1
WLAN 2
IEEE 802.11 HomeRF GSM/ GPRS CDMA 3
( ) (Infrared) (Laser) (Microwave) (DSSS) (FHSS) (HomeRF) (Bluetooth) 4
( ) IrDA (Direct-Beam IR, DB/ IR) (Diffuse IR, DF/ IR) (Ominidirectional IR, Omini/ IR) 5
( ) (line-of-sight)) DB/IR DF/IR ) Omni/IR 6
( ) (Optical Wireless, OW) Laser Diode 7
( ) ( ) 8
( ) (Direct Sequence Spread Spectrum) (Spreading Code) (Background Noise) 9
( ) ( ) 10
( ) ( ) chipping code chipping code (PN Code) IEEE 802.11 DSSS 11-bit Barker sequence chipping code 11
( ) DSSS 7-bit chipping code Data bits 1 0 Chipping code 1011011 1011011 Coded signal 0100100 1011011 Coded signal 0100100 1011011 Chipping code 1011011 1011011 12
( ) ( ) (Frequency Hopping Spread Spectrum) (Narrowband) (Pattern) 13
( ) ( ) ( ) 14
( ) ( ) ( ) (FHSS) 15
( ) (Line of Sight) 16
( ) 17
( ) HomeRF (Home Radio Frequency) PDA 18
( ) 2.4GHz IEEE 802.11 Bluetooth 1600 (hop) IEEE 802.11 FHSS (4-hop/ ) 19
( ) (Piconet) 8 ( 10 ) 20
( ) (Ad-Hoc Network) (Infrastructure Network) (Multi-points Connection Network) (Roaming Network) 21
( ) ( ) 22
( ) ( ) 23
( ) ( ) 24
( ) ( ) 25
IEEE 802.11 HomeRF GSM/ GPRS CDMA 26
IEEE 802.11 (Wireless LAN, WLAN) PDA IEEE 802.11 (Wi-Fi) 27
IEEE 802.11( ) ( ) ISM (Industrial, Science, and Medical) WLAN ISM 2.4~2.4835 GHz 5.725~5.850 GHz 28
IEEE 802.11( ) WLAN LAN WLAN LAN WLAN 29
IEEE 802.11( ) WLAN Credit-card numbers (Hackers) Sensitive financial data Anything you prefer to keep private 30
IEEE 802.11( ) 1997 IEEE 802.11 WLAN 31
IEEE 802.11( ) 1999 IEEE 802.11a (5GHz 54Mbps) IEEE 802.11b (2.4GHz 11Mbps) 2003 IEEE 802.11g (2.4GHz 54Mbps) 32
IEEE 802.11( ) IEEE 802.11 OSI 33
IEEE 802.11( ) IEEE 802.11 (Association) (Disassociation) (Reassociation) (Authentication) (Deauthentication) (Privacy) (Delivery of the Data) 34
IEEE 802.11( ) IEEE 802.11 802.11 Basic Service Set, BBS No-Transition 35
IEEE 802.11( ) IEEE 802.11 802.11 BBS- Transition 36
IEEE 802.11 IEEE 802.11 802.11 ESS- Transition 37
IEEE 802.11 IEEE 802.11 (Association) (Access Point, AP) 38
IEEE 802.11 IEEE 802.11 (Disassociation) (1) (2) 39
IEEE 802.11 IEEE 802.11 (Reassociation) 40
IEEE 802.11 IEEE 802.11 (Authentication) IEEE 802.11 (Open System) (Shared Key) 41
IEEE 802.11 IEEE 802.11 ( ) 42
IEEE 802.11 IEEE 802.11 ( ) 43
IEEE 802.11 IEEE 802.11 (Deauthentication) 44
IEEE 802.11 IEEE 802.11 (Privacy) 802.11 45
IEEE 802.11 IEEE 802.11 (Delivery of the Data) 46
IEEE 802.11 IEEE 802.11 IEEE 802.11 (Wireless Ethernet) CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) 47
IEEE 802.11 IEEE 802.11 ( ) DCF CSMA/CD RF 48
IEEE 802.11 IEEE 802.11 ( ) CSMA/CA 49
IEEE 802.11 IEEE 802.11 ( ) RTS/CTS MAC 2346-byte 50
IEEE 802.11 IEEE 802.11 ( ) Medium access with handshake Busy medium RTS Data Time DIFS Backoff CTS ACK Time SIFS SIFS SIFS 51
IEEE 802.11 IEEE 802.11 ( ) RTS/CTS 52
IEEE 802.11 IEEE 802.11 ( ) Hidden Node Problem A B AP A B 53
Area cleared by RTS IEEE 802.11 IEEE 802.11 ( ) CTS A RTS RTS/CTS Hidden Node Problem AP Area cleared by CTS B 54
