Chapter 5-Cellular Networks - Copy

7/28/2019 Chapter 5-Cellular Networks - Copy

1/70

Wireless Networks

Satellite

Systems

Cellular

Networks

Wireless LANs

Example1:

GSM, 9.6 Kbps,

wide coverage

Example2:

3G, 2 Mbps,

wide coverage

Example1:

802.11b

11 Mbps,

100 Meters

Otherexamples:

802.11g,

HiperLAN2

Wireless WANs

Personal

Area

Networks

Business

LANs

Example1:

Bluetooth

1 Mbps,

10 Meters

Other examples:wireless sensor

networks, UWB

Example1:

Motorola

Iridium

up to 64 Mbps

globally

Example 2:

Deep space

communication

Wireless

Local Loops

(Fixed Wireless)

Wireless MANs

Example1:

LMDS

37 Mbps,

2-4 Km

Example2:

FSO

1.25 Gbps

1-2 KM

Paging

Networks

Example1:

FLEX,

1.2 Kbps

Example2:ReFLEX,

6.4Kbps


2/70

Cellular Networks


3/70

Outline

Fundamentals of cellular network

Brief History of cellular network

GSM


4/70

Copyright: A. Umar

A Cellular Network

Public

Switched

Telephone

Network(PSTN)

And

internet

Mobile

Switching

Center

(MSC)

Base Transceiver Station (BTS)Mobile User

Cell 1

Cell 2

Cordless connection

Wired connection

HLR VLR

HLR = Home Location Register

VLR = Visitor Location Register


5/70

Introduction to cellular networks

Cell covers specific geographical region

BTS(Base transceiver station)

Create cell (similar to Access point)

Mobile station(MS)

Attached to network through BTS

Mobile switching center (MSC)

Connect cell to wide area net

Manages call setups

handles mobility (HLR,VLR)


6/70

History

1G: Basic mobile telephony service analog cellular technology

American Mobile Phone (AMPS) and NMT in Europe

Uses FDMA

2G: service for mass users

Digital cellular technology

D-AMPS: combines FDMA/TDMA

Global System for mobile Communication (GSM ) Combines FDMA/TDMA

Code Division multiple Access(CDMA)

Uses CDMA


7/70

History

2.5G:Mobile Internet/data services together withvoice services

Packet switching technology adding into 2G

Two types :evolved from GSM General Packet Radio Service(GPRS )

Enhanced data rates for global Evolution (EDGE)

EDGE provides a better data rates using enhanced

modulation

CDMA -2000

Evolved from the CDMA


8/70

History

3G: Broad Band internet, multimedia andemerging new applications

Universal Mobile TelecommunicationSystem(UMTS) GSM next step, using CDMA

CDMA-2000 1x EV-DO(Evolution-Data Optimized)

Uses CDMA/TDMA

up to 3Mbps

144 kbps - 384 kbps for high-mobility, highcoverage

2 Mbps for low-mobility and low coverage


9/70

History

4G: LTE ( Long Term Evolution )

More on seminar


10/70

Copyright: A. Umar

1G(


11/70

Cellular concepts

0G Wi d d


12/70

Copyright: A. Umar

0G Wire ess o d days Mobile radio telephones were used for military

communications in early 20th century

Car-based telephones first introduced in mid 1940s Single large transmitter on top of a tall building

Single channel used for sending and receiving

To talk, user pushed a button, enabled transmission and

disabled reception.Became known as push-to-talk . CB-radio, taxis, police cars use this technology

IMTS (Improved Mobile Telephone System)introduced in 1960s

Used two channels (one for sending, one for receiving) No need for push-to-talk

Used 23 channels from 150 MHz to 450 MHz


13/70

Copyright: A. Umar

First-Generation Cellular

Advanced Mobile Phone Service (AMPS) invented atBell Labs and first installed in 1982

Key ideas:

Exclusively analog

Geographical area divided into cells (typically 10-25km)

Cells are small: Frequency reuse exploited in nearby (not

adjacent) cells

As compared to IMTS, could use 5 to 10 times more users in

same area by using frequency re-use (divide area into cells)

Smaller cells also required less powerful, cheaper, smaller

devices


14/70

Copyright: A. Umar

Cellular Network Organization Cell design (around 5km radius)

Served by base station consisting of transmitter,receiver, and control unit

Base station (BS) antenna is placed in highplaces ( high rise buildings) -

Operators pay per month for BS Different frequencies assigned to each cell

Cells set up such that antennas of all neighbors areequidistant (hexagonal pattern)

