Pan-European standard (ETSI, European Telecommunications Standardisation Institute)
simultaneous introduction of essential services in three phases (1991,1994, 1996) by the European telecommunication administrations (Germany: D1 and D2)
seamless roaming within Europe possible
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GSM: Overview
TODAY MANY PROVIDERS ALL OVER THE WORLD USE GSM (MORE THAN 200 COUNTRIES IN ASIA, AFRICA, EUROPE, AUSTRALIA, AMERICA)
MORE THAN 1.2 BILLION SUBSCRIBERS IN MORE THAN 630 NETWORKS
MORE THAN 75% OF ALL DIGITAL MOBILE PHONES USE GSM (74% TOTAL)
OVER 200 MILLION SMS PER MONTH IN GERMANY, > 550 BILLION/YEAR WORLDWIDE (> 10% OF THE REVENUES FOR MANY OPERATORS) [BE AWARE: THESE ARE ONLY ROUGH NUMBERS…]
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GSM Working frequencies
GSM 900:
890-915 MHz UPLINK
935-960MHz DOWNLINK
GSM 1900:
1850-1910 MHz UPLINK
1930-1990 MHz DOWNLINK
GSM 1800:
1710-1785 MHz UPLINK
1805-1880 MHz DOWNLINK
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Performance characteristics of GSM (wrt. analog sys.)
COMMUNICATION :
mobile, wireless communication; voice and data services
TOTAL MOBILITY
international access, chip-card enables use of access points of different providers
WORLDWIDE CONNECTIVITY
one number, the network handles localization
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Performance characteristics of GSM (wrt. analog sys.)
HIGH CAPACITY
better frequency efficiency, smaller cells, more customers per cell
HIGH TRANSMISSION QUALITY
high audio quality and reliability for wireless, uninterrupted phone calls at higher speeds (e.g., from cars, trains)
SECURITY FUNCTIONS
access control, authentication via chip-card and PIN
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Disadvantages of GSM
THERE IS NO PERFECT SYSTEM!!
no end-to-end encryption of user data
no full ISDN bandwidth of 64 kbit/s to the user, no transparent Bchannel
reduced concentration while driving
electromagnetic radiation
abuse of private data possible
roaming profiles accessible
high complexity of the system
several incompatibilities within the GSM standards
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GSM Services
GSM OFFERS
SEVERAL TYPES OF CONNECTIONS
voice connections, data connections, short message service
multi-service options (combination of basic services)
THREE SERVICE DOMAINS
Bearer Services
Telematic Services
Supplementary Services
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GSM Services
TELE SERVICES:
GSM mainly focuses on voice-oriented tele services via mobile phones.
All these basic services have to obey cellular functions, security measurements etc.
These comprise
encrypted voice transmission
message services
basic data communication with terminals as known from the PSTN or ISDN (e.g., fax).