IEEE 802.11 IEEE 802.11 (Direct Sequence Spread Spectrum DSSS) (Frequency Hopping Spread Spectrum FHSS) (Infrared) 55
IEEE 802.11 IEEE 802.11 2.4GHz ISM (Industrial, Scientific and Medical) 56
IEEE 802.11 IEEE 802.11 (Frequency Pattern) 57
IEEE 802.11 IEEE 802.11 (Base Band) (Spreading Signal) 58
IEEE 802.11 IEEE 802.11 IEEE 802.11 IR (LOS) 59
IEEE 802.11 IEEE 802.11 10 1~2 Mbps 60
IEEE 802.11 IEEE 802.11a 5GHz UNII (Unlicensed National Information Infrastructure) 6Mbps~54Mbps OFDM (Orthogonal Frequency Division Multiplexing) 61
IEEE 802.11 IEEE 802.11a 802.11a U-NII U-NII 62
IEEE 802.11 IEEE 802.11a 802.11a center frequency (MHz) = 5000 + 5 n, n = 0~200 UNII-lower band 5.180GHz n =(5180-5000)/5= 36 63
IEEE 802.11 IEEE 802.11b 802.11 2.4 GHz ISM 11 Mbps CCK (Complementary Code Keying) 802.11b 2M DSSS 64
IEEE 802.11 IEEE 802.11b HR/DSSS 5.5 Mbps 11 Mbps 802.11 DSSS 1 Mbps 2 Mbps IEEE 802.11b (1 Mbps 2 Mbps 5.5 Mbps 11 Mbps) 65
IEEE 802.11 IEEE 802.11g OFDM CCK OFDM ( 54 Mbps) CCK 802.11b 66
IEEE 802.11 HomeRF GSM/ GPRS CDMA 67
HomeRF HomeRF ITU (International Telecommunication Union ) 100 mw 50 68
HomeRF( ) HomeRF 69
HomeRF( ) HomeRF SWAP (Shared Wireless Application Protocol) DECT (Digital European Cordless Telephone) FHSS 50 70
HomeRF( ) 5.6 HomeRF 71
IEEE 802.11 HomeRF GSM/ GPRS CDMA 72
1998 Ericsson IBM Intel Nokia Toshiba 73
( ) 10 2.4 GHz ISM IEEE 802.11 1600 74
( ) ( ) (Piconet) 8 (Master) (client) TDMA 1 Mbps 75
( ) ( ) (FEC) (ARQ) 76
( ) ( ) 77
( ) (Polling) 78
IEEE 802.11 HomeRF GSM/ GPRS CDMA 79
GSM GSM/ GPRS 1982 (Conference of Posts and Telegraphs, CEPT) 80
GSM( ) GSM/ GPRS (European Telecommunication Standard Institution, ETSI) 1990 GSM (Global System for Mobile ) GSM 100 81
GSM( ) GSM/ GPRS GSM 9.6 Kbps 119 82
GSM/ GPRS GSM( ) GSM (Mobile Station, MS) (Base-station System, BS) 83
GSM/ GPRS GSM( ) GSM (Mobile-services Switching Center, MSC) (Database) GSM (Home Location Register, HLR) (Visitor Location Register, VLR) 84
GSM/ GPRS GSM( ) GSM (Operation and Maintenance Center, OMC) 85
GSM/ GPRS GPRS GPRS (General Packet Radio Services ) GSM GPRS 86
GSM/ GPRS GPRS GSM 9.6 Kbps GPRS 10 115 Kbps 87
GSM/ GPRS GPRS GPRS GSM WAP GPRS Always Connected 88
IEEE 802.11 HomeRF GSM/ GPRS CDMA 89
CDMA CDMA (Code Division Multiple Access, ) CDMA 90
CDMA 91
(1) IEEE 802.11 (3) Bluetooth (2) HomeRF (4) DECT Ans: 3 92
IEEE 802.11 (1) CSMA/CD (3) Polling (2) CSMA/CA (4) SWAP Ans: 2 93
(1) IrDA (3) 802.11 FHSS (2) Bluetooth (4) HomeRF Ans: 1 94
ISM (1) 2.4 ~ 2.4835 GHz (2) 5.15 ~ 5.35 GHz (3) 5.725 ~ 5.825 GHz (4) 1.8 ~ 1.9 GHz Ans: 4 95
UNII (1) 2.4 ~ 2.4835 GHz (2) 5.15 ~ 5.25 GHz (3) 5.25 ~ 5.35 GHz (4) 5.725 ~ 5.825 GHz Ans: 1 96
WLAN 5GHz (1) IEEE 802.11b (2) IEEE 802.11a (3) IEEE 802.11g (4) IEEE 802.11 Ans: 2 97
IEEE 802.11b (1) 1, 2, 5.5 11 Mbps (2) 802.11 (3) 5 GHz (4) 802.11b Ans: 3 98
(1) 50 IEEE 802.11a (2) 802.11b (3) 54Mbps (4) Ans: 2 99
IEEE 802.11g (1) 54Mbps (2) IEEE 802.11b (3) 2 GHz (4) 802.11a Ans: 3 100
ISM UNII 101
802.11 FH 802.11 DS 802.11a 802.11b 802.11g WLAN 102
802.11 FH HomeRF Bluetooth 103
Bluetooth 1998 104