wireless generations 1g, 2g & 3g syed azhar hussain 99-ce-282

Wireless Generations1G, 2G & 3G

Syed Azhar Hussain99-CE-282

2Wireless Generations

Outline

Cellular Network Concept

First Generation

– AMPS

Second Generation

– Cellular Access Technologies

• FDMA, TDMA, CDMA

– GSM

Third Generation

– UMTS


Cell Concept

Cell phone is basically a radio

Combination of telephone (Alexander Graham Bell) and wireless communications (Guglielmo Marconi)

Originally used powerful radio telephones

– Problems

• Needed to be very powerful

• Not many distinct frequencies (50)

Finally split cities into cells to allow cell reuse and reduce the required power – the cell concept

– Each cell has a tower

– About 800 frequencies across a cell

– Size of cell is about 10 sq. miles


Basics

Mobile: Any radio terminal that could be moved during operation or a radio

terminal that is attached to a high-speed mobile platform (e.g. a cellular

telephone in a fast moving vehicle) whereas the portable describes a radio

terminal that can be hand-held and used by someone at walking speed.

Subscriber: A mobile or portable user (user pay fee).

Subscriber Unit or Mobile Station: Each user communication device.

Mobiles or Users: Collective group of users in a wireless system. Many users

may actually user portable terminals.

Base Stations: A fixed stations in a mobile radio system used for

communication with mobile stations. They are located at the center or on the

edge of a coverage region and consist of radio channels and transmitter and

receiver antennas mounted on a tower.

Mobile Switching Center: Switching center, which coordinates the routing of

calls in large service area. In a cellular radio system, MSC connects cellular

base station and the mobiles to the PSTN. An MSC is also called a mobile

telephone switching office (MSTSO).


Basics

Control Channel: Radio Channels used for transmission of call setup, call

request, call initiation and other beacon or control purpose.

Forward Channel: Transmission of information from the base to a mobile

station.

Reverse Channel: Transmission of information from the mobile to a base

station.

Roamer: A mobile station, which operates in a service area (market) other

than that from which service has been subscribe.

Handoff: The process of transferring a mobile station from one channel or

base station to another.

Page: A brief message, which is broadcast over the entire service area.


Classification

Simplex: Communication is possible in only one direction (no acknowledge) e.g. Paging Systems.

Half duplex: Communication is bi directional but use same channel for both receiving and transmission (push-to-talk and release-to-listen).

Half duplex: Communication is bi directional but allows simultaneous transmission and reception b/w subscriber and base station. Implemented by FDD (frequency division duplex; separate channel) or TDD (time division duplex; adjacent time slots).


Generic WCS (Wireless Communication System)

Switch

BaseStation

BaseStation

HandsetHandsetPSTN

(Public SwitchedTelephone Network)


Cellular Communications

CellsRadio Tower FrequenciesClustersFrequency ReuseCell SplittingHandoff

PSTN


Cellular Call Setup

1. Phone scans for towers for strongest signal on control channel

2.Transmit Mobile Identification Number (MIN), Electronic Serial Number (ESN), and telephone number

3. MTSO sets up call

MobileTelephoneSwitching

OfficeMTSO

Cellular Service SubscriberCar Phone = 2W

Hand Phone = 0.7W

PSTN


Wireless “Generations”

First Generation (1989)

Analog voice using FM channels

Also called AMPS (Advanced Mobile Phone System)

Solved the issue of “mobility”


Multiple Access

The basis for any mobile system is its air interface design, and

particularly the way the common transmission medium is shared

between users, that is, multiple access scheme.

