By:By:

Khalid El-DarymliKhalid El-Darymli

Basheer Adamu AliyuBasheer Adamu Aliyu

By:By:

Khalid El-DarymliKhalid El-Darymli

Basheer Adamu AliyuBasheer Adamu Aliyu

IntroductionIntroduction Cellular Communications:Cellular Communications:

- T- The basics of radio telephony systems, including he basics of radio telephony systems, including both analog and digital systems.both analog and digital systems.

- - The basic components of a cellular system and The basic components of a cellular system and identify digital wireless technologies. identify digital wireless technologies.

Global System for Mobile Communication Global System for Mobile Communication (GSM):(GSM):

- A short history of network evolution - A short history of network evolution

- - Introduction to basic GSM conceptsIntroduction to basic GSM concepts, , specifications, specifications, networks, and services.networks, and services.

What is a cellular mobile communicationWhat is a cellular mobile communication?? A cellular mobile communications system uses a A cellular mobile communications system uses a

large number of low-power wireless transmitters large number of low-power wireless transmitters to create to create cellscells——the basic geographic service area the basic geographic service area of a wireless communications system.of a wireless communications system.

Variable power Levels allow cells to be sized Variable power Levels allow cells to be sized according to the subscriber density and demand according to the subscriber density and demand within a particular region. within a particular region.

Mobile users travel from cell to cell, their Mobile users travel from cell to cell, their conversations are handed off between cells to conversations are handed off between cells to maintain seamless service.maintain seamless service.

Channels (frequencies) used in one cell can be Channels (frequencies) used in one cell can be reused in another cell some distance away.reused in another cell some distance away.

Cells can be added to accommodate growth, Cells can be added to accommodate growth, creating new cells in unserved areas or creating new cells in unserved areas or overlaying cells in existing areas.overlaying cells in existing areas.

Mobile Communications PrinciplesMobile Communications Principles

Basic Mobile Telephone Service Network Basic Mobile Telephone Service Network

Cellular System ArchitectureCellular System Architecture

CellsCells ClustersClusters Frequency ReuseFrequency Reuse Cell SplittingCell Splitting HandoffHandoff

Analog Cellular Systems:Analog Cellular Systems:1- 1- The Advanced Mobile Phone Service (AMPS):The Advanced Mobile Phone Service (AMPS): It was released in 1983 using the 800-MHz to 900-MHz frequency It was released in 1983 using the 800-MHz to 900-MHz frequency

band and the 30-kHz bandwidth for each channel as a fully band and the 30-kHz bandwidth for each channel as a fully automated mobile telephone service.automated mobile telephone service.

Uses frequency modulation (FM) for radio transmission. Uses frequency modulation (FM) for radio transmission. It was the first standardized cellular service in the world and is It was the first standardized cellular service in the world and is

currently the most widely used standard for cellular communications. currently the most widely used standard for cellular communications. Designed for use in cities, AMPS later expanded to rural areas. Designed for use in cities, AMPS later expanded to rural areas. Limitations: Limitations: low calling capacity, limited spectrum, no room for low calling capacity, limited spectrum, no room for

spectrum growth, poor data communications, minimal privacy, spectrum growth, poor data communications, minimal privacy, inadequate fraud protection.inadequate fraud protection.

2- 2- Narrowband Analog Mobile Phone Service (NAMPS)Narrowband Analog Mobile Phone Service (NAMPS)-- It came withinIt came within the second generation of analog cellular systems. the second generation of analog cellular systems.-- WasWas designed to solve the problem of low calling capacity. designed to solve the problem of low calling capacity. -- It It is now operational in 35 U.S. and overseas is now operational in 35 U.S. and overseas -- Uses frequency division to get 3 channels in the AMPS 30-kHz single Uses frequency division to get 3 channels in the AMPS 30-kHz single

channel bandwidth.channel bandwidth. It is a US cellular radio systemIt is a US cellular radio system combines existing voice combines existing voice

processing with digital signaling, tripling the capacity of today's processing with digital signaling, tripling the capacity of today's AMPS systems.AMPS systems.

Cellular System Components:Cellular System Components:

Public Switched Telephone Network Public Switched Telephone Network (PSTN) (PSTN)

Mobile Telephone Switching Office Mobile Telephone Switching Office (MTSO) (MTSO)

Cell site with antenna system Cell site with antenna system Mobile Subscriber Unit (MSU) Mobile Subscriber Unit (MSU)

Digital SystemsDigital Systems

Frequency Division Frequency Division Multiple AccessMultiple Access ((FDMA)FDMA)

Time Division Time Division Multiple AccessMultiple Access ((TDMATDMA ) ) also calledalso called (DAMPS)(DAMPS)

Code Division Code Division Multiple AccessMultiple Access ((CDMACDMA ) )

