There are many topics that could have been discussed in the first 21st century issue of our magazine. Many significant events of the past century will become history as a turning point in the development of communications. However, instead of the past, we will focus on the future of communications. The previous issues of "The World of Constant Connection" extensively covered the innovations on the world market of mobile communications, which will soon become a part of everyday life for you - our subscribers.

Today we will discuss GPRS (General Packet Radio Service), a system which a couple of years ago was known only in scientific circles. The trial launch was carried out in November of 1999 in Great Britain, and became a significant step in the development of mobile communications.

2001 will be a most intensive year for mobile network operators in terms of the implementation of new technologies.  Many operators will be engaged in the final implementation of the successfully piloted new systems, while the operators with no new technologies will face the unfavourable prospects of future competition.

The technological competition involves not only companies but also countries. Japanese communications systems clearly surpass European technologies. The possibilities provided by the Japanese DoCoMo are still unattainable for Europeans. On their part, European communication technologies lag behind the Japanese ones, but are more advanced than those used in America. Historically, wireless technology appeared earlier in America, and as a result the major part of the continent is covered by the older generation networks which rival and even block the introduction of new systems. Recently, however, new generation technologies of wireless communications have appeared in America and the high level of Internet development in the country will become one of the key factors in their rapid growth.

An issue of special significance in the tough technological competition is finding a proper solution to the transitional stage tasks. From a financial point of view, moving to the 3G technologies should be painless, both for subscribers, for whom such a change must not be expressed in a simultaneous change of their mobiles for the ones compatible with new generation systems, and operators, for whom such a move must not mean a complete change of the existing network and stations with the new equipment.

For GSM operators, such an interim technology is the GPRS. Established in 1997, GPRS acts as a link between the current systems and 3G technologies.
GPRS has proved equally interesting for the companies with no licenses for the new generation networks and the ones already owning OMTS licenses. For the companies in the first category, GPRS is a part of a long-term project, allowing these companies to meet the increased demands of the market for wireless-technologies-based data transfer and to remain competitive for a while with those companies that have moved or will soon move to 3G technologies. As for the license-owner companies, GPRS will become the basis for the new generation systems structure.

Calculations show that GPRS will be quite expensive for operators.  A well-known British consulting company Ovum estimates that the cost of implementing such a network system in its entirety may reach US$240 million for the average European operator. A system launch includes the construction of a new parallel network together with the infrastructure and a link with external systems.

In order to have a better idea of the GPRS system, we will discuss its logical architecture (see the chart).

The left part of the diagram shows the architecture of the GSM network, while the right part shows the block-diagram necessary for the operation of GPRS.
SGSN (Serving GPRS Support Node) is an MSC analogue for GPRS, and its main functions are:

finding new MC in the coverage area

receiving/sending of MC existing packages

interaction of BSS (BSC+BTS) with other SGSN and GGSN

GGSN (Gateway GPRS Support Node) is an interface among SGSN and external package networks, e.g. the Internet.

PCU (Packet Controller Unit) provides SGSN interaction with BTS.

OMC-G (Operation & Maintenance GPRS) provides the common administration of GPRS, i.e. all the equipment of SGSN and GGSN.

The unity of SGSN and GGSN makes GSN (GPRS Support Node).

As is seen in the chart, the system is connected with two different systems which vary in transmission method:
 Circuit Switching Networks
 Packet Switching Networks

Circuit Switching Networks are mainly used for voice transmission, an example of which is a fixed telephone network. They transmit information as an uninterrupted flow, during which a circuit is completed between two connected subscribers and kept until the end of the session.

As for Packet Switching Networks, until recently they were used exclusively for data transfer (local networks, Internet, Intranet). Unlike Circuit Switching Networks, they divide transmittable information into small fragments or packets, which are tracked separately and reach the place of destination independently, even taking their own paths.

GPRS brings together the networks of these two units, thus paving the way for the establishment of the new generation systems, based fully on the Packet Switching Mode.

GPRS is only a technology. Of greater significance are the novelties it will bring to public life. Those changes are difficult to imagine today. As mentioned in the interview with the Development Director of the British Company One2One, "it is too difficult to forecast what we will have in five years. It is enough to go back five years to guess how difficult it was to imagine the things we have got today."

LEVAN BUCHUKURI
Director of Marketing,
Customer Care and
Strategic Planning
MagtiCom