Mobile & Ad Hoc Network

Chandra Prakash

Assistant Professor

LPU

1Chandra Prakash, LPU

Objectives of the Chapter

Introduction

Fundamentals of Wireless Communication Technology

The Electromagnetic Spectrum

Radio Propagation Mechanisms

Characteristics of the Wireless Channel

Evolution of mobile Cellular Networks

Generations of Cellular Mobile Communication

GSM, GPRS,CDMA ,PCS, UMTS

Wireless LANs, Wi-Fi

IEEE 802 Networking Standard

2 Chandra Prakash, LPU

Evolution of mobile

Cellular Networks

It all started like this

• First telephone (photophone) – Alexander Bell, 1880

• First radio communication system – G. Marconi(1897)

• The first car mounted radio telephone – 1921

Going further• 1946 – First commercial mobile radio-telephone service by Bell and

AT&T in Saint Louis, USA. Half duplex (PTT)

– Push-to-talk cellular calls provide half-duplex communications

while one person transmits, the other(s) receive. This combines

the operational advantages of PTT with the interference

resistance and other virtues of mobile phones.

• 1973 – First handheld cellular phone – Motorola.

• First cellular net Bahrein 1978

Introduction to cellular network

A cellular network

Radio network distributed over land areas called cells,

Each cell served by at least one fixed location transceiver known

as a cell site or Base Station(BS).

When joined together these cells provide radio coverage over a

wide geographic area.

Enables a large number of portable transceivers (e.g., mobile

phones, pagers, etc.) to communicate with each other and with fixed

transceivers and telephones anywhere in the network, via base

stations, even if some of the transceivers are moving through more

than one cell during transmission.

Cellular Network

Cellular Network

Some Cellular Terminology

Cell- service area divided into small area known as cell

• Mobile station (MS) - Device used to communicate over the cellular

network.

• Base station transceiver (BST) - Transmitter/ receiver used to transmit/

receive signals over the radio interface section of the network.

• Base station controller (BSC) - Controls communication between a

group of BST's and a single MSC.

• Mobile switching centre (MSC) - The heart of the network, sets up and

maintains calls made over the network.

• Public switched telephone network (PSTN) - The land based section of

the network.

• Handoff/Handover : handover or handoff refers to the process of

transferring an ongoing call or data session from one channel connected

to the core network to another. Handoff decision made based on signal

strength.

Why Cellular ?

Cellular networks offer a number of advantages over alternative

solutions:

• Wireless access (very convenient)

• Access from anywhere within the coverage area.

• Reduced power use:

• Low power radio (hence better portability and more talk-time per battery

charge)

• ―Spectral efficiency‖ (more users in a limited frequency band) through

frequency reuse:

• increased capacity

• larger coverage area

• reduced interference from other signals

Cellular principles

In a cellular radio system, a land area to be supplied with radio service is divided into regular shaped cells, which can be hexagonal, square, circular or some other irregular shapes, although hexagonal cells are conventional.

Each of these cells is assigned multiple frequencies (f1 - f6) which have corresponding radio base stations.

Example of frequency reuse factor or pattern 1/4

The group of frequencies can be reused in other cells, provided that the same frequencies are not reused in adjacent neighbouring cells as that would cause co-channel interference. This increased the capacity in a cellular network.

Cont…• In a standard FDMA system, there must be at least a one cell gap between

cells which reuse the same frequency.

• The frequency reuse factor is the rate at which the same frequency can be

used in the network.

• It is 1/K where K is the number of cells which cannot use the same

frequencies for transmission. Common values for the frequency reuse

factor are 1/3, 1/4, 1/7, 1/9 and 1/12 (or 3, 4, 7, 9 and 12 depending on

notation).

Generations of Cellular Mobile

Communication

Cellular mobile communication has generations:

– Generation (0)

– Generation # 1

– Generation #2

– Generation #2.5

– Generation #3

– Generation #4

Generation 0 (0g)

• Radio Telephone -1945

• Not officially categorized as mobile phones, since they did not

support the automatic change of channel frequency during calls,

which allows the user to move from one cell (the base station

coverage area) to another cell, a feature called "handover".