In North America, two 25-MHz bands allocated toAMPS

One for transmission from base to mobile unit

One for transmission from mobile unit to base


15/70

possible radio coverage of the cell

(omni-directional)

idealized shape of the cellcell

segmentation of the area into cellscellular network concepts

use of several carrier frequencies

not the same frequency in adjoining cells

cell sizes vary from some 100 m up to 35 km depending on user density,

geography, transceiver power etc.

hexagonal shape of cells is idealized (cells overlap, shapes depend ongeography)

if a mobile user changes cells handover of the connection to the neighbor cell


16/70

Copyright: A. Umar

E

A

DF

G C

B

E

A

DF

G C

B

E

A

DF

G C

B

Cell Design

Cells grouped into a cluster of seven

Letters indicate frequency use

For each frequency, a buffer of two cells is used before reuse

To add more users, smaller cells (microcells) are used

Frequencies may not need to be different in CDMA (soft handoff)


17/70

How to accommodate many users?


18/70

Copyright: A. Umar

Approaches to Increase Capacity

Adding/reassigning channels - some channelsare not used for traffic

Frequency borrowing frequencies are takenfrom adjacent cells by congested cells. High traffic cells borrows channel from low traffic

cells

Cell splitting cells in areas of high usage canbe split into smaller cells Decrease the transmission power


19/70

Cellular hierarchy

Femtocell- smallest unit of the hierarchy

Cover only few meters where devices are in thephysical range of the user. e.g. WPANs

Picocells: covers few tens of meters. E.g. WLAN

Microcells :covers hundreds of meters

Macrocells: several kilometer coverage

Megacells: national wide coverage.

E.g Satellites


20/70

Global System for Mobile Communication

(GSM)


21/70

GSM Overview Formerly: Groupe Spciale Mobile (founded 1982)

Now: Global System for Mobile Communication

Pan-European standard (ETSI, EuropeanTelecommunications Standardization Institute)

Goal: was to provide a mobile phone system that allowsusers to roam throughout Europe and provides voiceservices compatible to ISDN and other PSTN systems.

Today many providers all over the world use GSM(219 countries in Asia, Africa, Europe, Australia, America)

more than 5 billion subscribers in more than 800 networks

more than 80% of all digital mobile phones use GSM

Today more people use mobile phone system than thefixed telephones than toilets!


22/70

GSM Technologies

A 2G cellular network (a digital network for voice

communication) Circuit switching for voice (mainly)/data (limited)

transmission rate Connection-oriented service: establish a communication path

(channel) for point-to-point communication

Multiplexing Frequency division multiplexing (FDM) plus Time division

multiplexing (TDM) (adding to Space division multiplexing,

SDM) Uses 124 pair of channels per cell, each channel can support 8

users through TDM (992 users max actually 500 users)

Some channels are used for control signals, etc


23/70

Prof. Dr.-Ing. Jochen H. Schiller

www.jochenschiller.de MC -

2011

1 2 3 4 5 6 7 8

higher GSM frame structures

935-960 MHz

124 channels (200 kHz)

downlink

890-915 MHz124 channels (200 kHz)

uplink

time

GSM TDMA frame

GSM time-slot (normal burst)

4.615 ms

546.5 s577 s

tail user data TrainingSguard

space S user data tailguard

space

3 bits 57 bits 26 bits 57 bits1 1 3

GSM - TDMA/FDMA


24/70

GSM Technologies..

Mobility management Two-tier architecture: HLR and VLR

Location area for location update together withpaging for searching

Services

Mainlyfor voice communication

Data communication is very limited (i.e., 9.6kbit/s)

and supporting SMS


25/70

Performance Characteristics of GSMComparing with 1G cellular network

Communication Mobile communication for voice and data services

Total mobility International access, chip-card enables use of access points of different

providers (roaming services)

Worldwide connectivity One number, the network handles localization and interoperability

High capacity Better frequency efficiency (frequency reuses), smaller cells, more customers

per cell

High transmission quality High audio quality and reliability for wireless, uninterrupted phone calls at

higher speeds (e.g., from cars, trains)

Security functions

encryption, authentication via chip-card and PIN


26/70

GSM: Mobile Services

GSM offers

several types of connections voice connections, data connections, short

message service

voice communication services Basic telephony

Emergency number common number throughout Europe (112); mandatory

for all service providers; free of charge; connection withthe highest priority (preemption of other connectionspossible)

Voice mailbox


27/70

GSM: Mobile Services

Non-Voice-services group 3 fax

electronic mail ( Message Handling System,

implemented in the fixed network) Short Message Service (SMS)

alphanumeric data transmission to/from themobile terminal (160 characters) using the

signaling channel, thus allowing simultaneoususe of basic services and SMS(almost ignored inthe beginning now the most successful add-on!)


