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Flashcards in Cellular Communications Deck (79):
1

radio communication was invented by

Nikola Tesla and Guglielmo Marconi

2

He made the first public demonstration of wireless (radio) telegraphy

Nikola Tesla

3

He conducted long distance (over see) telegraphy in 1897

Guglielmo Marconi

4

first walkie-talkie was used by the US military

1940

5

from AT&T’s Bell Labs invented the transistor (semiconductor device used to amplify and switch electronic signals)

John Bardeen
Walter Brattain
William Shockley
1947

6

in 1979 the first commercial cellular phone service was launched by

Nordic Mobile Telephone (in Finland, Sweden, Norway, Denmark)

7

voice-oriented systems based on analog technology

1G (first generation)

8

Examples of 1G systems

Advanced Mobile Phone Systems (AMPS) and cordless systems

9

- voice-oriented systems based on digital technology
- more efficient and used less spectrum than 1G

2G (second generation)

10

Examples of 2G systems

Global System for Mobile (GSM)
US Time Division Multiple Access (US-TDMA)

11

high-speed voice-oriented systems integrated with data services

3G (third generation)

12

Examples of 3G systems

General Packet Radio Service (GPRS)
Code Division Multiple Access (CDMA)

13

still experimental, not deployed yet;
based on Internet protocol networks and will provide voice, data and multimedia service to subscribers

4G (fourth generation)

14

is a method used by service providers to improve the efficiency of a cellular network and to serve millions of subscribers using a limited radio spectrum

Frequency reuse

15

the entire network coverage area is divided into cells based on the principle of frequency reuse

Network Cells

16

basic geographical unit of a cellular network

cell

17

is the area around an antenna where a specific frequency range is used

cell

18

is represented graphically as a hexagonal shape, but in reality it is irregular in shape

cell

19

is a group of adiacent cells, usually 7 cells

cluster

20

their coverage is large (aprox. 6 miles in diameter); used in remote areas, high-power transmitters and receivers are used

macrocell

21

their coverage is small (half a mile in diameter) and are used in urban zones; low-powered transmitters and receivers are used to avoid interference with cells in another clusters

microcell

22

covers areas such as building or a tunnel

picocell

23

moving a call from one zone (from the transmitter-receiver from one zone) to another zone due to subscriber’s mobility

handover

24

allowing the subscriber to send/receive calls outside the service provider’s coverage area

roaming

25

when the subscriber enters another cell a unique frequency is assigned to him; used in analog systems

Frequency Division Multiple Access / FDMA

26

each subscriber is assigned a time slot to send/receive a data burst; is used in digital systems

Time Division Multiple Access / TDMA

27

each subscriber is assigned a code which is used to multiply the signal sent or received by the subscriber

Code Division Multiple Access / CDMA

28

this channel is used by a cellular phone to indicate its presence before a frequency/time slot/code is allocated to him

Control Channel

29

Cellular services (5):

◘ voice communication
◘ Short Messaging Service (SMS)
◘ Multimedia Messaging Service (MMS)
◘ Global Positioning System (GPS)
◘ Wireless Application Protocol (WAP) – to access the Internet

30

MSC

Mobile Switching Center

31

the coordinator of a cellular network, it is connected to several BSCs, it routes calls between BSCs; links the cellular network with other networks like PSTN through fiber optics, microwave or copper cable

Mobile Switching Center or MSC

32

BSC

Basic Station Controller

33

it is an interface between BTSs and it is linked to BTSs by cable or microwave links; it routes calls between BTSs; it is also connected to the MSC

Basic Station Controller or BSC

34

BTS

Base Transceiver Station

35

main component of a cell and it connects the subscribers to the cellular network

Base Transceiver Station or BTS

36

MSU

Mobile Subscriber Unit

37

Components of a cellular phone (6)

◘ radio transceiver
◘ antenna
◘ control circuitry
◘ man-machine interface
◘ subscriber identity module (SIM)
◘ battery (usually Li-ion)

38

formats the data sent to and from the BTS; controls signal transmission and reception

control circuitry

39

consists from a keypad and a display; is managed by the control circuitry

man-machine interface

40

integrated circuit card that stores the identity information of subscriber

SIM or subscriber identity module

41

GSM

Global System for Mobile Communication

42

global digital standard for cellular phones that offered roaming facility; used in Europe