• Technologies used in pre cellular systems included the Push to

Talk (PTT or manual), Mobile Telephone System (MTS), Improved

Mobile Telephone Service (IMTS), and Advanced Mobile Telephone

System (AMTS) systems.

First generation (1G)

Radio signals that 1G networks use are analog [routines for sending

voice] ,

Mostly telephony only:

Virtually no data capability other than special device with analog

modem.

In 1G network, voice calls were simply modulated to a higher

frequency, typically to 150MHz and up.

No International roaming

All systems are incompatible

Little capacity – cannot accommodate masses of subscribers

This generation is now mostly obsolete.

First Generation Technology

• 1G system deployed in US and canada was known as AMPS.

• Advanced Mobile Phone System (AMPS)

– AMPS is an analog cellular phone system using FDMA.

– A total of 40MHz of spectrum was allocated from the 800MHz band by the Federal

Communications Commission (FCC) for AMPS.

– It was first deployed in Chicago, with a service area of 2100 square miles .

– AMPS offered 832 full duplex channels, with a data rate of 10 kbps.

– Although omnidirectional antennas were used in the earlier AMPS implementation, it was

realized that using directional antennas would yield better cell reuse.

– A 7-cell reuse pattern was adopted for AMPS.

– Designed for grade of service (GoS) of 2% blocking.

• In Europe, TACS (Total Access Communications System) was introduced

with 1000 channels and a data rate of 8 kbps.

• AMPS and TACS use the frequency modulation (FM) technique for radio

transmission

Second Generation (2G)

• A new design was introduced into the mobile switching center of second-

generation systems.

• The use of base station controllers (BSCs) lightens the load placed on the

MSC (mobile switching center) found in first-generation systems

• In addition to enhancements in MSC design, the mobile-assisted handoff

mechanism was introduced .

• In 2G, voice communications were digitally encrypted.

• Allowed enhanced data services

– The data capability includes Internet access and picture sharing.

• Support some limited data communications, such as Fax and short

messaging service (SMS)

Second Generation (2G)

• Increased capacity

• More security

• Compatibility

Compared to first-generation systems, second-generation (2G) systems

use digital multiple access technology

Multiple access technology,

TDMA (time division multiple access) and

CDMA (code division multiple access).

Global System for Mobile Communications, or GSM , uses TDMA

technology to support multiple users

Examples of 2G

• A 2G system is called personal communications services (PCS) in

marketing literature.

• Global System for Mobile (GSM) used in Europe ,

• Cordless Telephone

• Personal Access Communications Systems (PACS),

• Digital European Cordless Telephone (DECT),

• IS-36 used in US.

• Personal Digital communication (PDC) in Japan.

Global System for Mobile (GSM)

What is GSM

Global System for Mobile (GSM) is a second generation

cellular standard developed to cater voice services and

data delivery using digital modulation

More than 800 million end users in 212 countries (Asia,

Africa, Europe, Australia, America, India etc..) and

representing over 70% of today's digital wireless market.

source: GSM Association

• Developed by Group Spéciale Mobile in1982

Aim : to replace the incompatible analog system

• Presently the responsibility of GSM standardization resides with special mobile

group under ETSI ( European telecommunication Standards Institute )

• Under ETSI, GSM is named as ― Global System for Mobile communication‖

• Phase I of GSM specifications was published in 1990

• Commercial service started in mid-1991

• More than 1300 million subscribers in world and 45 million subscriber in India.

• GSM technology was the first one to help establish international roaming.

This enabled the mobile subscribers to use their mobile phone connections in

many different countries of the world’s is based on digital signals ,unlike 1G

technologies which were used to transfer analogue signals.

GSM Since Beginning

GSM

GSM in WorldGSM in India

Figures: March, 2005

37%

1%4%43%

4%

3%

3%

3% (INDIA)

3%

Arab World

Asia Pacific

Africa

East Central Asia

Europe

Russia

India

North America

South America

Figures: March 2005

Bharti

27%

BSNL

22%

Spice

4%

IDEA

13%

Hutch

19%

BPL

6%

Aircel

4%

Reliance

3%MTNL

2%

Bharti

BSNL

Hutch

IDEA

BPL

Aircel

Spice

Reliance

MTNL

GSM in India

Advantages of GSM over Analog system

Capacity increases

Reduced RF transmission power and longer battery life.

