Q&A: GSM

 

What is GSM?
What are the advantages of GSM?
Where is GSM available?
What is the history of GSM?
Why have some TDMA operators transitioned to GSM?
Why have some CDMA operators transitioned to GSM?
How are GSM operators migrating to GSM?
What is a SIM card?
What companies manufacture GSM handsets and network infrastructure?

 

What is GSM?
Global System for Mobile communications (GSM) is the most widely used wireless technology in the world today. GSM is a second generation (2G) wireless technology that provides high-quality voice and circuit-switched data services in a wide variety of spectrum bands, including 450, 850, 900, 1800 and 1900 MHz GSM pioneered many of the world's most popular data services, such as Short Message Service (SMS) and Multimedia Message Service (MMS). 

GSM is a digital or Personal Communications System (PCS) technology. The phrase, “GSM family of technologies,” is often used as a catch-all term to refer to GSM, General Packet Radio System (GPRS), Enhanced Data for GSM Evolution (EDGE), Universal Mobile Telecommunication System, also known as WCDMA (UMTS) - High Speed Packet Access (HSPA) and Long Term Evolution (LTE), which provide a smooth, cost-effective evolution to third generation (3G) wireless technology. As of May 2009, more than 3.8 billion people worldwide – approximately 52 percent of the world's population – use GSM technology. GSM commands an 89 percent share of the wireless market (4Q 2008).

GSM allows multiple users to share a single radio channel through a technique called Time Division Multiplexing (TDM), where a channel is divided into six time slots. Each caller is assigned a specific time slot for transmission, which allows multiple callers to share a single channel simultaneously without interfering with one another. This design makes efficient use of spectrum and provides seven times more capacity than analog, or Advanced Mobile Phone Service (AMPS), which is a first generation (1G) technology. GSM also uses a technique called frequency-hopping, which minimizes interference from outside sources and makes eavesdropping virtually impossible.

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What are the advantages of GSM?
The advantages of GSM can be divided into two main categories: user benefits and operator benefits.

Key user benefits include:

  • Clear voice quality, which helps make GSM a viable alternative to wireline telephony for consumers and businesses. Although data is an increasingly popular wireless application, voice continues to be the primary reason why people use wireless technology.
  • International roaming with service available in more than 219 countries, as of the first quarter of 2009, the most of any wireless technology by a wide margin. As a result, users enjoy the convenience of being reachable with their GSM devices and phone numbers when traveling abroad, as well as the ability to access messaging and other advanced services that they use in their home markets. Partnerships within the GSM community help to keep users' roaming charges affordable and allow for any roaming charges to be automatically billed to their accounts back in their home markets. Roaming is particularly important for operators for two reasons: first, it drives a significant amount of revenue; and second, roaming support helps operators attract enterprise customers.
  • Spectral flexibility, with user devices available for the 450, 850, 900, 1800 and 1900 MHz bands, the widest variety of any wireless technology. Tri- and quad-band GSM phones are common, reducing the chances that users will ever travel to an area without at least one GSM network to which they can connect.
  • Tight security, including inherent protection from eavesdropping and hacking. This helps make GSM voice and data an attractive alternative to analog cellular and Wi-Fi in the eyes of users, particularly enterprises.
  • Data support, including SMS, web browsing and circuit-switched data.
  • Subscriber Identity Module (SIM) cards, which allow customers to buy a new or additional phone, or a GSM PC Card modem, and instantly transfer their settings, preferences and contacts to the other device.
  • Product selection. The GSM family’s 89 percent worldwide market share (4Q 2008) makes it attractive popular choice for handset manufacturers and application developers. As a result, GSM customers enjoy the largest selection of handsets, PC card modems and other devices, as well as innovative voice and data services. The GSM family’s market share also translates into large volumes of network infrastructure and user devices, which drive down costs.
  • Research and development is heavily supported for the entire GSM family of technologies due to the scope and scale of more than 3.8 billion customers worldwide.

