ETCP 5G RAN Architecture and Deployment 3

Question 1

What is the primary purpose of Ericsson's Radio Dot System?

Accepted Answer

Delivering indoor 4G/5G coverage in large buildings using distributed small radio units

Answer

The Ericsson Radio Dot System is an in-building small cell solution where compact radio dot units connect via standard Ethernet to a central baseband unit for indoor coverage.

Question 2

In 5G NR, what does 'SSB (Synchronization Signal Block)' enable a UE to do?

Accepted Answer

Detect the cell, acquire time/frequency synchronization, and decode the master information block (MIB)

Answer

The SSB contains the PSS, SSS, and PBCH, allowing a UE to detect a 5G cell, synchronize its timing and frequency, and read basic system information.

Question 3

What is the role of the RRC (Radio Resource Control) protocol in Ericsson's 5G RAN?

Accepted Answer

Managing UE state (idle/connected/inactive), bearer setup, handover, and system information broadcast

Answer

RRC runs in the gNB-CU and controls UE state transitions, connection setup, measurement configuration, handover procedures, and system information broadcasting.

Question 4

What does PDCP (Packet Data Convergence Protocol) do in Ericsson's 5G RAN stack?

Accepted Answer

Performs header compression, ciphering, integrity protection, and in-sequence delivery for data packets

Answer

PDCP provides IP header compression (ROHC), encryption, integrity protection, and in-sequence delivery for both control and user plane data in the 5G RAN.

Question 5

In Ericsson's 5G NR, what is the 'UE Inactive state' introduced to improve network efficiency?

Accepted Answer

An intermediate state between Connected and Idle that preserves UE context in the RAN to enable fast re-activation without a full RRC connection setup

Answer

The RRC Inactive state (introduced in 5G NR) stores UE context in the last-serving gNB, enabling the UE to resume data activity with minimal signaling overhead compared to a full re-establishment.

ETCP - Ericsson Technical Certification Program Practice Test

ETCP - Ericsson Technical Certification Program Practice Test

ETCP 5G RAN Architecture and Deployment 3