Scalable Inter-Satellite Optical Wireless Communication Based on CWDM and EDFAs for 6G and NTN Backhaul

This study presents a scalable inter-satellite optical wireless communication (IS-OWC) system based on coarse wavelength division multiplexing (CWDM) and high-power erbium-doped fiber amplifiers (EDFAs) to support high-bandwidth data transmission to address 6G and non-terrestrial network (NTN) backhaul needs. An 18-channel CWDM arrangement supports an aggregated data rate of 180 Gbps through 5500 km optical wireless link. Every channel takes up a unique wavelength (1270–1610 nm with 20 nm separation), designed to provide maximum interference protection and high spectral efficiency. Signal amplification is ensured by EDFAs to provide data continuity over long distances. Performance parameters like bit error ratio (BER) and Q-factor exhibit reliable transmission up to 4500 km and degradation beyond this distance to warrant error correction and sophisticated modulation to support far-range use cases. The study demonstrates the promise of CWDM-based IS-OWC with EDFAs to be an economical high-speed option for 6G and NTN backhaul to offer mass-scale access in remote and underserved regions.