p1 introduction to wireless comm system

8/11/2019 P1 Introduction to Wireless Comm System

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INTRODUCTION TO WIRELESS

COMMUNICATION SYSTEMS

References:Bernhard (Chapter 1, 4, 6-14)

Rappaport (Chapter 1)

Prasad (Chapter 1)

Kaaranen (Chapter 1)


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INTRODUCTION

Communication Medium

Acoustical

Optical

Mechanical

Electrical

- wired

- wireless

Wirelessversus Mobile

Privateversus Public


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Communication history heliographs, flags (semaphore), ...

150 BC smoke signals for communication;(Greece)

1794, optical telegraph, Claude Chappe

Electromagnetic Wave

1831-79 Faraday and Maxwell demonstrateselectromagnetic induction and theory ofelectromagnetic fields

H. Hertz (1857-94): demonstrates the wave

character of electrical transmission through space

HISTORY


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1896 Guglielmo Marconi

first demonstration of wirelesstelegraphy

long wave transmission, hightransmission power necessary ( +200kw)

1907 Commercial Trans-Atlantic connections

huge ground stations (30 by 100m antennas) 1915 Wireless voice transmission NY - SF

1920 Discovery of short waves (< 100m) by Marconi

reflection at the ionosphere

(cheaper) smaller sender and receiver, possibledue to the invention of the vacuum tube (1906, LeeDeForest and Robert von Lieben)

HISTORY


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1920 First commercial radio broadcast in Pgh.

1928 many TV broadcast trials

1933 Frequency modulation (E. H. Armstrong) 1935 First telephone call around the world

1958, then 1972 A-Netz and B-Netz in Germany

analog, 160 MHz, connection setup from the fixed

network too (but location of the mobile station hasto be known)

1974 FCC allocates 40 MHz for Cellular telephony

1982 Start of GSM-specification in Europe (Global

System for Mobile communication)

1983 Start of the American AMPS (Advanced MobilePhone System, analog)

1984 CT-1 standard (Europe) for cordless telephones

HISTORY


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1986 C-Netz in Germany

analog voice, 450 MHz, handoff possible, digital

signaling, automatic location of mobile device still in use today (as T-C-Tel), services: FAX,

modem, X.25, e-mail, 98% coverage

1991 Specification of DECT

Digital European Cordless Telephone (today: DigitalEnhanced Cordless Telecommunications)

- ~100 - 500 m range, 120 duplex ch., 1,2 Mbps datatransmission, voice encryption, authentication

1992 Start of GSM

fully digital, 900 MHz, 124 channels

automatic location, handoff, cellular

roaming in Europe - now worldwide > 100 countries

services: data with 9,6 kbps, FAX, voice, ...

HISTORY


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1994 E-Netz in Germany

GSM with 1800 MHz, smaller cells, supported by 11

countries

1996 HiperLAN (High Performance Radio Local Area Network)

standardization of type 1: 5,155,30GHz, 23,5 Mbps

recommendations for type 2 and 3 (both 5 GHz) and 4

(17 GHz) as wireless ATM-networks (up to 155 Mbps) 1997 Wireless LAN - IEEE802.11

IEEE-Standard, 2,42,5 GHz and infrared, 2 Mbps

already many products (with proprietary extensions)

1998 Specification of GSM successors for UMTS (Universal Mobile Telecommunication

System) as European proposals for IMT-2000

HISTORY


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2000

IMT2000/UMTS tested and deployed with multimedia

services

2010s

Wireless Broadband communication will be available with B-

OFDM and all IP

2010s+

Radio over fiber (such as fiber optic micro cell)

HISTORY/FUTURE?