International roaming capability.

Better security against fraud (through terminal validation and user

authentication).

Encryption capability for information security and privacy.

Compatibility with ISDN,leading to wider range of services

Integrated Services Digital Network (ISDN) is a set of

communications standards for simultaneous digital transmission of voice,

video, data, and other network services over the traditional circuits of

the public switched telephone network(PSTN).

Advantages

Uses radio frequency efficiently, Due to digital radio path it is more

tolerable to disturbance.

Speech quality much better than analog system

Data transmission is supported throughout the GSM system

Speech is encrypted and subscriber information security is

guaranteed.

GSM uses TDMA technology to support multiple users.

GSM Services (3 Types) Tele-services :

Telecommunication services that enable voice communication via mobile

phones

Offered services

Mobile telephony

Emergency calling

Bearer or Data Services

Include various data services for information transfer between GSM and

other networks like PSTN[Public switched telephone n/w.], ISDN

[Integrated services digital n/w] etc at rates from 300 to 9600 bps

Short Message Service (SMS)

up to 160 character alphanumeric data transmission to/from the mobile

terminal

Voice mailbox

Electronic mail

GSM ServicesSUPPLIMENTRY SERVICES

Call related services :

• Call Waiting- Notification of an incoming call while on the handset

• Call Hold- Put a caller on hold to take another call

• Call Barring- All calls, outgoing calls, or incoming calls

• Call Forwarding- Calls can be sent to various numbers defined by the user

Architecture of GSM Network Structure

GSM System Architecture-I

Mobile Station (MS)

Mobile Equipment (ME)

Subscriber Identity Module (SIM)

Base Station Subsystem (BSS)

Base Transceiver Station (BTS)

Base Station Controller (BSC)

Network Switching Subsystem(NSS)

Mobile Switching Center (MSC)

Home Location Register (HLR)

Visitor Location Register (VLR)

Authentication Center (AUC)

Equipment Identity Register (EIR)

• PSTN: Public switched telephone

network (telephone lines, fiber optic

cables, microwave transmission links, cellular

networks, communications satellites)

• ISDN: Integrated Services Digital Network

(digital transmission of voice, video, data, and

other network services)

TERMINOLOGIES:

• BTS: Base Transceiver Stations (Cell Site)

• MSC: Mobile Switching Center

• HLR: Home Location Register

• VLR: Visiting Location Register

• EIR: Equipment Identity Register

• IMSI(International Mobile Subscriber Identity) -> stored in SIM (Subscriber Identity Mobile)

• AUC: Authentication Centre

The Gateway Mobile Switching Centre (GMSC) is a special kind of MSC that is

used to route calls outside the mobile network. Whenever a call for a mobile

subscriber comes from outside the mobile network, or the subscriber wants to

make a call to somebody outside the mobile network the call is routed through the

GMSC.

GSM System Architecture-I

1. Mobile Station (MS)

1.1 Mobile Equipment (ME)

1.2 Subscriber Identity Module (SIM)

2. Base Station Subsystem (BSS)

2.1 Base Transceiver Station (BTS)

2.2 Base Station Controller (BSC)

3. Network Switching Subsystem(NSS)

3.1 Mobile Switching Center (MSC)

3.2 Home Location Register (HLR)

3.3 Visitor Location Register (VLR)

3.4 Authentication Center (AUC)

3.5 Equipment Identity Register (EIR)

System Architecture

1. Mobile Station (MS)

1.1 Mobile Equipment (ME)

Portable, vehicle mounted,hand held device

Uniquely identified by anIMEI (International MobileEquipment Identity)

Voice and data transmission

Monitoring power and signalquality of surrounding cellsfor optimum handover

Power level : 0.8W – 20W

160 character long SMS.

1.2 Subscriber Identity Module (SIM)

Smart card contains the International Mobile Subscriber Identity (IMSI)

Allows user to send and receive calls and receive other subscribed services

Encoded network identification details - Key Ki,Kc and A3,A5 and A8 algorithms

Protected by a password or PIN

Can be moved from phone to phone – contains key information to activate the phone

System Architecture

2. Base Station Subsystem (BSS)

2.1 Base Transceiver Station

(BTS):

Encodes,encrypts,multiplexes,

modulates and feeds the RF

signals to the antenna.

