EST Terms for Boards

In an asynchronous data system:

Each computer word is preceded by a start bit and followed by a stop bit to frame the word.

Super group pilot is:

Fed in at a GTE.

In discrete time systems, the solution obtained by assuming the input x(n) of the system is zero is known as:

Homogenous solution

Which of the following pulse modulation systems is analog?

PWM

The circuitry used to increase the operating frequency of a transmitter up to a specified value is called the:

Pump chain

A bit stream would be portioned into an even stream and an odd stream in which of these systems?

QPSK

The resonant frequency of an antenna may be increased by:

Shortening the radiating element.

A communication between a computer and a keyboard involves what transmission mode?

Simplex

Skip distance is the:

The minimum distance reached by a signal after one reflection by the ionosphere.

Another term for ripple amplitude for a ceramic filter is:

The peak-to-valley ratio.

A radiolink receiver has a noise figure of 8 dB and an IF bandwidth of 12 MHz. What is the FM improvement threshold in dBW?

-115.21 dBW

What provides redundancy to ensure synchronization and inherent error detection?

Block coding

What is the simplest AM detector?

Diode detector

What of an antenna is defined as the ratio of the induced voltage to the incident electric field?

Effective height

Which two types of radiation from the sun influence propagation?

Electromagnetic and particle emissions

In discrete time systems, zero-state response is also known as:

Forced response

Which is not a type of pulse modulation?

Pulse-frequency modulation (PFM)

The use of cryptography to transforming messages is to make them:

Secure and immune to attacks.

The process of conversion of data along with its formatting is called:

Source Coding

An "eye pattern" shows a good channel when:

The eye is maximally open

In cyclic redundancy checking, what forms the check bits?

The remainder

Which coding scheme requires DC continuity:

unipolar NRZ

Compared to PCM, adaptive delta modulation can transmit voice:

with a lower bit rate but the same quality

Suppose a receiver has a noise figure of 2.1 dB, what is its thermal noise level in 1 Hz of bandwidth or noise density?

-201.9 dBW

What will the path unavailability be for a path 50 km long over flat terrain in a relatively humid region, operating at 6 GHz with a 40-dB fade margin?

0.009 %

An 8 GHz radio link is to be established between Station A and Station B, 35 miles apart. Based on the initial system gain/loss calculations radio link will work satisfactorily if the first Fresnel zone is 60 percent cleared from an obstruction located 20 miles from Point A. What will be the minimum height of the antenna in feet to satisfy this condition?

150 ft

What is the minimum number of wires needed to send data over in serial communication link layer?

2

What equation defines the composition of an ISDN basic access line?

2B + D

A cycle slip would occur whenever the original phase error's magnitude exceeds:

2π radians

In traffic engineering, what is one (1) Erlang?

36 CCS

Echo suppressors are used on all communications system when the round-trip propagation time exceeds _______.

50 ms

SONET sends ________ frames per second.

8000

Once an SSB signal has been generated, it must be amplified by:

A linear amplifier to avoid distortion

Local oscillator reradiation refers to radiation through the:

Antenna

What type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium?

Attenuation

Which of the following is based on ATM technology?

B-ISDN

The original electrical information signal to be transmitted is called the:

Baseband signal

Which of the following statements about wired and wireless LANs is correct?

Both operate in the lower two layers of the TCP/IP protocol suite.

If the ASCII character G is sent and the character D is received, what type of error is this?

Burst

Which of the following topologies requires the installation of terminating resistors at two locations?

Bus

Communication systems are most often categorized by what characteristic?

Carrier frequency

Th so-called "stolen" bits in DS-1 framing are used to:

Carry signaling

In a balanced-ring modulator, the carrier suppression is accomplished by:

Center-tapped transformers causing cancelling magnetic fields

The Smith chart consists of the:

Constant R and constant X circles

A complex LC filter that removes delay distortion from signals that are travelling down long transmission lines is called a(n):

Delay equalizer

Ideally, the number of point sources an antenna can resolve is numerically equal to:

Directivity

What type of transmission impairment in which the signal loses strength due to the different propagation speeds of each frequency that makes up the signal?

Distortion

The _______ technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, the signal modulates another carrier frequency.

FHSS

What is the main problem with the TRF design?

Frustration in tuning to receive more than one station.

What coding assigns shorter codes to symbols that occur more frequently and longer codes to those that occur less frequently?

Huffman coding

Over how much distance can we transmit digital audio without loss of quality?

