Quiz 6

What does the term "bit rate" refer to in the context of digital communication?

The number of bits transmitted per unit of time

A signal travels from point A to point B. At point A, the signal power is 100 W. At point B, the power is 90 W. What is the attenuation in decibels? Give one decimal. 

0.5

If the bandwidth of the channel is 5 Kbps, how long does it take to send a frame of 100,000 bits out of this device? 

20

A line has a signal-to-noise ratio of 1000 and a bandwidth of 4000 KHz. Whatis the maximum data rate supported by this line? Give your answer in Mbps. Round to the nearest integer. 

40

A file contains 2 million bytes. How long does it take to download this file using a 56-Kbps channel? Give your answer in seconds. Round to the nearest integer. 

286

A file contains 2 million bytes. How long does it take to download this file using a 1 Mbps channel? Give your answer in seconds. Round to the nearest integer. 

16

A signal with 200 milliwatts power passes through 10 devices, each with an average noise of 2 microwatts. What is the SNRdB?

40

What is the theoretical capacity of a channel with 20 KHz bandwidth and SNRdB of 40. Round to the nearest integer. Giver your ansewr in Kbps. 

I dont know

We have a channel with 4 KHz bandwidth. If we want to send data at 100 Kbps, what is the minimum SNRdB? Round to the nearest dB. 

I dont know

Determine the average power of the original signal if noise power = 10 mW and SNR of the noisy signal = 30 dB. Give your answer in mW

10000

We have a channel with a 1-MHz bandwidth. The SNR for this channel is 63. What is the signal level?

I dont know

What is the transmission time of a packet sent by a station if the length of the packet is 1 million bytes and the bandwidth of the channel is 200 Kbps? give your answer in seconds. 

40

What is the length of a bit in a channel with a propagation speed of 2 × 108 m/s if the channel bandwidth is 100 Mbps? Give your answer in meters. 

2

How many bits can fit on a link with a 2 ms delay if the bandwidth of the link is 100 Mbps? Give your answer in bits. 

200000

What is the total delay (latency) for a frame of size 5 million bits that is being sent on a link with 10 routers each having a queuing time of 2 μs and a processing

time of 1 μs. The length of the link is 2000 Km. The speed of light inside the link is 2 × 108 m/s. The link has a bandwidth of 5 Mbps. Give the exact answer. 

1.01003

In the above question (Q16), which component of the total delay is dominant? 

Transmission time

Match the baseband or Broadband communication system

Sending a digital signal from one station on a LAN to another station without modulation -> Baseband

Modulate several voice signals and send them through air -> Broadband