Key operator benefits include:

  • Economies of scale. GSM is the most widely used wireless technology in the Americas and worldwide. It is available in more than 219 countries and territories worldwide as of May 2009, with an 89 percent share of market. More than 3.8 billion people worldwide, approximately 52 percent of the world's population, use GSM. This market size requires high volumes of handsets and infrastructure, which attract vendors and application developers while reducing costs. With this lower overhead, GSM operators are able to price their services more competitively yet profitably.
  • Spectral flexibility, with network infrastructure available for the 450, 850, 900, 1800 and 1900 MHz bands. This is the widest variety of any wireless technology. As a result, operators have more deployment options. For example, an operator that wants to cover a sparsely populated rural area might choose 450 MHz GSM infrastructure because signals travel farther at lower frequencies, so fewer base stations are needed. Those savings can be passed on to customers and investors.
  • Spectral efficiency, up to seven times more capacity than analog/AMPS. GSM operators also can upgrade to EDGE, which allows the use of advance voice-coding technologies that can triple voice capacity in the same amount of spectrum.
  • International roaming is available in more than 219 countries as of 1Q 2009– the most of any wireless technology. Roaming is particularly important for operators for two reasons: first, inbound roaming can contribute a substantial portion of a GSM operator's total revenue, especially for rural and regional operators; and second, roaming support helps operators attract business users, who want to be accessible with their current mobile devices and phone numbers while traveling throughout the Americas and the rest of the world.
  • Device selection, including handsets, modems and telemetry products. The GSM family’s 89 percent global market share drives large device volumes, which translates into a wide selection at a variety of features and prices. Affordability is one of the reasons why GSM is a popular choice for providing voice and data services in developing countries and underserved markets.
  • Tight standardization, which helps ensure interoperability between infrastructure and devices from multiple manufacturers providing operators with multiple equipment selection options.
  • Future-proof evolutionary path. GSM is the first step in a smooth, flexible, cost-effective migration to 3G. Each subsequent step leverages the previous step, and provides backward compatibility, ensuring that investments and customers are maintained during the migration. The standards behind GSM's upgradeability and interoperability are coordinated and supported by key international organizations such as the Third Generation Partnership Project (3GPP). The evolutionary steps to 3G after GSM and GPRS include EDGE, UMTS and HSPA.

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Where is GSM available?
A better question might be, “Where is GSM not available?” GSM services are available in more than 220 countries, as of May 2009.

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What is the history of GSM?
In 1982, a consortium of European countries created the Group Spéciale Mobile (GSM) to develop a cellular technology that would provide seamless international roaming and support for advanced services not available on analog networks. The European Telecommunications Standards Institute (ETSI) took over the project in 1989 and finalized the first set of technical specifications.

The first GSM network was launched in 1991, followed by several more the following year. As countries outside Europe adopted the technology, it became clear that GSM would be a global rather than European technology, so the GSM acronym was changed to stand for Global System for Mobile communications.

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Why have some TDMA operators transitioned to GSM?
The primary reason why Time Division Multiple Access (TDMA) operators have migrated to GSM is for the evolution to 3G offered by the GSM family of technologies. However, there are also many benefits in choosing GSM as a 2G technology.

By transitioning to GSM, TDMA operators and their customers enjoy access to worldwide roaming – more than 220 countries as of May 2009 – and a much larger selection of infrastructure and handsets. GSM also provides TDMA operators with a smooth, cost-effective migration path to third generation (3G) technology.

GSM's roaming capabilities and global footprint are particularly attractive to TDMA operators because worldwide roaming revenue is a significant and growing revenue source. In 2008, there were 365 million roamers worldwide contributing more than $24 billion in revenue, according to Informa Telecoms & Media, an independent analyst firm. By 2013, the number of roamers is expected to hit 600 million and contribute more than $31 billion in revenue.

Since 2001, more than 50 TDMA operators across the Americas have migrated to GSM. Examples of operators in North America include Cingular Wireless/AT&T Wireless (U.S.) and Rogers Wireless (Canada). In Latin America, América Móvil moved all of its properties, including Telcel in Mexico and likewise Telefónica properties such as Movistar have been migrated to GSM.

TDMA-to-GSM migrations are one of the reasons why GSM is the fastest-growing wireless technology in the Americas, increasing from 6 percent of the regional market in 2000 to 70 percent of the market by the end of 2008 (Informa Telecoms & Media). By the end of 2010, GSM is expected to comprise 75 percent of subscriptions in the Western Hemisphere.

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Why have some CDMA operators transitioned to GSM’s 3GPP evolution?
For the most part, all the same reasons for a TDMA operator to migrate to GSM’s 3GPP technology apply to a CDMA operator, particularly since there is no confirmed path beyond 3G commercially adopted by any CDMA operators (beyond CDMA2000 1x EV-DO).  For this reason, CDMA operators are choosing to deploy third generation HSPA (e.g. Telus and Bell Canada) and then later deploy LTE. In other examples, CDMA network operators will deploy LTE and develop interworking between the CDMA standard and the 3GPP LTE standard (e.g. Verizon).

