ieee protocols 802.11

Introduction to IEEE 802.11 Protocols

. ByNarender reddy13W91A0421

TECHNICAL SEMINAR

Outline:

Introduction

IEEE 802.11 Protocol Layers

IEEE 802.11 standards

Summary

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Introduction:

Access anytime, anywhere internet.

IEEE 802.11 is a set of standards for wireless Local Area Networks

(WLANs) computer communication, developed by the IEEE

LAN/MAN Standards Committee.

1997 working group approved IEEE 802.11 as the world’s first

wireless LAN standard.

IEEE 802.11 is a subset of IEEE 802 LAN standard.

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IEEE 802.11 Protocol:

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Covers physical and data link layer acc. to OSI

Physical layer:

Data Link layer

Spread Spectrum

FHSS

DSSS

Logic Link Control (LLC)Media Access Control (MAC)

IEEE 802.11 standards :

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802.11 is a set of IEEE standards that govern wireless networking transmission methods. They are commonly used today in their 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac ,802.11ad versions to provide wireless connectivity in the home, office and some commercial establishments.

USAGE:


IEEE 802.11 b(1999)

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Frequency = 2.4 GHz (ISM band)Maximum Speed =11 MbpsRange = about 38meters(Varies)Encoding Scheme = DSSSModulation Technique= BPSK(1 Mbps), DQPSK(2 Mbps), CCK(5.5 Mbps,11Mbps)Released in the year 1999


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IEEE 802.11 a

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Frequency = 5 GHzMaximum Speed = 54 MbpsRange = about 35 meters(Varies)Encoding Scheme = OFDMReleased in the year 1999


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IEEE 802.11 a

Multipath Effect(Multipath Fading) is simply a term used to describe the multiple

Paths the radio wave may follow between

transmitter and receiver


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IEEE 802.11 a

Orthogonal Frequency Division Multiplexing(OFDM)

OFDM a digital multi-carrier modulation method. A large number of closely-spaced orthogonal sub-carriers are used to carry data.

Although the principles and some of the benefits have been known since the 1960s, OFDM is popular for wideband communications today by way of low-cost digital signal processing components that can efficiently calculate the FFT.


IEEE 802.11 a

A simple idealized OFDM system(Implementation using FFT Algorithm)

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Receiver :


IEEE 802.11 a

OFDM Pros &ConsRobust against narrow-band co-channel interference.

Robust against intersymbol interference (ISI) and fading caused by multipath

propagation.

High spectral efficiency as compared to conventional modulation schemes, spread

spectrum, etc.

Efficient implementation using Fast Fourier Transform (FFT).

Sensitive to Doppler shift.

Sensitive to frequency synchronization problems.

High peak-to-average-power ratio (PAPR), requiring linear transmitter circuitry, which

suffers from poor power efficiency. 13


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IEEE 802.11 g

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Frequency= 2.4 GHz Maximum Speed = 54 Mbps Range = about 38 meters(Varies) Encoding Scheme = OFDM Bandwidth =20mhz Released in the year 2003


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IEEE 802.11n

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Frequency = 5 GHz,2.4 GHz Modulation = OFDM Addition of Mimo Maximum Speed = 150 Mbps Range = about 70 meters(Varies) Encoding Scheme = OFDM Released in the year =2009


IEEE 802.11 n

Multiple Input Multiple Output(MIMO)

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In radio, Multiple-input and Multiple-output is used of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology.

IEEE 802.11 standard :

IEEE 802.11ad

Frequency band=60GHzModulation=SC,OFDMMaximum speed=6.7Gbs/secRange about=1-10mBandwidth=2160mhzReleased in the year =2012

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ASUS Product :

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IEEE 802.11ay:

Frequency band=60mhz Bandwidth =8000 Maximum speed=100Gb/s Released date= 2017 Modulation= OFDM, single carrier

Summary:

IEEE 802.11ad standard Significantly improves throughput and

range compared with older 802.11 standards.

802.11ad is the only 802.11standard that operates in either the

60GHz and 2.4GHz frequency bands.

It is the first to standardize the use of multiple input, multiple output

(MIMO) antenna design.

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Technology

ieee protocols 802.11