Wireless Communications & Mobile Technologies Flashcards

Which cellular network element manages radio resources and controls base stations in a 4G LTE network?

Answer: eNodeB (eNB)

In LTE, the eNodeB (evolved Node B) manages radio resource allocation and connects directly to the core network, unlike older architectures with separate controllers.

What is the approximate maximum theoretical downlink speed for LTE Advanced (LTE-A)?

Answer: 1 Gbps

LTE Advanced, through carrier aggregation and advanced MIMO, achieves theoretical peak downlink speeds of up to 1 Gbps.

In a CDMA system, how are multiple users distinguished on the same frequency channel?

Answer: By unique spreading codes

CDMA assigns each user a unique pseudo-random spreading code, allowing all users to share the same frequency simultaneously.

What does OFDMA stand for and what is its key advantage in 5G NR?

Answer: Orthogonal Frequency Division Multiple Access; it allows multiple users to share subcarriers simultaneously

OFDMA divides the available spectrum into subcarriers that can be assigned to different users simultaneously, improving efficiency in dense networks.

Which unlicensed spectrum band is most commonly used by Bluetooth devices?

Answer: 2.4 GHz ISM band

Bluetooth operates in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band, using frequency hopping to reduce interference.

What is the purpose of a Distributed Antenna System (DAS) in telecommunications?

Answer: To extend wireless coverage within buildings or large venues by distributing antennas throughout the space

A DAS uses a network of spatially separated antennas connected to a common source to improve indoor or in-building wireless coverage.