By transitioning to GSM, Code Division Multiple Access (CDMA) operators and their customers enjoy access to international roaming in more than 219 countries as of May 2009. That's significantly more than CDMA2000 1x, which was available in 102 countries in May 2009, according to the CDMA Development Group.  Entire regions of the world such as Eastern Europe have no CDMA network deployments and now much of Latin America is without coverage as well.

GSM's roaming capabilities and global footprint are particularly attractive to CDMA operators because worldwide roaming revenue is a significant and growing revenue source. In 2008, there were 365 million roamers worldwide, according to Informa Telecoms and Media, an independent analyst firm. By 2013, the number of roamers is expected to hit 600 million. By migrating to GSM, CDMA operators are better positioned to capitalize on this opportunity.

Another benefit is a larger selection of infrastructure and user devices. This selection is a byproduct of GSM's global market share: 89 percent of the worldwide wireless market, as of May 2009. This market size requires high volumes of handsets and infrastructure, which attract vendors and application developers while reducing costs. With GSM's lower overhead, former CDMA operators are better able to price their services more competitively yet profitably.

Since 2003, 12 CDMA operators across the Americas have either migrated to GSM, committed to this migration or have deployed new GSM networks alongside their existing CDMA networks. As previously mentioned, in North America, Canada’s Telus Mobility and Bell Canada recently announced plans to deploy a UMTS-HSPA network to run alongside current CDMA networks. In Latin America, a few examples of CDMA operators moving to GSM include América Móvil (Argentina and Mexico) and Vivo (Brazil). GSM has quickly become the dominant wireless technology across the Americas, and is the top choice of Latin American operators. Market share of CDMA has declined in Latin America and the Caribbean from 19 percent as of 1Q 2007 to 8.3 percent as of March 2009 as many operators and their customers are choosing GSM technologies.

CDMA-to-GSM migrations are one of the reasons why GSM is the fastest-growing wireless technology in the Americas, increasing from 6 percent of the market in the Western Hemisphere in 2000 to more than 70 percent of the market by the end of 2008, according to Informa Telecoms & Media.

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How are GSM operators migrating to 3G?
GSM provides the foundation for 3G services and is part of a family of technologies that includes GPRS, EDGE and UMTS-HSPA. Each migration step leverages the previous step and provides backward compatibility, ensuring that investments and customers are maintained during the migration, which can take several years or more. The standards behind GSM's upgradeability and interoperability are coordinated and supported by the global standards organization Third Generation Partnership Project (3GPP).

The first step in a GSM operator's migration to 3G begins with the deployment of GPRS, an IP-based technology that provides peak packet data at rates of up to 115 kbps. After GPRS, an operator may choose to deploy EDGE and then UMTS-HSDPA or go directly from GPRS to UMTS-HSDPA, depending on its business plan and market conditions. Whatever the choice, the GSM family of technologies provides a smooth, flexible and cost-effective migration path to 3G.

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What is a SIM card?
The Subscriber Identity Module (SIM) card is a wafer-thin, thumbnail-size microchip used by all GSM devices, including phones and GSM-GPRS PC card modems. Like a credit card or smart card, the SIM card securely stores information about the user's account and subscription services, and it can be used to support services such as wireless e-commerce, or m-commerce.

The SIM card is removable, allowing customers to switch GSM devices when purchasing a new phone or adding a PC card – without the hassle of configuring the new device or the loss of personalized subscription services, such as messaging. The SIM card makes it easier for users to change GSM operators and keep the same phones. This flexibility makes GSM-based data networks, such as GPRS and UMTS-HSPA, attractive for a wide variety of data applications.

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What companies manufacture GSM handsets and network infrastructure?
Thousands of models of GSM phones, PDAs and GSM-GPRS modems are currently available from major manufacturers, including Apple, HP, HTC, Motorola, Nokia, Sony Ericsson, and Research in Motion (BlackBerry). GSM devices are available in a wide variety of price points and feature sets, including high-end models with color screens and built-in digital cameras. Additionally, because GSM is an open standard, any vendor can manufacture GSM equipment. This freedom is one of the many reasons why GSM operators and customers enjoy such a broad selection of equipment and vendors.

GSM network infrastructure is available from dozens of vendors, including Alcatel-Lucent, Ericsson, Huawei, Nokia Siemens Networks, Nortel and Motorola.

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