For around 100 years wireless data transmission has been realised with microwave technology for many applications. Now, it is time to extend the physical layer by optical communication. This technology extension is supported by high demand in connectivity for data exchange. It is covering various possible links, such as those between airplanes and satellites, links from space to ground station on earth, or simply data transmission between satellites.
Optical communication is offering five major advantages versus microwave technology:
• transmission cost per bit is significantly lower,
• total capacity can be increased,
• no license approval is required,
• excellent beam steering over hemisphere, and
• bridging of long distance, up to 80,000 km approved.
Status of Technology
In 2016, inter-satellite data transmission between two LEO satellites was approved. Every satellite was equipped with a Laser Communication Terminal (LCT). When the two satellites are in visibility range, they start to transmit data at 5.6 Gbps over an 8,000 km distance. This success was a key milestone in free space optical communication. Finally, it is the confirmation that technology is ready, and it kicks off a myriad of innovations, ideas for applications, or just the empowering to take the next step.