPRS is
concerned, standards development is the easy part, said David J. Goodman, director of WINLAB. It is much more
complex than a comparatively simple telephone system, and there is a great degree of flexibility in deciding how to
operate a GPRS system.
A few months before the ETSI standards were formally released, WINLAB researchers had
developed a simulation software to demonstrate performance of GPRS technologies under various usage scenarios,
Lucent’s Schefczik said. Today, the simulation is available from WINLAB only for the uplink portion of data
transmission, from a data station to the headend or mainframe.
“The big frontier in wireless is data, but no one
is using wireless for data, especially for Internet access,” Goodman said.
“Today, you’ll get circuit
switched data, but people want something (that is) more like the ethernet you find in your office. GPRS is a step in that
direction.”
Companies represented among the approximately 100 seminar attendees included AT&T Labs,
Cisco Systems, Ericsson, Lucent, Nokia Corp. and Nortel. When WINLAB began planning the GPRS seminar several
months ago, Goodman said he expected perhaps a dozen guests.
“The reason we convened this meeting is that
all these companies asked us how they could work with us, and a lot of them are competing with each other. My
purpose is to set a research agenda,” Goodman said.
For Ericsson’s Olofsson, GPRS is far more important as a
segue to third generation wireless communications than as a stand-alone standard.
“The future scenario is
multimedia over [Internet Protocol] and multimedia over GPRS, and we must support this if we want GPRS to be a part
of third generation (wireless),” he said.
“We cannot view GPRS as a stable standard on its own but must
see it as part of 3G that therefore deserves our attention.”
