Richtfunk

Richtfunk (directional radio) is a fixed wireless communication technology that uses highly directional microwave or millimeter-wave links to connect geographic locations over distance. It typically provides point-to-point backhaul for networks and is used to bridge telecom networks, corporate networks, or mobile base stations where fiber is unavailable or expensive.

In operation, two fixed sites carry transmitting and receiving equipment connected to data networks. A parabolic dish or other narrow-beam antenna is aimed precisely toward the opposite station to form a line-of-sight link. The system uses microwave frequencies, commonly in licensed bands such as around 6 GHz, 11/13 GHz, 18 GHz, 23 GHz, and sometimes 28 or 60 GHz. Data rates can range from a few Mbps up to multiple Gbps with modern equipment; modulation and channel bonding allow scalable capacity.

Deployment requires line of sight, clearance from obstructions, site surveying, and careful alignment. Weather effects, notably rain fade at higher frequencies, can reduce reliability and throughput.

Licensing and spectrum management vary by country; most Richtfunk links operate in licensed bands, though some unlicensed or lightly licensed options exist in certain regions. Systems include outdoor radio equipment, mounting structures, and sometimes backup power.

Advantages include high capacity, relatively quick deployment, and independence from fiber for last-mile backhaul. Limitations include sensitivity to weather, need for towers or elevated sites, potential line-of-sight maintenance, and regulatory constraints.

Historically developed in the mid-20th century, Richtfunk remains a common solution for telecom backhaul and private networks, often serving as a complement to fiber communications, especially in challenging terrains or interim deployments.