05 September 2024

NEC Corporation has successfully developed and demonstrated a radio-over-fibre system with a 1-bit fibre transmission method making it possible to affordably build stable millimetre-wave communication networks for Beyond 5G/6G.

With this method, high-frequency analogue signals can be transmitted using an inexpensive electrical-to-optical converter for general-purpose digital communications, enabling the realisation of a compact distributed antenna unit at low cost.

As a result, a stable millimetre-wave communication environment can be inexpensively achieved in high-rise buildings, underground malls, factories, railways, indoor facilities, and other obstacle-laden environments.

High-speed wireless communications leveraging millimetre-wave technology are expected to be a key technology for Beyond 5G/6G. Moreover, since 80% of mobile communication traffic occurs indoors, millimetre-wave is being considered as an indoor solution.

However, since there is significant propagation loss and high linearity in the millimeter-wave frequency band, it is imperative to ensure line of sight between base stations and terminals to achieve sufficient quality of service (QoS). While dense installation of distributed antenna units (DA) for direct transmission and reception of data with terminals and avoiding obstacles is known to be effective in resolving these issues, the size, power consumption, and cost of installing the required number of DA have proven to be major issues.

To overcome these issues, NEC developed a radio-over-fiber system (RoF) and a related transmission method which enables inexpensively building stable millimetre-wave communication networks in high-rise buildings, underground malls, factories, railways, indoor facilities, and other obstacle-laden environments. It will therefore promote the uptake of high-speed and large-capacity communications using millimetre waves for Beyond 5G/6G.