13-07-2012, 02:04 PM
Global System for Mobile communications
[attachment=27551]
INTRODUCTION
GSM
GSM is a standard for a Global System for Mobile communications. Global System for Mobile communications, a mobile phone system based on multiple radio cells (cellular mobile phone network). It has been agreed upon and is completed by ETSI, the European Telecommunications Standards Institute.
Two main standards are followed:
GSM 900 (global system for mobile communications in the 900 MHz band)
DCS 1800 (digital cellular system for the 1800 MHz band)
GSM 900 is a designed for extensive radio coverage even in rural areas. DCS 1800 is designed for radio coverage in areas with very high subscriber density.
GSM is a global standard, GSM 900 being used in most European, Asian and pacific countries, GSM 1800 being used in the same place to increase the capacity of the system, and GSM 1900 being used primarily in the US.
Global System for Mobile Communication (GSM) is a set of ETSI standards specifying the infrastructure for a digital cellular service. The standard is used in approx. 85 countries in the world including such locations as Europe, Japan and Australia1.
The international designation of a public mobile radio network is PLMN (public land mobile network), as opposed to the PSTN (public switched telephone network).
Several PLMN, which are designed on the basis of same standards, are compatible to each other. Therefore, a mobile subscriber can use the GSM/DCS specific mobile equipment and services in these compatible networks.
GPRS
The General Packet Radio Service (GPRS) is a new non-voice value added service that allows information to be sent and received across a mobile telephone network. It supplements today's Circuit Switched Data and Short Message Service. GPRS is NOT related to GPS (the Global Positioning System), a similar acronym that is often used in mobile contexts.
General Packet Radio Service (GPRS) enabled networks offer 'always-on', higher capacity, Internet-based content and packet-based data services. This enables services such as color Internet browsing, e-mail on the move, powerful visual communications, multimedia messages and location-based services.
GPRS is used to implement high-speed data transmission between the MS and some other party. GPRS utilizes multiple BTSs in the same BSS. The MS sends different packets to different BTSs, which are reconstructed at the SGSN. This enables the MS to use a higher transmission speed than one transmission channel can handle.
GPRS facilitates several new applications that have not previously been available over GSM networks due to the limitations in speed of Circuit Switched Data (9.6 kbps) and message length of the Short Message Service (160 characters). GPRS will fully enable the Internet applications you are used to on your desktop from web browsing to chat over the mobile network. Other new applications for GPRS, profiled later, include file transfer and home automation- the ability to remotely access and control in-house appliances and machines.
3GSM
3GSM is the latest addition to the GSM family. 3GSM is about having third generation mobile multimedia services available globally. 3GSM focuses on visionary communications, in more ways than one. It's about the new visual ways in which people will communicate and the unique vision of the GSM community, which has always focused on the future needs of our customers.
The technology on which 3GSM services will be delivered is built around a core GSM network with a Wideband-CDMA (W-CDMA) air interface, in some markets, EDGE air interfaces, which has been developed as an open standard by operators in conjunction with the 3GPP standards development organization. Allocated 3G spectrum in the 2GHz band selected 3GSM as the best technology to deliver the optimum combination of speed, capacity and capability in a broadband
wireless world.Already over 85% of the world's network operators have chosen 3GSM's underlying technology platform to deliver their third generation services. 3GSM is a key element of GSM-The Wireless Evolution.
A BRIEF HISTORY OF GSM
The development and success of GSM has been an outstanding example of international enterprise in action. Operators, governments and manufacturers have come together in a remarkable venture that has created a new, dynamic and genuinely global telecommunications in market. It’s an example of co-operation that has affected and will continue to affect, the lives of millions both socially and economically.
THE BEGINNING:
The scenario of mobile phones in the 1980’s can be summed up quite beautifully by considering the case of a car that race through the autobahns of GERMANY but stops dead when it crosses the border and enters FRANCE.
As the business was becoming increasingly international the cutting edge of the communication industry focused on exclusively local cellular solutions. And none of these was remotely compatible with other. NMT 450 in the Nordic and Benelux countries. TACS in the UK and C-NETZ in Germany. Radiocom 2000 in France and RTMI/RTMS in Italy. All these networks enabled you to call the office if you were in your own home, but not if you were with a client in another country.
Each country developed its own system, which was incompatible with everyone else's in equipment and operation. This was an undesirable situation, because not only was the mobile equipment limited to operation within national boundaries, which in a unified Europe were increasingly unimportant, but there was a very limited market for each type of equipment, so economies of scale, and the subsequent savings, could not be realized.
