Frequently Asked Questions

   About Global System for Mobile Communications (GSM)

   Digital Spread Spectrum (DSS) Cordless Telephone Technology

About Global System for Mobile Communications (GSM)

What is GSM?
The Global System for Mobile Communications (GSM) is an international digital cellular telecommunications standard. The GSM standard was released by ETSI (European Standard and Technology Institute) back in 1989. First commercial services were launched in 1991. After it's early introduction in Europe the standard went global in 1992 with GSM services introduced in Australia. Since GSM has become the most widely adopted and fastest-growing digital cellular standard, it positioned to become the world's dominant cellular standard.

How widespread is GSM today?
As of January 1999, GSM accounted for more than 120 million subscribers, according to the GSM Memorandum of Understanding (MoU) Association. With 324 GSM networks in 129 countries in operation, GSM provides almost complete coverage around the globe.

Where is GSM adopted?
GSM provides almost global coverage. With 324 GSM networks operational in: Albania, Andorra, Armenia (Republic), Australia, Austria, Azerbaijan, Bahrain, Bangladesh, Belgium, Bosnia Herzegovina, Brunei Darussalam, Bulgaria, Burkina Faso, Cambodia (Kingdom), Cameroon, Canada, Chile, China (PR), Cote d'Ivoire, Croatia, Cyprus, Czech (Republic), Denmark, Egypt, Estonia, Ethiopia, Fiji, Finland, France, French Polynesia, French West Indies, Georgia, Germany, Ghana, Gibraltar, Greece, Guernsey, Guinea, Hong Kong, Hungary, Iceland, India, Indonesia, Iran, Ireland, Isle of Man, Italy, Jersey, Jordan, Kenya, Kuwait, Lao, Latvia, Lebanon, Lesotho, Libya, Lithuania, Luxembourg, Macau, Macedonia (FYROM), Madagascar, Malawi, Malaysia, Malta, Mauritius, Monaco, Mongolia, Morocco, Mozambique, Namibia, Netherlands, New Caledonia, New Zealand, Norway, Oman (Sultanate of), Pakistan, Papua New Guinea, Philippines, Poland, Portugal, Qatar, Reunion (La), Romania, Russia, Saudi Arabia, Senegal, Seychelles, Singapore, Slovak Republic, Slovenia, South Africa, Spain, Sri Lanka, Sudan, Sweden, Switzerland, Syria, Taiwan, Tanzania, Thailand, Turkey, U.S.A., Uganda, Ukraine, United Arab Emirates, United Kingdom, Uzbekistan, Yugoslavia (Fed Rep), Zimbabwe

What is the anticipated market size for GSM phones?
By 2001, market research firms estimate that there will be in excess of 250 million GSM subscribers worldwide. GSM then will accommodate for almost 60% of the global cellular subscriber base with yearly shipments in excess of 100 million phones.

What other variations of GSM exist?
Anticipating capacity problems in the 900MHz frequency band, ETSI had already defined an 1800MHz variant - DCS1800 - in the first release of the GSM standard in 1989. In Europe, PCN (Personal Communication Network) services that targeted a wider range of voice and data applications were introduced based on GSM. Network operators that utilized these services received licenses for the 1800MHz band. The UK's Mercury One-2-One launched the first commercial network based on DCS1800 in 1993. In 1997, "DCS1800" was renamed "GSM1800".

In 1994, the US Federal Communications Commission (FCC) auctioned large blocks of spectrum in the 1900MHz band. The aim was to introduce digital wireless networks to the country in the form of a new kind of mass market Personal Communications Service (PCS). In the competitive spirit of the times, the FCC deliberately ensured that the PCS licenses were neutral with respect to technology. For GSM, one of the world's most lucrative markets beckoned. The GSM service in the US was named "PCS1900". It was renamed "GSM1900" in 1997.

