CTA Wireless Communications & Mobile Technologies 3

Question 1

What is 'spectrum refarming' in the context of mobile networks?

Accepted Answer

Repurposing legacy spectrum bands (e.g., 2G/3G) for newer technologies like 4G/5G

Answer

Selling spectrum licenses to foreign operators

Answer

Increasing antenna height to cover more area

Answer

Moving all traffic to unlicensed spectrum

Question 2

Which metric measures the ratio of useful signal power to total interference plus noise power in a wireless link?

Accepted Answer

SINR (Signal-to-Interference-plus-Noise Ratio)

Answer

BER (Bit Error Rate)

Answer

VSWR (Voltage Standing Wave Ratio)

Answer

EVM (Error Vector Magnitude)

Question 3

What is the key characteristic of a 'small cell' compared to a macrocell tower?

Accepted Answer

Small cells have lower transmit power and shorter range, used to boost capacity in dense areas

Answer

Small cells operate only indoors

Answer

Small cells always use licensed spectrum

Answer

Small cells cannot support 5G

Question 4

What does 'beamforming' enable in 5G massive MIMO systems?

Accepted Answer

Redirecting radio energy toward specific users instead of broadcasting in all directions

Answer

Eliminating the need for base station hardware

Answer

Converting millimeter waves to microwave frequencies

Answer

Reducing the number of required antenna elements

Question 5

Which US regulatory body is responsible for licensing and regulating wireless spectrum?

Accepted Answer

NTIA (National Telecommunications and Information Administration) for federal use; FCC for commercial use

Answer

FTC (Federal Trade Commission)

Answer

FCC only, for all spectrum uses

Answer

IEEE spectrum committee

Question 6

What is the primary technical difference between HSPA+ and LTE in terms of network architecture?

Accepted Answer

LTE uses a flat all-IP architecture; HSPA+ relies on the older 3G RNC/NodeB hierarchy

Answer

HSPA+ uses packet switching; LTE uses circuit switching

Answer

LTE operates only in licensed bands; HSPA+ uses unlicensed bands

Answer

HSPA+ supports MIMO; LTE does not