recent trends.ppt

7/30/2019 RECENT TRENDS.ppt

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RECENT TRENDS IN WIRELESSCOMMUNICATION

ByPoonam Yadav

E.C.E 8th SEM.

ROLL NO. -7610342


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Outline

Objective and Introduction

Wireless time-line and initial technologies

Current Generations

Modern Wireless Systems

Comparison of various technologies

Conclusion and References


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Objectives

Where is wireless broadband today? Where has it comefrom in the last decade? What is its future potential?

What are key wireless communication concepts?

How do they feature in modern/emerging wirelesssystems (Wifi: 802.11a/b/g/n, 3G, mobile WIMAX:802.16e)?

Modern wireless systemsWiFi , Bluetooth, Zibgee,3G, GSM, CDMA, WiMAX, UWB,. .


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Why Wireless?

Characteristics

Mostly radio transmission

Advantages

Spatial flexibility

Ad hoc networks No problems with wiring

Robust against disasters like earthquake, fire

Disadvantages

Low transmission rates for higher no. of users Many national regulations, global regulations

Restricted frequency range, interferences of frequencies

Nevertheless, in the last 10-20 years, it has really been a wireless

revolution


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Wireless Evolution Timeline


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Early Wireless Systems

1

st

Generation: Analog: early 80s AMPS: FDMA with 30 KHz FM voice channels.

FCC increased the cellular spectral allocation from 40 MHz to 50 MHz.

Two 25MHz channels: DL and UL (FDD)

Drawbacks: Analog - very susceptible to static and noise

2nd Generation: digital: early 90s

higher capacity, improved cost, higher data rates for support of digital

services,

DECT: 1880-1900 MHz spectrum, multicarrier /TDMA/TDD structure

FHMA/TDMA/TDD provides up to 120 channels

Interference-free wireless operation ~100 to 500 mts outdoor

Average data transmission: 1.2 Mbps


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2G Cellular Systems

GSM (Global System for Mobile)Specifications:

fully digital

900MHz or 1800 MHz

124 channels

Automatic location,

hand-over, frequency reuse

Services: data with

9.6kbps, voice

Transmission power

in handset: max. 2 W

IS-95 - uses direct-sequence CDMA with binary modulation and

coding.


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Tradeoffs: Mobility/Coverage/Bitrate


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Wi-Fi

Local area networking technology designed to provide in-buildingor campus broadband coverage

Based on IEEE 802.11a/b/g/n standards

Much higher peak data rates + larger bandwidth (20 MHz)

Beyond buildings: Metropolitan-wide (Muni-Fi), NeighborhoodArea Networks (NaN), hotspots

Wide availability of terminal devices

Covers greater distances

Wi-Fi systems - not designed to support high-speed mobility.

High power consumption

Requires more expensive hardware


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IEEE 802.11 Standards

Standard Date Scope

IEEE 802.11 1997 Medium Access Control (MAC): One common MAC for

WLAN applications

Physical Layer: Infrared at 1 and 2 Mbps

Physical Layer: 2.4 GHz FHSS at 1 and 2 Mbps

Physical Layer: 2.4 GHz DSSS at 1 and 2 Mbps

IEEE 802.11a 1999 Physical Layer: 5 GHz OFDM at rates 6 to 54 Mbps

IEEE 802.11b 1999 Physical Layer: 2.4 GHz DSSS at 5.5 and 11 Mbps

IEEE 802.11g 2003 Physical Layer: Extended 802.11b to data rates > 20

Mbps

IEEE 802.11n ongoing Physical / MAC:Enhancements to enable higher

throughput


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Bluetooth

Short range communication technology

Short distances {10m (1mW), 100m (100 mW)}

Lower power than Wi-Fi

Connect and exchange infomobile phones, PC, laptops,GPS receivers,

2.4 GHz band

Data rate of 1 Mbps

smallscale applications

Frequency-hopping for multiple access with a carrierspacing of 1 MHz for 8 devices


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2.5 G and 2.75 G

GPRS (General Packet Radio Service) packet oriented Mobile data service to users of GSM

Data rates: from 56 up to 114 kbps

TDMA/FDD

ServicesMMS, SMS, Internet application through WAP

EDGE (Enhanced Data rates for GSM Evolution)

Extension on standard GSM

increases data rates (up to 236.8 kbps for 4 timeslots) using ahigh-level modulation format combined with FEC coding.

CDMA 2000

Hybrid 2.5G/3G technology

CDMA for digital radio, voice, signaling data,.


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CDMA Broadband: 1xEV-DO

High-speed data standard defined as an evolution to secondgeneration IS-95 CDMA systems

Peak downlink data rate of 2.4 Mbps in a 1.25 MHz channel.

Flexibility to support both user- and application- level QoS User-level QoSproviders offer premium services

Application-leveloperators allocate resources - applicants need

Multimode 1xEV-DO - will let subscribers receive incoming voicecalls even while actively downloading data

Support high speed internet access at pedestrian or vehicle speeds

Multicast and broadcast services - supported


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WLAN

Linking of two or more computers or devices using OFDMmodulation

Communication in a limited area + mobility

Convenient, cost efficient, ease of integration with othernetworks and network components

Typical rangein order of tens of meterssufficient forhome, but insufficient for larger structure

Speed 1-108 Mbpsslow compared to slowest commonnetworks(100 Mbps to several Gbps)


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WiMAX (IEEE 802.16)

WiMAX - Worldwide Interoperability for Microwave Access Wireless transmission of data - from point-to-point links to

portable internet access

2 Mbps symmetric broadband speed

802.16-2004fixed WiMAXno support for mobility

802.16e-2005mobile WiMAXsupport for mobility

Applications:

Connecting Wi-Fi hotspots to internet

Wireless alternative to cable and DSL for broadband access

Data and telecommunication services

Portable connectivity


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C

O

MP

A

R

I

SO

N


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Ultra Wide Band (UWB)

Objectivetransmit large amount of digital data - over a widespectrum of freq bands - very low power, short distance.