Frequency hopping

Communicates with Mobile

station and BSC

Consists of Transceivers (TRX)

units

2.2 Base Station Controller (BSC)

Manages Radio resources for BTS

Assigns Frequency and time slots for all MS’s in its area

Handles call set up

Transcoding and rate adaptation functionality

Handover for each MS

Radio Power control

It communicates with MSC and BTS

System Architecture

3. Network Switching Subsystem(NSS)

3.1 Mobile Switching Center (MSC)

Heart of the network

Manages communication between GSM and other networks

Call setup function and basic switching

Call routing

Billing information and collection

Mobility management

- Registration

- Location Updating

- Inter BSS and inter MSC call handoff

MSC does gateway function while its customer roams to other network by using HLR/VLR.

3.2 Home Location Registers (HLR)

permanent database about mobile subscribers in a large service area(generally one per GSM network operator)

database contains IMSI,MSISDN,prepaid/postpaid,roaming restrictions,supplementary services.

System Architecture

3.Network Switching Subsystem

3.3 Visitor Location Registers (VLR)

Temporary database which updates whenever new MS enters its area, by HLR database

Controls those mobiles roaming in its area

Reduces number of queries to HLR

Database contains IMSI,TMSI,MSISDN,MSRN,Location Area,authentication key

3.4 Authentication Center (AUC)

Protects against intruders in air interface

Maintains authentication keys and algorithms and provides security triplets ( RAND,SRES,Kc)

Generally associated with HLR

System Architecture

3.Network Switching Subsystem

3.5 Equipment Identity Register (EIR)

Database that is used to track handsets using the IMEI (International Mobile Equipment Identity)

Only one EIR per PLMN (public land mobile network )

GSM Specifications-1

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 1900

GSM450

Security in GSM

On air interface, GSM uses encryption and TMSI instead of IMSI.

SIM is provided 4-8 digit PIN to validate the ownership of SIM

3 algorithms are specified :

- A3 algorithm for authentication

- A5 algorithm for encryption

- A8 algorithm for key generation

Personal Communication System

Cellular System vs. Personal Communication System/Network (PCS/PCN)

Personal Communication Services [PCS] is a system, very similar to

Cellular Phone Service with great emphasis on personal services

(such as Paging, Caller ID, and E-mail) and mobility

PCS can be defined in a broader sense as a set of capabilities that

allows some combination of personal mobility and service

management.

Originated in UK, to improve its competitiveness in the field

PCS PCS has smaller Cell size, therefore, requires more infra-structure

PCS works in 1.85-1.99 GHz band

PCS uses TDMA Technology but with 200 KHz Channel

Bandwidth with eight time-slots[as compared to 30 KHz and 3

time-slots used by Digital Cellular Phone System IS-54/IS-136]

Several PCS systems have been developed to meet rapid growth prompted

by market demand. Most of them are connected to Public Switched

Telephone Network (PSTN) to integrate with the wired service.

Two of the most popular PCS systems are:

Cellular telephony

Cordless and low-tier PCS telephony

Personal communications services (PCSs)

PCS/PCN:

PCS calls for more personalized services whereas PCN refers to

Wireless Networking Concept- any person, anywhere, anytime

can make a call using PC.

PCS and PCN terms are sometime used interchangeably. In

Europe, the term "personal communication networks (PCNs)" is

used instead of PCS.

Form objectives for third-generation wireless

PCS handsets low power, small and light

Provide a limited range & mobility within Urban Centers

Personal Communication System (PCS)

A system where wired and wireless networks are integrated for

establishing communication.

PSTN: Public Switched Network.

MSC: Mobile Switching Center. Also called MTSO

(Mobile Telephone Switching Office).

BS: Base Station.

MS: Mobile Station. Also called MU (Mobile Unit)

or Mobile Host (MH).

HLR: Home Location Register.

VLR: Visitor Location Register.

EIR: Equipment Identify Register.

AC: Access Chanel.

PSTN

BS

VLR

HLR

EIR

AC

MSC (MTSO)MSC (MTSO)

MSMS Wireless component

2.5 G Mobile Systems

• The move into the 2.5G world will begin with General Packet Radio

Service (GPRS).

