lecture on mobile communication systems by mukul mittal lecturer e.c.e g.p.c.g, patiala(9463376309)...

LECTURE ON

“MOBILE COMMUNICATION SYSTEMS”

BY

Mukul Mittal

Lecturer E.C.E

G.P.C.G, Patiala(9463376309)

mukul_mittal85@yahoo.co.in

Terminologies

Base Station: A fixed station in a mobile radio system used for radio communication with mobile stations.

M.S.C :Switching centre which co-ordinates the routing of calls and connects the cellular base stations and the mobiles to the P.S.T.N

MIN: Mobile identification number

E.S.N: Electronic Serial Number

S.C.M: Station class marks

SIM: Subscriber Identity Module

ADVANCED MOBILE PHONE SYSTEM(AMPS)

• AMPS is known as the first generation (1G) analog commercial cellular systems . It is one of the earliest cellular systems or mobile phone system standard. It introduced in early 1980s.

• It is based on Analog modulation .• This allowed a larger number of phones to be

supported over a geographical area.• It is the earliest radio standard in North America

• Frequency allocated by FCC on 824-849 MHz for downlink & 869-894 MHz for uplink traffic.

• The base station also assigns the subscriber unit a supervisory audio tone(SAT tone)and a voice mobile attenuation code(VMAC) as it moves the call to the voice channel.

• Blank and burst mode is provided to initiate hand offs.

• In AMPS handoff decisions are made by the MSC.

GSM(Global System For Mobile)

• It Is a second generation technology.• GSM was originally developed to serve as the

pan-european cellular service.• By the end of 1993, several non-european

countries in Asia, Australia had adopted GSM• By 2001 there are 350 million GSM

subscribers around the world

Architecture Of GSM

Base Trans receiver Station

• Base Transceiver Station (BTS)

Wireless transmission

Wireless diversity

Wireless channel encryption

Conversion between wired and wireless signals

Frequency Hopping

• Base Band Unit:

voice and data speed adapting and channel coding

• RF Unit:

modulating/demodulating, transmitter and receiver

• Common Control Unit:

BTS operation and maintenance

Base Station ControllerControls:

– Wireless link distribution between MS and BTS– Communication connection and disconnection– MS location, handover and paging– Voice encoding, trans encoding (TC) rate, adaptation, – The operation and maintenance functions of BSS.

Mobile Service Switching Center ( MSC )• holds all the switching functions and manages the

necessary radio resources, like updating the location registration carrying out the inter-BSC and inter-MSC tender

Inter-working with other networks (IWF).

Manages the mobile subscribers database subscriber information, part of the mobile location information, 3 identities essential i.e the International Mobile subscriber Identity , the Mobile station ISDN Number ,the VLR address.

AUC/EIRProviding the authentication key used for authorizing the subscriber access to the associated GSM .

• Equipment Identity Register(s) (EIR)• Handling Mobile Station Equipment Identity

Visitor Location Register

• dynamically stores subscriber information needed to handle incoming/outgoing calls

• Mobile Station Roaming Number• When a roaming mobile enters an MSC area. This

MS warns the associated VLR of this situation; the mobile enter a registration procedure through which it is assigned a mobile subscriber roaming number (MSRN)

• Temporary Mobile Subscriber Identity, if applicable

• The location area in which the mobile has been registered

• Data related to supplementary service parameters

OMC(Operation Maintenance Centre)

• Maintains all telecommunication hardware and network operations with a particular market

• Manages all charging and billing procedures• Manages all mobile equipments in the system• The interface between BSC and MSC is called

A interface and interface between BTS and BSC is called Abis interface

• A interface uses an SS7 Protocol called the signaling correction control part(SCCP) Which supports communication between MSC and BSS.

