Telecommunications Final ULL
The bathtub curve depicts what?
The general life-cycle failure rate for a component or system.
Put a nice square wave into a cable at one end and given a cable length great enough, you can get only a sinusoidal wave at the far end of the cable. Under a Layman's understanding of Fourier Analysis, the likely explanation for this is that the cable filtered out what from the original square wave?
The harmonics
A situation where a phone network, design for normal statistics, experiences large loads under abnormal statistics.
The racetrack effect
A car battery, motor, and a microphone are examples of transducers?
True
At the federal level, FCC jurisdiction covers all communications that is between states or that is into and out of the United States or has the potential to cross state lines or into/out of the United States?
True
Encapsulation and DeEncapsulation is a function OSI Layers in Layered Model of data communications?
True
Multiplexing and Demultiplexing is a function OSI Layers in the Layered Model of data communications?
True
Sam modulation combines a number of phases with a number of amplitudes in combination to send multiple bits per baud noise?
True
Sectoring promotes frequency reuse
True
Single mode fiber suffers from chromatic dispersion but not modal dispersion?
True
The radio portion of the electromagnetic spectrum is in a lower frequency band than that associated with the visual light band?
True
The telecommunications Act of 1996 was intended to modernize federal telecommunications regulations so that more competition was promoted in the telecommunications industry?
True
VOIP can be used to carry telephone trunks?
True
With frequency modulation, the receiver can better discriminate between the actual signal and the noise, usually affects the amplitude of incoming signal?
True
Phone lines connecting only form phone switch to phone switch?
Trunks
In the TCP/IP version of the OSI Model, this helps to identify the application program, e.g. email, web browser, etc. needing to revive the packets handed up from the transport layer.
Well-known TCP ports
Modems are important nowadays for what main reason?
Wireless transmission
A smart trunk can carry how many digitized phone calls?
23
A T1 circuit can carry how many digitized phone calls?
24
On the busy hour of the busiest day of the year, at a certain company, the SMDR reports to you that the average call holding time is 30 seconds, and that the call frequency is 900 calls per hour. What is the traffic volume in ccs? remember ccs is call seconds divided by 100.
270ccs
A 256 QAM modulation scheme would allow 256 unique digital symbols to be transmitted where each symbol is mad up of how many bits?
8
Which one of these has the highest bandwidth?
A 1-Kilometer length of single mode fiber.
With FHSS (CDMA - spread spectrum), how does communications take place?
A different hopping pattern "code" is used for each trunk
From Fig 2, it would be correct to say that the graph best represents (choose the best answer):
A frequency domain graph of an Amplitude Modulated carrier.
From Fig. 1 assume Signal A is the same information signal used to modulate both carrier signals, i.e. both Signal B and Signal C. In Figure 1, it would be correct to say that Signal B is (choose the best answer):
A time domain graph of Amplitude Modulated carrier.
From Fig. 1 assume Signal A is the same information signal used to modulate both carrier signals, i.e. both Signal B and Signal C. In Figure 1, it would be correct to say that Signal C is (choose the best answer):
A time domain graph of Frequency Modulated carrier.
Sectoring is a way to do what?
Achieve frequency reuse
An analog signal which has been sampled at less than the Nyquist rate for conversion to a digital signal will cause a problem called what at the receiver when it is converted back?
Aliasing
A PBX is meant to do what? Choose the best answer
Allow a greater number of calls to be statistically handled with fewer trunks.
This helps to find your cell phone when a call comes in.
Auto affiliation
Present in single mode fiber?
Chromatic Dispersion
Analog to digital conversion is important for what reasons?
Computers and networks are digital as this makes information easier to transmit and process, but most information to be sensed in the physical world is analog in nature
The following is a form of AC signaling in the telephone network?
Dial Tone
The US Justice Department split of AT&T from the Bell Companies and the split of the Bell Companies from each other in 1984 is generally know as what?
Divestiture
With Amplitude modulation of a carrier it is always necessary to transmit a powerful carrier?
False
With asynchronous communications the data signal is sent along with a clock signal?
False
Out of the following Telecommunications mediums, which has the greatest distance x bandwidth product?
