Hamdard University BangladeshHamdard Nagar, Gazaria, Munshiganj

IEEE 802.11 Project

Presentation Outline

Introduction Architecture MAC Sublayer Distribution Coordination Function Point Coordination Function MAC Layer Frame Physical Layer IEEE 802.11 FHSS IEEE 802.11 DSSS IEEE 802.11 Infrared

2/13

Introduction of IEEE 802.11

Released in 1997Define the specification for wireless LAN.Covers physical and data-link layer.

3/13

Architecture

Define two kinds of services.

4/13

MAC Sub-layer

5/13

Distribution Coordination FunctionIf a station has MAC frame to transmit, it listens to the medium.

If the medium is idle, station may transmit.Otherwise it must wait until current transmission is complete.

6/13

Data

SourceDestination

Point Coordination Function

7/13

Implemented in infrastructure network.Use repetition interval.

NAV

Polled Station

Oth

ers

Repetition Interval

Contention-free

MAC Layer Frame

8/13

framecontrol duration address

1address

2address

4address

3 payload FCS

2 2 6 6 6 2 6 0 - 2312 4sequence

control

Type FromDSSubtype To

DSMore frag WEPMore

dataPower

mgtRetry RsvdProtocolversion

2 2 4 1 1 1 1 1 11 1

Physical Layer

9/13

IEEE 802.11 Frequency-Hopping Spread Spectrum

10/13

IEEE 802.11 Direct-Sequence Spread Spectrum

11/13

12/13

IEEE 802.11 Infrared

Thanks To All