GSM 450 is a new member of the GSM family that opens up mobile services to more users and provides new business opportunities for operators, so what benefit does GSM 450 offer?

Article by Azman Avunny and Hans Bendes re-printed with kind permission from Mobile Communications Africa Magazine, Aug/Sep 99.

Worldwide, there are more than 180 million GSM users in 900, 1800 and 1900 MHz bands, and this figure is increasing by over 8 million new subscribers every month. Some 31 African countries currently use GSM networks. Among the fastest growing markets for GSM is South Africa, presently in fourth position. A new frequency band is now being standardised for GSM - 450 MHz - that brings a coverage bonus effect for current GSM operators and access to a world-leading standard for NMT operators. GSM 450 will evolve with the core GSM specification and it will include seamless roaming with other GSM bands.

Standardisation of GSM 450 is a development from the ongoing evaluation of a digital standard for the analogue NMT 450, conducted by the NMT MoU. The services included in GSM 450 correspond to the services and features in Release 99 of the GSM technical specifications.

Cost-efficient
Operation in the 450 MHz band offers a coverage advantage over other systems operating in higher frequencies. This is derived from physics, as a signal attenuates less the lower its frequency. Since the GSM 450 signal travels further than GSM 900 or 1800, this means fewer investment costs for the operator as fewer cell sites are required to cover rural and coastal areas and highways. Implementing GSM 450 together with an existing GSM service is even more cost-effective, since most of the same infrastructure can be used. In countries where a cellular service is starting up, GSM 450 therefore offers a very attractive solution as large areas can be covered with less investment.

Of course, GSM 450 also delivers valuable capacity for existing GSM operators. Together with the adaptive antennas and advanced cell planning techniques available, it is possible to provide radio capacity for city areas.

Extended range, using adjacent time slots, is applied in order to achieve coverage ranges up to 120 km, making full usage of the lower frequency band. In multi-band operation GSM 450 also brings additional coverage as a bonus for operators of current GSM systems. This means that they are perceived as more attractive when customers choose an operator at a retail outlet, where they will look at the coverage maps of different operators to ascertain which service is most comprehensive. In other words, the coverage bonus attracts more customers to their existing network as well as enabling them to extend their network. This is especially true for GSM 1800 operators: with GSM 450 they can enter new business segments and compete with operators already enjoying good coverage.

Going for EDGE (Enhanced Data rate for GSM Evolution), the down-banded frequency will also ease the foreseen coverage shortcomings with high-speed GSM data transmission utilising EDGE. Operators can use the same cell structure for EDGE on 450 as for 900, thus saving the cost of new complementary additional sites. Depending on the operator's strategy for the coverage of high-speed data services, GSM 450 allows both GSM 1800 and GSM 900 operators to trim their cost of operation for sites covering rural and suburban areas, as fewer cell sites are needed. For operators that only offer GSM 450, a new business opportunity can arise, since they can sell 'coverage' to other operators on higher frequency bands.

Clear evolution path
The need for operators to attract investment to expand their networks is key. Investors will clearly choose to invest in futureproof technologies that can demonstrate a defined evolution path towards third generation multimedia services. For operators currently running analogue NMT 450 services, GSM 450 offers a logical step to digital systems. This progression is essential if operators are to attract new subscribers, as most will want the greater range of services that digital networks provide. These services include worldwide roaming, secure calling via GSM's unique SIM card and data services such as SMS (Short Message Service) and GPRS (General Packet Radio Services). Moving to GSM 450 also gives users access to cost-effective terminals.

In general, GSM terminals developed by the end of 2000 are likely to be dual band terminals. The cost penalty for adding another band will be low. When GSM 450 infrastructure is available, there will be terminals available on the market that will allow users to seamlessly roam between bands as they travel.

When will it be available?
A field-test for GSM 450 will start this autumn. The commercial launch of the service is planned for the beginning of 2001, the main markets for which will be Africa, Europe and Asia-Pacific. Both the Global mobile Suppliers Association and the GSM Association are giving their support to the standardisation and development of GSM 450.

Azman Avunny is Marketing Manager and Hans Bendes is Strategic Product Manager for GSM Systems at Ericsson, a member company of the GSA.

Background
The 450 MHz band has been used for commercial analogue mobile telephony since the 1980s; since then mobile subscriber penetration numbers have increased dramatically. However, the subscriber volumes of several analogue operators have been decreasing in recent years with the trend towards digitalisation. However, the 450 MHz band continues to be a valuable asset because operation in the 450 MHz band offers an advantage in coverage over other systems operating in higher frequencies (800/900 and 1800/1900 MHz). This is a particular cost benefit in terms of coverage provision, for example in large areas, for coastal service and rural areas, requiring fewer cell sites than networks in higher bands. Down-banding will also ease the foreseen coverage shortcomings with high-speed data services. Mobile cellular operators have a keen desire to access these bands.

Further information about the GSA

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