Infinite

Which one of the following is not useful quantity for comparing the noise performance of radio receivers?

Input noise voltage

If no stations are picked up on the lower half of the AM band, the likely problem is:

LO tracking

What is required to generate an M X N linear spatial filter?

MN mask coefficients

Which of the following attacks is threatening integrity?

Masquerading

The purpose of an antenna coupler is to:

Match the output impedance of the transmitter with the antenna`s impedance to provide maximum power transfer.

Which of these is a technique that is used to verify a message's integrity?

Message Digest

The advantages provided by carrier elimination in SSB do not apply to transmission of:

Music

Which of the following encoding methods does not provide for synchronization?

NRZ-L

If a light ray crosses the boundary between two materials with different refractive indices:

No refraction would take place if the angle of incidence was 0°.

PPM and PWM are superior to PAM systems in:

Noise characteristics

Basic group B:

Occupies the frequency range from 60 to 108 kHz.

As the meridional ray is propagated along the optic fiber it:

Passes repeatedly through the center of the core.

Which layer of the Open Systems Interconnection (OSI) model defines the medium, network interfaces, connecting hardware, and signaling methods used on a network?

Physical

_______ requires one primary station and one or more secondary stations.

Polling

In the OSI model, decryption and encryption are the features of:

Presentation layer

Receiving electromagnetic emissions from stars is called:

Radio astronomy

The sensitivity of a receiver has to do with its ability to:

Receive weak stations

What transmission mode that generally involves dedicated circuits?

Simplex

Which of the following is not true for TDMA?

Single carrier frequency for single user

If the ASCII character H is sent and the character L is received, what type of error is this?

Single-bit

When the modulation index of an AM wave is doubled, the antenna current is also doubled, the AM system being used is:

Single-sideband, suppressed carrier (J3E)

What is the difference between a balanced modulator and a regular modulator?

There is no carrier produced in the output of a balanced modulator.

When two computers using IPv6 want to communicate but the packet must pass through an IPv4 region, which transition strategy should be used?

Tunneling

Ladder logic programming consists primarily of:

Virtual relay contacts and coils

If the system is initially relaxed at time n=0 and memory equals to zero, then the response of such state is called as:

Zero-state response

In mobile IP communication, the first phase is called __________.

agent discovery

In SONET, for each byte, the bits are transmitted ____________.

from most significant to the least significant

What is the basic equation of radiation applied to any antenna irrespective of the type of the antenna?

iL= Qv

The data acquisition system implies input data collection __________

in digital form

When the load in the network reaches the network capacity, the packet delay _______ and the network throughput reaches _______.

increases sharply; its maximum

Voice over IP requires a _________ level of reliability.

low

Baseband transmission of a digital signal is possible only if we have a ____ channel.

low-pass

For a ______ channel, the Nyquist bit rate formula defines the theoretical maximum bit rate.

noiseless

Transmission delay (time) is the ratio of:

packet length to transmission rate

Which of the following compression method is not lossless?

predictive coding

The address field of a frame in HDLC protocol contains the address of the _______ station.

secondary

Which of the following devices is used to physically connect computers in the same VLAN?

switch

If the sender is a host and wants to send a packet to another host on another network, the logical address that must be mapped to a physical address is ______.

the IP address of the router found in the routing table

If the sender is a host and wants to send a packet to another host on the same network, the logical address that must be mapped to a physical address is ______.

the destination IP address in the datagram header

A local area network (LAN) is defined by:

the geometric size of the network

RJ-45 is a type of connectors used in _________ cabling.

twisted-pair

In Ethernet addressing, if the least significant bit of the first byte is 0, the address is _________.

unicast

If you want a 17-mile loop, allowing 100 Ω per mile of loop (for the 1700-Ω limit), what diameter of copper wire would you need?

0.0331 in.

In bit stuffing, we sometimes need to add an extra ___________ bit in the payload.

0`s

Assume the following: a 4-GHz downlink, 5° elevation angle, EIRP is+30 dBW; satellite range is 25,573 statute miles, and the terminal G/T is +20.0 dB/K. Calculate the downlink C/No.

79.8 dBW

In ISDN, signaling component that supports traffic between the end-user and network is called ________.

Access signaling

If the lower sideband overlaps the basebands, the distortion is called:

Aliasing

Sensitivity of a sensor can be depicted by:

Bode plot

Which error detection method involves polynomials?

CRC