• Each subscriber in the GSM network is provided with a IMSI(INTERNATIONAL MOBILE SUBSCRIBER IDENTITY).this number acts as a identity for home user

CDMA

• When the multiple users occupying the same band by having different codes is called as CDMA

• In CDMA pseudorandom codes are used to detect specified desired code words which are correlated in time otherwise other code words appears as noise due to de correlation.

• The receiver decodes the code word of the transmitter

• There is near and far problem in CDMA which is removed by RSSI( Radio signal strength indicator)

Features of CDMA

• With the use of more numbers of Users efficiency decreases because more noise is increases

•Multiple fading is removed by using the rake receiver

•The channels data rate is very high in CDMA system

•Provide soft Hand off

•Self Jamming is a Problem in CDMA

•Privacy

•Grace Degradation

• In CDMA the data is braked into K Chips according to affixed pattern

• Let the code of user A is <1,-1,-1,1,-1,1> and user B Is <1,1,-1,1,1> and user C is <1,1,-1 , 1,1,-1>

• the code received at the output if user a is considered as:

• (1*1) +(-1*-1)+(-1*-1)+(1*1)+(-1*-1)+(1*1) =6

• The other code words are not selected an there sum is not 6 or less than 6, may be zero.

• The given codeword with data is decoded.

G.P.R.S(General Packet Radio Service )

• GPRS facilitates instant connections and high immediacy whereby information can be sent or received immediately.

There are 3 classes of GPRS:

• Class A: Can be connected to GPRS service and GSM service (voice, SMS), using both at the same time.

• Class B: an be connected to GPRS service and GSM service (voice, SMS), but using only one or the other at a given time.

• Class C: Are connected to either GPRS service or GSM service (voice, SMS). Must be switched manually between one or the other service.

BLUE TOOTH TECHNOLOGY

• Short range wireless technology.• optical range of 10 meter (optional 100 meter mode)• 1mW transmission power.• Bluetooth is a packet based protocol with master slave

structure.• Operate in free ISM(industrial, scientific and medical)

band• 2.4000 GHz to 2.4835 GHz• Provide multiple levels of security• Frequency hopping spread spectrum• Data encoding• Data Encryption

A piconet is a collection of device connected between two device connected via Bluetooth technology.

class Max Permitted power (mw)

Max Permitted Power(dbm)

Range (Approx)

Class 1 100 mv 20 dbm 100m

Class 2 2.5 mv 4dbm 10m

Class 3 1 mv 0 dbm 1 m

WIFI( Wireless Fidelity)• A portable wireless service based on local area

network architecture, which means the reach of any specific access point is limited at best to about 100 meters(300feet).

• It is based upon the access points(AP). The access point is to broadcast a wireless signal that computers can detect and tune into.

• It works by use of radio technologies called IEEE802.11a/b/g/n to provide secure and reliable connectivity.

GPS(Global Positioning System)•It is a satellite based navigation system made up of a network of 24 satellites placed into orbit.•GPS signal contains three bits of information i.e pseudorandom code, ephemeris data, almanac data•GPS Consists of:

Space segment

Control segment

User segment

Control Segment

Space Segment

User Segment

Three Segments of the GPSThree Segments of the GPS

Monitor Stations

GroundAntennas

Master Station

RFID(Radio Frequency Identification )

• RFID is a microchip combined with a antenna in a compact package. The tag’s antenna picks up the signal from an RFID reader or scanner and then returns the signal, with the some additional data.

• DTH(Direct-To-Home television) DTH is defined as the reception of satellite programmes with a personal dish in an individual home.

• DTH does away with the need for the local cable operator and puts the broadcaster directly in touch with the consumer. Only cable operators can receive satellite programmes and they then distribute them to individual homes

CONCLUSION• There are new and emerging technologies like

GSM and CDMA for mobile communication.• For data Communication on mobiles we have

GPRS technology.• For wireless data communication we have WIFI

and WIMAX.• For small Distance communication we have

BLUETOOTH technology.• For all time control on devices we have GPS

technology.• To control on intruder we have RFID technology.

THANKS

FOR

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