In November 1995, American Personal Communications (APC) launched the first commercial GSM service in the US. This was achieved just a few months after APC had obtained its license - a feat, which would have been impossible with any other technology.

What is dual-band GSM?
Originally, network operators were licensed in either the 900MHz or the 1800MHz frequency bands. Quickly it became obvious that 900MHz could provide nationwide coverage, but had severe limitations in dense areas. Conversely, operators in the 1800MHz band realized that they had enough spectrum to cover these dense areas. However, due to the higher frequency and the lower output power which results in a smaller cell size (four times less coverage), the 1800 MHz operators were faced with the issue that they couldn't provide nationwide coverage economically.

With the introduction of the GSM Phase II standard, handover and roaming between both frequency bands had been defined. This introduction enabled regulatory bodies to provide split frequency band licenses to new network operators.

Why was GSM created?
The pressure for a unified and enhanced cellular system formed the basis for the definition of the GSM standard. Digital technology was chosen to leverage from the system integration capabilities of the semiconductor industry to enable smaller, lower power consuming and lower cost hand-portables.

Among a variety of potential air-interfaces, Time-Division-Multiple-Access (TDMA) was selected, because the strength of its technical performance and the support of major players for this technology.

What are the benefits of GSM?
Compared to older cellular transmission standards GSM includes a variety of network access, voice, and data services. Features like seamless roaming and handover provide a maximum level of flexibility to the user while being on the move. GSM for the first time enabled users to access personal communication services anytime, anywhere.

A variety of data services built into the GSM standard allow the user to directly access Fax, Data and in the future even Internet services. Short message services enable the user of a GSM phone to combine traditional cellular voice services with paging services in a single unit.

GSM has been defined as a platform, which is adaptable to a variety of new market requirements. This will enable the user to utilize a maximum of personal communication-- a must for the modern cellular subscriber.

Is GSM a secure system?
One of the most attractive features of GSM is that it is a very secure network. All communications, both speech and data, are encrypted to prevent eavesdropping. In fact, in the early stages of its development, GSM was found to have an encryption algorithm that was too powerful for certain export regulators. This could have had serious implications for the global spread of GSM by limiting the number of countries to which it could be sold. Fortunately, the MoU reacted promptly to this threat. Alternative algorithms were developed that enabled the free dissemination of the technology worldwide.

What is the SIM card used for in GSM?
Subscriber Identity Module (SIM) cards identify GSM subscribers. This card holds a user's identity number, authentication key and algorithm. While the choice of algorithm is the responsibility of individual GSM operators, they all work closely together through the MoU to ensure security of authentication.

Such "smartcard" technology has proven itself to be a potent weapon in the battle for network security. This application represents only a fraction of the SIM card's potential. For example, it's no longer necessary for users to own a terminal - travelers can simply rent GSM phones at the airport and insert their SIM card. Since it's the card rather than the terminal that enables network access, feature access and billing, the user is immediately on-line.

Advances in memory and processing capacity have already encouraged GSM operators to develop SIM cards that will customize the subscriber services portfolio on offer. Enterprising operators will use SIM card-enabled services to establish their market identity and give them an edge in an increasingly competitive environment.

What is GSM phase II?
During the definition of the GSM standard the rate of progress was too slow and didn't match with the pace of the market that required a new cellular standard. Based on this decision, GSM was made to be released in a phased approach. Phase I focused mainly on voice and basic network access services. Phase II allows for the definition of current and future voice, complex network access and a wide variety of data services required to deliver modern personal communication services to the end user. The GSM Phase II standard had been released in 1996.

What is Type Approval?
The cornerstone of GSM is international roaming. For this to be possible, all networks and handsets have to be compatible. With so many manufacturers creating so many products in so many countries, it was critical that each type of terminal was subject to a rigorous approval regime. Rogue terminals could cause untold damage to the GSM networks. Each handset model introduced into the market must pass a defined number of tests, at a certified laboratory, to ensure a maximum level of interoperability of equipment from various suppliers.