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VISION

People and their machines should be able to access

information and communicate with each other easily

and securely, in any medium or combination of media-voice, data, image, video, or multimedia-any time,

anywhere, in a timely, cost-effective way

Dr George H.Heilmeier IEEE Communication

Mag.October 1992


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Advantages

Cost independent of terrain and distance

Suitable for incremental capacity enhancement, i.e. flexibleplanning

Reduced maintenance effort, i.e. better reliability

Ease of installation and maintenance, i.e. suitability for temporary

or emergency services

Dynamic use of medium, i.e trunking capability

Limited mobility

Suitable for multiple operators, i.e. service liberalisation

Limitation

Capacity limited by frequency allocation, i.e. cellular design is

expensive

Margin has to be provided for multipath propagation effect, i.e.

expensive for normal urban application

Power source required at terminal end

WIRELESS ADVANTAGES/LIMITATION


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FAMILY TREE (Ramjee Prasad)


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GENERATIONS


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SERVICES

Walkie Talkie/Radiophone

PagingPrivate Mobile Radio and Trunked Mobile Radio

Cordless System

Cellular System and Personal Communication

Bluetooth, Adhoc Network and Wireless PAN

Wireless Local Loop (WiLL/RiLL)

Wireless LAN (WLAN) and Wireless ATM (WATM)

Local Multipoint Distribution Services (LMDS)

Mobile Satellite

DSRR and etc.


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WALKIE TALKIE

Push on and off

Half duplex

Low quality

Short Distance

No privacy to user


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Radio paging is defined in CCIR Recommendation 584 as:a non-speech, one-way, personal selective calling system with alert, without

message or with defined message such as numeric or alphanumeric

Simplex and up to 1000 character (Low quality) can be sent Strength: inexpensive, small receiver, wide area, no antenna

required, discrete communication of messages

Weakness: no confirmation of received message, malicious user

Form of paging: Public (wide area) and Private (on site)

The Paging Network Controller (PNC) handles the user interfaceand the user features of a paging system via PSTN

The Transmission Network (TN) is the infrastructure through which

the pages are distributed to Paging Base Stations (PBS) which are

located over a wide geographical area.

Older paging concepts: 2Tone, 5Tone, NEC, Golay, Voice Paging

RDS (Radio Data System) and based on sequential tone

Today, there are two different digital:

Post Office Code Standard Advisory Group (POCSAG)

European Radio Messaging System (ERMES)

PAGING


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Private Mobile Radio

Use one radio channel

Duplex operation

Serve needs of certain group Control fleet of mobile e.g. police, taxi, etc.

Use common channel

Buy or rent equipment

Pay to system operator for accessing fee Limitation

Congestion

Limited number of channels

Low capacity system

High transmission power from RBS Interference because no frequency re-use

Lack of control over users and lack of privacy

No link to PSTN

Limited support of voice and data transmission


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PMR


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TRUNKED RADIO


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TRUNKED RADIO

TRUNKED RADIO


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TRUNKED RADIO

Standard

MPT1327 (1988)

Analog system in Great Britain, Germany etc. Service - normal call, priority call, recorded announcement,

conference call, radio telegram etc.

Signalling standard is possible to configure the systems of

any type and size: Single-site system (2-20 channels), RegionalNetwork (2 - 100 channels), Multi-regional or national network

Other related standards - MPT 1343 (terminal), 1347 (fixed

network), 1352 (network conformity)

Band 3 Sub Band 1 - 177.2125 > 183.4875 MHz Base Transmit /

Mobiles Transmit + 8 MHz

Band 3 Sub Band 2 - 201.2125 > 207.4875 MHz Base Transmit /

Mobiles Transmit - 8 MHz

Data network e.g. MOBITEX, MODACOM, ARDIS, COGNITO

Trans European TErrestrial Trunked RAdio (TETRA) Introduced by Mobile Digital Trunked Radio System (MDTRS)

2 families: Voice plus Data Standard (V+D) and Data only (Packet

Data Optimized Standard, PDO)

410-415 MHz (Portable Tx), 420-425 MHz (Base Tx)

