06-12-2009, 10:30 PM
Global System for Mobile communications
(GSM: originally from Group Special Mobile) is the most popular standard for mobile phones in the world.the GSM digital standard was proven to work in 1988. In GSM both signalling and speech channels are both digital call quality and hence is considered as 2G mobile phone system.This has also meant that data communication were built into the system using the 3rd Generation Partnership Project (3GPP).The digital nature of GSM allows the transmission of data (both synchronous and asynchronous) to or from ISDN terminals, although the most basic service support by GSM is telephony.It utilizes digital technology and operates in 900 MHz and 1.8 GHz frequency bands except in North America where it operates in 1.9 GHz band.The GSM logo is used to identify compatible handsets and equipment .
Basic technology employed and working
GSM divides up the radio spectrum bandwidth by using a combination of Time- and Frequency Division Multiple Access (TDMA/FDMA) schemes on its 25 MHz wide frequency spectrum, dividing it into 124 carrier frequencies (spaced 200 Khz
apart). Each frequency is then divided into eight time slots using TDMA, and one or more carrier frequencies are assigned to each base station. The fundamental unit of time in this TDMA scheme is called a Ëœburst periodâ„¢ and it lasts 15/26 ms (or approx. 0.577 ms). Therefore the eight Ëœtime slotsâ„¢ are actually Ëœburst periodsâ„¢, which are grouped into a TDMA frame, which subsequently form the basic unit for the definition
of logical channels. One physical channel is one burst period per TDMA frame
Advantage to consumers
-better voice quality and low-cost alternatives to making calls, such as the SMS.
-Its universality makes international roaming very common between mobile phone operators, enabling subscribers to use their phones in many parts of the world.
Advantage to operators
-ease of deploying equipment from any manufacturers that implement the GSM standard.
-offer roaming services.
Recent additions to the GSM technology
-Release ''97 of the standard added packet data capabilities, by means of General Packet Radio Service (GPRS). GPRS essentially supplements present-day circuit switched data and short message services (SMS), and serves as an enabler of mobile wireless data services, and an optimizer of the radio interface for bursty packet mode traffic.
-Release ''99 introduced higher speed data transmission using Enhanced Data Rates for Global Evolution (EDGE).It allows data transmission speeds of 384 Kbit/s to be achieved.
Timeline of development of GSM technology
1982 CEPT establishes a GSM group in order to develop the standards for a pan-European cellular
mobile system
1985 Adoption of a list of recommendations to be generated by the group
1986 Field tests were performed in order to test the different radio techniques proposed for the air
interface
1987 TDMA is chosen as access method (in fact, it will be used with FDMA) Initial Memorandum
of Understanding signed by the telecommunication operators (representing 12 countries)
1988 Validation of the GSM system
1989 The responsibility of the GSM specifications is passed to the ETSI
1990 Appearance of the phase I of the GSM specifications
1991 Set date for the Ëœofficialâ„¢ commercial launch of the GSM service in Europe
1992 Actual launch of commercial service, and enlargement of the countries that signed the GSM “
MoU > Coverage of Larger cities / airports
1993 Coverage of main roads GSM services start outside Europe
1995 Phase II of the GSM specifications Coverage of rural areas
Seminar report pdf download:
[attachment=551]
(GSM: originally from Group Special Mobile) is the most popular standard for mobile phones in the world.the GSM digital standard was proven to work in 1988. In GSM both signalling and speech channels are both digital call quality and hence is considered as 2G mobile phone system.This has also meant that data communication were built into the system using the 3rd Generation Partnership Project (3GPP).The digital nature of GSM allows the transmission of data (both synchronous and asynchronous) to or from ISDN terminals, although the most basic service support by GSM is telephony.It utilizes digital technology and operates in 900 MHz and 1.8 GHz frequency bands except in North America where it operates in 1.9 GHz band.The GSM logo is used to identify compatible handsets and equipment .
Basic technology employed and working
GSM divides up the radio spectrum bandwidth by using a combination of Time- and Frequency Division Multiple Access (TDMA/FDMA) schemes on its 25 MHz wide frequency spectrum, dividing it into 124 carrier frequencies (spaced 200 Khz
apart). Each frequency is then divided into eight time slots using TDMA, and one or more carrier frequencies are assigned to each base station. The fundamental unit of time in this TDMA scheme is called a Ëœburst periodâ„¢ and it lasts 15/26 ms (or approx. 0.577 ms). Therefore the eight Ëœtime slotsâ„¢ are actually Ëœburst periodsâ„¢, which are grouped into a TDMA frame, which subsequently form the basic unit for the definition
of logical channels. One physical channel is one burst period per TDMA frame
Advantage to consumers
-better voice quality and low-cost alternatives to making calls, such as the SMS.
-Its universality makes international roaming very common between mobile phone operators, enabling subscribers to use their phones in many parts of the world.
Advantage to operators
-ease of deploying equipment from any manufacturers that implement the GSM standard.
-offer roaming services.
Recent additions to the GSM technology
-Release ''97 of the standard added packet data capabilities, by means of General Packet Radio Service (GPRS). GPRS essentially supplements present-day circuit switched data and short message services (SMS), and serves as an enabler of mobile wireless data services, and an optimizer of the radio interface for bursty packet mode traffic.
-Release ''99 introduced higher speed data transmission using Enhanced Data Rates for Global Evolution (EDGE).It allows data transmission speeds of 384 Kbit/s to be achieved.
Timeline of development of GSM technology
1982 CEPT establishes a GSM group in order to develop the standards for a pan-European cellular
mobile system
1985 Adoption of a list of recommendations to be generated by the group
1986 Field tests were performed in order to test the different radio techniques proposed for the air
interface
1987 TDMA is chosen as access method (in fact, it will be used with FDMA) Initial Memorandum
of Understanding signed by the telecommunication operators (representing 12 countries)
1988 Validation of the GSM system
1989 The responsibility of the GSM specifications is passed to the ETSI
1990 Appearance of the phase I of the GSM specifications
1991 Set date for the Ëœofficialâ„¢ commercial launch of the GSM service in Europe
1992 Actual launch of commercial service, and enlargement of the countries that signed the GSM “
MoU > Coverage of Larger cities / airports
1993 Coverage of main roads GSM services start outside Europe
1995 Phase II of the GSM specifications Coverage of rural areas
Seminar report pdf download:
[attachment=551]
