Industry Specification Group (ISG) on Millimetre Wave Transmission (mWT) Activity Report 2023

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 traditional microwave (6-42 GHz) and millimetre-wave (50-300 GHz and above) ranges 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.

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

The group’s work 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 services in the timeframe beyond 2020. This considers new mobile and fixed access requirements in terms of topologies, data rates, latency and range.

ISG mWT publications continue to draw the attention of the global telecoms industry and are widely used as reference by other industry organizations and standardization bodies.

In 2023 ISG mWT published a revised version of Group Specification GS mWT 024 that defines a Wireless Transport Profile for Standard SDN Northbound Interfaces; this update includes E-LAN.

It was accompanied by the publication of a new Group Report GR mWT 028 that defines new KPIs for planning microwave and millimetre wave backhaul network. These KPIs consider the evolution of wireless backhaul, considering issues such as more challenging requirements from 5G deployments, new technologies aimed at more efficient interference mitigation and cancellation, the increasing use of spectrum in the millimetre-wave range, stand-alone and aggregated (BCA), and a different typology and mix of services being transported.

During the year several ISG mWT members contributed to ETSI White Paper #58 (published July 2023), titled ‘Worldwide analysis and proposals to promote and facilitate the wireless transport network as the key enabler for fast mobile backhaul network modernization’.

Work also commenced during the year on a multi-part Conformance Test Specification for Wireless Transport Profile for Standard SDN Northbound Interfaces. To be published as a Group Specification, it comprises:

  • Part 1: Implementation Conformance Statement (ICS)
  • Part 2: Test Suite Structure (TSS) and Test Purposes (TP)
  • Part 3: Abstract Test Suite (ATS) and partial Implementation eXtra Information for Testing (IXIT)

Meanwhile further progress has been made on three Group Reports, addressing:

  • Use of innovative antenna systems (integral and separated TX/RX antennas) within millimetre wave transmission, and impacts on standards and regulations
  • Propagation measurements and modelling for PP radio links in the E, W and D bands
  • Coexistence between FS and other services

During the year ISG mWT has maintained its regular liaison with ETSI ATTM TM4 on antenna and equipment, in particular for systems operating in the so-called D-Band frequency range (130-174,8 GHz) and W-band frequency range (92‑114,25 GHz).

The Group has also been liaising with ITU-R WP 3M on prediction methods for LOS MIMO microwave links.

Relevant activities within CEPT ECC (particularly WG SE, SE19, SE21, SE40), ITU‑R WP5C and GSMA continue to be monitored on an ongoing basis.

Held in February 2023, the fourth millimetre Wave Transmission (mWT) Software Defined Networking (SDN) Plugtests™ event took place at ETSI’s headquarters in Sophia Antipolis. Following previous mWT Plugtests events centred on a Northbound Interface (NBI) using the RESTCONF protocol, this fourth event looked at the Southbound Interface (SBI) using the NETCONF protocol. The event focused on demonstrating the ability of a Software Defined Network (SDN) to operate from an end-to-end service point of view, by controlling a chain of Millimetre Wave network devices. In the process, the aim was to establish a common set of parameters required to enable interoperability and end-to-end service management. Seven network equipment vendors participated, in addition to four network operator observers. A total of 397 tests were executed during the week-long event, with a success rate of 99.2% being observed.

See the full list of ISG mWT Work Items currently in development here.