REM B LVL 2 Flashcards
ISDN is based on the concept of ______.
A. ARDIS
B. SS7
C. CDPD
D. CCS
D. CCS
ISDN is a complete network net framework designed around the concept of common channel signaling. While telephone users throughout the world rely on the PSTN to carry conventional voice traffic, new end-user data and signaling services can be provided with a parallel, dedicated signaling network.
ISDN provides integrated end user access to only packet switched networks.
A. False
B. True
C. Partly true
D. Partly false
A. False
ISDN provides integrated end-user access to both circuit switched and packet switched networks with digital end-to-end connectivity.
Which component of the Local Area Network (LAN) usually in the form of hardware card inside the user station, implements the non- physical protocols?
A. Protocol Stack
B. User Station
C. Physical Medium
D. Physical Interface Unit
A. Protocol Stack
PRI interface in ISDN serves small capacity terminals.
A. False
B. True
C. Partly false
D. Partly true
A. False
ISDN end users may select between two different interfaces. The BRI (basic rate interface) is intended to serve small capacity terminals while the PRI (primary rate interface) is intended for large capacity terminals.
Signalling component that supports traffic between the end- user and network is called:
A. Access signalling
B. Subscriber system signalling
C. Network signalling
D. Digital subscriber signalling
A. Access signalling
Access signalling supports traffic between the end user and the network. It defines how end users obtain access to the PSTN and the ISDN for communication or services.
ISDN is based on the concept of _____.
A. SS7
B. ARDIS
C. CDPD
D. CCS
D. CCS
ISDN is a complete network framework designed around the concept of common channel signalling. While telephone users throughout the world rely on the PSTN to carry conventional voice traffic, new end-user data, and signalling services can be provided with a parallel, dedicated signalling network.
What network is usually the size of a military base?
A. Wide area network
B. Local area network
C. Office area network
D. Campus area network
D. Campus area network
Which network is suitable for a building?
A. LAN
B. MAN
C. PAN
D. WAN
A. LAN
LAN network is used to connect computers in a small area such as school, office, residence, etc. It is less expensive and very secure.
The SSH Connection Protocol runs on top of the SSH Transport Layer Protocol and assumes that a secure authentication connection is in use.
A. Partly true
B. Partly false
C. False
D. True
D. True
The statement is true. The SSH Connection Protocol does run on top of the SSH Transport Layer Protocol.
ISM frequency load as infrared IEEE 802.11 legacy standard
A. 5.1 GHz
B. 2.4 GHz
C. 1.2 GHz
D. 1.5 GHz
B. 2.4 GHz
In the OSI model, when data is transmitted from device A to device B, the header from A’s layer 5 is read by B’s ______ layer.
A. transport
B. session
C. physical
D. presentation
B. session
Under the Open System Interconnection hierarchical model, which of the 7 layers are responsible in allowing interoperability among unrelated software systems?
A. Layers 3 - 4
B. Layers 4-6
C. Layers 1-3
D. Layers 5-7
D. Layers 5-7
What type of network architecture would be the easiest to setup and maintain?
A. Wide area network
B. Local area network
C. Peer-to-peer network
D. Metropolitan network
C. Peer-to-peer network
As the data packet moves from the lower to the upper layers, headers are ________.
A. Rearranged
B. Added
C. Modified
D. Subtracted
D. Subtracted
What is the main function of the transport layer?
A. Updating and maintenance of routing tables
B. Synchronization
C. Process-to-process delivery
D. Node-to-node delivery
C. Process-to-process delivery
The physical layer is concerned with the transmission of ________ over the physical medium.
A. Programs
B. Bits
C. Protocols
D. Dialogs
B. Bits
The ________ protocol transmission begins with a start-of-header (SOH) character followed by a length (LEN) character, which tells how long the block of data is.
A. SDLC
B. Kermit
C. Bisync
D. Xmodem
B. Kermit
Which layer functions as a liaison between user support layers and network support layers?
A. Physical layer
B. Transport layer
C. Application layer
D. Network layer
B. Transport layer
Which type of bridge builds and updates its tables from address information in frames?
