Dynamic THz Backhaul for 6G Local Area Networks: Architecture, Analysis, Challenges and Future Directions

As the communications technology advances towards the era of sixth-generation (6G) communication systems, densification of networks is still one of the promising ways to improve the overall network capacity. Dense networks impose strict requirements and deployment problems for the backhaul infrastructure and its operations. Millimeter wave and low terahertz (THz) bands (30-500 GHz) offer ample capacity to meet any data rate requirements, but are challenging to implement on small-scale devices due to large antenna gain requirements. These are less concerning in a backhaul infrastructure, where devices are more costly and equipped to support such specifications. This article studies the opportunities presented by utilizing THz communications for backhaul operations with tailored architectures for 6G local area networks. Herein, urban microcell and small cell base station networks are investigated. Constraints for backhaul links in these networks are considered from various perspectives including the channel, hardware, physical layer signal processing, and intelligent network management challenges. Even though the THz frequency bands show remarkable potential for dense backhaul operations due to their large capacity, many practical challenges remain that must be addressed for real-world implementation.