lecture (1): mobile generations

Lecture (1): Mobile Generations

By: Dr. Lway Faisal Abdulrazak

PhD in Wireless Communication

[email protected]

Sulaimani Polytechnic University

Department: Telecommunication Engineering

Subject: Modern Mobile Networks

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Presentation Outline Outlines

• Introduction

• Mobile Generations

• Spectrum

Wireless Communications History

– 1st short wave communication experiment was done in 1895 witnessed by L.T.Governer, and the credit changed to J.C.Bose, recognized by IEEE.

– Marconi invented the wireless telegraph in 1896 and sent telegraphic signals across the Atlantic Ocean in 1902.

– 1914 – first voice communication over radio waves.

– Many sophisticated military radio systems were developed during and after WW2 (1939-1945).

– Communications satellites launched in 1960s.

– Cellular has enjoyed exponential growth since 1988, with more than 3 billion users worldwide today.

– In 1964, Motorola invented first mobile phone.

– In 1973, 1st man held device came from Motorola.

Introduction

Electromagnetic radiation spectrum

Introduction… Cont.

Type of Cells:

Satellite

Macrocell Microcell

Urban In-Building

Picocell

Global

Suburban

Basic Terminal PDA Terminal

Audio/Visual Terminal


Wireless LAN Standards

• 802.11b (Current Generation)

– Standard for 2.4GHz ISM band (80 MHz) – Frequency hopped spread spectrum – 1.6-10 Mbps, 500 ft range

• 802.11a (Emerging Generation)

– Standard for 5GHz NII band (300 MHz) – OFDM with time division – 20-70 Mbps, variable range – Similar to HiperLAN in Europe

• 802.11g (New Standard)

– Standard in 2.4 GHz and 5 GHz bands – OFDM – Speeds up to 54 Mbps

Since 2008,

all WLAN

Cards have

all 3

standards


Satellite Systems • Different orbit heights

– GEOs (39000 Km) – MEOs (5000-12000Km) – LEOs (2000 Km)


Paging Systems • Broad coverage for short messaging

• Message broadcast from all base stations

Bluetooth IEEE 802.15 • Short range (10m, extendable to 100m), 2.4 GHz band

• (700 Kbps) and 3 voice channels.

Data flow (simplex, half-duplex, and full-duplex)


# Benefits of cellular technology • Group of cells called cluster.

• Smaller cells = frequency reuse = more number of users

• As demand increases (more channels needed)

– Number of base stations is increased (by reducing cell size)

– Transmitter power is decreased correspondingly to avoid interference.

• Adjacent cells assigned different frequencies.

• The same frequency is reused in different areas.

• In GSM networks a frequency reuse with k = 3, 4, 7,12 or 21.


# Frequency reuse:

>Reuse factor = 3 >Reuse factor = 4


Handoff : It depends on signal strength (90dBm- 100dBm)

RSSI: Reduced signal strength indicator

Frequency Reuse Problems: 1. Adjacent-Channel Interference: Comes from imperfect

filters that allow frequency leakage into the band.


2. Co-Channel Interference: occurs when the same

carrier frequency reaches the same receiver from two separate

transmitters. Seperation distance is the solution.


Reasons for interference

Environmental factors:

• Terrain (mountains, hills, plains, water bodies, etc.);

• The quantity, heights, distribution and materials of buildings;

• The vegetation and weather conditions;

• Natural and artificial electromagnetic noises;


Solution -Anti-interference:

Frequency Hopping Technology

Dynamic power control (DPC)

Discontinuous Transceiving (DTX)

Diversity receiving technique

• Time Division Duplex (TDD):

– Transmit and receive using same set of channel

Tx Rx

Ch1 Ch2 Ch3 Ch4


• Frequency Division Duplex (FDD):

– Transmit and receive using different set of channel.

Tx

Ch1 Ch2

Rx

Ch1 Ch2

Fundamentals of Multiple Access Schemes

FDMA

TDMA

CDMA


-Frequency Division Multiple Access (FDMA)

– One channel per user.

– Used in analog system only.

