Industry Specification Group (ISG) on Millimetre Wave Transmission (mWT)

Chair: Renato Lombardi, Huawei Technologies (UK)

Facilitating the use of microwave and millimetre-wave spectrum bands for large volume backhaul and fronthaul applications to support mobile network implementation, wireless local loop and other services that benefit from high speed wireless transmission.

Widescale deployment of 4G/5G, and the number of connections required for massive machine-type communications in the Internet of Things, are making unprecedented demands on radio access networks and backhauling.

Spectrum in the 30 - 300 GHz range offers enormous amounts of under-utilized bandwidth, providing more spectrum for radio transmission than lower bands with a wider channel bandwidth and fibre-like capacity. These frequencies are a major enabler for the evolution of mobile communications, including 5G and machine-type communications on a massive scale in the IoT that will make unprecedented demands on radio access networks and backhauling.

Our Industry Specification Group on millimetre Wave Transmission (ISG mWT) provides a platform for stakeholders in the microwave and millimetre-wave value chain to exchange technical information, increasing the awareness and confidence of operators worldwide in the use of microwave and millimetre-waves.

The increase in capacity needed for 5G backhaul, and the importance of microwave/millimetre wave as a backhaul medium, demand innovative ways to harness the use of spectrum for fixed services. As mobile networks evolve from 4G to 5G, a key challenge is providing increased capacity, with a consequent need for more spectrum and its more efficient use. Our work in ISG mWT therefore aims to remove bottlenecks in releasing new spectrum, and to change spectrum licensing rules to make microwave and millimetre-wave wireless backhaul practical in the medium/long term for 5G operators.

In parallel, the group continues to explore how current mWT technology and its evolution can satisfy future applications – such as 5G and Fixed Wireless Access in the timeframe beyond 2020. This considers new mobile and fixed access requirements in terms of topologies, data rates, latency and range.

In 2020 ISG mWT published a Group Report GR mWT 019, detailing the metrics and necessary equipment implementation to describe error performance related aspects in radio equipment used for fixed services.

Relating to SDN, a Group Report [published in 2021 as GR mWT 025 aims to improve network and services automation through a detailed description of use cases under a ‘close-to-implementation’ approach for wireless backhaul networks with the analysis focused on functionalities related to network and services automation of a variety of YANG data models to be implemented on a dedicated SDN southbound interface.

Work also neared completion on a further Group Report examining fixed service RF frequency ranges above 174.8 GHz. This report addresses the current status of standardization activities and regulatory framework; it also tracks potential applications, expected industry trends and activities.

Two new Work Items were launched during the year, addressing the modernization of microwave and millimetre-wave backhaul to better fit 5G deployments. The first WI targets aims to produce a Group Report analyzing the introduction of innovative antenna technology in millimetre wave radio links. The second defines a new way of evaluating backhaul performance, defining new KPIs with a geographical or hub approach taking into account the evolution of transport services.

Conducted remotely due to Covid-19 restrictions, ETSI’s second and third mWT SDN (Software Defined Network) Plugtests™ events focused on the benefits of using a standard Northbound Interface (NBI) to minimize interoperability issues and simplify multi-vendor/multi-technology operation. Achieving a 92% success rate across all test executions, the events attracted participation from seven vendors and four Tier-1 operators, representing a majority share of the market. The success of these Plugtests events drove progress on other SDN related topics (NBI profile and network services automation).

Notwithstanding the challenges of the pandemic, during 2020 ISG mWT attended several conferences aiming at advancing the Spectrum Agenda – a vital element in improving spectrum regulations and licensing to address 5G requirements and technology evolution.


  • Group Specification on definition of wireless transport profile for standard SDN northbound interfaces
  • Group Report (GR) on current status of standardization activities and regulatory framework - FS RF frequency ranges above 174.8 GHz
  • GR on mWT coexistence approach between FS and other services
  • GR on use of innovative antenna systems (integral and separated TX/RX antennas) in mWT and impact on standards and regulations
  • GR on KPIs for planning microwave and millimetre-wave backhaul network