Question

1) Select the true statement regarding the establishment of successful communications.

		a. transmission power must only be sufficient to overcome signal attenuation since noise cannot be eliminated
		b. it is critical to know the signal-to-noise ratio (SNR) at the receiver, i.e., SNR at the transmitter is not as important
		c. when determining the capacity of a communications link it is not important to understand the link characteristics of the medium (guided or unguided) in which the signal will propagate
		d. the capacity of a transmission link is not dependent upon signal frequency bandwidth

2)

The Shannon-Hartley Theoretical Capacity formula tells you the maximum data rate capacity achievable. By using modern M’ary modulation techniques you can easily reach higher data rate capacities.

a) True

b) False

3)

What is needs to be considered to ensure successful communications over guided or unguided mediums?

		a. determining the EM noise environment in which communications will take place
		b. understanding the frequency and frequency bandwidth limitations associated with the assigned communication frequencies
		c. matching modulation or line coding methods to the characteristics of communications being established
		d. all of the above must be considered

4)

Select the correct statement(s) regarding SMF and MMF fiber optic cables.

		a. multimode fiber (MMF) has a wider core diameter that supports multiple modes of light; as such, MMF can support higher data capacities compared to single-mode fiber (SMF)
		b. MMF suffers from modal delay, which results in digital signal distortion
		c. SMF cables are constructed with a small optical core, which means its data capacity is much less than MMF fiber which have a larger diameter core
		d. all are correct statements

Answer 1

1) Option (d) is the correct answer.

The capacity of a transmission link is not dependent upon signal frequency bandwidth.

Option (a) is incorrect as transmission power must be more than be sufficient to overcome signal attenuation since noise can't be eliminated.

Option (b) is incorrect as SNR at the transmitter is very important.

Option (c) is incorrect as when determining the capacity of a communications link it is important to understand the link characteristics of the medium (guided or unguided) in which the signal will propagate.

2) It is false.

The Shannon-Hartley Theoretical Capacity formula tells you the maximum data rate capacity achievable considering the presence of noise. It states:

C <= B log₂ (1 + SNR)

In this equation, 'C' is the maximum data transfer rate without any noise or other disturbance in the channel.

3) Option (d) is the correct answer.

The following scenarios need to be considered to ensure successful communications over guided or unguided mediums:

(i) Determining the EM noise environment in which communications will take place.

(ii) Understanding the frequency and frequency bandwidth limitations associated with the assigned communication frequencies.

(iii) Matching modulation or line coding methods to the characteristics of communications being established.

So, we can say all three given options are true.

4) Option (d) is the correct answer.

The correct statements regarding SMF and MMF fibre optic cables are the following:

(i) Multimode fibre (MMF) has a wider core diameter that supports multiple modes of light; as such, MMF can support higher data capacities compared to single mode fibre (SMF).

(ii) MMF suffers from modal delay, which results in digital signal distortion.

(iii) SMF cables are constructed with a small optical core, which means its data capacity is much less than MMF fibre which have a larger diameter core.

So, we can say all three given options are true.

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