-Time Division Multiple Access (TDMA)

– Example 3 users per channel with 3 time slot

– Used in Digital System

Format Source

encode Encrypt

Channel

encode Multiplex

Information

Transmit

Transmitter

Modulate

Multiple

access


1st Generation: Introduced in 1980’s.

Analog cellular mobile

Data speed 2.4kbps

Uses FDMA techniques with

30KHz .

2nd Generation : First digital mobiles-1990’s

Data support : 9.6-19.2Kbps

Used for voice transmission.

2.5G representing handsets with data

capabilities over GPRS.

3rd Generation : Introduced in 2000 by IMT-2000

3G is arrived Data rates are 128Kbps for

mobile stations For fixed applications

2Mbps. Universal global roaming

multimedia video calling

accommodate web-based applications

Mobile Generations

4th Generation :

High-speed data access, 100Mb for Mobile

and 1GB for Stationary.

High-quality video streaming

5th Generation :

It is a packet based, High speed, high

capacity, and low cost per bit. Support

interactive multimedia, Scalability,

voice, streaming video, Internet, more

effective and more attractive.

What is GSM ?

Global System for Mobile (GSM) is a second generation cellular standard

developed for voice services and data delivery using digital modulation.

Mobile Generations… Cont.

• Developed by Group Spéciale Mobile, which was an initiative of CEPT

(Conference of European Post and Telecommunication )

• Presently the responsibility of GSM standardization resides with special

mobile group under ETSI ( European telecommunication Standards

Institute ) GSM 900

Mobile to BTS (uplink): 890-915 Mhz

BTS to Mobile (downlink):935-960 Mhz

Bandwidth : 2* 25 Mhz

GSM 1800

Mobile to BTS (uplink): 1710-1785 Mhz

BTS to Mobile(downlink) 1805-1880 Mhz

Bandwidth : 2* 75 Mhz

• GSM 900 uses 25 MHz frequency

spectrum with 124 channels Each

channels have 200 KHz bandwidth. Each

two channels are separated by 1.6 KHz

guard band. Each channel have 8 time

slots which allows 8 subscribers to use

same frequency by TDMA.

BSS — Base Station System

BTS — Base Transceiver Station

BSC — Base Station Controller

MS — Mobile Station

NSS — Network Sub-System

MSC — Mobile-service Switching Controller

VLR — Visitor Location Register

HLR — Home Location Register

AuC — Authentication Server

GMSC — Gateway MSC

GSM 2G Architecture

SS7 BTS

BSC MSC

VLR

HLR AuC

GMSC

BSS

PSTN

NSS

A

E

C

D

PSTN Abis

B

H

MS

GSM — Global System for Mobile communication



2.5 Generation ( Future of GSM)

HSCSD (High Speed circuit Switched data)

Data rate : 76.8 Kbps (9.6 x 8 kbps)

GPRS (General Packet Radio service)

Data rate: 14.4 - 115.2 Kbps

EDGE (Enhanced data rate for GSM Evolution)

Data rate: 547.2 Kbps (max)

SS7 BTS

BSC MSC

VLR

HLR AuC

GMSC

BSS

PSTN

NSS

A

E

C

D

PSTN Abis

B

H

MS




NSS — Network Sub-System






2.5G Architectural Detail

SGSN — Serving GPRS Support Node

GGSN — Gateway GPRS Support Node

GPRS — General Packet Radio Service

IP

2G+ MS (voice & data)

PSDN Gi

SGSN

Gr

Gb

Gs

GGSN

Gc

Gn

2G MS (voice only)


GPRS features • Radio resources are allocated for only one or a few packets at a

time, so GPRS enables:

– many users to share radio resources, and allow efficient transport of

packets

– fast setup/access times

– connectivity to external packet data networks

• GPRS also carries SMS in data channels rather than signaling

channels as in GSM


EDGE • Enhanced Data rates for Global Evolution

• Increased data rates with GSM compatibility

– Still 200 KHz bands; still TDMA

– 8-PSK modulation: 3 bits/symbol give 3X data rate

– Shorter range (more sensitive to noise/interference)