28/70

GSM: Mobile Services.

Supplementary service :May differ between

different service providers, countries and protocol

versions

Caller identification: CallerID forwarding of caller number:callDiverting

automatic call-back

conferencing with up to 7 participants

locking of the mobile terminal (incoming or outgoingcalls)


29/70

Architecture of the GSM System

GSM is a PLMN (Public Land Mobile Network) Main components

MS (mobile station)

BS (base station)

MSC (mobile switching center) LR (location register)

Subsystems

RSS (radio subsystem): covers all radio aspects

NSS (network and switching subsystem): call forwarding, handover,switching

OSS (operation subsystem): management of the network


30/70

Components

Mobile

Station

Base

Transceiver

Station

switching

center

Database

Management
http://localhost/var/www/apps/conversion/tmp/scratch_2/?rm=show_details&modell=1380http://localhost/var/www/apps/conversion/tmp/scratch_2/?rm=show_details&modell=1380


31/70

Prof. Dr.-Ing. Jochen H. Schiller

www.jochenschiller.de MC -

2009

GSM: overview

fixed network

BSC

BSC

MSC MSC

GMSC

OMC, EIR,

AUC

VLR

HLR

NSS

with OSS

RSS

VLR


32/70

Um

Abis

ABSS

radio

subsystem

MS MS

BTS

BSCBTS

BTS

BSCBTS

network and

switching subsystem

MSC

MSC

fixed

partner networks

IWF

ISDN

PSTN

PSPDN

CSPDN

SS7

EIR

HLR

VLR

ISDN

PSTN

GSM: system architecture


33/70

System architecture: radio subsystem

Components MS (Mobile Station) BSS (Base Station Subsystem):

consisting of BTS (Base Transceiver Station):

sender and receiver

BSC(Base Station Controller):

controlling several transceivers

Interfaces Um : radio interface

Abis : standardized, open interfacewith 16 kbit/s user channels

A: standardized, open interface with64 kbit/s user channels

Um

Abis

A

BSS

radio

subsystem

network and switching

subsystem

MS MS

BTS

BSC MSCBTS

BTSBSC

BTS

MSC


34/70

Radio subsystem

The Radio Subsystem (RSS) comprises the cellularmobile network up to the switching centers

Components Base Station Subsystem (BSS):

Base Transceiver Station (BTS):

radio components including sender, receiver, antenna

if directed antennas are used one BTS can cover several cells

Base Station Controller (BSC):

switching between BTSs, controlling BTSs,

mapping of radio channels (Um) onto terrestrial channels (A

interface) BSS = BSC + sum(BTS)

Mobile Stations (MS) MS=ME(mobile Equipment ) + SIM( subscriber identity module)


35/70

Base Transceiver Station and Base

Station Controller

Tasks of a BSS are distributed over BSC and BTS

BTS comprises radio specific functions

BSC is the switching center for radio channels

Functions BTS BSC

Management of radio channels X

Frequency hopping (FH) X X

Management of terrestrial channels X

Mapping of terrestrial onto radio channels X

Channel coding and decoding X

Rate adaptation X

Encryption and decryption X X

Paging X X

Uplink signal measurements X

Traffic measurement X

Authentication X

Location registry, location update X

Handover management X


36/70

Mobile station

Terminal for the use of GSM services

Mobile Equipment (ME)

represents physical terminals, such as a mobile or PDA.

Subscribers identity module (SIM) Stores all user specific data(Static)

i.e Card-type, subscribed service, personal identity

number(PIN) ,PIN unblocking key (PUK), International

mobile subscriber identity(IMSI) ,phone book.

MS=ME + SIM

System architecture: network and


37/70

System architecture: network and

switching subsystem Components

MSC (Mobile Services Switching Center): IWF (Interworking Functions) ISDN (Integrated Services Digital Network) PSTN (Public Switched Telephone Network) PSPDN (Packet Switched Public Data Net.) CSPDN (Circuit Switched Public Data Net.)