GPRS is a radio technology for GSM networks that adds packet-

switching protocols with

– shorter setup time for ISP connections,

– and the possibility to charge by the amount of data sent, rather

than connection time.

• Packet switching is a technique whereby the information (voice or data) to

be sent is broken up into packets, of at most a few Kbytes each, which are then

routed by the network between different destinations based on addressing data

within each packet.

2.5 G

• The next generation of data heading towards third generation and personal

multimedia environments builds on GPRS and is known as Enhanced

Data rate for GSM Evolution (EDGE).

• 2.75G was the name given to the evolution of EDGE (Enhanced Data

rates for GSM Evolution) or Enhanced GPRS (EGPRS).

• EDGE allow GSM operators to use existing GSM radio bands to

offer wireless multimedia IP-based services and applications at

theoretical maximum speeds of 384 kbps with a bit-rate of 48 kbps per

timeslot and up to 69.2 kbps per timeslot in good radio conditions.

Implementing EDGE will be relatively painless as it will require relatively

small changes to network hardware and software as it uses the same

TDMA frame structure, logic channel and 200 kHz carrier bandwidth as

today's GSM networks.

As EDGE progresses to coexistence with 3G wideband -CDMA, data rates

of up to ATM like speeds of 2 Mbps could be available.

General Packet Radio Service (GPRS)

Constraints with existing network… WHY

GPRS?

Data Rates too slow – about 9.6 kbps

Connection setup time too long

Inefficient resource utilization for bursty traffic

Proves expensive for bursty traffic utilization

No efficient method for packet transfers

GPRS

General Packet Radio Service:-Radio technology that adds

packet-switching protocols

GPRS is a step towards 3G and is often referred to as 2.5G

GPRS support flexible data transmission rates than GSM as well as

continuous connection to the network.

It works on TDMA & CDMA technology, depending upon the

multiplexing used.

Short for General Packet Radio Service, a standard for

wireless communications which runs at speeds up to 115 kilobits

per second, compared with current GSM (Global System for

Mobile Communications) systems’ 9.6 kilobits.

Cont…

GPRS, which supports a wide range of bandwidths, is an efficient

use of limited bandwidth and is particularly suited for sending and

receiving small bursts of data, such as e-mail and Web browsing, as

well as large volumes of data.

It consists of a packet wireless access network and an IP-based

backbone. GPRS is designed to transmit small amounts of

frequently sent data or large amounts of infrequently sent data.

GPRS has been seen as an evolution toward UMTS (Universal

Mobile Telecommunications Systems). Users can access IP services

via GPRS/GSM networks.

Comparison of GSM & GPRS

GSM GPRS

Data Rates 9.6 Kbps 14.4 to 115.2 Kbps

Modulation Technique GMSK

(Gaussian Minimum Shift Keying)

GMSK

(Gaussian Minimum Shift

Keying)

Billing Duration of connection Amount of data

transferred

Type of Connection Circuit – Switched Technology Packet - Switched

Technology

Benefits of GPRS

New Data Services

High Speed (Data Rate 14.4 – 115 kbps)

Efficient use of radio bandwidth

Circuit switching & Packet Switching can be used in

parallel

Constant connectivity

General Packet Radio Service (GPRS)

SGSN: A Serving GPRS Support Node is responsible for the delivery of data packets from

and to the mobile stations within its geographical service area.

GGSN : Gateway GPRS Support Node is responsible for the interworking between the

GPRS network and external packet switched networks, like the Internet and X.25 networks.

ARCHITECTURE

GPRS services include both point-to-point and point-to-multipoint

communications

GPRS Architecture is same as GSM except few hardware

modifications :

GPRS includes GSNs

SGSN : Serving GPRS Support Node

GGSN : Gateway GPRS Support Node

GPRS Register

SGSN(Serving GPRS Support Node)

Delivers data packets to mobile stations & vice-versa

Detect and Register new GPRS MS in its serving area

Packet Routing, Transfer & Mobility Management

Authentication, Maintaining user profiles

Its location register stores location info. & user profiles

GGSN – Gateway GPRS Support Node

Interfaces GPRS backbone network & external packet data networks.