CORDLESS SYSTEM


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CORDLESS SYSTEM

The cordless telephone, as its name implies, replaces the cord to the

handset with a radio link, giving user degree of mobility

Cordless telephone consists of (1)Base unitand (2)Portable unit The range to the fixed base unit can be many tens of meters,

depending on its siting

The principal difference between cellular and cordless communication

technologies is the degree of mobility provided to the subscriber

Cellular system allow mobile subscriber to communicate continuouslyover wide areas by providing handover to adjacent cells while cordless

system restrict mobility to a finite area

First generation cordless (CT-1) system are based on analogue

technologies and charaterised by variable quality and are prone to

interference with nearby system. Other disadvantages:

poor speech quality

limited range

bulky

short battery life

poor security

CORDLESS FREQUENCY


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CORDLESS FREQUENCY

1.7 MHz(CT-0)- The earliest analog models (just above the AM band).No longer in production, and were very susceptible to interference from

fluorescent lights and nearby automobile ignition systems 46-47 MHz(330m)- This band contains a huge installed base of

analog models. Low-power walk-talkies and baby monitors share this

same frequency band of 10-25 channels. Some models use audio

inversion for scrambling. The unscrambled models are very easily heard

by practically any radio scanner or a neighbor with a similar phone. This

band can be quite crowded, depending on density of users in a givenarea.

902-928 MHz (1.5-21, km)- Identified by their shorter non-telescoping antennas. Only the models with digital spread spectrum

(DSS) cannot be readily heard by a radio scanner but not the analog

models. This band is much less crowded than the 46-47 MHz band and

have 80 channels. Each manufacturer uses some but not all of the

available channels

2.7 GHz- Consists of 50-100 channels. Few radio scanners cover thisband, and analog and digital spread spectrum models are available to

ensure privacy.

Others - 5.8 GHz (http://www.vtech.com/about/press/5.8GHz_phone.pdf)


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CORDLESS STANDARD

SWAP - Shared Wireless

Access Protocol

CTM - Cordless Terminal

Mobility

CT 2 d CT3 (DECT)


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CT-2 and CT3 (DECT)

CT2 Use digital technology

3 main applications: Domestic use (Residential), Cordless PABX ,Telepoint

promoted as Telepoint

DECT A standard originally developed by ETSI (1992) in Europe

Applications includes domestic cordless, Telepoint, cordless PBXs, and

RLL Support multiple bearer channels for speech and data transmission,

handover, location registration, and paging

DECT is closer to a cellular system than to a classical cordless

telephone. However, the interface to the PSTN or ISDN network

remains the same as for PBX or corded telephone

DIGITAL CORDLESS


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DIGITAL CORDLESS


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SATELLITE


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SATELLITE (Orbit and Application)


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WLAN


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WLAN

Wireless equivalent of Ethernet

Unlicensed: ISM Band (2.4 GHz)

BenefitsMobility, Installation speed and simplicity,Installationflexibility, Reduced cost of ownership, Scalability

Base stations (APs): Connect to Ethernet

Laptop Cards: Drivers for Windows, Linux, MacOS

Typical range is up to 300 m/30 m

Technology

Spread spectrum (wideband) RF

Use more spectrum for better reliability

Frequency Hopping (FH) Spread Spectrum

Direct-Sequence (DS) Spread Spectrum

Narrowband RF

Infrared Standard developed by IEEE and ETSI BRAN

WLAN STANDARD


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WLAN STANDARD

ETSI BRAN

HIPERLAN- HIgh

PErformance Radio LANHIPERLAN/1- 1996

uses 5.15-5.30 GHz band

data rates up to 20 Mbps

channel access method:

EY-NPMA (Elimination

Yield Non-Pre-emptive

Multiple Access)

HIPERLAN/2- 2000

only minor differences

from IEEE 802.11a

uses 5.15-5.30 GHz

data rates of 6, 9, 12, 18,

27, 36 and 54 Mbps

2 operating modes:

centralized and direct

mandatory FEC

IEEE standards

802.11

provides 1 or 2 Mbps transmission in the2.4 GHz band

using either FH or DS

802.11a

provides up to 54 Mbps in the 5GHz

band

uses an orthogonal frequency divisionmultiplexing (OFDM)encoding scheme

802.11b

also referred to as 802.11 High Rateor

Wi-Fiby WECA

provides 11 Mbps transmission (with a

fallback to 5.5, 2 and 1 Mbps) in the 2.4GHz band.

uses only DS

802.11g

provides 20+ Mbps in the 2.4 GHz band.

