1 history of mobile & cellular

A Brief Overview By

Engr.Abdul Razzaque Memon

MCS (IT/MIS) ; B.E (Electronics) ; PE (PEC) ; BA (Arts)

Web: http://www.uldhdqpia.webs.com

E-Mail : [email protected]

Communication Technologies: Acoustical Optical Mechanical Electrical

wiredwireless

By : Engr. Abdul Razzaque Memon

Use of light as communication heliographs, flags (semaphore), ... 150 BC smoke signals for communication;

(Greece) 1794, optical telegraph, Claude Chappe

Electromagnetic Wave: 1831-79 Faraday and Maxwell demonstrates

electromagnetic induction and theory of electromagnetic fields

H. Hertz (1857-94): demonstrates the wave character of electrical transmission through space


Attributes of Telecommunication Speed

- Ability to transmit in real-time Coverage

- Regional, National and International Reliability Cost

- 1860’s: 20 word telegram $5-$100 Security


High Tech of 19th Century

1850 – First submarine line 1858 – First transatlantic cable - breaks after 3 month 1866 – Higher quality cable

- London to Bombay in 4 ½ mins.

1924 – Telegram around the world in 80 secs.


1896 Guglielmo Marconi first demonstration of wireless

telegraphy long wave transmission, high

transmission power necessary ( +200kw) 1907 Commercial transatlantic connections

huge ground stations (30 by100m antennas) 1915 Wireless voice transmission NY - SF 1920 Discovery of short waves (< 100m) by

Marconi reflection at the ionosphere (cheaper) smaller sender and receiver, possible

due to the invention of the vacuum tube (1906, Lee DeForest and Robert von Lieben)


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, 160MHz, connection setup from the fixed

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

1974 FCC allocates 40Mhz for Cellular telephony 1981 Start of Cellular-specification in Europe

(Global System for Mobile communication) 1983 Start of the American AMPS (Advanced

Mobile Phone System, Analog) 1984 CT-1 standard (Europe) for cordless

telephonesBy : Engr. Abdul Razzaque Memon

1986 C-Netz in Germany analog voice, 450MHz, hand-over 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: Digital Enhanced Cordless Telecommunications)

- ~100-500m range, 120 duplex channels, 1.2Mbit/s data transmission, voice encryption, authentication

1992 Start of GSM fully digital, 900MHz, 124 channels automatic location, hand-over, cellular roaming in Europe - now worldwide in more than 100

countries services: data with 9.6kbit/s, FAX, voice, ...


1994 E-Netz in Germany GSM with 1800MHz, smaller cells, supported by 11

countries 1996 HiperLAN (High Performance Radio Local

Area Network) standardization of type 1: 5.15 - 5.30GHz, 23.5Mbit/s recommendations for type 2 and 3 (both 5GHz) and 4

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

IEEE-Standard, 2.4 - 2.5GHz and infrared, 2Mbit/s already many products (with proprietary extensions)

1998 Specification of GSM successors for UMTS (Universal Mobile Telecommunication

System) as European proposals for IMT-2000



cellular phones satellites wireless LANcordlessphones

1992:GSM

1994:DCS 1800

2005?:UMTS/IMT-2000

1987:CT1+

1982:Inmarsat-A

1992:Inmarsat-BInmarsat-M

1998:Iridium

1989:CT 2

1991:DECT

199x:proprietary

1995/96/97:IEEE 802.11,HIPERLAN

2005?:MBS, WATM

1988:Inmarsat-C

analog

digital

1991:D-AMPS

1991:CDMA

1981:NMT 450

1986:NMT 900

1980:CT0

1984:CT11983:

AMPS

1993:PDC

Wireless Communication

Transmitting voice and data using electromagnetic waves in open space

Electromagnetic waves Travel at speed of light (c = 3x108 m/s) Has a frequency (f) and wavelength ()

c = f x Higher frequency means higher energy

photons The higher the energy photon the more

penetrating is the radiation


Electromagnetic Spectrum


30MHz – 300MHz VHF300 MHz – 3GHz UHF3Ghz - 30GHz SHF> 30 GHz EHF

104 102 100 10-2 10-4 10-6 10-8 10-10 10-12 10-14 10-16

104 106 108 1010 1012 1014 1016 1018 1020 1022 1024

IR UV X-RaysCosmic

RaysRadio

Spectrum

1MHz ==100m100MHz ==1m 10GHz ==1cm

Microwave

Visible light

< 30 KHz VLF30Khz - 300KHz LF 300KHz – 3MHz MF3 MHz – 30MHz HF

Frequency Carries/Channels

The information from sender to receiver is carrier over a well defined frequency band. This is called a channel

Each channel has a fixed frequency bandwidth (in KHz) and Capacity (bit-rate)

Different frequency bands (channels) can be used to transmit information in parallel and independently.