The Gateway GPRS Support Node is the ―last port of call‖ in the GPRS

network before a connection between an ISP or corporate network’s

router occurs.

The GGSN is basically a gateway, router and firewall rolled into one.

GPRS in INDIA

BPL Mobile

Bharti Cellular

Hutchison Max

Hutchison Essar

Idea Cellular

GPRS characteristics

GPRS uses packet switched resource allocation

• resources allocated only when data is to be sent/received

• Flexible channel allocation

• one to eight time slots

• available resources shared by active users

• up and down link channels reserved separately

• GPRS and circuit switched GSM services can use same

time slots alternatively

Traffic characteristics suitable for GPRS

• Intermittent, bursty data transmissions

• Frequent transmissions of small volumes of data

• Infrequent transmission of larger volumes of data

Enhanced Data rates for GSM

Evolution (EDGE)

(Enhanced Data rates for GSM

Evolution )

Referred as Enhanced GPRS or EGPRS

Inherits all features from GSM and GPRS.

Only difference is instead of binary (Gaussian minimum-shift keying)GMSK ,

it uses 8-PSK modulation (Phase-shift keying ) which triple the capacity

compared to GSM.

EDGE is considered a pre-3G radio technology

EDGE requires no hardware or software changes to be made in GSM core

networks. EDGE-compatible transceiver units must be installed and the base

station subsystem needs to be upgraded to support EDGE.

8-PSK is more susceptible to errors than GMSK, thus have 9 different

modulation and coding schemes, each designed for different quality control.

Third Generation (3G)

3G or 3rd generation mobile telecommunications is a generation of

standards for mobile phones and mobile Telecommunication services

fulfilling the International Mobile Telecommunications-2000 (IMT-

2000) specifications by the International Telecommunication Union .

Application services include wide-area wireless voice telephone, mobile

Internet access, video calls and mobile TV, all in a mobile environment.

3G: voice (circuit-switched) & data (packet-switched)

Third generation offers multi-media communication capabilities, at

higher bit rates, with improved spectrum efficiency.

The EDGE standard is the development of GSM towards 3G.

Third Generation Technology (3G)

Digital system with multimedia services including video phone and

relatively higher speed (say up to 1 Mbps) Internet access.

Permanent web connection upto 2Mbps

Internet, phone and media: 3 in 1

Wideband code division multiple access (W-CDMA) and UMTS are some

of 3G standard.

The standard based on GSM is called UMTS.

Universal Mobile Telecommunications System (UMTS) is a third

generation mobile cellular technology for networks based on

the GSM standard.

3G has just been launched in India and is available on select mobile

operators for select cities. But to access these services, a 3G compatible

mobile phone is required.

3G

3G used completely different radio frequencies from 2G,

so it required different equipment to achieve the new high data

transfer rates.

Enormous costs of additional spectrum licensing fees delayed the

introduction of 3G in many countries.

3G data transfer rates are 384kbits/s to 2Mbits/s, so it allows for

previously unavailable services like video calls, video

conferencing, online conference call, mobile TV, online gaming etc.

Universal Mobile Telecommunication

System

(Universal Mobile Telecommunication

System) The Universal Mobile Telecommunications System (UMTS)

is commonly referred to as a third-generation system.

It was targeted to be deployed in 2002.

UMTS employs an ATM-based switching network

architecture and aims to provide services for both mobile and

fixed subscribers by common call-processing procedures.

Full packet driven architecture

For voice and for data transmissions.

Packet based networks allow for an increased amount of traffic on a

medium.

The UMTS architecture is split into 3 networks :

1. Core (switching) networks:

o The core network is responsible for performing switching

and transmission functions

2. Control (service) networks:

o The control network supports roaming through the

presence of mobility management functions

3. Radio Access networks.

o provides channel access to mobile users and performs radio

resource management and signalling

UMTS will include both terrestrial and global satellite

components.

