Mobile Communication

Mobile Communication

Difficulties with old system • Every state had a different standard for cell phones • Changing through was not possible • Phone in one state was not supported in the other • This led to slow growth in technology

Cellular Structure • A cell is a small area having its own transreceiver • The size of cell depends on number of users.

…Cellular Structure • Handoff : changing the cells in use

• Keeps the phone in range continuously

Disadvantages of Cellular Networks • Need for more infrastructure • Need for fixed network to connect Base Stations • Some residual interference from co-channel cells • Handover procedure required

GSM • Global System for Mobile communications • Group formed for standardization of technology

Call Pathway Mobile Station

ME

SIM

Base Station Subsystem

BTS

BSC

Network Subsystem

Other Networks

PSTN

MSC/ VLR

GMSC

PLMN

EIR SD

HLR

AUC

Internet

+

Note: Interfaces have been omitted for clarity purposes.

Mobile phone -> BTS -> BSC -> MSC -> PSTN / MSC MSC / PSTN -> MSC -> BSC -> BTS -> Mobile phone

Mobile Station (MS) • Mobile Equipment – Fixed – Portable

•

International Mobile Equipment Identity (IMEI) number

• Subscriber Identity Module (SIM) • • • •

Personal Identification Number (PIN) International Mobile Subscriber Identity (IMSI) number Enables access to subscribed services Smart card

What is SIM card? • Subscriber Identity Module • Works as a user ID • It is the KEY for entering mobile network • It is the removable part of the phones

Call Pathway Mobile Station

ME

SIM

Base Station Subsystem

BTS

BSC

Network Subsystem

Other Networks

PSTN

MSC/ VLR

GMSC

PLMN

EIR SD

HLR

AUC

Internet

+

Note: Interfaces have been omitted for clarity purposes.

Mobile phone -> BTS -> BSC -> MSC -> PSTN / MSC MSC / PSTN -> MSC -> BSC -> BTS -> Mobile phone

Base Transceiver Station - BTS – – – –

Usually referred to as the Base Station Provides the interface to the network for the MS Handles all communications with the MS Less “intelligent” than analogue equivalent • cheaper than analogue systems • bypass analogue in less wealthy countries

– “intelligence” now deployed on MS • for example, when to perform a handover

– Transmitting power determines cell size

Base Station Controller - BSC – Controls Base Stations • up to several hundred depending on manufacturer

– Manages radio channels • allocation and release

– Coordinates Handover – Physical location may vary – Abis interface • between BSC and BTS

Call Pathway Mobile Station

ME

SIM

Base Station Subsystem

BTS

BSC

Network Subsystem

Other Networks

PSTN

MSC/ VLR

GMSC

PLMN

EIR SD

HLR

AUC

Internet

+

Note: Interfaces have been omitted for clarity purposes.

Mobile phone -> BTS -> BSC -> MSC -> PSTN / MSC MSC / PSTN -> MSC -> BSC -> BTS -> Mobile phone

Mobile Switching Centre (MSC) – Performs all switching/exchange functions – Handles – registration – authentication – location updating

– A GSM network must have at least one MSC – May connect to other networks • Gateway MSC (GMSC)

CDMA • CDMA (Code Division Multiple Access) splits calls into fragments and send them over different frequencies simultaneously • Can be thought as improved GSM • It can support more users in a channel • It is more secure • 27% of mobile phones are CDMA phones

SMS • SMS=Short Message Service=Current Worldwide “Killer Application” • A basic text messaging service for sending messages up to 160 characters to mobile phones • Billions of messages are sent each month very profitable for providers

Rich Call

Browsing

Versatility of Content and User Benefits

Evolution of messaging

Messaging

Mobile Multimedia

SMS

Text

Multimedia Message Picture Service Messaging

Text & Graphics

Digital image input

New content types Time

SMS pathway • Messages are sent to a Short Message Service Centre (SMSC) which provides a store-and-forward mechanism. • If a recipient is not reachable, the SMSC tells the message for later retry • Some SMSC only provide forward and forget method

GPRS • GPRS - General Packet Radio Service • It is used to connect internet through mobile • Provides high speed data connectivity

BLUETOOTH

What’s With the Name? • King Harald Bluetooth (A.D. 940 to 985) • 10th century Viking king in Denmark • Credited for uniting the country and established Christianity • Viking states included Norway & Sweden, which is the connection to Ericsson (creator of bluetooth) •Similarly Bluetooth is to connect Computers and Mobiles

What Is Bluetooth? • Designed to be used to connect both mobile devices and other instruments that require a wire • Simplifying communications between: - devices and the internet - data synchronization • “USB without wires” • Short range wireless radio technology - operate range of 10 meters

Bluetooth Devices Bluetooth will soon be enabled in everything from: • Telephones • Headsets • Computers • Cameras • PDAs • Cars • Etc …

Bluetooth Products • Bluetooth-enabled PC Card

1

Bluetooth Products • Bluetooth-enabled PDA

2

Bluetooth Products • Bluetooth-enabled Cell Phone

3

Bluetooth Products • Bluetooth-enabled Head Set

4

Advantages (+) • Wireless (No Cables) • No Setup Needed • Low Power Consumption (1 Milliwat) • Industry Wide Support

Power Requirement • Battery with longer talk time, light weight, proper shape. • Easy recharging, long life. • Lithium Ion & recently lithium polymer.

USES • • • • • •

SMS,MMS Camera, Video Recording Music player, Radio Games Text reader, NEWS Video conferencing

DISADVANTAGES • Possible Cancer linkage. • Pain in fingers due to constant messaging & hearing problems. • Disposal problem • For terrorist activity

FUTURE • Runtime information about hotels & libraries. • During emergency, lost can find way back. • Mobile T.V.