Which of the following are 4G limitations that justify a roll-out to 5G? (Choose three.)

The transition from 4G to 5G is driven by the need to support new, demanding applications that 4G networks cannot adequately handle. 5G is designed around three primary use cases: enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communication (URLLC), and massive Machine-Type Communication (mMTC). eMBB directly addresses the throughput limitations of 4G (A), targeting peak data rates up to 20 Gbps. URLLC is specifically designed to overcome 4G's shortcomings in reliability (B) and latency (C), aiming for 99.999% reliability and end-to-end latency as low as 1 ms. These improvements are crucial for applications like autonomous vehicles, remote surgery, and industrial automation, which were not feasible with 4G technology.

D. Beamforming is not supported: This is incorrect. Beamforming techniques were introduced and utilized in 4G/LTE-Advanced standards (e.g., TM7), although 5G employs much more advanced Massive MIMO and beamforming capabilities.

1. Nokia Bell Labs 5G Foundation Certification Student Guide (SR20), Module 2: 5G Use Cases and Requirements, Section 2.2 "5G Performance Requirements". This section details the ITU-defined performance targets for 5G in latency, reliability, and data rates, which are significant improvements over 4G capabilities.

2. International Telecommunication Union (ITU), Recommendation ITU-R M.2410-0 (11/2017), "Minimum requirements related to technical performance for IMT-2020 radio interface(s)". Table 2 in Section 5 specifies the minimum requirements for 5G, including 1 ms latency for URLLC and peak data rates of 20 Gbit/s (downlink), explicitly highlighting the performance gaps of previous generations.

3. Dahlman, E., Parkvall, S., & Skold, J. (2018). 5G NR: The Next Generation Wireless Access Technology. Academic Press. Chapter 2, "Background of 5G," discusses the limitations of LTE in meeting the demands for higher data rates, lower latency, and improved reliability, which became the key drivers for 5G development.

4. Agiwal, M., Roy, A., & Saxena, N. (2016). "Next Generation 5G Wireless Networks: A Comprehensive Survey." IEEE Communications Surveys & Tutorials, 18(3), 1617-1655. https://doi.org/10.1109/COMST.2016.2532458. Section III.A, "Limitations of 4G Networks," explicitly lists low data rates, high latency, and lack of support for diverse QoS requirements (like ultra-reliability) as key shortcomings driving 5G research.