Universal Mobile Telecommunication System

UMTS

Offers voice and data services the same as EDGE

Services offered will be classed into one of the following

Conversational Streaming Interactive Background

Real-Time Best-effort, guarantee of quality

delivery

Voice Streaming

Video

Web Pages MMS, SMS,

emails

UMTS (Universal Mobile Telecommunication System)

UMTS

(Universal Mobile Telecommunication System)

3G is also known as UMTS (Universal Mobile

Telecommunication System) UMTS uses Wideband-Code Division Multiple Access (W-CDMA)

Also known as “IMT-2000 Direct Spread”

Modulation is done with Quadrature phase shift keying (QPSK)

This encodes 2 bits with each change

Supports two modes of operation

Frequency Division Duplex (FDD)

Time Division Duplex (TDD)

UMTS

(Universal Mobile Telecommunication System)

The UMTS network comprises:

(a) the mobile terminal,

(b) the base transceiver station (BTS),

(c) the cell site switch (CSS),

(d) mobile service control points (MSCP), and

(e) the UMTS mobility service (UMS).

UMTS employs a hierarchical cell structure, with macrocells

overlaying microcells and picocells.

Highly mobile traffic is operated on the macrocells to reduce the

number of handoffs required.

UMTS aims to support roaming across different networks.

3G UMTS

Types of Cells and Base station to use them Macro Cell These cover a large area and will give slow access

144 Kbps – max speed of 500 Km/h

Micro Cell These should cover a medium area

384 Kbps max speed 120 Km/h

Pico Cell Less than 100 metres

2 Mbps – max speed of 10 Km/h

Difficult to predict Actual distances and bandwidth depend on local conditions

Cell Splitting

3G UMTS

Types of Cells and Base station to use them

Cells will operate in a hierarchy overlaying each other

Satellite

Macro-Cell

Micro-Cell

Urban

In-Building

Pico-Cell

Global

Suburban

GSM Evolution to UMTS

Telecommunications

• Mobility

• Circuit switching services

• Packet switching services

UMTS

Internet

• Internet access

• E-mail

• Real-time images transfer

• Multimedia documents transfer

Contents

• Video on-demand

• Interactive video services

• Radio and television

• Entertainment services

• Location based services

Convergence of media, data & telecom

Node B

UTRAN

UMTS Basic Architecture Release 99

GMSC

HLR

PSTN/ISDN

BTS

GSM BSS

RNC

BSCMSC/VLR

SGSN

Circuit Domain

Packet Domain

INTRANETS

GGSN

Other PLMN

INTERNET

Radio Access Network Core Network

MS

UE

ME

ME

Universal Terrestrial Radio Access Network,Radio Network Controller

Cont… UMTS is also designed to offer data rate on-demand.

The network will react to a user's needs, based on his/her profile and

current resource availability in the network. UMTS supports the

virtual home environment (VHE) concept, where a personal

mobile user will continue to experience a consistent set of services even

if he/she roams from his/her home network to other UMTS operators.

VHE supports a consistent working environment regardless of a user's

location or mode of access.

UMTS will also support adaptation of requirements due to different data

rate availability under different environments, so that users can continue

to use their communication services.

Fourth Generation

The next step in wireless communications.

A 4G system will be able to provide a comprehensive IP solution

where voice, data and streamed multimedia can be given to users

on an "Anytime, Anywhere" basis, and at higher data rates than

previous generations.

4G mobile phones are all set to provide data transfer rates of

100Mbit/s to 1Gbit/s,

Digital system with voice over-IP (VOIP) technology. That is, the services

are integrated into all IP network.

What is 4G?• Fourth Generation Technology

– Faster and more reliable

– 100 Mb/s

– Lower cost than previous generations

– Multi-standard wireless system

– Bluetooth, Wired, Wireless

– Ad Hoc Networking

– IPv6 Core

– OFDM used instead of CDMA

– Potentially IEEE standard 802.11n

– Most information is proprietary

Fourth Generation Technology

One of the main ways in which 4G differed technologically from 3G was

in its elimination of circuit switching, instead employing an all-IP

network.

4G ushered in a treatment of voice calls just like any other type of

streaming audio media, utilizing packet switching

over internet, LAN or WAN networks via VoIP.

Concept of Global Village

Generation Wireless Networks

Type of Networks

By Network Formation and Architecture

• Infrastructure-based network.

• Infrastructureless (ad hoc) network.

By Communication Coverage Area.

1. Wireless Wide Area Networks (Wireless WANs)

• Infrastructure-based networks

• Connections can be made over large geographical areas, across cities or even

countries

• Use of multiple antenna sites or satellite systems maintained by wireless service

providers.