– New GSM/ EDGE radios but evolved ANSI-41 core network

3G Architecture (UMTS) — 3G Radios

SS7

IP

BTS

BSC MSC

VLR

HLR AuC

GMSC

BSS

SGSN GGSN

PSTN

PSDN

CN

C D

Gc Gr

Gn Gi

Abis

Gs

B

H




RNS — Radio Network System

RNC — Radio Network Controller

CN — Core Network








A E PSTN

2G MS (voice only)


UMTS — Universal Mobile Telecommunication System

Gb

3G UE (voice & data)

Node B

RNC

RNS

Iub

IuCS

ATM

IuPS


3G rel4 Architecture (UMTS) — Soft Switching

SS7

IP/ATM

BTS

BSC MSC Server

VLR

HLR AuC

GMSC server

BSS

SGSN GGSN

PSTN

PSDN

CN

C D

Gc Gr

Gn Gi

Gb

Abis

Gs

B

H




RNS — Radio Network System

RNC — Radio Network Controller

CN — Core Network








A Nc

2G MS (voice only)


Node B

RNC

RNS

Iub

IuCS

IuPS

3G UE (voice & data)

Mc

CS-MGW

CS-MGW Nb

PSTN Mc

ATM


GSM Evolution for Data Access:

1997 2000 2003 2003+

GSM

GPRS

EDGE

UMTS

9.6 kbps

115 kbps

384 kbps

2 Mbps

GSM evolution 3G


THANKS TO ALL

Glossary • AMPS: advanced mobile phone service; another acronym for analog cellular

radio

• BTS: base transceiver station; used to transmit radio frequency over the air interface

• CDMA: code division multiple access; a form of digital cellular phone service that is a spread spectrum technology that assigns a code to all speech bits, sends scrambled transmission of the encoded speech

• DAMPS: digital advanced mobile phone service; a term for digital cellular radio in North America.

• DCSdigital cellular system

• E–TDMA: extended TDMA; developed to provide fifteen times the capacity over analog systems by compressing quiet time during conversations

• ESN: electronic serial number; an identity signal that is sent from the mobile to the MSC during a brief registration transmission

• FCC: Federal Communications Commission; the government agency responsible for regulating telecommunications in the United Sates.

• FCCH: frequency control channel

• FDMA: frequency division multiple access; used to separate multiple transmissions over a finite frequency allocation; refers to the method of allocating a discrete amount of frequency bandwidth to each user

Glossary FM: frequency modulation; a modulation technique in which the carrier

frequency is shifted by an amount proportional to the value of the modulating signal

FRA: fixed radio access

GSM: Global System for Mobile Communications; standard digital cellular phone service in Europe and Japan; to ensure interpretability between countries, standards address much of the network wireless infra

MS or MSU: mobile station unit; handset carried by the subscriber

MSC: mobile services switching center; a switch that provides services and coordination between mobile users in a network and external networks

MTSO: mobile telephone switching office; the central office for the mobile switch, which houses the field monitoring and relay stations for switching calls from cell sites to wireline central offices (PSTN)

MTX: mobile telephone exchange

NADC: North American digital cellular (also called United States digital cellular, or USDC); a time division multiple access (TDMA) system that provides three to six times the capacity of AMPS

NAMPS: narrowband advanced mobile phone service; NAMPS was introduced as an interim solution to capacity problems; NAMPS provides three times the AMPS capacity to extend the usefulness of analog systems

Glossary

• PCS: personal communications service; a lower-powered, higher-frequency competitive technology that incorporates wireline and wireless networks and provides personalized features

• PSTN: public switched telephone network; a PSTN is made of local networks, the exchange area networks, and the long-haul network that interconnect telephones and other communication devices on a worldwide b

• RF: radio frequency; electromagnetic waves operating between 10 kHz and 3 MHz propagated without guide (wire or cable) in free space

• SIM: subscriber identity module; a smartcard which is inserted into a mobile phone to get it going

• SNSE: supernode size enhanced

• TDMA: time division multiple access; used to separate multiple conversation transmissions over a finite frequency allocation of through-the-air bandwidth; used to allocate a discrete amount of frequency ban

lecture (1): mobile generations

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