Personal Personal Communications Communications Service Service (PCS)(PCS)

AMPS/DAMPS ComparisonAMPS/DAMPS Comparison

Analog Digital

Spectrum 824 MHz to 891 MHz 824 MHz to 891 MHz

Channel bandwidth 30 kHz 30 kHz

Conversations per channel

1 3 or 6

Subscriber capacity 40 to 50 conversations per cell 125 to 300 conversations per cell

TX/RCV type continuous time shared bursts

Carrier typeconstant phase variable

frequency constant frequency variable

phase

Mobile/base relationship

mobile slaved to base authority shared cooperatively

Privacy poor better—easily scrambled

Noise immunity poor high

Evolution of Mobile Telephone SystemsEvolution of Mobile Telephone Systems

Cellular Subscriber Growth WorldwideCellular Subscriber Growth Worldwide

GSMGSM

Milestones in the GSM historyMilestones in the GSM history

What is a GSM?What is a GSM? It is a digital cellular radio network which allows It is a digital cellular radio network which allows

one network channel to support multiple one network channel to support multiple conversations by means of time division conversations by means of time division multiplexing (TDM or TDMA).multiplexing (TDM or TDMA).

GSM was designed by the GSM design group GSM was designed by the GSM design group during the latter part of the 1980s, and is the during the latter part of the 1980s, and is the major digital cellular radio network in Europe, major digital cellular radio network in Europe, where it is used in the 900MHz radio band. where it is used in the 900MHz radio band.

GSM has been standardized to 900MHz, 1800MHz GSM has been standardized to 900MHz, 1800MHz and 1900MHz, and continuous to grow through out and 1900MHz, and continuous to grow through out Europe, Africa, Asia Pacific and the Americas. Europe, Africa, Asia Pacific and the Americas.

GSM is one of the major contenders for becoming GSM is one of the major contenders for becoming the de facto technical standard for digital cellular the de facto technical standard for digital cellular networks and personal communications systems. networks and personal communications systems.

The Switching System: The Switching System:

- Home Location Home Location Register (HLR)Register (HLR)

- Mobile Services Mobile Services Switching Center Switching Center (MSC)(MSC)

- Visitor Location Visitor Location Register (VLR)Register (VLR)

- Authentication Center Authentication Center (AUC)(AUC)

- Equipment Identity Equipment Identity Register (EIR)Register (EIR)

Additional Functional Additional Functional Elements:Elements:

- Message Center (MXE)Message Center (MXE) - Mobile Service Node Mobile Service Node

(MSN)(MSN) - Gateway Mobile Gateway Mobile

Services Switching Services Switching center (GMSC)center (GMSC)

- GSM Interworking Unit GSM Interworking Unit (GIWU)(GIWU)

The GSM NetworkThe GSM Network

A basic GSM networkA basic GSM network

The Base Station The Base Station System (BSS)System (BSS)

- Base Station Base Station Controllers (BSCs) Controllers (BSCs)

- The Base The Base Transceiver Transceiver Stations (BTSs). Stations (BTSs).

GSM Network AreasGSM Network Areas

The GSM network is made The GSM network is made up of geographic areas, as up of geographic areas, as shown in figure.shown in figure.

The The cellcell is the area given is the area given radio coverage by one radio coverage by one base transceiver station. base transceiver station.

The GSM network identifies The GSM network identifies each cell via the cell global each cell via the cell global identity (CGI) number identity (CGI) number assigned to each cell. assigned to each cell.

The location area is a The location area is a group of cells. group of cells.

It is the area in which the It is the area in which the subscriber is paged. subscriber is paged.

Each LA is served by one Each LA is served by one or more base station or more base station controllers, yet only by a controllers, yet only by a single MSC.single MSC.

Each LA is assigned a Each LA is assigned a location area identity (LAI) location area identity (LAI) number. number.

An MSC/VLR service An MSC/VLR service area represents the area represents the part of the GSM part of the GSM network that is network that is covered by one MSC covered by one MSC and which is and which is reachable, as it is reachable, as it is registered in the VLR registered in the VLR of the MSC of the MSC

The PLMN service The PLMN service area is an area area is an area served by one served by one network operator network operator

GSM Subscriber ServicesGSM Subscriber Services

TelephonyTelephony (also referred to as (also referred to as teleservices) and teleservices) and datadata (also referred to as (also referred to as bearer services). bearer services).

Dual-tone multifrequency (DTMF)Dual-tone multifrequency (DTMF) Facsimile group IIIFacsimile group III Short message servicesShort message services Cell broadcastCell broadcast Voice mailVoice mail Fax mailFax mail

Supplementary ServicesSupplementary Services

Call forwardingCall forwarding Barring of outgoing callsBarring of outgoing calls Barring of incoming callsBarring of incoming calls Advice of charge (AoC)Advice of charge (AoC) Call holdCall hold Call waitingCall waiting Multiparty serviceMultiparty service Calling line identification Calling line identification

Presentation/restrictionPresentation/restriction Closed user groups (CUGs)Closed user groups (CUGs)

Basic Operation:Basic Operation: 1- Mobile Station Initialization:1- Mobile Station Initialization:

System Broadcast Information.

