Exploring Device-to-Device (D2D) Communication in Cellular Technology: 5G and Beyond

This study explores the capabilities and performance of Device-to-Device (D2D) communication within the 5G network framework, focusing on the DECT NR+ standard. Developed by the European Telecommunications Standards Institute (ETSI), DECT NR+ aims to meet the stringent requirements of 5G technology. The hypothesis assumes that DECT NR+ can significantly enhance communication efficiency and reliability in D2D scenarios. To test this hypothesis, hardware and software tools from Nordic Semiconductor was utilized, including the nRF9161 Development Kit, nRF Connect for Desktop and nRF Connect SDK. These tools facilitated the setup and evaluation of seamless communication between devices using the DECT NR+ standard. Key performance metrics were systematically evaluated, including latency, coverage, Packet Success Rate (PSR), data rate, and power consumption. The results indicated that DECT NR+ provides robust data rate performance, achieving up to 2.2 Mbps, and high PSR in controlled environments up to a critical distance, beyond which PSR declined. The maximum observed range was 220 meters, which is notable but still less compared to other technologies as LTE-M and NB-IoT. Latency analysis revealed a linear relationship between Round Trip Time (RTT) and packet size, with higher Modulation and Coding Scheme (MCS) values improving latency performance. However, observed RTTs did not fully meet the Ultra-Reliable Low Latency Communication (URLLC) standards, suggesting the need for further optimization. Finally, Power consumption analysis showed that DECT NR+ demonstrated significantly lower power consumption compared to Wi-Fi, especially during idle and active operation, and was comparable to NB-IoT and LTE-M. Future implementations of the complete DECT NR+ stack and additional power-saving features are expected to enhance this efficiency further. In conclusion, this thesis contributes to the ongoing development and optimization of DECT NR+ technology, underscoring its promise as a versatile and efficient solution for future wireless communication challenges. Future work will focus on addressing the identified optimization areas to further enhance DECT NR+ performance.