Microwave technology Full-duplex transmission with 10 GBit/s uplink and downlink

Nokia has demonstrated a full-duplex transmission in the D-band, in which 10 Gbit/s were transmitted in the uplink and downlink via one channel. The advantages of this and what is behind the technology.

The limited radio frequency spectrum is increasingly becoming a problem for mobile phone users and network operators. A limited number of frequency bands for wireless communication such as mobile telephony, WLAN and satellite communication is increasingly leading to congestion and competition for available frequencies. In addition, there is an increasing demand for capacity and the growing number of devices and technologies that rely on wireless communication.

Advances in microwave transmission technology can ease the burden. This is because microwaves are often used for connections between mobile radio stations and the core network (backhaul) as well as between the antennas of a mobile radio cell and the baseband unit, which is responsible for signal processing (fronthaul). Especially when alternatives such as fiber optics are not available.

World's first complete wireless duplex transmission

Progress has been made in microwave transport technology: Nokia has realized the world's first wireless full-duplex transmission. It enables data to be transmitted simultaneously in both directions via the same connection. Sending and receiving take place at the same time and via the same channel, without delays or interference. The advantages of full-duplex transmission:

• Simultaneous bidirectional communication means that the entire bandwidth is used more effectively.

• No additional time for switching between transmit and receive mode results in less delay and therefore less latency.

• Particularly advantageous for real-time applications such as voice and video transmissions.

Operators around the world are striving for greater spectrum efficiency in their networks. Network equipment suppliers such as Nokia are therefore researching technologies that go beyond traditional systems that use separate frequencies for transmission and reception. One approach is to use Line of Sight MIMO. Higher capacity is achieved using multi-antenna technology. However, Nokia is taking a different approach.

Nokia has demonstrated the world's first wireless full-duplex transmission for fixed point-to-point connections in the D-band at frequencies from 130 to 175 GHz. The simultaneous transmission and reception of signals over a single channel effectively doubles the capacity of a conventional system. The technicians demonstrated a capacity of 10+10 GBit/s. Specifically, this was 10 GBit/s in the uplink and 10 GBit/s in the downlink via a 2 GHz channel. This works both for the connections between mobile radio stations and the core network (backhaul) and between the antennas of a mobile radio cell and the baseband unit that handles the signal processing (fronthaul).

A new standard for growing capacity requirements

Full-duplex technology not only increases spectrum efficiency by 100 percent compared to current systems, but also offers other obvious advantages for network operators:

• Increase energy efficiency by up to 100 percent,

• up to 50 percent less hardware and

• Simpler design, as full-duplex systems only require a single component for all applications.

For mobile users, this in turn means more reliable and faster services that can support the next generation of wireless applications. Full duplex technology has significant advantages over Line of Sight MIMO. The latter technique uses multiple antennas to transmit signals directly over multiple lines of sight, which is particularly useful in busy or wide-area environments.

For temporary 5G networks at major events

Full-duplex technology can help to set up temporary 5G networks for events such as festivals, sporting events or conferences more efficiently and quickly. A complex fiber optic connection is not necessary. The technology makes it possible to use wireless connections more efficiently. Thanks to the increased efficiency and capacity, high network quality is possible, even when many users are online at the same time. Finally, the technology stabilizes wireless connections between the various components of a temporary network, making it easier to set up high-performance networks with less physical effort. (heh)