Spectrum Aggregation for 6G: Lessons from 5G Carrier Aggregation and Dual Connectivity

2026-06-05

AI Summary

This work addresses the challenge of efficiently aggregating heterogeneous spectrum—from sub-6 GHz to millimeter wave bands—for 6G, a task for which 5G dual connectivity (DC) proves inadequate due to architectural fragmentation and complex handover procedures. Building on practical insights from 5G carrier aggregation (CA) and DC deployments, the paper proposes enhanced CA as the unified spectrum aggregation paradigm for 6G, deliberately moving away from the interim DC architecture to establish a streamlined and scalable multi-band coordination framework. The proposed approach delineates concrete enhancement pathways for CA in critical dimensions such as bandwidth expansion, resource scheduling, and cross-band coordination, thereby laying a high-capacity, spectrally efficient, and architecturally cohesive foundation for 6G wireless access.

Abstract

Spectrum aggregation has been a key enabler of LTE and 5G capacity growth, but it will become even more fundamental in 6G as networks expand across low bands, existing mid bands, new upper-mid/centimetric bands, and millimeter wave bands. This article examines how 5G carrier aggregation (CA) and dual connectivity (DC) inform the design of 6G spectrum aggregation. We argue that, while DC was instrumental in accelerating early non-standalone 5G deployment, it also introduced architectural fragmentation and long-term migration complexity. In contrast, CA provides a cleaner and more scalable foundation for multi-band operation in standalone 6G. Building on lessons from 5G, we advocate enhanced CA as the preferred 6G aggregation framework and point out the corresponding key enhancement directions.

Problem

• spectrum aggregation
• 6G
• carrier aggregation
• dual connectivity
• multi-band operation

Innovation

• Carrier Aggregation
• Dual Connectivity
• 6G Spectrum Aggregation
• Multi-band Operation
• Standalone Architecture