Register with the System

… … continuouscontinuous,,, ,,, Basic Operation,Basic Operation,

2- Mobile Call Organization:2- Mobile Call Organization:

1

3

2

4

5

… … continuous,,, continuous,,, Basic Operation,Basic Operation,

3- Call Handover:3- Call Handover:

4- Ending a Call4- Ending a Call : :

Signal QualityLevelsShortBurst

Time Align

VoiceAdjacent Cell

Freq. ListTune to New

Channel

… … continuous,,, continuous,,, Basic Operation,Basic Operation,

5- Receiving a Call on a Mobile:5- Receiving a Call on a Mobile:

MS receives the channel number of the paging

channel to monitor

Request Service Page Request

Assign a Channel

The MS will listen to this channel until

it hears its identification number

What is Special about 3GsWhat is Special about 3Gs?? Third Generation System promising a Third Generation System promising a

wide range of personal mobility wide range of personal mobility features using a multimedia-like features using a multimedia-like phonephone ..

home shopping, interactive education and home shopping, interactive education and training with virtual reality support, training with virtual reality support, navigation, multi-media multi-party navigation, multi-media multi-party consultation, entertainment, multi-consultation, entertainment, multi-connection surveillance, information connection surveillance, information seeking and retrieval, communicating seeking and retrieval, communicating laptop PCs and video communication.laptop PCs and video communication.

MESSAGINGMESSAGING SMSSMS ability to send and receive text messages ability to send and receive text messages

to and from mobile telephonesto and from mobile telephones EMSEMS ability to send a combination of simple melodies, pictures, ability to send a combination of simple melodies, pictures,

sounds, animations, modified text and standard text as an sounds, animations, modified text and standard text as an integrated message for display on an EMS compliant integrated message for display on an EMS compliant handset.handset.

MMSMMS The Multimedia Messaging Service (MMS) confers the ability to The Multimedia Messaging Service (MMS) confers the ability to

send still images such as mobile postcards, mobile pictures, send still images such as mobile postcards, mobile pictures, mobile screensavers, mobile greeting cards, mobile maps and mobile screensavers, mobile greeting cards, mobile maps and business cards. Additionally, moving images, cartoons and business cards. Additionally, moving images, cartoons and interactive videointeractive video

3G Applications3G Applications

AudioAudio VoIPVoIP Still & Moving ImagesStill & Moving Images Virtual Home EnvironmentVirtual Home Environment Electronic AgentElectronic Agent Software DownloadSoftware Download

FEATURESFEATURES NETWORK REQUIREMENTSNETWORK REQUIREMENTS

Radio Controller Ntw, Node B. Radio Controller Ntw, Node B. (Base Station)(Base Station)

1.1. CELL PLANNING CELL PLANNING freq Alloc, Radio Interface, freq Alloc, Radio Interface, Wider coverageWider coverage

2.2. CORE NETWORKCORE NETWORK Switching, Trnasit, Switching, Trnasit,

BACKBONE NETWORKBACKBONE NETWORK Packet Delivery, IP Packet Delivery, IP RoutingRouting

3.3. SUPPORT SYSTEM CHANGESSUPPORT SYSTEM CHANGES Billiing, Billiing, Intelligent Ntw Systems, etcIntelligent Ntw Systems, etc

DisadvantagesDisadvantages

It is very difficult to configure WAP It is very difficult to configure WAP phones for new WAP services, with 20 phones for new WAP services, with 20 or so different parameters needing to or so different parameters needing to be entered to gain access to a WAP be entered to gain access to a WAP service.service.

Compared with the installed Compared with the installed base of Short Message Service base of Short Message Service (SMS) compliant phones, the (SMS) compliant phones, the relative number of handsets relative number of handsets supporting WAP is tiny. supporting WAP is tiny.

WAP services are expensive WAP services are expensive

Prospects and Trends:Prospects and Trends:

Bigger and better screen technologyBigger and better screen technology Video is central to the technology Video is central to the technology

demonstrationdemonstration Consumer electronics and mobile Consumer electronics and mobile

phones convergephones converge 3G is video in your palmwith varying 3G is video in your palmwith varying

small, medium or large screen sizes. small, medium or large screen sizes. The broadband bandwidth on 3G The broadband bandwidth on 3G

networks enables mobile multimedianetworks enables mobile multimedia

Problems and ChallengesProblems and Challenges

•Handover•Handset size•Functionality