Mobile Phones

Done By: 1. Saed Fathi 1998 / 2104

2. Ramy Ghaboun 2002 / 1895

3. Abd Al_Rhman Tabeel 2001 / 0306

Supervision :

Dr.eng. Basil Hammad

Contents

• Introduction• Cells• Multiple Access• Mobile Generations

Introduction

• What is a mobile phone ?

It is a device for sending voice and data through radio signals to

the mobile and telephone network.

• What is BTS ?

Base Transceiver (transmitter and receiver) Station.

MobileNetwork

Cells

ACTUAL COVERAGEAREA OF CELL 1

• Cell

• Cluster

• Hexagon shape

Space Division Multiple Access (SDMA)

PATTERN CAN BEREPLICATED OVERTHE ENTIRE EARTH

200 FREQUENCIESIN ONE CELL

TOTAL NUM BER OFFREQUENCIES = 1400

WORLDWIDE

MANY CELLS CAN SHARESAME FREQUENCIES IFSEPARATED IN SPACE

•Why Wireless?

Frequency Division Multiplexing (FDMA)

k2 k3 k4 k5 k6k1

f

t

c

f

t

c FREQUENCY BAND

Time Division Multiplexing (TDMA)

f

t

c

Combination Between FDMA &TDMA

f

t

c

Code Division Multiplexing (CDMA)

First Generation

• Single cell systems- Push-to-talk Phones.

- Dual-channel Phones.

• Cellular systems- AMPS. - TACS.- AMPS & TACS.

2 . Generationnd

INTERFACE TO LANDTELEPHONE NETWORKS

HIERARCHYOF CELLS

CELL TRANSMITTER& RECEIVER

PHONE

SIM:IDENTIFIES ASUBSCRIBER

2 . Generation GSM Architecture

nd

2.5 Generation General (GPRS) Architecture

Cell HandoverAS PHONE MOVES FROM CELL “A” TO CELL “B”: • CELL “A” MUST HAND THE CALL OVER TO “B” • PHONE MUST CHANGE FREQUENCIES • CELL “A” MUST STOP TRANSMITTING

Minimum performancecontour

Handover thresholdcontour

A Bx y

z

2 Subscriber Services: There are two basic types of services offered through GSM:

Telephon (also referred to as teleservices) and data (also referred to as bearer services).

•Short Message Services.

•Cell Broadcast.

•Call Forwarding.

•Call Hold.

•Call Waiting.

•Multiparty Services.

•Closed User Groups (CUGS).

nd

3 . Generationth

UMTS -Main Characteristics

• The main Features of 3G systems, known collectively as IMT–2000, are single family of compatible standards

• Main characteristics

• UMTS supports the virtual home environment (VHE) concept

UMTS –Data Rates

• The UMTS architecture is split into:

core (switching) networkUMTS Terrestrial Radio Access Network (UTRAN)

User Equipment

UMTS Architecture

UTRAN-Node B

Summary• First

• Analog, circuit-switched (AMPS)

• Second• Digital, circuit-switched (GSM)

– 10 Kbps

• 2.5– Digital, packet-switched, TDMA (GPRS)

40-400 Kbps

• Third– Digital, packet-switched, wideband CDMA (UMTS)

0.4 – 2 Mbps

• Fourth– Data rate 100 Mbps.

Q A&

Code Division

1 10DATA

1 1 1 1 1 1 1 10 0 0 0 0 00000“CODE”

0 0 0 0 0 0 0 0 0 011 1 1 1111DATA CODE

+1

-1

ACTUALSIGNAL

Code Division

1 00DATA B

0 1 1 0 0 1 1 10 1 0 0 0 10100“CODE” B

1 0 0 1 0 0 0 1 1 111 0 0 1011DATA CODE

+1

-1

ACTUALSIGNAL

B

Two CDMA Signals+1

-1

ACTUALSIGNAL

A

+1

-1

ACTUALSIGNAL

B

ACTUALSIGNAL

A+B

+2

-2

Recovering Data A From A+B +2

-2

ACTUALSIGNAL

A+B

1 1 1 1 1 1 1 10 0 0 0 0 00000“CODE” A

+2

-2

-(A+B) *CODE A

+1

-1

INTEGRAL1

0

1