• No se han encontrado resultados

CAPÍTULO 1: FUNDAMENTACIÓN TEÓRICA

1.6 Fundamentos Contables

39 Class 4 office having only outward and inward calling

service. Class 4P

Switching Office 40 Class 4 office provided human operators for both outward

and inward calling service. Class 4C

41 Switching office that provide service to small groups of

class 4 offices within a small area of a state. Class 3 Primary Center

42

Sectional centers that could provide service to

geographical regions varying in size from part of a state

to all of several states. Class 2 Sectional

43

Regional centers were the highest ranking office in the DDD network in terms of the size of the geographical are

served and the trunking options available. Class 1 Regional Center

44

Toll trunks in tandem, excluding the two terminating links at the ends of the connection.

Intermediate Links

45

A global standard for telecommunications defined by the ITU.

Common Channel Signaling System No. 7 (SS7 or C7) 46

Refers to the exchange of information between call

components required to provide and maintain service. Signaling 47

An architecture for performing out of band signaling in

support of common telephone system functions. SS7

48 Long distance access is now accomplished through an access point.

Point of Presence (POP)

49

A telecommunications term that describes the legal boundaries for the responsibility of maintaining

equipment and transmission lines. POP

50

Provide access to the SS7 network, access to databases

used by switches inside and outside the network. Signaling Points

51

Codes that are carried in signaling messages exchanged between signaling points to identify the source and

destination of each messages. Point Codes

52 Local telephone switches equipped with SS7 compatible

software and terminating signal links Service

Switching Points 53 The packet switches of the SS7 network.

Signal Transfer Points

54

It serves as an interface to telephone company databases.

Service Control Points

55 Another name for service control points.

Signal Control Points

56 Provides access from one level of the protocol to another. Primitive

CHAPTER 19 CELLULAR TELEPHONE CONCEPTS

Item s

Definitions Terms

1

The term for mobile telephone services which began in 1940s and are sometimes called Manual telephone systems.

Mobile Telephone Manual System (MTSs)

2 The frequency used by MTSs. 35 MHz-45MHz

3 Switch that was used by MTS to activate the

transceiver. Push-to-Talk

(PTT)

4

It was introduced in 1964 which used several carrier frequencies and could, therefore, handle several simultaneous mobile conversations at the same time.

Improved Mobile Telephone System (IMTS)

5

The term suggested any radio transmitter, receiver, or

transceiver that could be moved while operation. Mobile

6

The term that described a relatively small radio unit that was handled, battery powered, and easily carried by a

person moving at walking speed. Portable

7

It is similar to two-way mobile radio in that most communications occurs between base stations and

mobile units. Cellular Telephone

8

It operates on half duplex and use PTT transceivers.

Examples of two-way radio:

Citizens Band (CB)

Public land mobile radio Two-Way Radio

9

A one to one system that permits two-way simultaneous transmissions and operates the same way as the

standard wire line telephone service. Mobile Telephone

10

Hinted of a cellular telephone scheme that he referred to as simply a small-zone radio telephone system in the

July 28, 1945. E.K. Jett

11

On June 17, 1946, they introduced the first American commercial mobile radio-telephone service to private customers.

AT&T and

Southwestern Bell 12 A radio telephone service introduced by AT&T in 1947. Highway Service.

13

Unveiled the most famous mobile telephone to date: the fully mobile shoe phone in 1966 in a television show

called Get Smart. Don Adams

14

The year when FCC granted AT&T the first license to operate a developmental cellular telephone service in

Chicago. 1975

15 A satellite-based wireless personal communications satellite (PCSS)

Iridium

16 Another term for cellular telephone. Cellular Radio

17 A large geographic market area. Coverage zone

18 It is employed to increase the capacity of a mobile telephone channel.

Frequency Reuse

19

The shape that was used because it provides the most effective transmission by approximating a circular pattern while eliminating the gaps present between

adjacent circles. Honeycomb

20 Large cells that typically has 1 mile and 15 miles radius with base station transmit power 1W and 6 W.

Macrocells

21

The smallest cells that typically has radius of 1500 feet or less with base station transmit powers between 0.1

W and 1 W. Microcells

22 The process in which the same set of frequencies can be allocated to more than one cell, provided the cells

Frequency Reuse

are separated by sufficient distance.

23

A geographic cellular radio coverage area containing

three groups of cells. cluster

24 Typically equal to 3,7, or 12. Cluster size

25

The process of finding the tier with the nearest

co-channel cells. First Tier

26 Two cells using the same set of frequencies. Co-channel cells

27

The interference between the co-channels cells.

Adding radio channels to a system:

Decreasing the transmit power per cell

making cells smaller

filling vacated coverage areas with new cells

Co-channel Interference

28

The ratio of the cell radius and distance from the nearest co-channel cell

The ratio of the cell radius and distance from the nearest

co-channel cell 29 Channel next to one another in the frequency domain. Adjacent Channel 30 It results from imperfect filters in receivers that allow

nearby frequencies to enter the receiver. Adjacent-Channel Interference 31

Most prevalent when a mobile unit is receiving a weak

signal from the base station. Near-Far Effect

32

The area of a cell, or independent component coverage areas of cellular system is further subdivided thus

creating more areas. Cell Spliting

33

Occurs when number of the number of subscriber wishing to place a call at any given time equals the

number of channels in the cell. Maximum Traffic

Load 34 A condition occurs when a new call is initiated in an

area where all the channels are in use. Blocking

35

Smaller areas when a single omnidirectional antenna is replaced by several directional antennas, each radiating

within smaller area. Sectors

36 Using directional antennas. Sectoring

37 Placing two receive antennas one above the other. Space Diversity

38

A means of avoiding full-cell splitting where the entire area would otherwise need to be segmented into

smaller cells. Dualization

39

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 40 The locations of radio-frequency transceivers. It serves

are central control for all users within that cell. Base Stations 41 It handles all cell-site control and switching functions. Cell-Site

Controller

42

Occurs when a mobile unit moves from one cell to

another company’s service. Roaming

43

It controls channel assignment, call processing, call setup and call termination.

Different Names:

Electric Mobile Exchange (EMX)- Bell Lab.

AEX- Ericcson

NEAX-NEC

Switching Mobile Center (SMC)

Master Mobile Center (MMC)-Novatel

Mobile Switching Center- PCS networks

Mobile Telephone Switching Office (MTSO)

44

The transfer of a mobile unit from one base station’s control to another base station’s control.

Four stages:

Initiation

Resource reservation

execution

completion Handoff

(Handover) 45 A connection that is momentarily broken during the

cell-to-cell transfer. It is a break before-make process.

Hard Handoff 46 A flawless hand off with no perceivable interruption of

service.

Soft Handoff 47 It is used by computers that is based on variations in

signal strength and signal quality.

Handoff Decision

48

Either the mobile unit or the network determines the need for a handoff and initiates the necessary network

procedures. Initiation

49 Appropriate network procedures reserve the resources

needed to support the handoff. Resources

Reservation 50 The actual transfer of control from one base station to

another base station takes place.

Execution 51 Execution Unnecessary network resources are

relinquish and made available to other mobile units.

Completion 52 Roaming from one company’s calling area into another

company’s calling area.

Interoperator Roaming

53

Stands for Electronics Industries

Association/Telecommunications Industry Association,

developed the IS-41 Protocol. EIA/TIA

54

It aligns with a subprotocol of the SS7 protocol stack that facilitates communications among database other

network entities. IS-41

55 Stands for Cellular Telecommunication Industry Association.

CITA

Documento similar