It was clear that there would be an escalating demand for a technology that facilitated flexible and reliable mobile communication. But there was a big disadvantage, which threatened to affect the first generation mobile networks. It was the problem of capacity or the lack of it. It was this that leads to the decline of the entire analog networks in the early 1990’s; they collapsed under the pressure of demand.
It also became clear to industry watchers that localized solutions to the development of mobile communications did not make ling-term economic sense. Given the daunting R&D costs facing operators and manufacturers, it was essential to be able to exploit the economies of scale inherent in global market penetration. Home market revenue simply wouldn’t justify sustained programs of investment.
In the alphabet soup that is the communications industry, the CEPT merits a very special place in history. The Europeans realized this early on, and in 1982 the Conference of European Posts and Telegraphs (CEPT) formed a study group called the GROUPE SPÉCIAL MOBILE (GSM) to study and develop a pan¬-European public land mobile system. Its objective was to develop the specification for a pan-European mobile communications network capable of supporting the many millions of subscribers likely to turn to mobile communications in the years ahead. The proposed system had to meet certain criteria as following:
Good subjective speech quality,
Low terminal and service cost,
Support for international roaming,
Ability to support handhold terminals,
Support for range of new services and facilities,
Spectral efficiency, and
ISDN compatibility.
From the start, the GSM had it in mind that the new standard was likely to employ digital rather than analogue technology and operate in the 900MHz frequency band. Digital technology offered an attractive combination of performance and spectral efficiency. In other words, it would provide high quality transmission and enable more callers simultaneously to use the limited radio band available. In addition, such a system would allow the development of advanced features like speech security and data communications.
By going digital it would also be possible to employ the VLSI technology. It would have severe implications both for manufacturers and consumers. Handsets could be cheaper and smaller.
Finally the digital approach neatly complemented the Integrated Services Digital Network (ISDN) which was being developed by the land line communications networks and with which the GSM systems had to interact.
In 1989, GSM responsibility was transferred to the European Telecommunication Standards Institute (ETSI), and phase I of the GSM specifications was published in 1990. Commercial service was started in mid¬1991, and by 1993 there were 36 GSM networks in 22 countries, with 25 additional countries having already selected or considering GSM.
[attachment=27551]
INTRODUCTION
GSM
GSM is a standard for a Global System for Mobile communications. Global System for Mobile communications, a mobile phone system based on multiple radio cells (cellular mobile phone network). It has been agreed upon and is completed by ETSI, the European Telecommunications Standards Institute.
Two main standards are followed:
GSM 900 (global system for mobile communications in the 900 MHz band)
DCS 1800 (digital cellular system for the 1800 MHz band)
GSM 900 is a designed for extensive radio coverage even in rural areas. DCS 1800 is designed for radio coverage in areas with very high subscriber density.
GSM is a global standard, GSM 900 being used in most European, Asian and pacific countries, GSM 1800 being used in the same place to increase the capacity of the system, and GSM 1900 being used primarily in the US.
Global System for Mobile Communication (GSM) is a set of ETSI standards specifying the infrastructure for a digital cellular service. The standard is used in approx. 85 countries in the world including such locations as Europe, Japan and Australia1.
The international designation of a public mobile radio network is PLMN (public land mobile network), as opposed to the PSTN (public switched telephone network).
Several PLMN, which are designed on the basis of same standards, are compatible to each other. Therefore, a mobile subscriber can use the GSM/DCS specific mobile equipment and services in these compatible networks.
GPRS
The General Packet Radio Service (GPRS) is a new non-voice value added service that allows information to be sent and received across a mobile telephone network. It supplements today's Circuit Switched Data and Short Message Service. GPRS is NOT related to GPS (the Global Positioning System), a similar acronym that is often used in mobile contexts.
General Packet Radio Service (GPRS) enabled networks offer 'always-on', higher capacity, Internet-based content and packet-based data services. This enables services such as color Internet browsing, e-mail on the move, powerful visual communications, multimedia messages and location-based services.
GPRS is used to implement high-speed data transmission between the MS and some other party. GPRS utilizes multiple BTSs in the same BSS. The MS sends different packets to different BTSs, which are reconstructed at the SGSN. This enables the MS to use a higher transmission speed than one transmission channel can handle.