A. Simple
B. Transparent
C. Simple and Transparent
D. None of these choices
B. Transparent
Which address is used on the internet for employing the TCP/IP protocols?
A. specific address
B. port address
C. all of these choices
D. physical address and logical address
C. all of these choices
The physical, logical, port and specific addresses are used in TCP/IP protocol. All the addressing schemes, that is physical (MAC) and logical address, port address and specific address are employed in both TCP/IP model and OSI model. In TCP/IP, the addresses are more focused on the internet implementation of these addresses.
According to the PPP (Point-to- Point Protocol) transition state diagram, options are negotiated in the _______ state.
A. Authenticating
B. Networking
C. Terminating
D. Establishing
D. Establishing
According to the PPP (Point-to- Point Protocol) transition state diagram, verification of user identification occurs in the _______ state.
A. Networking
B. Authenticating
C. Terminating
D. Establishing
B. Authenticating
TCP/IP model was developed _______ the OSI model.
A. After
B. Simultaneous to
C. With no link to
D. Prior to
D. Prior to
Several TCP/IP prototypes were developed at multiple research centers between 1978 and 1983, whereas OSI reference model was developed in the year 1984. TCP/IP was developed with the intention to create a model for the Internet while OSI was intended to be a general network model.
“A user intending to connect to one LAN may unintentionally lock onto a wireless access point from the neighboring network.” Which type of Wireless network threat would you classify this under?
A. Accidental Association
B. Denial of Service
C. Malicious Threat
D. Network Injection
A. Accidental Association
This threat falls under Accidental Association.
When several processes access the same data concurrently and the outcome of the execution depends on the particular order in which the access takes place is called ______.
A. dynamic condition
B. race condition
C. essential condition
D. critical condition
B. race condition
When several processes access the same data concurrently and the outcome of the execution depends on the particular order in which access takes place is called race condition.
Cable modems use 64-QAM for ______.
A. Either upstream or downstream
B. Both upstream and downstream
C. Downstream
D. Upstream
C. Downstream
Unipolar, bipolar, and polar encoding are types of ______ encoding.
A. line
B. NRZ
C. block
D. Manchester
A. line
The modem will automatically adjust itself to the highest speed possible but will drop back to a lower speed or different mode if the receiving modem cannot handle the highest speed. Most modems is use today are the V.90 or V.92 type and are capable of speeds up to _____.
A. 64 kbps
B. 128 kbps
C. 24 kbps
D. 56 kbps
D. 56 kbps
In cyclic redundancy checking, what is the CRC?
A. The quotient
B. The dividend
C. The remainder
D. The divisor
C. The remainder
What modular connector attaches the modem to the telephone line?
A. An N-type
B. An RJ-45
C. A BNC
D. An RJ-11
D. An Rj-11
Lossy techniques provide _______ when compared to lossless techniques.
A. none of the mentioned
B. lower compression ratios
C. much higher compression ratios
D. similar compression ratios
C. much higher compression ratios
Cryptography, a word with Greek origin, means:
A. Secret coding
B. Secret writing
C. Secret message
D. None of these choices
B. Secret writing
Cryptography, a word with Greek origins, means “secret writing.” However, we use the term to refer to the science and art of transforming messages to make them secure and immune to attacks.
In asynchronous transmission, the gap time between bytes is _______.
A. Fixed
B. A function of the data rate
C. Variable
D. Zero
C. Variable
In a two-wire circuit, data transmission and reception occur:
A. Only in one direction at a time
B. Simultaneously on the same wires
C. Using separate pairs of wires
D. Without the need for wires
A. Only in one direction at a time
In a two-wire circuit, data transmission and reception occur in only one direction at a time, typically in half-duplex mode.
A walkie-talkie operates in ________.
A. full duplex
B. half duplex
C. simplex
D. semi-duplex
B. half duplex
A walkie-talkie operates in half duplex mode. It can only send or receive a transmission at any given time.
Which circuit configuration is suitable for full-duplex communication?