Multiple access scheme defines how the radio spectrum is

divided into channels, and how the channels separate the

different users of the system.FDMA, TDMA, CDMA


AMPS

AMPS – Advanced Mobile Phone System

Analog cell phone standard deployed across North America

Approved by FCC in 1983 – first deployed in Chicago

Utilizes 824MHz-894MHz frequencies

832 available frequencies

– 790 Voice

– 42 Data (signaling)

30 KHz wide – voice quality

FDMA

NAMPS – Narrowband AMPS –

– 3x AMPS capacity



2G - Second Generation (1998)Digital modulation used for speech compressionStill a voice-only network, except for limited circuit switched data capabilitySeveral different system types:– TDMA - time division multiple access– CDMA - code division multiple access– GSM - global mobile system (the original acronym is

French) – Group Special Mobile.Solved the issue of “capacity”


Cellular Access Technologies

There are three common technologies used by cell phone networks for transmitting information:

Frequency Division Multiple Access (FDMA)

– FDMA puts each call on a separate frequency.

Time Division Multiple Access (TDMA)

– TDMA assigns each call a certain portion of time on a designated frequency.

Code Division Multiple Access (CDMA)

– CDMA gives a unique code to each call and spreads it over the available frequencies.

The last part of each name is multiple access. This simply means that more than one user (multiple) can use (access) each cell.


FDMA

In a FDMA system, the total system bandwidth is divided into several frequency channels that are allocated to users.

824.04 MHz

893.7 MHz

45 MHz


TDMA

In a TDMA system, one frequency channel is divided into time slots that are allocated to users, and the users only transmit during their assigned timeslots. Examples of demand-assignment contention less protocols are token bus and token ring LANs described by the IEEE in the 802.4 and 802.5 standards.

824.04 MHz

893.7 MHz

Digital decoding

6.7MS

Digital encoding


CDMA

CDMA takes an entirely different approach from TDMA. CDMA, after digitizing data, spreads it out over the entire bandwidth it has available. Multiple calls are overlaid over each other on the channel, with each assigned a unique sequence code. CDMA is a form of spread spectrum, which simply means that data is sent in small pieces over a number of the discrete frequencies available for use at any time in the specified range.

Digital decoding

Digital decoding

1850MHz

1990MHzCDMA


GSM

GSM – Groupe Spécial Mobile

GSM is an international digital cellular standard in Europe, Asia, Australia, and Africa

Originally, the acronym GSM stood for Groupe Spécial Mobile, a group formed by the Conference of European Posts and Telegraphs (CEPT) in 1982 to research the merits of a European standard for mobile telecommunications.

Commercial service using the GSM system did not actually start until 1991.

GSM was developed as a digital system using TDMA technology.


GSM

GSM uses TDMA

900 MHz – 1800 MHz (Europe and Asia)

1900 MHz (North America)

Used for digital PCS services

One phone for all standard GSM worldwide except North America

To switch providers – switch SIM (subscriber identification modules) cards


GSM Features

Uses encryption to make phone calls more secure

Data networking

Short Message Service (SMS) for text messages and paging

Call forwarding

Caller ID

Call waiting


GSM Network Architecture

BTS

BSC TRAU

Um

Abis Ater A PSTN

D

C

MSC

HLR/AuC

BSSNSS

MS

VLR

MS – Mobile StationBSS – Base Station SubsystemBTS – Base Trans StationBSC – Base Station ControllerTRAU - Transcoder / Rate Adaptation UnitMSC – Mobile Switching CentreNSS – Network Switching SubsystemVLR – Visitor Location RegisterHLR – Home Location RegisterAuC – Authentication Centre

MS – Mobile StationBSS – Base Station SubsystemBTS – Base Trans StationBSC – Base Station ControllerTRAU - Transcoder / Rate Adaptation UnitMSC – Mobile Switching CentreNSS – Network Switching SubsystemVLR – Visitor Location RegisterHLR – Home Location RegisterAuC – Authentication Centre


Evolving Standards and Terminology

1st GenerationAMPS

Bell Wireless AllianceCantel

2nd GenerationIS-95A (CDMA) and IS-136 (TDMA)

Bell Wireless Alliance (CDMA)ATT Rogers (Cantel) (TDMA)Clearnet (CDMA)Microcell (GSM)