Databases HLR (Home Location Register) VLR (Visitor Location Register) EIR (Equipment Identity Register)

Protocol SS7 (signaling system no. 7)

network

subsystem

MSC

MSC

fixed partner

networks

IWF

ISDN

PSTN

PSPDN

CSPDN

SS7

EIR

HLR

VLR

ISDN

PSTN


38/70

Network and switching subsystem

NSS is the main component of the public mobile network GSM Switching, Hand over , mobility management ( localization ),

Components Mobile Services Switching Center (MSC)

controls all connections via a separated network to/from a mobileterminal within the domain of the MSC - several BSC can belong to a

MSC

Databases (important: scalability, high capacity, low delay)

Home Location Register (HLR)

central master database containing user data, permanent and semi-permanent data of all subscribers assigned to the HLR (one provider

can have several HLRs)

Visitor Location Register (VLR)

local database for a subset of user data, including data about all user

currently in the domain of the VLR


39/70

Mobile Services Switching Center The MSC (mobile services switching center) plays a

central role in GSM

switching functions ( b/n BSC)

Hand over functions for mobility support

management of network resources

interworking functions via Gateway MSC (GMSC)

integration of several databases.

location registration and forwarding of locationinformation

provision of new services (fax, data calls)

support of short message service (SMS)

generation and forwarding ofaccounting and billinginformation


40/70

GSM: elements and interfaces

NSS

MS MS

BTS

BSC

GMSC

IWF

OMC

BTS

BSC

MSC MSC

Abis

Um

EIR

HLR

VLR VLR

A

BSS

PDN

ISDN, PSTN

RSS

radio cell

radio cell

MS

AUCOSS

signaling

O


41/70

Operation subsystem

enables centralized management and maintenance of allGSM subsystems Components

Authentication Center (AUC) Used to protect user identity and data transmission.

authentication parameters and Encryption keys aregenerated and stored May be situated in special protected part of the HLR

Equipment Identity Register (EIR) registers GSM mobile stations devices Black list(stolen or locked ), Gray list( malfunctioning MS) White list (Valid devices)

Operation and Maintenance Center (OMC) control and monitor radio subsystem and the network

subsystem entities via the O interface . Traffic monitoring , status report of the network entities


42/70

Copyright: A. Umar

Databases recap

Mobile Switching Center (MSC) is at core; consists ofseveral databases

Home location register (HLR) database storesinformation about each subscriber that belongs to it

Visitor location register (VLR) database maintainsinformation about subscribers currently physically inthe region

Authentication center database (AuC) used forauthentication activities, holds encryption keys

Equipment identity register database (EIR) keepstrack of the type of equipment that exists at themobile station


43/70

GSM frequency bands

Type Channels Uplink [MHz] Downlink [MHz]

GSM 850 128-251 824-849 869-894

GSM 900

classical

extended

0-124, 955-1023

124 channels

+49 channels

876-915

890-915

880-915

921-960

935-960

925-960

GSM 1800 512-885 1710-1785 1805-1880

GSM 1900 512-810 1850-1910 1930-1990

GSM-R

exclusive

955-1024, 0-124

69 channels

876-915

876-880

921-960

921-925

- Please note: frequency ranges may vary depending on the country!

- Channels at the lower/upper edge of a frequency band are typically not used


44/70

Example coverage of GSM networks (www.gsmworld.com)T-Mobile (GSM-900/1800) Germany O2 (GSM-1800) Germany

AT&T (GSM-850/1900) USA Vodacom (GSM-900) South Africa

(GS 900)


45/70

ETMTN (GSM-900) Ethiopia


46/70

Localization and calling

To always know where a user currently is , GSM

performs periodic location updates even if the MS

is not in use( as long as it is logged on to the GSM

network ). HLR always contains info about the current location

VLR of the MSC informs the HLR about the location

change.