Global System for Mobile Communication / GSM

43

first name of GSM before

Group Special Mobile

44

GSM operate in frequency bands of:

900MHz, 1800 MHz, 1900 MHz

45

IMEI

International Mobile Equipment Identity Key

46

a unique 15 digit number identifying each phone, is incorporated in the cellular phone by the manufacturer

International Mobile Equipment Identity Key / IMEI

47

is located on a white sticker/label under the battery, but it can also be displayed by typing *#06# on the phone

IMEI

48

IMSI

International Mobile Subscriber Identity Key

49

a 15-digit unique number provided by the service provider and incorporated in the SIM card which identifies the subscriber

International Mobile Subscriber Identity Key / IMSI

50

TMSI

Temporary Mobile Subscriber Identity Key

51

is a temporary number, shorter than the IMSI, assigned by the service provider to the phone on a temporary basis

Temporary Mobile Subscriber Identity Key / TMSI

52

Types of Registers: (3)

- HLR / Home Location Register
- VLR / Visitor Location Register
- EIR / Equipment Identity Register

53

is a database maintained by the service provider containing permanent data about each subscriber

Home Location Register (HLR)

54

database that stores temporary data about a subscriber; it is kept in the MSC of the of the area the subscriber is located in

Visitor Location Register (VLR)

55

database located near the MSC and containing information identifying cell phones

Equipment Identity Register (EIR)

56

- 1st level security mechanism for a GSM cellular network
- is a database that stores the list of authorized subscribers of a GSM network

Authentication Center (AuC)

57

is a switching center of the GSM network; coordinates BSCs linked to it

GSM Mobile Switching Center

58

GSM Uplink/BTS Transmit

935-960 MHz
1805-1880 MHz
1930-1990 MHz

59

GSM Downlink/BTS Receive

890-915 MHz
1710-1785 MHz
1850-1910 MHz

60

uplink and downlink channels have a bandwidth of

25 MHz

61

GSM carrier frequencies

124

62

GSM time slots for each carrier frequencies

0.577 ms

63

is used to communicate management data (setting up calls, location) between BTS and the cell phone within a GSM cell

GSM control channel

64

GSM control channels can have the following types: (3)

broadcast channel
common control channel
dedicated control channel

65

type of control channel used for the initial synchronization between the cell phone and the BTS

Broadcast Channel

66

Types of Broadcast Channel (3)

Frequency Correction Channel (FCCH)
Synchronization Channel (SCH)
Broadcast Control Channel (BCCH)

67

is composed from a sequence of 148 zeros transmitted by the BTS

Frequency Correction Channel / FCCH

68

follows the FCCH and contains BTS identification and location information

Synchronization Channel / SCH

69

contains the frequency allocation information used by cell phones to adjust their frequency to that of the network; is continuously broadcasted by the BTS

Broadcast Control Channel / BCCH

70

type of control chan. used for call initiation

Common Control Channels

71

the BTS uses this channel to inform the cell phone about an incoming cal

Paging Channel / PCH

72

is an uplink channel used by the cell phone to initiate a call

Random Access Channel / RACH

73

channel used to set up a call; once the cell phone has used PCH or RACH to receive or initiate a call, it uses __ to communicate to the BTS

Access Grant Channel / AGCH

74

control channel sed to manage calls

Dedicated Control Channels

75

used along with SACCH to send and receive messages; relays signalling information

Standalone Dedicated Control Channel / SDCCH

76

on the downlink BTS broadcasts messages of the beacon frequency of neighboring cells to the cell phones; on the uplink BTS receives acknowledgement messages from the cell phone

Slow Associated Control Channel / SACCH

77

used to transmit unscheduled urgent messages; is faster than SACCH as it can carry 50 messages per second, while SACCH an caryy only 4.

Fast Associated Control Channel / FACCH

78

GSM Security (3)

- Personal Identification Number (PIN)
- User Authentication
- TMSI-based Security

79

this security measure is within the cell phone and the service provider is not involved

Personal Identification Number / PIN