A. Simplex circuit
B. Two-wire circuit
C. Four-wire circuit
D. Half-duplex circuit
C. Four-wire circuit
Four-wire circuits support full- duplex communication, allowing devices to transmit and receive data simultaneously without interference.
Which circuit configuration is more susceptible to signal interference and crosstalk?
A. Half-duplex circuit
B. Two-wire circuit
C. Simplex circuit
D. Four-wire circuit
B. Two-wire circuit
Two-wire circuits are more susceptible to signal interference and crosstalk due to the shared use of the same wires for transmission and reception.
A technique of transmitting data or images or videos (information) using a continuous signal.
A. network
B. multiple
C. analog
D. direct
C. analog
Analog is a technique of transmitting data or images or videos (information) using a continuous signal, which varies in amplitude, phase or some other property.
It is an undesired shift or width change in digital bits of data due to circuitry action which causes bits to arrive at different times.
A. impulse
B. Jitter
C. parity
D. allas
B. Jitter
Telephone networks operate in this mode.
A. semi-duplex
B. simplex
C. half duplex
D. full duplex
D. full duplex
Telephone networks operate in full duplex mode. It can transmit data in both the directions.
Which type of circuit uses separate pairs of wires for transmitting and receiving data?
A. Two-wire circuit
B. Simplex circuit
C. Half-duplex circuit
D. Four-wire circuit
D. Four-wire circuit
A four-wire circuit uses separate pairs of wires for transmitting and receiving data, allowing for simultaneous bidirectional communication without interference.
The technique of transmitting each data word one after another without start and stop bits, usually in multiword blocks, is referred to as ______.
A. isochronous data transmission
B. synchronous data transmission
C. plesiochronous data transmission
D. asynchronous data tr transmission
B. synchronous data transmission
S-interface is a_____ bus.
A. Two wire bus
B. Single wired bus
C. Four wire bus
D. None of the mentioned
C. Four wire bus
Which encoding method uses alternating positive and negative values for 1s?
A. Manchester
B. AMI
C. NRZ-I
D. RZ
B. AMI
MPEG compression:
A. none of the mentioned
B. stores multiple frames’ values together
C. stores the differences between successive frames
D. stores the compression values of each frame
C. stores the differences between successive frames
A subnet mask in class A can have ______ 1s with the remaining bits 0s.
A. Three
B. Four
C. Nine
D. Thirty-three
C. Nine
IP addresses with subnet mask of 255.255.0.0 belongs to what class?
A. Class D
B. Class A
C. Class C
D. Class B
D. Class B
Which of the following is NOT a popular asynchronous ASCII- coded data transmission between personal computers via modem?
A. Bisync
B. Xmodem
C. Kermit
D. MNP
A. Bisync
A ________ sine wave is not useful in data communications; we need to send a _________ signal.
A. single-frequency; double-frequency
B. single-frequency; composite
C. none of these choices
D. composite; single-frequency
B. single-frequency; composite
_________ is a client-server program that provides an IP address, subnet mask, IP address of a router, and IP address of a name server to a computer.
A. NAT
B. CIDR
C. DHCP
D. ISP
C. DHCP
In message switching system, an incoming message gets ________ especially if the required route is busy.
A. stored in a queue & retransmitted
B. lost
C. recovered
F. sampled
A. stored in a queue & retransmitted
In _______ routing, the full IP address of a destination is given in the routing table.
A. Host-specific
B. Default
C. Network-specific
D. Next-hop
A. Host-specific
A subnet mask in class B can have _______ 1s with the remaining bits 0s.
A. Three
B. Fourteen
C. Seventeen
D. Nine
C. Seventeen
The IP address of 192.192.192.192/30 belongs to what class?
A. Class C
B. Class A
C. Class less
D. Class B
C. Class less
Lossy and lossless are classifications of:
A. all of the mentioned
B. files
C. compression algorithms
D. multimedia storage systems
C. compression algorithms
The internet features search engines to help users find information in a systematic and organized manner. Which of the following is not a search engine?
A. Lycos
B. Netscape
C. Yahoo
D. Google
B. Netscape
The IP address of 192.192.192.192/24 belongs to what class?
