New chapter 3- tm quizz

New chapter 3- tm quizz

What technique reduces the number of required cables in a wired network while providing better utilization of the cables used?

Packet switching

What broadcasts in the LF band?

WWVB

Which agency is responsible for assigning and regulating radio frequencies in the United States?

FCC

How does packet switching allow access to the network?

Packets can be sent by any device as long as no other device is sending a packet.

What causes crosstalk?

Signals from one frequency encroaching on its neighbor's channel frequency.

What does a mixer do?

It converts an input frequency to a specific desired output frequency by combining it with a carrier frequency.

Which organization focuses on telecommunication signals?

ITU-T

Which statement is true regarding multiple access methods?

Longer CDMA spreading codes allow more users to share the frequency band.

Which data flow requires two frequency channels?

Full-duplex transmission.

How does CDMA provide multiple access?

It uses a different PN code for each user.

How does TDMA provide multiple access?

It divides the transmission time into several slots, giving each user a different time slot.

What prevents CDMA devices from intercepting each other's signals?

Others' transmissions will appear to be random noise without knowledge of the correct PN code and starting chip.

What type of filter blocks frequencies below a minimum threshold and above a maximum threshold?

Bandpass filter.

What standards are developed by IETF?

Internet protocols.

The FCC approved the use of unlicensed spectrum in the 6 GHz band for wireless communication. What band is 6 GHz in?

SHF (Super High Frequency).

Which radio system component is an active device?

Amplifier.

What are de facto standards?

Common practices that the industry simply followed without being created by a standards organization.

How many filters are used when transmitting an AM signal, and why?

Two filters: one to the IF signal to eliminate undesirable harmonics, and one to the mixer output to eliminate frequencies outside the intended sideband limits.

Which organization writes regulations rather than standards?

FCC.

How does FDMA provide multiple access?

It divides the bandwidth into smaller frequency bands or channels, dedicating each channel to a specific user.

WLANs do NOT operate in which band?

Millimeter Wave.

Where does a mixer fit within the components of a radio transmitter circuit?

Modulator, Filter, Mixer, Filter, Amplifier, Antenna.

What switching method gives two users a dedicated connection, but only as long as needed?

Circuit switching.

What do standards allow you to do?

Connect devices from multiple vendors on the same network.

What do the IEEE 802.3 standards cover?

Ethernet, defining the physical and data link layers for wired Ethernet connections.