1. Bab 4
Politeknik Telkom 2008

2. IEEE 802.11 IEEE 802.11 WiFi (Wireless Fidelity) Type of WiFi
IEEE a
IEEE b
IEEE g

3. IEEE 802.11a Radius 50 meter Not Compatible with 802.11b and 802.11g
Maximum data rate 54 Mbps
Frekuensi band 5 GHz
Power 2 W - 2,5 W

4. IEEE 802.11b Radius 100 meter Compatible with wireless 802.11
Maksimum data rate 11 Mbps
Frekuensi band 2,4 GHz
Power 1 W

5. IEEE 802.11g Compatible with wireless 802.11
Maksimum data rate 54 Mbps
Frekuensi band 2,4 GHz
Power 1,5 W

6. Frekuensi
2,4 GHz  ISM frequency (Industrial, Scientific dan Medical).
802.11a and for WMAN  5 GHz frequency

7. Teknik Spread spectrum
Direct Sequence Spread Spectrum (DSSS)  11 channel, bandwidth/channel 22 MHz
Frequency Hopping Spread Spectrum (FHSS)  79 channel, bandwith/channel 1 MHz

8. Device of WLAN
Access Point
Client device

9. Access Point

10. Access Point
Access Point Mode :
Root
Repeater
Bridge

11. Root mode
WLAN client
Access Point
Jaringan kabel

12. Repeater mode Access Point Root mode WLAN client Repeater mode
Jaringan kabel

13. Bridge mode
Access Point
Mode bridge
Jaringan kabel

14. Client device
PCMCIA
PCI Wireless Adapter

15. SSID (Service Set Identifier)
SSID  group identifier of WLAN
SSID send in a Beacon by Access point to WLAN client
Beacon use to control and synchronize communication in WLAN

16. Beacon information Synchronization Time Parameter FH and DS SSID
Data Rate

17. Wifi Scanning  passive / active AP sending probe-response
Client send authentication-request to AP
AP receive authentication confirmation from client
Client send association-request to AP
AP confirm association-request from client