Chapter 10

mobile telecommunication switching office

Each base station is connected to _____, which serves multiple base stations.

were analog

First generation cellular networks ______.

Frequency division

First generation cellular networks made use of _____ multiplexing.

Transmitter

A cellular network uses multiple low power ________.

Rake

In a multipath environment, if the multiple version of a signal arrive more than one chip interval apart from each other, the receiver can recover the signal by correlating the chip sequence with the dominant incoming signal. The remaining signals are treated as noise. However, even better performance can be achieved of the receiver attempts to recover the signals from multiple paths and then combine them with suitable delays. This principle is used in the ________ receiver.

Reflection

______ occurs at the edge of an impenetrable body that is large compared to the wavelength of the radio wave. When a radio wave encounters such an edge, waves propagates in different directions with the edge as the source. Thus, signals can be received even when there is no unobstructed line-of-sight fro the transmitter.

adaptive equalization

_______ can be applied to transmissions that carry analog information or digital information and is used combat intersymbol interference.

Third generation (3G) Packet

The Objective of the ________ of wireless communication is to provide fairly high speed wireless communications to support multimedia, data, and video, in addition to voice.

Adaptive equalization

The efforts to compensate for the errors and distortions introduced by multipath fading fall into three general categories ; forward error correction, diversity techniques , and ______.

Fading

The time variation of received signal power caused by changes in the transmission medium is referred to as _____, which is a major technical problem for cellular networks.

(CDMA) Code division multiple access

Second generation systems provide multiple channels per cell, but each channel is dynamically shared by a number of users time division multiple access or ______.

handshake

A _______ is used to identify the user and register its location.

CDMA

A technique in widespread use in second generation cellular networks is ______.

(AMPDS) Advanced Mobile Phone Service

Sine the early 1980s the most common first-generation system in Not American has been the _____ developed by AT& T.

fast fading

Affecting not only mobile phones in automobiles, but even a mobile user walking down an urban street, _____ occurs when there are rapid variations in signal strength.

a handoff

As the mobile units move they pass from cell, whcih requires transferring of the call from one base transceiver to another. This process is called______.

Slow fading

As the mobile user covers distances well in excess of wavelength, the urban environment changes as the user passes building of different heights, vacant lots, and intersections. Over these longer distances, there is a change in the average received power level abut which the rapid fluctuations occur. This is referred to as ______.

Base station

Each cell in a cellular network is allocated a band of frequencies and is served by a ______ consisting of transmitter, receiver and control unit.

Scattering

If there is no clear line-of-sight to the transmitter, such as in an urban area at street level, then diffraction and _____ are the primary means of signal reception.

flat fading

Nonselective, or _____, is the type of fading in which all frequency components of the received signal fluctuate in the same proportions simultaneously.

Dijkstra

One of the most widely used models to develop guidelines for sell size was developed by ______.

MTSO Mobile telecommunication switching office

The ______ connects call between mobile units, makes connections between a fixed subscriber to the public network and a mobile subscriber to the cellular network and a mobile subscriber to the cellular network, assigns the choice channel to each call, performs handoffs, and monitors the call for billing information.

CDMA

The dominant technology for third generation system is ________.

(OFDMA) Orthogonal frequency division multiple access.

The key technology for 4G systems is _____________.

Reuse factor

The number of cells in a repetitious pattern, ( each cell in the pattern uses a unique band of frequencies), is termed the ________.

Multirate

The term_______ refers to the provision of multiple fixed data rate logical channels to given user, in which different data rates are provided on different logical channels. The traffic on each logical channel can be switched independently though the wireless and fixed networks to different destinations.

multimedia and voice

Third generation wireless communication supports_______.

Control channels

________ are used to exchange information having to do with setting up and maintaining calls and with establishing a relationship between a mobile unit and the nearest base station.

reflection

________ occurs when electromagnetic signal encounters a surface that is large relative to the wavelength of the signal.

Microcells

are useful in city streets in congested areas, along highways, and inside large public buildings.