47/70

Localization

To locate the MS several numbers are needed. Mobile subscriber international ISDN number (MSISDN)

Phone number E.g. +251917111213

country code (CC) (+251) Ethiopia

National Destination code(NDC). ( 917 ) Jimma

Subscriber number(SN)..(111213) individual

International mobile subscriber identity (IMSI)

Used by the network provider

Mobile country code (MCC) Mobile network code (MNC)-code of network provider

Mobile subscriber identification number (MSIN)


48/70

Localization

Temporary mobile subscriber identity (TMSI) To hide the IMSI by BSC

By the VLR

Mobile station roaming number (MSRN)

Temporary address to hide the identity and location of asubscriber by MSC Visitor country code (VCC)

Visitor national destination code(VNDC)

International mobile Equipment identity (IMEI) Unique code to each mobile equipment

device specific theft protection

Stored in EIR( Equipment identity register )

Dial *#06#


49/70

Mobile Terminated Call(MTC)

PSTNcalling

stationGMSC

HLR VLR

BSSBSSBSS

MSC

MS

1 2

3

45

6

7

8 9

10

11 12

1316

10 10

11 11 11

14 15

17

1: calling a GSM subscriber 2: forwarding call to GMSC

3: signal call setup to HLR

4, 5: request MSRN from VLR

6: forward responsible

MSC to GMSC

7: forward call to

current MSC

8, 9: get current status of MS

10, 11: paging of MS

12, 13: MS answers

14, 15: security checks

16, 17: set up connection

Mobile Originated Call(MOC)


50/70

Prof. Dr.-Ing. Jochen H. Schiller www.jochenschiller.de MC - 2009

Mobile Originated Call(MOC)

1, 2: connection request

3, 4: security check

5-8: check resources (free circuit)

9-10: set up call

PSTNGMSC

VLR

BSS

MSC

MS1

2

6 5

3 4

9

10

7 8


51/70

MTC/MOCBTSMS

paging request

channel request

immediate assignment

paging response

authentication request

authentication response

ciphering commandciphering complete

setup

call confirmed

assignment command

assignment complete

alerting

connect

connect acknowledge

data/speech exchange

BTSMS

channel request

immediate assignment

service request

authentication request

authentication response

ciphering commandciphering complete

setup

call confirmed

assignment command

assignment complete

alerting

connect

connect acknowledge

data/speech exchange

MTC MOC

GSM R i


52/70

GSM Roaming

The ability for a cellular customer to automaticallymake and receive voice calls, send and receive data, oraccess other services when travelling outside thegeographical coverage area of the home network, by

means of using a visited network. Roaming Agreements between network operators

required .

National Roaming(visited network in the same country as

the home network) International Roaming( visited network is outside the

home country)

H R i W k


53/70

How Roaming Works

Subscribe for the roaming service roaming agreement is needed b/n operators .

Phone support the radio frequency

e.g. 850, 900, 1800 and 1900 MHz

Switch on your phone in the foreign network.

Note that when roaming you have to pay both

for calls that you make and receive.

GSM d t k i f


54/70

GSM coverage and network info

ETHIOPIA

Network Information Operator: Ethiopian Telecommunications

Corporation Also known as: ETMTN Currently : Ethiotelecom

Technology: GSM

Frequency: 900

Launch Date: APR 1999

Services Short Message Service

Source :www.mobileworldlive .com


55/70

Roaming Partners: ETMTN A Afghanistan, Albania, Algeria, Angola, Argentina, Armenia, Australia, Austria,

Azerbaijan, B Bahrain, Bangladesh, Belarus, Belgium, Benin, Bosnia Herzegovina,Botswana, Brazil, Bulgaria, Burkina Faso, Burundi,C Cameroon, Canada, Chad, China,Comoros, Congo, Cote D Ivoire, Croatia, Cyprus, Czech Republic, D Denmark, DjibouitE Egypt, Equatorial Guinea, Estonia, F Finland, France, G Gabon, Gambia, Georgia,Germany, Ghana, Greece, Guinea, Guinea Bissau, H Hong Kong, Hungary, I Iceland

India, Indonesia, Iran, Iraq, Ireland, Israel, Italy, J Jamaica, Japan, Jordan,K Kazakhstan, Kenya, Korea, Kuwait, L Latvia, Lebanon, Lesotho, Liberia, Libya,Liechtenstein, Lithuania, Luxembourg, M Madagascar, Malawi, Malaysia, Mali ,MaltaMauritius, Mexico, Mongolia, Morocco, Mozambique, N Namibia, Netherlands,Niger, Nigeria, Norway, O Oman, P Pakistan, Panama, Papua New Guinea,Philippines, Poland, Portugal, Puerto Rico, Q Qatar, R Romania, Russia, Rwanda,S Saudi Arabia, Senegal, Serbia, Seychelles, Sierra Leone, Singapore, Slovakia,Slovenia, South Africa, Spain, Sri Lanka, Sudan, Swaziland, Sweden, Switzerland,

Syria,T Tanzania, Thailand, Togo, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan,U Uganda, Ukraine, United Arab Emirates, United Kingdom, United States, Uruguay,Uzbekistan, Y Yemen, Z Zambia, Zimbabwe.