Frequency & Wavelength of Some Technologies

AMPS Phones: frequency ~= 800 Mhz wavelength ~= 37.5 cm

GSM Phones: frequency ~= 900 Mhz wavelength ~= 33 cm

PCS Phones frequency ~= 1800 Mhz (1.8 Ghz) wavelength ~= 16.6 cm

Bluetooth: frequency ~= 2.4 Gz wavelength ~= 12.5 cm


Simplex/Duplex Communication

Normally, on a channel, a station can transmit only in one way.

This is called simplex transmision

To enable two-way communication (called full-duplex communication)

We can use Frequency Division Multiplexing

We can use Time Division Multiplexing


What is Mobility

Initially Internet and Telephone Networks is designed assuming the user terminals are static

No change of location during a call/connection A user terminals accesses the network always from

a fixed location Mobility and portability

Portability means changing point of attachment to the network offline

Mobility means changing point of attachment to the network online


Degrees of Mobility

Walking Users Low speed Small roaming area Usually uses high-bandwith/low-latency access

Vehicles High speeds Large roaming area Usually uses low-bandwidth/high-latency access Uses sophisticated terminal equipment (cell

phones)


Need for Wireless/Mobile Networking

Demand for Ubiquitous Computing Anywhere, anytime computing and

communication You don’t have to go to the lab to check your

email Pushing the computers more into background

Focus on the task and life, not on the computer Use computers seamlessly to help you and to

make your life more easier. Computers should be location aware

Adapt to the current location, discover services


Very Basic Cellular/PCS Architecture


Base Station(BS) Mobile Station

Base Station Controller

Mobility Database

Mobile Switching

Center(MSC)

Radio Network

Public SwitchedTelephone Network


Mobile Communications Network

BS MSC PSTN

PBX

Residence

Mobile Station(Phone)

LandLine

LandLine

Cell Site

Base stationsand other cell

sites

Two- to Three-Mile Radius

BS = Base StationMSC = Mobile Switching Center

Major Mobile Radio Standards-USA

Standard Type Year Intro

Multiple Access

Frequency Band(MHz)

Modulation Channel BW(KHz)

AMPS Cellular 1983 FDMA 824-894 FM 30

USDC Cellular 1991 TDMA 824-894 DQPSK 30

CDPD Cellular 1993 FH/Packet 824-894 GMSK 30

IS-95 Cellular/PCS 1993 CDMA 824-8941800-2000

QPSK/BPSK 1250

FLEX Paging 1993 Simplex Several 4-FSK 15

DCS-1900 (GSM)

PCS 1994 TDMA 1850-1990 GMSK 200

PACS Cordless/PCS

1994 TDMA/FDMA 1850-1990 DQPSK 300


Major Mobile Radio Standards-Europe

Standard Type Year Intro

Multiple Access

Frequency Band(MHz)

Modulation Channel BW(KHz)

ETACS Cellular 1985 FDMA 900 FM 25

NMT-900 Cellular 1986 FDMA 890-960 FM 12.5

GSM Cellular/PCS 1990 TDMA 890-960 GMSK 200KHz

C-450 Cellular 1985 FDMA 450-465 FM 20-10

ERMES Paging 1993 FDMA4 Several 4-FSK 25

CT2 Cordless 1989 FDMA 864-868 GFSK 100

DECT Cordless 1993 TDMA 1880-1900 GFSK 1728

DCS-1800 Cordless/PCS

1993 TDMA 1710-1880 GMSK 200


World Cellular Subscriber Growth


Cellular Networks

First Generation (1G) Analog Systems Analog Modulation, mostly FM AMPS Voice Traffic FDMA/FDD multiple access

Second Generation (2G) Digital Systems Digital Modulation Voice Traffic TDMA/FDD and CDMA/FDD multiple access