A. Class B
B. Class D
C. Class C
D. Class A
C. Class C
If a symbol is composed of 3 bits, there are _______ data levels.
A. 8
B. 2
C. 4
D. 16
A. 8
M = 2 = 2 = 8
Data flow between two devices can occur in _______ way/s.
A. All of these choices
B. Full-duplex
C. Half-duplex
D. Simplex
A. All of these choices
Data flow between two devices can occur in one of three ways: simplex, half-duplex, or full-duplex
The symbol time in FDMA systems is _______ thus intersymbol interference is _______.
A. Large, high
B. Large, low
C. Small, high
D. Small, low
B. Large, low
The symbol time of a narrowband signal is large as compared to the average delay spread. This implies that the amount of intersymbol interference is low and, thus, little or no equalization is required in FDMA narrowband systems.
CT2 is analog version of first generation cordless telephones.
A. True
B. Partly true
C. False
D. Partly false
C. False
CT2 is a digital version of the first generation, analog, cordless telephones. When compared with analog cordless phones, CT2 offers good speech quality and is more resistant to interference.
In layering, n layers provide service to:
A. n+1 layer
B. n-1 layer
C. n layer
D. none of these choices
A. n+1 layer
In layering n layer provides service to n+1 layer and use the service provided by n-1 layer.
In DS-1, a bit is “stolen” out of each channel:
A. every other frame
B. every twelfth frame
C. every frame
D. every sixth frame
D. every sixth frame
_______ ,synchronization overhead is required in TDMA due to ________ transmission.
A. Low, burst
B. High, burst
C. No, burst
D. High, continuous
B. High, burst
High synchronization overhead is required in TDMA systems because of burst transmissions. TDMA transmissions are slotted, and this requires the receivers to be synchronized for each data burst.
IS-95 was not compatible with existing AMPS frequency band.
A. True
B. Partly false
C. False
D. Partly true
C. False
Like IS-136, IS-95 system was designed to be compatible with the existing US analog cellular system (AMPS) frequency band. Hence, mobile and base stations can be economically produced for dual mode operation.
IS-95 uses same modulation technique for forward and reverse channel.
A. False
B. Partly true
C. Partly false
D. True
A. False
IS-95 uses different modulation and spreading technique for the forward and reverse links. On the forward link, the base station simultaneously transmits the user data for all mobiles in the cell by using different spreading sequence for each mobile.
Due to _______ transmission scheme _______ bits are needed for overhead in FDMA systems.
A. Discontinuous, few
B. Discontinuous, many
C. Continuous, few
D. Continuous, many
C. Continuous, few
Since FDMA is a continuous transmission scheme, fewer bits are needed for overhead purposes (such as synchronization and framing bits) as compared to TDMA.
US digital cellular system based on CDMA was standardized as:
A. IS-95
B. IS-76
C. IS-136
D. IS-54
A. IS-95
A US digital cellular system based on CDMA was standardized as Interim Standard 95 (IS-95). It was standardized by US Telecommunication Industry Association (TIA) and promised increased capacity.
Which of the following is not true for TDMA?
A. No requirement of duplexers
B. Single carrier frequency for single user
C. Discontinuous data transmission
D. High transmission rates
B. Single carrier frequency for single user
TDMA share a single carrier frequency with several users, where each user makes use of non-overlapping time slots. The number of slots per frame depends on several factors, such as modulation technique, available bandwidth etc.
In _______, the serial binary data is mixed with a higher-frequency pseudorandom binary code at a faster rate, and the result is used to phase-modulate a carrier.
A. direct-sequence SS (DSSS)
B. quadrature amplitude modulation (QAM)
C. frequency-hopping SS (FHSS)
D. orthogonal frequency-division multiplexing (OFDM)
A. direct-sequence SS (DSSS)
In CRC there is no error if the remainder at the receiver is:
A. Zero
B. Equal to the remainder at the sender
C. Nonzero
D. The quotient at the sender
A. Zero
Which error detection method can detect a single-bit error?