56/70

Hand over

Hand off is used to provide continuity ofservices while a mobile unit moves from one

cell to another.

hand off is necessary due to the limited powerof the MS and BTS

Reason for hand over

> Low signal strength ( out of cell range ) > Load balancing (too high in one cell)


57/70

Hand over

Hand off parameters (measurements)

word error indicator( WEI)

Demodulation error

Received signal strength indicator (RSSI)

Quality indicator (QI)

Quality with respect to interference

The handoff algorithm will be based on thevalue of this parameters .(threshold value )


58/70

Types of handover

In general there are 3 types of handovers forcellular network. Mobile controlled hand over (MCHO)

Mobile unit measures the parameters and make handover

decision by itself . Network controlled hand over (NCHO)

Base station measures the parameters and makes thehandover decision.

Mobile Assisted hand over (MCHO) Mobile unit measures the parameters and sends the values

to the network.

Then the base station(BS) makes the hand over decision.

Used by GSM.

4 types of GSM handover


59/70

4 types of GSM handover

MSC MSC

BSC BSCBSC

BTS BTS BTSBTS

MS MS MS MS

1

2 3 4

1. Intracell HO

2. Intercell /Intra-BSC HO

3. Inter-BSC/Intra-MSC HO

4. Inter-MSC HO

Handover decision


60/70

Handover decision

receive level

BTSold

receive level

BTSnew

MS MS

HO_MARGIN

BTSold BTSnew


61/70

Hand off decisions algorithms

Using Relative signal strength

Switch to BTS with better signal

Using Relative signal strength and threshold

Switch to BTS with better signal plus threshold

Common hand of problems

False handoff(multipath propagation )

Ping pond effect

Handover procedure


62/70

Handover procedure

HO access

BTSold BSCnew

measurement

result

BSCold

Link establishment

MSCMS

measurement

report

HO decision

HO required

BTSnew

HO request

resource allocation

ch. activation

ch. activation ackHO request ackHO commandHO commandHO command

HO completeHO completeclear commandclear command

clear complete clear complete


63/70

63

GSM Evolution review


64/70

Evolution of cellular communication

Services

From voice communication to voice and data

communication

Technologies

From circuit switching to packet switching

High speed circuit switched data


65/70

High-speed circuit-switched data

(HSCSD)

is an enhancement to the original data

transmission mechanism of the GSM system,

four times faster than GSM, up to 38.4 kbit/s.

circuit-switched mode.

Higher speeds are achieved as a result of

superior coding methods, and the ability to

use multiple time slots to increase data

throughput.

High Speed Circuit Switched Data


66/70

66

High Speed Circuit Switched Data

(HSCSD)

General Packet Radio Service


67/70

General Packet Radio Service

(GPRS)

2.5G is a packet oriented mobile data service.

usage charging is based on volume of data.

Use packet switching method.

provides data rates of56-114 kbps GPRS extends the GSM Packet circuit switched data

capabilities and makes the following services possible: "Always on" internet access

Multimedia messaging service (MMS) Push to talk over cellular (PoC/PTT)

Instant messaging (IM)

Global Packet Radio Service


68/70

68

Global Packet Radio Service

(GPRS)


69/70

69

Evolution ofGSM

EDGE (Enhanced Data rate for GSM Evolution) 2.5 G , also known as Enhanced GPRS (EGPRS)

new modulation scheme, GMSK(Gaussian minimum-shift keying) &8PSK ( 8 phase shift keying)

384 kbps is the maximum data rate

designed for service providers that may or may not migrate to UMTS

UMTS (Universal Mobile Telecommunications Systems)

3G

144kbps for vehicular access

384 kbps for wide-area coverage (pedestrian) 2 Mbps for local coverage (stationary)

WCDMA (wideband CDMA)

Adopted by Europe and Japan


70/70

Evolution of CDMA

CDMA2000 1X 2.5G

use CDMA channel access, to send voice, data, andsignaling data between mobile phones and cell sites.

up to 153 kbps

CDMA2000 1xEV-DO (Evolution-Data Optimized)

3G

broadband Internet access

Uses CDMA/TDMA

up to 3Mbps

Documents

Chapter 5-Cellular Networks - Copy