User`s guide

184 Appendix A
General Information on the GSM System
The GSM System
The GSM System
A GSM mobile phone transmits speech as bursts of encoded data. An RF carrier is
modulated by the special form of frequency modulation known as the Gaussian
Minimum Shift keying (GMSK). Signals are transmitted in short bursts (577 µs
each) using the method called Time Division Multiple Access (TDMA) on
Absolute RF Channels (ARFCNs) spaced 200 kHz apart.
RF Channels
The next table shows the RF channel frequencies and channel numbers for each
radio standard.
Power Classes
The power classes are defined as follows:
GSM900 E-GSM DCS1800 PCS1900
Uplink
890.2 to
914.8 MHz
880.2 to
914.8 MHz
1710.2 to
1784.8 MHz
1850.2 to
1909.8 MHz
Downlink
935.2 to
959.8 MHz
925.2 to
959.8 MHz
1805.2 to
1879.8 MHz
1930.2 to
1989.8 MHz
ARFCN
Range
1 to 124 0 to 124,
975 to 1023
512 to 885 512 to 810
12345
GSM900, E-GSM
+39 dBm +37 dBm +33 dBm +29 dBm
DCS1800
+30 dBm +24 dBm +36 dBm
PCS1800
+30 dBm +24 dBm +33 dBm