A. CRC
B. Two-dimensional parity check
C. Simple parity check
D. All of these choices
D. All of these choices
Which of the following best describes a single-bit error?
A. A single bit is inverted.
B. A single bit is inverted per data unit.
C. A single bit is inverted per transmission
D. Any of these choices
B. A single bit is inverted per data unit
In CRC the quotient at the sender ______?
A. Is discarded
B. Is the remainder
C. Becomes the divisor at the receiver
D. Becomes the dividend at the receiver
A. Is discarded
Using the Shannon formula to calculate the data rate for a given channel, if C = B, then _________.
A. Not enough information is given to answer the question
B. The signal is greater than the noise
C. The signal is less than the noise
D. The signal is equal to the noise
D. The signal is equal to the noise
The most common hamming codes are a generalized version of?
A. Hamming(7, 4) code
B. Hamming(5, 7) code
C. Hamming (8, 4) code
D. Hamming(6, 3) code
A. Hamming(7,4) code
The most common hamming codes generalize to form hamming(7, 4) code. It encodes four bits of data into seven bits by adding three parity bits.
Eight level FSK and binary PSK yields an equivalent sensitivity.
A. Partly false
B. Partly true
C. True
D.False
C. True
Binary PSK and 8-level FSK provides an equivalent sensitivity. The main drawback of 8-level FSK is that it yields al equivalent sensitivity to binary PSK at the expense of a greater receiver bandwidth requirement.
A special digital modulation technique that achieves high data rates in limited-bandwidth channels is called
A. Quadrature amplitude modulation (QAM)
B. Delta modulation
C. Pulse-coded modulation (PCM)
D. Pulse amplitude modulation (PAM)
A. Quadrature amplitude modulation (QAM)
BPSK uses non-coherent demodulator.
A. Partly true
B. True
C. Partly False
D. False
D. False
BPSK uses coherent or synchronous demodulation. It requires the information about the phase and frequency of the carrier be available at the receiver.
______ offers the potential for improving the coherent optical receiver sensitivity by increasing the choice of signaling frequencies.
A. MFSK
B. MPSK
C. MDSK
D. MASK
A. MFSK
Multilevel FSK includes 4-level or 8-level FSK. It improves the receiver sensitivity by reducing the deviation and increasing the usage of signaling frequencies.
QPSK provides twice the bandwidth efficiency and ______ energy efficiency as compared to BPSK.
A. Same
B. Four times
C. Twice
D. Half
A. Same
The bit error probability of OPSK is identical to BPSK but twice as much data can be sent in the same bandwidth. Thus, when compared to BPSK, QPSK provides twice the spectral efficiency with exactly the same efficiency.
The bandwidth of OQPSK is _to QPSK.
A. Identical
B. Four times
C. Half
D. Twice
A. Identical
The spectrum of an OQPSK signal is identical to that of QPSK signal. Hence, both signals occupy the same bandwidth. The staggered alignment of the even and odd bit streams in OQPSK signal does not change the nature of spectrum.
External modulation for _______
modulation format allows the most sensitive coherent detection mechanism.
A. PSK
B. DSK
C. FSK
D. ASK
A. PSK
External modulation for PSK is usually straightforward. It is therefore utilized to provide the modulation format which allows the most sensitive coherent detection mechanism.
Which modulation technique involves tribits, four different phase shifts, and two amplitudes?
A. 8PSK
B. 8QAM
C. 16PSK
D. QPSK
B. 8QAM
_______can potentially provide spectral conservation through the use of multilevel signaling.
A. MFSK
B. DFSK
C. ASK
D. M-ary PSK
D. M-ary PSK
In M-ary schemes, the spectral efficiency is increased by the factor log M. this is purely for M-level schemes which can provide multilevel signaling patterns.
In 16-QAM, there are 16_______
A. Amplitudes
B. Bps
C. Combination of phase and amplitude
D. Phases
C. Combination of phase and amplitude
By applying cos(2pieft), BPSK signal is equivalent to_____
A. Double sideband suppressed carrier amplitude modulated waveform
B. Single sideband suppressed carrier amplitude modulated waveform
C. SSB amplitude waveform
D. Frequency modulated waveform
A. Double sideband suppressed carrier amplitude modulated waveform
The BPSK signal is equivalent to a double sideband suppressed carrier amplitude modulated waveform, where cos(2ft) is applied as the carrier. Hence, a BPSK signal can be generated using a balanced modulator.
