What is a radio link?

A radio link is a wireless connection (also called wireless Point-to-Point connection) between two nodes, or radio units, in a data network.

Each radio unit consists of a transceiver (a device that can both send and receive communication) and a highly directive antenna. This means that the antenna only (>99%) emits or receives power in the direction it is pointing. The two radio units are therefore mounted so that they are directed towards each other with no obstacles, such as buildings, in between them that can hinder or disturb the transmission. As the connection is very directive it enables very high signal to noise ratio and thereby high data rates.

Radio links are quick to deploy as they do not require any physical cable to be layed down in the ground. This makes it in many cases a more cost-efficient solution than fiber.

Depending on frequency, the maxium communication range varies between a few meters to hundreds of kilometers. The primary downside is that radio links require direct so called line-of-sight for optimum performance. Compared to fiber the connection is less stable as bad weather can interrupt the connection, in particular at higher frequencies. By proper system design this can be mitigated and most radio links have an availability of over 99.999% (i.e. a downtime of less than 55 min per year).

Most radio links for telecommunication operate at microwave frequencies in the range of 6 – 23 GHz. However, capacity increases with frequency. Links operating in the traditional frequency bands are capable of delivering up to 500 Mbit/s while at millimeter wave (e.g. in the E-band) capacities beyond 10 Gbit/s are possible.