WLAN STANDARD


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WLAN STANDARD

IEEE 802.11 FH1, 2 Mb/s

ETSI BRAN H123 Mb/s

ETSI BRAN H29-54 Mb/s

IEEE802.11a9-54 Mb/s

IEEE 802.11 DS1, 2 Mb/s

IEEE 802.11b HR1, 2, 5.5, 11 Mb/s

Proxim OpenAir FH1.6 Mb/s

HomeRF FH1.6 Mb/s

1996

2000

1997

1998

1999

2.4 GHz (BW 80 MHz) 5 GHz (BW 450 MHz)

ETSI BRAN H29-54 Mb/s

IEEE 802.11b HR1, 2, 5.5, 11 Mb/s

IEEE 802.11gstandard

20+ Mb/s

WLANproducts

2002

WATM


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WATM

WATM- Wireless Asynchronous Transfer Mode ATM + Radio Access

WATM provides wireless broadband access to a fixed ATM network

Created in 1996 by ATM Forum Working Group (WG)

ATM Data rate:155-622 MbpsTransmission medium:Fiber optics

Cell-switching and multiplexing technology:Fixed 53-byte cells

and Connection-oriented

Constant or variable data rate, different service types

Useful for high-speed LAN interconnectionAllows user terminal mobility withhigh-speed capacity and QoS

FIXED WIRELESS ACCESS


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FIXED WIRELESS ACCESS

MOBILEWIRELESS ACCESS

(MWA)

NARROW BAND(NWA)

BROAD BAND(BWA)

MULTI MEDIA(MWS)

FIXED WIRELESS ACCESS(FWA) or

WIRELESS LOCAL LOOP(WLL)

NOMADIC WIRELESS ACCESS(NWA) or

WIRELESS LOCAL AREANETWORKS (WLAN)

WIRELESS ACCESS(WA)

WHAT IS FWA?

BROADBAND, BROADERBAND, NARROWBAND, VOICE, DATA,

INTERNET, VIDEO, TELEMEDICINE, TELE-EDUCATION,

CONNECTIVITY, . . .DATA OVER FWA; MEGABYTES AND EVEN GIGABYTES/SECOND

DEFINITIONS IN JRG 8A-9BWIRELESS ACCESS

MOBILE WIRELESS ACCESS

NOMADIC WIRELESS ACCESS

BROADBAND WIRELESS ACCESSEND USER AND END USER CONNECTION POINT

HAPS

MULTIPOINT SYSTEMS

FWA IS NOT AN ALLOCATION OR SPECTRUM DESIGNATION

WIRELESS LOCAL LOOP (WLL)


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WIRELESS LOCAL LOOP (WLL)

WLLis a generic term for an access system that uses a wireless

link to connect subscribers to their local exchange in place of

conventional copper cable

Benefit

low installation and maintenance costs

rapid deployment

reduced outside plant requirement

immediate availability of enhanced services Systems WLL is based on:

Cellular/MicrocellularCordlessSatellite (specific and adjunct)

Other names

Radio In The Loop (RITL)Fixed-Radio Access (FRA)


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MMDS


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MMDS

LMDS (Local Multi Point Distribution System)


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LMDS (Local Multi-Point Distribution System) LMDS is a broadband wireless access technology to deliver voice,

data, Internet and video services that provides point-to-multipoint

microwave connections in the 28-GHz and 31-GHz range. (27.5 to

29.5 GHz band in the US)L(Local)- Denotes that propagation characteristics of signals in this

frequency range limit the potential coverage area of a single cell site;

(up to 5 miles)

M(Multipoint)- Indicates that signals are transmitted in a point to

multipoint or broadcast method.D(Distribution)- refers to the distribution of signals, which may

consists of simultaneous voice, data, Internet, and video traffic.

S(Service)- Implies the nature of relationship between operator andclient. The services offered are basically depended on the operator

choice of business.

Cable modem, XDSL/ADSL and fiber deployment is often

undesirable - existing buildings and infrastructure

impractical - terrain

costly - extensive build-up

Shot haul and Line-Of-Sight (LOS) connection

LMDS


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LMDS


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DATA SERVICES

p1 introduction to wireless comm system

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