• Examples :Cellular networks (like GSM networks or CDMA networks) and satellite

networks

87Chandra Prakash, LPU

Type of Networks 2. Wireless Metropolitan Area Networks (Wireless MANs).

– Referred as fixed wireless , infrastructure-based networks

– Enable users to establish broadband wireless connections among multiple locations ,for

example, among multiple office buildings in a city or on a university campus

– Serve as backups for wired networks

– Radio waves and infrared light can be used to transmit data.

3. Wireless Local Area Network (Wireless LANs)

– Enable users to establish wireless connections within a local area with in a 100 m range

– Provide flexible data communication systems that can be used in temporary offices or

other spaces that can operate in infrastructure-based or in ad hoc mode

– Include 802.11 (Wi-Fi) and Hiperlan2

4. Wireless Personal Area Networks (Wireless PANs).

– Enable users to establish ad hoc, wireless communication among personal wireless

devices such as PDAs, cellular phones, or laptops that are used within a personal

operating space, typically up to a 10 meter range.

– Two key Wireless PAN technologies are

• Bluetooth : is a cable-replacement technology that uses radio waves to transmit data

to a distance of up to 9–10 m,

• Infrared: connect devices within a 1 m range.88Chandra Prakash, LPU

IEEE 802 Networking Standard

IEEE 802 Networking Standard

• we need to have set of rules/standards for the data to travel

from one computer to other computer.

• Its developed by IEEE (Institute of Electrical and Electronics

Engineers, Inc.)

• The number 802 was simply the next free number IEEE could

assign, though ―802‖ is sometimes associated with the date the first

meeting was held — February 1980.

• The standards such as IEEE 802 helps industry provide advantages

such as, interoperability, low product cost, and easy to manage

standards.

• IEEE standards deal with only Local Area Networks (LAN) and

Metropolitan Area Networks (MAN).

IEEE 802 Networking Standard

IEEE 802.11

• IEEE 802.11 is a set of standards for implementing wireless local

area network (WLAN) computer communication in the 2.4, 3.6 and

5 GHz frequency bands. They are created and maintained by

the IEEE LAN/MAN Standards Committee (IEEE 802)

• 802.11 specifies an over-the-air interface between a wireless

client and a base station or between two wireless clients. The

IEEE accepted the specification in 1997.

IEEE 802.11

There are several specifications in the 802.11 family:

• 802.11 — applies to wireless LANs and provides 1 or 2 Mbps transmission in

the 2.4 GHz band using either frequency hopping spread spectrum (FHSS) or

direct sequence spread spectrum (DSSS).

• 802.11a — an extension to 802.11 that applies to wireless LANs and provides

up to 54-Mbps in the 5GHz band. 802.11a uses an orthogonal frequency

division multiplexing encoding scheme rather than FHSS or DSSS.

• 802.11b (also referred to as 802.11 High Rate or Wi-Fi) — created a standard

of wireless LAN operations in 2.4 GHz industrial, scientific and medical

(ISM) Band , which is freely available for use throughout the world. This

standard known as Wi-Fi (Wireless-Fidelity).It can offer data rates of up-to

11 MBPS.

• 802.11e — a wireless draft standard that defines

the Quality of Service (QoS) support for LANs, and is an enhancement to

the 802.11a and 802.11b wireless LAN (WLAN) specifications. 802.11e

adds QoS features and multimedia support to the existing IEEE 802.11b

and IEEE 802.11a wireless standards, while maintaining full backward

compatibility with these standards.

• 802.11g — applies to wireless LANs and is used for transmission over

short distances at up to 54-Mbps in the 2.4 GHz bands.

• 802.11n — 802.11n builds upon previous 802.11 standards by adding

multiple-input multiple-output (MIMO). The real speed would be 100

Mbit/s (even 250 Mbit/s in PHY level), and so up to 4-5 times faster than

802.11g.

• 802.1X — Not to be confused with 802.11x (which is the term used to

describe the family of 802.11 standards) 802.1X is an IEEE standard for

port-based Network Access Control that allows network administrators to

restricted use of IEEE 802 LAN service access points to secure

communication between authenticated and authorized devices.