Fractional bandwidth: W/fc >=20%, or more than 500 MHz of

absolute bandwidth

Operating range: 3.1 GHz to 10.6 GHz

Limited transmit power of -41 dBm/MHz

1.6 1.9 2.4

Bluetooth,

802.11b

Cordless Phones

Microwave OvensGPS

PCS

5

802.11a

-41 dBm/MhzPart 15 Limit

UWB

Spectrum

Frequency (Ghz)

EmittedSignal

Power

10.63.1


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UWB Communication

UWB is an impulse radio: sends pulses of tens of picoseconds(10

-12

)to nanoseconds (10-9)

Duty cycle of only a fraction of a percent

Uses a lot of bandwidth (GHz)

Modulation - OFDM

Excellent ranging capability; Synchronization (accurate/rapid) an

issue.

Impulse

Modulation

3 10 GHzfrequency

Ultrawideband

Comm

unication

time

1 0 1

(FCC Min=500Mhz)


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UWB Applications

Short range, indoor applications - high data rates, low power

see-through-the-wall precision radar imaging technology,

Precision locating and tracking, etc

Most computer and consumer electronic devices require wires to play,

record or exchange data. UWBeliminates wiresPlay a just recorded

video on a HDTV

without wires

A portable MP3 playercould stream audio to

speakers anywhere

Mobile computer-digital

projector wirelessly


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ZigBee (IEEE 802.15.4)

Objectivedevelop products that are v.low cost, low data rate

Very low power consumption (no recharge for months or

years!), up to 255 devices

Data rates of 20, 40, 250 kbps

CSMA-CA channel access

Frequency of operation in ISM bands

868 MHz in Europe,

915 MHz in USA, Australia

2.4 GHz worldwide

Home automation, consumer electronics applications,

RFID/tagging applications (supply-chain), Hospital care


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3GPP LTE: Long-Term Evolution

Improve the UMTS mobile phone standard to cope withfuture technology evolutions

Goals: improved spectral efficiency, lowering costs,improving services, use of new spectrum, better

integration with other open standards

Based upon OFDMA in downlink and SC-FDMA inuplink, MIMO

3GPP2 has longer term plans to offer higher data rates by

moving to higher bandwidth operation. Support up to 70-200 Mbps in downlink and up to 85

Mbps in the uplink using up to 20 MHz of bandwidth.

Expected to be available until about 2010.


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Data rate

10 kbits/sec

100 kbits/sec

1 Mbit/sec

10 Mbit/sec

100 Mbit/sec

0 GHz 2 GHz1GHz 3 GHz 5 GHz4 GHz 6 GHz

802.11a

UWB

ZigBee

Bluetooth

ZigBee

802.11b

802.11g

3G

UWB


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Range

1 m

10 m

100 m

1 km

10 km


802.11a

UWB

ZigBee BluetoothZigBee

802.11b,g

3G

UWB


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Power Dissipation

1 mW

10 mW

100 mW

1 W

10 W


802.11a

UWB

UWB

ZigBee

Bluetooth

ZigBee

802.11bg3G


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Conclusion

Wireless Technologyrapidly growing and generating tremendouschanges in telecommunications and networking

Data transmission rates increased tremendously from 9.6 kbps (GSM)to 2Mbps (WCDMA), increasing more than 200 times within last 10years

More ambitious 4Gapproximately 1 Gbps

Great demands on capacity and quality offered over wirelesscommunication links have pushed us hard to innovate new designmethodologies and concepts for the wireless systems and networks.

But, despite many promising technologies, the reality that

services many usersat high data rates

. (fixed and mobile) with reasonable bandwidth and power resources while maintaining high coverageand quality of service.. has not yet been achieved.


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References

Internet Resources

http://en.wikipedia.org/wiki/Wireless

http.//focus.ti.com/apps/docs/appshomepage.tsp

http://www.jcisonline.org/iis/2005_IIS/PDFs/Choi_Park_Fernandez_Kim.pdf

http://www.intel.com/technology/comms/uwb

http://www.palowireless.com/uwb/tutorials.asp http://whatis.techtarget.com/definition/ultra-wideband.html

http://en.wikipedia.org/wiki/Wireless_LAN

http://www.networkworld.com/news/tech/2002/0225tech.html

http://en.wikipedia.org/wiki/3GPP_Long_Term_Evolution

http://en.wikipedia.org/wiki/ZigBee http://en.wikipedia.org/wiki/High_Speed_Packet_Access

http://en.wikipedia.org/wiki/IEEE_802.11

http://en.wikipedia.org/wiki/CDMA2000_1xEV-DO#CDMA2000_1xEV-DO


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References (2)

Books William Stallings; Wireless Communications & Networks;

Pearson Pentice Hall, India, 2008 (Second edition)

X. Shen, M. Guizani; Ultra-wideband wireless communications

and networks; John Wiley & sons Ltd, Great Britain, 2006 Hsiao-Hwa Chen,Next Generation Wireless Systems and

Networks; John Wiley & sons Ltd, Great Britain, 2006

Articles

Rafael Kolic; Ultra Widebandthe Next-Generation Wireless

Connection


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Thank You

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