2.5G Digital Systems Voice + Low-datarate Data

Third Generation (3G) Digital Voice + High-datarate Data Multimedia Transmission also


Data Rates of 1G, 2G, 3G:

2nd Generation GSM -9.6 Kbps (data rate)

2.5 Generation HSCSD (High Speed ckt Switched data)

Data rate : 76.8 Kbps (9.6 x 8 kbps)GPRS (General Packet Radio service)

Data rate: 14.4 - 115.2 KbpsEDGE (Enhanced data rate for GSM Evolution)

Data rate: 547.2 Kbps (max) 3 Generation

WCDMA(Wideband CDMA)Data rate : 0.348 – 2.0 Mbps


Upgrade Paths for 2G Technologies


IS-136PDC

GSMIS-95

IS-95B HSCSD

GPRS

EDGE

W-CDMAEDGE

TD-SCDMA

cdma200-1xRTT

cdma2000-1xEV,DV,DO

cdma200-3xRTT

2G

2.5G

3G

2G TechnologiescdmaOne (IS-95)

GSM, DCS-1900 IS-54/IS-136PDC

Uplink Frequencies (MHz)

824-849 (Cellular)1850-1910 (US PCS)

890-915 MHz (Eurpe)1850-1910 (US PCS)

800 MHz, 1500 Mhz (Japan)1850-1910 (US PCS)

Downlink Frequencies

869-894 MHz (US Cellular)1930-1990 MHz (US PCS)

935-960 (Europa)1930-1990 (US PCS)

869-894 MHz (Cellular)1930-1990 (US PCS)800 MHz, 1500 MHz (Japan)

Deplexing FDD FDD FDD

Multiple Access CDMA TDMA TDMA

Modulation BPSK with Quadrature Spreading

GMSK with BT=0.3 DQPSK

Carrier Seperation 1.25 MHz 200 KHz 30 KHz (IS-136)(25 KHz PDC)

Channel Data Rate 1.2288 Mchips/sec 270.833 Kbps 48.6 Kbps (IS-136)42 Kbps (PDC)

Voice Channels per carrier

64 8 3

Speech Coding CELP at 13KbpsEVRC at 8Kbps

RPE-LTP at 13 Kbps VSELP at 7.95 Kbps


2G and Data

2G is developed for voice communications You can send data over 2G channels by

using modem Provides adat rates in the order of ~9.6

Kbps Increased data rates are requires for

internet application This requires evolution towards new

systems: 2.5 G


2.5 Technologies

Evolution of TDMA Systems HSCSD for 2.5G GSM

Up to 57.6 Kbps data-rate GPRS for GSM and IS-136

Up to 171.2 Kbps data-rate EDGE for 2.5G GSM and IS-136

Up to 384 Kbps data-rate

Evolution of CDMA Systems IS-95B

Up to 64 Kbps


3G Systems

Goals Voice and Data Transmission

Simultanous voice and data access Multi-megabit Internet access

Interactive web sessions Voice-activated calls Multimedia Content

Live music


3G Systems

Evolution of Systems CDMA sysystem evaolved to CDMA2000

CDMA2000-1xRTT: Upto 307 Kbps CDMA2000-1xEV: CDMA2000-1xEVDO: upto 2.4 Mbps CDMA2000-1xEVDV: 144 Kbps datarate

GSM, IS-136 and PDC evolved to W-CDMA (Wideband CDMA) (also called UMTS)

Up to 2.048 Mbps data-rates Future systems 8Mbps Expected to be fully deployed by 2010-2015

New spectrum is allocated for these technologies


Interest to 3G Applications


Western Eastern USA Europe Europe Emails 4.5 4.7 4.3 City maps/directions 4.3 4.2 4.2 Latest news 4.0 4.4 4.0 Authorize/enable payment 3.4 3.8 3.0 Banking/trading online 3.5 3.4 3.2 Downloading music 3.1 3.4 3.2 Shopping/reservation 3.0 3.1 2.9 Animated images 2.4 2.7 2.6 Chat rooms, forums 2.3 2.9 2.2 Interactive games 2.0 2.2 2.4 Games for money 1.8 1.8 1.8

(Means based upon a six-point interest scale, where 6 indicates high interest and 1 indicates low interest.)

GSM Subscriber Growth



Education

1 history of mobile & cellular