2008
Chapter-3 L28: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
1
DEVICES AND COMMUNICATION
BUSES FOR DEVICES NETWORK–
Lesson-28: WIRELESS AND MOBILE
SYSTEM PROTOCOLS─ IEEE802.11
2008
Chapter-3 L28: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
2
Wireless Personal Area Network (WPAN)
λ
IrDA (Infrared Data Association)
λ Bluetooth 2.4 GHz
λ
802.11 WLAN and 802.11b WiFi
λ ZigBee 900 MHz
2008
Chapter-3 L28: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
3
λ IEEE standards 802.11a to 802.11g
λ 802.11a data transfer rates─ 1 Mbps
and 2 Mbps
λ 802.11b data transfer rates─ 5.5 Mbps
and 2 Mbps
λ FHSS or DSSS or Infrared 250 ns
802.11 Wireless LAN connected devices
2008
Chapter-3 L28: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
4
802.11b
λ Called wireless fidelity (WiFi)
λ 802.11b support data rates of 5.5 Mbps
by mapping 4 bits
λ 11 Mbps mapping 8 bits simultaneously
during modulation.
2008
Chapter-3 L28: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
5
Basic service set (BSS)
• Has one wireless station, which
communicates to an access point,
also called hotspot.
•
BSS support ad-hoc network, which
as and when node come nearby in
range of access point it forms the
network through extended service set
(ESS).
• A node free to move from one BSS
to another.
2008
Chapter-3 L28: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
6
802.11 protocol
embedded
device or
computer
Wireless Access Point
802.11 protocol
embedded
printer
802.11 protocol
embedded
device or
computer
802.11 protocol
embedded
device or
computer
802.11 protocol
embedded
device or
computer
To ESS
Ad hoc
network
BSS [Basic Service Set] WLAN
2008
Chapter-3 L28: "E