What encoding method is identified where binary 1 is transmitted first as a positive pulse, for one half of the bit interval, and then as a negative pulse for the remaining part of the bit interval?
A. Manchester encoding
B. nonreturn to zero (NRZ)
C. Alternate Mark Inversion (AMI)
D. return to zero (RZ)
A. Manchester encoding
Lempel-Ziv-Welch (LZW) is a universal lossless data compression algorithm. Who created LZW?
A. Terry Welch
B. Jacob Ziv
C. All of these choices
D. Abraham Lempel
C. All of these choices
Which of the following is false with respect to pulse position modulation?
A. Modulates a high frequency carrier
B. Pulse is narrow
C. Pulse width changes in accordance with the amplitude of modulating signal
D. Can be transmitted in broadband
C. Pulse width changes in accordance with the amplitude of modulating signal
In PPM, the pulses change position according to the amplitude of the analog signal. The pulses are very narrow. These pulse signals may be transmitted in a baseband form, but in most applications, they modulate a high-frequency radio carrier.
Which of the following data compression scheme replaces repeated characters or bit patterns with a code indicating the character or pattern and the number of repetitions?
A. Channel Coding
B. Huffman Coding
C. Shannon-Fano Coding
D. Run-Length Encoding
D. Run-Length Encoding
The_______
corresponds to average quantization noise power.
A. Variance
B. Mean
C. Probability density function
D. None of these choices
A. Variance
The variance corresponds to average quantization noise power. It is calculated assuming the quantization noise and probability distribution function.
The self-information of random variable is
A. 1
B. 0
C. Cannot be determined
D. Infinite
D. Infinite
The length of the code-word obtained by encoding quantized sample is equal to
A. I=2loq(to the base 2)L
B. I=log(to the base 2)L
C. I=log(to the base 2)L/2
D. I=log (to the base 10)L
B. I=log(to the base 2)L
The quantized samples which are digitally encoded into I bit value code-word. The length I can be calculated as I=log(to the base 2)L.
In a TDD one channel is sufficient for transmission.
A. True
B. Partly true
C. Partly false
D. False
A. True
Time-division duplexing (TDD) means that signals are transmitted simultaneously on a single channel by interleaving them in different time slots. Each time slot may contain one data word, such as 1 byte from an A/D converter or a D/A converter.
As long as the serial data rate is high enough, a user will never know the difference. The primary benefit of TDD is that only one channel is needed. It saves spectrum space and cost.
All local and long-distance connections are digital.
A. True
B. Partly true
C. Partly false
D. False
A. True
All modern telephone systems use digital transmission via PCM and TDM. The only place where analog signals are still used is in the local loop-the connection between a telephone company’s central office (CO) and the subscriber’s telephone, known as the customer premises equipment (CPE). All local and long-distance connections are digital.
ASCIl code is a
A. Fixed Length Code
B. None of these choices
C. Fixed & Variable length code
D. Variable length code
A. Fixed Length Code
ASCII code is a fixed length code. It has a fixed length of 7 bits.
Which system uses digital transmission?
A. ISDN
B. ISDN & LANs
C. None of the mentioned
D. LANs
B. ISDN & LANs
Though the signal type is analog or digital, the transmission takes place in the digital domain in ISDN and LANs.
While recovering signal, which gets attenuated more?
A. None of these choices
B. Low & High frequency component
C. High frequency component
D. Low frequency component
C. High frequency component
High frequency components are attenuated more when compared to low frequency components while recovering the signals.
Synchronization available in digital communication are
A. Carrier synchronization
B. All of the mentioned
C. Symbol synchronization
D. Frame synchronization
B. All of the mentioned
The synchronization techniques available in digital communication are symbol synchronization, frame synchronization and carrier synchronization.