2.5 Generation

Packet switched data at rates up to 144 kbps

Several different types:

– GPRS - evolved from GSM

– 1xRTT - evolved from CDMA

Will require a Core IP Network

Solves the issue of “mobility” with packet data


GPRS

GPRS – General Packet Radio Services

An evolution of GSM

Higher speed data services

GPRS has seamless interface capabilities to TCP/IP


From GSM to GSM/GPRS Network

BTS

BSC TRAU

Um

Abis AterA

PCU

Agprs

FrameRelay

Backbone

Gb Gb

MSC

VLR

PSTN

SGSN

PrivateIP

Backbone

GGSN

Gn Gn

ExternalPacket NetworksIntranet, Internet

Gi

HLR/AuC

D

C

Gr

MS

MS – Mobile StationBSS – Base Station SubsystemBTS – Base Trans StationBSC – Base Station ControllerTRAU - Transcoder / Rate Adaptation UnitMSC – Mobile Switching CentreNSS – Network Switching SubsystemVLR – Visitor Location RegisterHLR – Home Location RegisterAuC – Authentication Centre\SGSN – Serving GPRS Support NodeGGSN – Gateway GPRS Support Node

MS – Mobile StationBSS – Base Station SubsystemBTS – Base Trans StationBSC – Base Station ControllerTRAU - Transcoder / Rate Adaptation UnitMSC – Mobile Switching CentreNSS – Network Switching SubsystemVLR – Visitor Location RegisterHLR – Home Location RegisterAuC – Authentication Centre\SGSN – Serving GPRS Support NodeGGSN – Gateway GPRS Support Node


Research in Motion

GPRS in Canada/US

BlackBerry



3G -Third Generation (future)

Packet switched data at rates up to 2.4 Mbps

ITU standard - standards still evolving

Adds the high data rate component and quality of service parameters

Introduces an Open Standard concept that will foster increased development of wireless applications, much like the Internet.


UMTS

Universal Mobile Telecommunications SystemThird Generation (3G) TechnologyUses W-CDMA, FDD, TDDPhase 1, called Release 1999 (R99) is an evolution of the GSM network architectureKey features:– Open standards based– all IP in the core– decentralized network– service based

In plain English : a network that will allow IP devices to roam while providing 384 kbps to 2 Mbps access rates.If successful, may become the “World Standard”


UMTS

Will provide 2 Mbps in a local environment

Will provide 384 kbps at highway velocities

Will use IP over ATM to control different data types:

– controlling data latency and quality

Will use W-CDMA-FDD for macro mobility at 144 kbps

Will use W-CDMA-TDD for micro mobility at 2 Mbps


UMTS Architecture

UMTS Terrestrial Radio Access Network (UTRAN)

ATMBackbone

Node B(BTS)

UuRNC - Radio

Network Controller

Iu (CS & PS)

RNC

Iur

Iur

Iu (CS & PS)

Node B(BTS)

Uu

Access Network Core Network

Packet Domain

Circuit DomainUE

UE

ATMBackbone

Iub (ATM)

Iub (ATM)


UMTS Interfaces

Access Network Core Network

PrivateIP

Backbone

Node B(BTS)

Uu

Iub (ATM)

RNCIu

(CS & PS)

RNC

Iur

Iur

Node B(BTS)

Uu

TRAUMSC

VLR

SGSN

GGSN

Gn Gn

Gi

Iu CS

Iu PS

HLR/AuC

D

C

Gr

UE

UE

PSTN

ExternalPacket

Networks

ATMBackbone

ATMBackbone

Iub (ATM)Iu

(CS & PS)

wireless generations 1g, 2g & 3g syed azhar hussain 99-ce-282

Documents

wireless system

mobile stations

mobile radio system

wireless generations1g

mobile telephone

milessyed azhar hussain

mobile switching center

cellular base station