Cellular Telephone Concepts - Tomasi Flashcards Preview

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Flashcards in Cellular Telephone Concepts - Tomasi Deck (64):
1

ARTS

American Radio Telephone Service

2

AMPS

Advance Mobile Phone System

3

USDC

U.S. Digital Cellular

4

TIA

Telecommunications Industry Assiciation

5

PCSS

Personal Communications Satellite Systems

6

Why hexagon shape is chosen as the shape of a cell?

because it provides the most effective transmission by approximating a circular pattern while eliminating gaps inherently present between adjacent circles

7

Large cells or macrocells have radius between __ and base station transmit power of:

1 mile and 15 miles
1W and 6W

8

Smallest cells or microcells have radius between __ and base station transmit power of:

1500 ft or less
0.1 W and 1W

9

Process in w/c the same set of frequencies can be allocated to more than one cell, provided the cells are separated by sufficient distance

Frequency Reuse

10

Cluster size typically equal to

3,7,12

11

allows more calls to be handled by the system, provided the cells do not become too small

Cell Splitting

12

2 major kinds of interference produced within cellular telephone system

co-channel interference
adjacent channel interference

13

interference between 2 cells using the same set of frequencies

co-channel interference

14

occurs when transmissions from adjacent channels interfere with each other

adjacent-channel interference

15

most prevalent when a mobile unit is receiving a weak signal from the base station

near-far effect

16

when the area of a cell, or independent component coverage areas of a cellular system is further divided thus creating more cell areas

cell splitting

17

the point when a call reaches maximum capacity occurs when the number of of subscribers wishing to place a call at any given time equals the number of channels in the cell

maximum traffic load

18

Major drawback of cell splitting:

it results to more base station transfers (handoffs) per call and higher processing load per subscriber

19

process of subdividing highly congested cells into smaller cells; resizing or redistribution of cell areas

Cell Splitting

20

decreasing co-channel interference while increasing capacity by using directional antennas is called

Sectoring

21

placing 2 receive antennas; improves reception by effectively providing a larger target for signals radiated from mobile units

Space Diversity

22

Controls channel assignment, call processing, call setup and call terminations w/c includes signaling switching, supervision and allocating radio-frequency channels

MTSO / Mobile Telephone Switching Office

23

Only facility that connect an MTSO

Trunk Circuits

24

Connection that is momentarily broken during the cell-cell transfer

Hard Handoff

25

A flawless handoff; No perceivable interruption of service

Soft Handoff

26

Stages of handoff (4)

- initiation
- resource reservation
- execution
- completion

27

occurs when a signal level drops below a usable level and there are no usable channels available in the target cell to switch to

Blocking

28

Roaming from one company's calling area to another company's calling area is called __

Interoperator Roaming

29

MTS

Mobile Telephone Systems

30

PTT

Push-to-talk

31

IMTS

Improved Mobile Telephone Systems

32

The term ____ suggested any radio transmitter, receiver or transceiver that could be moved while in operation

Mobile

33

The term ____ described a relatively small radio unit that was handheld, battery powered and easily carried by a person moving at walking speed.

Portable

34

The modern, all-inclusive definition of a ___ ___ is any wireless telephone capable of operating while moving at any speed, battery powered and small enough to be easily carried by a person.

Mobile Telephone

35

Are fixed-position transceivers with relatively high-power transmitters and sensitive receivers.

Base Stations

36

Most two-way mobile radio systems can access the PTN only through a special arrangement called ___, and then they are limited to half-duplex operation where neither party can interrupt the other.

Autopatch

37

The cells that collectively use the complete set of available channel frequencies make up the ___

Cluster

38

is inversely proportional to the number of cells in a cluster

Frequency Reuse Ratio

39

cells without gaps in between

tessellate

40

It occurs if a new call is initiated in an area where all channels are in use

Blocking

41

It handles all cell-site control and switching functions

Cell-Site Controller

42

IS-41 relies on a feature called ___

Autonomous Registration

43

The process where a mobile unit notifies a serving MTSO of its presence and location through a base station controller

Autonomous Registration

44

Cellular Telephone Network Component (6)

- Electronic Switching Center
- Cell-Site Controller
- Radio Transceivers
- System Interconnects
- Mobile and Portable Telephone Units
- Communication Protocol

45

Is a digital telephone exchange located in the MTSO that is the heart of a cellular telephone system

Electronic Switching Center

46

Each cell contains a BSC that operates under the direction of a switching center (MTSO)

Cell-Site Controller

47

Are also part of the base station subsystem

Radio Transceivers

48

Four-wire leased lines are generally used to connect switching centers to cell sites and to the PTN

System Interconnects

49

Governs that way telephone calls are established and disconnected

Communication Protocol

50

The actual voice channel where mobile users communicate directly with other mobile and wireline subscribers through a base station

User Channel

51

Used for transferring control and diagnostic information between mobile users and a central cellular telephone switch through a base station

Control Channel

52

Base station TRANSMITS on __

Forward control channel & Forward voice channel

53

Base station RECEIVES on __

Reverse control channel & Reverse voice channel

54

Divide a group of channels into smaller groupings or segments of mutually exclusive frequencies

Segmentation

55

Is a means of avoiding co-channel interference, although it lowers the capacity of a cell by enabling reuse inside the reuse distance, which is normally prohibited

Segmentation

56

Is a means of avoiding full-cell splitting where the entire area would otherwise need to be segmented into smaller cells

Dualization

57

Transmission from base stations to mobile units are called

Forward Links

58

Transmission from mobile units to base station are called

Reverse Links

59

Forward links are sometimes called

Downlinks

60

Reverse links are sometimes called

Uplinks

61

Mode that allows all calls to pass through the network to the subscriber except for a minimal number of telephone numbers that can be blocked

Available Mode

62

Mode that is the PCS equivalent to called ID; the name of the calling party appears on the mobile unit's display

Screen Mode

63

Mode wherein all calls except those specified by the subscriber are automatically forwarded to a forwarding destination without ringing the subscriber's handset

Private Mode

64

Mode wherein no calls are allowed to pass through the subscriber

Unavailable Mode