Maritime Multi-Hop Communication over 5G Networks: An Indoor Testbed Implementation and Evaluation

5G is designed to offer reliable, low latency, and high bandwidth connectivity for different industry sectors. Yet, the limited 5G coverage and capacity in open sea areas pose challenges for maritime sector. Consequently, there is a shift from public 5G non-standalone (NSA) networks to private 5G standalone (SA) networks enabling more industry-tailored network configurations. In addition, new 5G features such as 5G Mobile Integrated Access and Backhaul (mIAB), Non-Public Network - Public Network (NPN-PN) interaction, and Non-Terrestrial Network (NTN) connectivity pave way to extend the 5G coverage and enhance capacity. This paper describes our lab testbed implementation and the insights we gained from the performance and challenges of a 5G multi-hop system in the context of maritime applications. The results indicate that the asymmetric 5G UL/DL ratio and increased latency due to overlay link management and signaling through multiple 5G RANs and 5G cores are areas for improvements. However, the experience obtained from the indoor tests has provided confidence to continue with the mobile multi-hop architecture for implementation in moving vehicles and vessels.