21. GSM
. , , . (. 21.1):
WWAN (Wireless Wide Area Network);
WMAN (Wireless Metropolian Area Network);
WLAN (Wireless Local Area Network);
WPAN (Wireless Personal Area Network).
21.1.
WWAN | 2, 2.5 3 | |
WMAN | IEEE 802.16, WiM, IEEE 802.11s, mesh- | |
WLAN | IEEE 802.11, Wi-Fi | |
WPAN | IEEE 802.15, Bluetooth |
, . 300 . / . .
, . (-) ITU-R (International Telecommunication Union-Radio Sector) . ITU-R , . . 21.2 , WWAN WLAN.
21.2.
WWAN | GSM 890 - 915 935 - 960 1710 - 1785 1805 - 1880 | GSM 1850 1910 1930 - 1990 | |
WLAN | IEEE 802.11 2400 2483 | IEEE 802.11 2400 2483 | IEEE 802.11 2471 2497 |
. 21.1 , , .
. 21.1. : ,
, .. . ( ). .
( ) , . . . , , . , [68].
|
|
. - , . GSM 16 ., .. . . , .. .
. , . . , , . - .
. , / .
GSM
. , , , . , , . :
) FDMA (Frequency Division Multiple Access) ;
) TDMA (Time Division Multiple Access) ;
) CDMA (Code Division Multiple Access) ;
) OFDMA (Orthogonal Frequency Division Multiple Access) - .
, ( ). GSM (Global System for Mobile Communication) FDMA TDMA. , 23 3G (UMTS), CDMA, 25 - WiMAX LTE, OFDMA.