# 3 GPP Evolution from 5G to 6G: A 10-Year Retrospective
## 6 3 GPP Release 19: 5G-Advanced Growth
### Enhancements to Existing Features  
MIMO remains a cornerstone of 5G technology, and Release 19 introduces the fifth phase of its evolution. To improve the accuracy and efficiency of beam management, the release enables UE-initiated beam reporting, which allows UEs to trigger reporting rather than relying on gNB requests. Another significant enhancement is the expansion of CSI reporting from 32 to 128 ports, enabling better support for larger antenna arrays, a critical feature for scaling MIMO systems in high-capacity scenarios. Coherent joint transmission capabilities are enhanced to address challenges in scenarios with non-ideal synchronization and backhaul (e.g., inter-site coherent joint transmission). New measurement and reporting mechanisms are introduced for time misalignment and frequency/phase offsets between TRPs. To further improve uplink throughput, the release incorporates enhancements to non-coherent uplink codebooks for UEs equipped with three transmit antennas. Additionally, asymmetric configurations are supported, where a UE receives downlink transmissionsfrom a macro gNB while transmitting to multiple micro TRPs in the uplink. These configurations include enhanced power control mechanisms and path loss adjustments to optimize performance in heterogeneous network environments. Mobility management is another focus area in Release 19, particularly through the extension of LTM. Initially introduced in Release 18 for intra-central unit (CU) mobility, the new enhancements extend support to inter-CU mobility, enabling smoother transitions across cells associated with different CUs. To further optimize mobility, Release 19 introduces conditional LTM. This combines the benefits of reduced interruption times from LTM with the reliability of CHO. Additionally, event-triggered layer 1 measurement reporting reduces signaling overhead compared to periodic reporting. The inclusion of CSI reference signal (CSI-RS) measurements alongside SSB measurements enhances the performance of mobility procedures. NR NTN evolution continues in Release 19, where 3 GPP defines new reference satellite payload parameters to address scenarios with reduced equivalent isotropic radiated power (EIRP) densities per satellite beam compared to previous releases. To accommodate the reduced EIRP, the release explores downlink coverage improvements. Given the large number of UEs expected within a satellite's coverage area, Release 19 also focuses on increasing the uplink capacity by incorporating orthogonal cover codes into the DFT-s-OFDM based PUSCH. To support MBS within NTNs, 3 GPP enhances MBS by defining signaling mechanisms for specifying intended service areas. Another significant advancement in Release 19 is the introduction of regenerative payload capabilities, enabling 5G system functionalities directly onboard satellite platforms. Unlike the transparent payloads supported in earlier releases, regenerative payloads allow for more flexible and efficient NTN deployments. Furthermore, NR NTN is evolving to support RedCap UEs. Release 19 further optimizes 5G-Advanced to better accommodate XR applications. This includes enabling transmission and reception during gaps or restrictions caused by RRM measurements and RLC's acknowledged mode of operation. Additionally, Release 19 explores improvements to the PDCP and uplink scheduling mechanisms, particularly focusing on incorporating delay information. 3 GPP also investigates techniques to support XR applications more efficiently, ensuring they meet the diverse and stringent QoS requirements associated with multi-modal XR use cases. At the NG-RAN architecture level, 3 GPP leverages AI/ML to address more use cases in Release 19. One new use case is AI/ML-based network slicing, where AI/ML is utilized to optimize resource allocation dynamically for different network slices. Another focused area is coverage and capacity optimization, with AI/ML being leveraged to adapt cell and beam coverage dynamically, a technique often referred to as cell shaping.