Fiber
Modulation is the technique whereby an information signal (i.e. Baseband signal) is used to modify a carrier signal in such a way as to encode the baseband signal's information onto the carrier for later extradition at the receiver which extracts the baseband signal through the demodulation process. Combining modulated signs at different frequencies onto the same channel is one example of a useful technique called broadband communications. But why is broadband communications advantageous?
It allows multiple baseband information signals to share a common medium and for the receiver to select any one or more of them receiving.
You are asked to calculate the amount of telephone traffic coming out of a telephone switch to the C/O. Why is this important?
It will help you to determine the number of combo trunks
Refer to Fig. 2. In Fig 2, the time domain representation of the carrier signal is best described by which labeled Item?
Item A
Refer to Fig. 2. the time domain representation of the upper side bans is best described by which labeled item?
Item B
Refer to Fig. 2. In Fig 2, The time domain representation of the information signal is best described by which labeled Item?
Item C
Telephone communications are detrimentally sensitive to what?
Latency or delay
The following most clearly explains the difference between the phone lines and phone trunks.
Lines connect between the switch and phones and trunks from switch to switch.
A _______ Address is a 12 midget HEX number.
MAC
The essential difference between connection-oriented and connection-less communications is that: A. With connection-oriented communications information is just sent through the network, establishing the network route hop by hop. B. With connection-oriented communications, in -order arrival of transmitted packets is not guaranteed. C. with connection-oriented communications, packets can take differing paths through the network. D. With connection-oriented communications, data communications total capacity in a shared network is increased since connection-oriented communications more efficiently shares the network. E. None of the Above
None of the above
The following most clearly explains the difference between tie trunks and combo trunks. A. Lines carry dc signaling while trunks carry ac signaling. B. Tie trunks carry dc signaling while lines carrying ac signaling. C. Trunks connect to voicemail while lines connect to phones. D. Lines connect between the switch and phones and trunks from switch to switch. E. Trunks connect only long distance calls while line only local calls. F. None of the above
None of the above
PSK is a special or restricted form of what?
Phase Modulation
The POP is what?
Point of Presence
Increasing the resolution employed by the analog to digital converted increases what?
Quantization Accuracy
In a PBX, records call statistics:
SMDR
A high speed computer network used for look-ahead call placement. It saves actual telephone system trunks from being seized in order to just check if the call phone is busy. Select the best answer.
SS7
A look-ahead call placement computer network for the phone system.
SS7
All of the following are ways to carry trunks with exception of what?
SS7--Trunks
Who archived the first US patent on a device we now generally know as the telegraph?
Samuel Morse
A method for improving frequency reuse in Cellular systems?
Sectoring
If the mean time to repair system decreases given the system maintains a constant failure rate, what impact will result for the system?
System Availability will increase
In the TCP/ID version of the OSI Model, this helps to handle flow control, missing packets, and packets arriving out of order?
TCP
The function of well-known ports is handled by what standard in the Transport Layer?
TCP
A concept where by the value of information to the receiver depends on just when information is received is known as what?
TVI- The theme value of information
The communications medium is also know generally as what?
The Channel
The Telecommunications Act of 1934 is an act of congress that created what Federal agency?
The FCC (Federal Communications Commission)
The Hartley-Shannon Theorm says that if a signal is to be reproduced faithfully through digital sampling, it should be sampled at twice the signal's highest frequency?
False
The Telephone Network is a prime example of a connection-less network?
False
The internet is a prime example of connection-oriented network?
False
The term dBm is just a gain or loss and cannot actually be measured in the lab as a power level?
False
Helps to keep communications code simple and fast?
Encapsulation
Availability is a concept which essentially says how long the system will run until it fails for the first time?
False
Digital signals do not contain noise?
False
Multimode fiber suffers from aromatic dispersion but not modal dispersion?
False
Reliability is a concept meant to express the probability in percent that a system will be found in an operative state, in other words (up time/total time) * 100%?
False
Samuel Morse's coding of the English alphabet into "Morse Code," smartly employed a method that used fewer symbols called dots and dashes for those letters that occurs less frequently in the English language, and more symbols for those letters that occur more often. This type of compression is generally know as what?
Huffman Coding
With half-duplex communications, communications takes place how?
In both directions, but only in one direction at a time