GPRS facilitates several new applications that have not previously been available over GSM networks due to the limitations in speed of Circuit Switched Data (9.6 kbps) and message length of the Short Message Service (160 characters). GPRS will fully enable the Internet applications you are used to on your desktop from web browsing to chat over the mobile network. Other new applications for GPRS, profiled later, include file transfer and home automation- the ability to remotely access and control in-house appliances and machines.
3GSM
3GSM is the latest addition to the GSM family. 3GSM is about having third generation mobile multimedia services available globally. 3GSM focuses on visionary communications, in more ways than one. It's about the new visual ways in which people will communicate and the unique vision of the GSM community, which has always focused on the future needs of our customers.
The technology on which 3GSM services will be delivered is built around a core GSM network with a Wideband-CDMA (W-CDMA) air interface, in some markets, EDGE air interfaces, which has been developed as an open standard by operators in conjunction with the 3GPP standards development organization. Allocated 3G spectrum in the 2GHz band selected 3GSM as the best technology to deliver the optimum combination of speed, capacity and capability in a broadband
wireless world.Already over 85% of the world's network operators have chosen 3GSM's underlying technology platform to deliver their third generation services. 3GSM is a key element of GSM-The Wireless Evolution.
A BRIEF HISTORY OF GSM
The development and success of GSM has been an outstanding example of international enterprise in action. Operators, governments and manufacturers have come together in a remarkable venture that has created a new, dynamic and genuinely global telecommunications in market. It’s an example of co-operation that has affected and will continue to affect, the lives of millions both socially and economically.
THE BEGINNING:
The scenario of mobile phones in the 1980’s can be summed up quite beautifully by considering the case of a car that race through the autobahns of GERMANY but stops dead when it crosses the border and enters FRANCE.
As the business was becoming increasingly international the cutting edge of the communication industry focused on exclusively local cellular solutions. And none of these was remotely compatible with other. NMT 450 in the Nordic and Benelux countries. TACS in the UK and C-NETZ in Germany. Radiocom 2000 in France and RTMI/RTMS in Italy. All these networks enabled you to call the office if you were in your own home, but not if you were with a client in another country.
Each country developed its own system, which was incompatible with everyone else's in equipment and operation. This was an undesirable situation, because not only was the mobile equipment limited to operation within national boundaries, which in a unified Europe were increasingly unimportant, but there was a very limited market for each type of equipment, so economies of scale, and the subsequent savings, could not be realized.
It was clear that there would be an escalating demand for a technology that facilitated flexible and reliable mobile communication. But there was a big disadvantage, which threatened to affect the first generation mobile networks. It was the problem of capacity or the lack of it. It was this that leads to the decline of the entire analog networks in the early 1990’s; they collapsed under the pressure of demand.
It also became clear to industry watchers that localized solutions to the development of mobile communications did not make ling-term economic sense. Given the daunting R&D costs facing operators and manufacturers, it was essential to be able to exploit the economies of scale inherent in global market penetration. Home market revenue simply wouldn’t justify sustained programs of investment.
In the alphabet soup that is the communications industry, the CEPT merits a very special place in history. The Europeans realized this early on, and in 1982 the Conference of European Posts and Telegraphs (CEPT) formed a study group called the GROUPE SPÉCIAL MOBILE (GSM) to study and develop a pan¬-European public land mobile system. Its objective was to develop the specification for a pan-European mobile communications network capable of supporting the many millions of subscribers likely to turn to mobile communications in the years ahead. The proposed system had to meet certain criteria as following:
Good subjective speech quality,
Low terminal and service cost,
Support for international roaming,
Ability to support handhold terminals,
Support for range of new services and facilities,
Spectral efficiency, and
ISDN compatibility.
From the start, the GSM had it in mind that the new standard was likely to employ digital rather than analogue technology and operate in the 900MHz frequency band. Digital technology offered an attractive combination of performance and spectral efficiency. In other words, it would provide high quality transmission and enable more callers simultaneously to use the limited radio band available. In addition, such a system would allow the development of advanced features like speech security and data communications.
By going digital it would also be possible to employ the VLSI technology. It would have severe implications both for manufacturers and consumers. Handsets could be cheaper and smaller.
Finally the digital approach neatly complemented the Integrated Services Digital Network (ISDN) which was being developed by the land line communications networks and with which the GSM systems had to interact.
In 1989, GSM responsibility was transferred to the European Telecommunication Standards Institute (ETSI), and phase I of the GSM specifications was published in 1990. Commercial service was started in mid¬1991, and by 1993 there were 36 GSM networks in 22 countries, with 25 additional countries having already selected or considering GSM.