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Microwave Backhaul Is Becoming Smarter, Denser and More Efficient

Fibre is usually presented as the preferred transport technology for mobile networks, particularly as operators introduce 5G Standalone and prepare for 5G-Advanced. In practice, however, fibre cannot economically or quickly reach every site.

Microwave transmission therefore remains an important part of mobile backhaul. It is especially relevant in rural and suburban areas, difficult terrain, temporary deployments and locations where operators need additional resilience alongside fibre.

Huawei’s 2025 Microwave Industry White Paper argues that microwave is evolving beyond its traditional role as a straightforward point-to-point connection. Future microwave networks will need to provide more capacity, operate reliably in challenging conditions, use spectrum more efficiently, simplify crowded sites and make greater use of AI-based automation. 

Microwave and fibre are complementary

The discussion around mobile transport is sometimes framed as a choice between fibre and microwave. In reality, most operators use a combination of both.

Fibre offers very high capacity and is generally well suited to dense urban networks and major aggregation sites. However, laying fibre can be expensive, time-consuming or impractical. Construction permissions, road closures, difficult terrain and long distances can all delay deployment.

Microwave can be installed more quickly and may offer a significantly lower deployment cost in locations where fibre infrastructure is not already available. It can also provide an independent backup path when a fibre connection is damaged.

Huawei describes this as microwave-fibre synergy. Fibre can be used in areas where it is economically and operationally practical, while microwave extends connectivity to sites that would otherwise be difficult to reach. Microwave can also form part of a ring or resilient transport architecture rather than serving only as a temporary replacement for fibre.

This role becomes particularly important as operators expand coverage into rural areas. The final few kilometres of a fibre deployment can be disproportionately expensive, especially when only a small number of sites or users are served.

Backhaul capacity requirements continue to increase

Mobile backhaul demand is being driven by several changes taking place at the same time.

Operators are adding more spectrum, deploying wider radio channels and introducing higher-capacity radio configurations. More sites are being upgraded with multiple bands, while 5G and 5G-Advanced are increasing both peak throughput and sustained traffic levels.

The white paper also highlights the growth of fixed wireless access. A mobile site serving home broadband customers can experience traffic patterns that are different from those of a traditional smartphone-focused network. Data consumption may be higher and concentrated for longer periods, increasing pressure on the backhaul connection.

Microwave systems therefore need to evolve from links designed around relatively predictable traffic to transport infrastructure that can accommodate significant capacity growth.

Increasing capacity is not simply a matter of allocating more spectrum. Spectrum is limited, particularly in heavily used bands, and operators may not always have access to wider channels. Vendors are consequently developing techniques that extract more capacity from the spectrum already available.

Spectrum efficiency is becoming the key differentiator

The white paper identifies spectrum efficiency as one of the most important areas of microwave development.

One approach is the continued use of higher-order modulation. More information can be transmitted within the same bandwidth when radio conditions are good enough to support it. Adaptive modulation can then reduce the modulation level when conditions deteriorate, helping the link maintain availability.

MIMO is another important technique. By using multiple spatial paths, a microwave system can transmit more than one data stream over the same frequency channel. This can significantly increase capacity without requiring a proportional increase in spectrum.

Full-duplex techniques are also being explored. Conventional frequency-division duplex microwave systems use separate frequencies for the two transmission directions. A full-duplex system aims to transmit and receive simultaneously using the same spectrum, although this requires extremely effective interference cancellation.

The practical challenge is that microwave links do not operate in isolation. Dense networks can contain many neighbouring paths, particularly around aggregation and hub sites. Increasing capacity on one link may create additional interference for another.

Interference management, cross-polarisation interference cancellation and coordinated spectrum reuse will therefore become increasingly important. The objective is not only to improve the efficiency of an individual link, but to increase the total capacity of the wider microwave network.

E-band will play a larger role

Traditional microwave bands provide a useful balance between capacity, link distance and availability. However, the amount of spectrum available in these bands is limited.

E-band, covering frequencies around 70 and 80 GHz, offers much wider channels and can provide fibre-like capacity over suitable distances. It is already being used for high-capacity urban links and short-range backhaul.

The limitation is propagation. Higher-frequency links are more affected by rainfall and atmospheric conditions, reducing the distance over which very high availability can be maintained.

This makes multiband configurations attractive. A high-capacity E-band link can be combined with a lower-frequency microwave link. Under normal conditions, both contribute to the available capacity. During heavy rain, the lower-frequency connection can continue carrying essential traffic even if the E-band capacity is temporarily reduced.

Such combinations allow operators to balance capacity and resilience rather than treating each microwave band as a separate solution.

All-weather performance remains essential

Microwave systems operate outdoors and must cope with rain, wind, temperature changes, ice, dust and other environmental conditions.

The Huawei white paper discusses developments in antenna design, materials and signal processing intended to maintain stable performance under challenging conditions. These include improved antenna surfaces and protective materials designed to reduce the accumulation of water, snow or contaminants.

Adaptive modulation and power control also remain important. A link can adjust its transmission parameters as conditions change, protecting availability while using higher-capacity modes whenever the radio environment allows.

For operators, the important measure is not simply the maximum speed achieved under ideal conditions. A backhaul link must provide predictable performance throughout the year and maintain essential services during periods of poor weather.

Hub sites need to become simpler

Capacity is only one part of the microwave challenge. Physical infrastructure is becoming increasingly difficult to manage.

Major hub sites may contain numerous microwave antennas, radio units, cables and mounting structures. Several operators may share the same tower, while each operator may also require links in multiple directions.

This creates several problems. Tower space and loading capacity are limited, installation becomes more complicated, and additional equipment can increase both capital and operating costs.

Huawei expects antenna sharing and point-to-multipoint architectures to play a greater role in simplifying these sites.

Antenna sharing can allow multiple links or transmission directions to use a smaller number of physical antenna systems. Point-to-multipoint solutions can serve several remote sites from a common hub rather than requiring a separate point-to-point antenna for every connection.

These architectures will not be suitable for every deployment. Point-to-point links continue to offer dedicated capacity and predictable performance. However, more flexible sharing options could reduce equipment requirements at particularly congested sites.

Simplification is therefore not only about reducing hardware. It can also reduce tower rental, installation effort, maintenance requirements and the time needed to add new links.

AI is moving into microwave operations

Microwave networks have traditionally been planned and managed using engineering rules, performance counters, alarms and periodic optimisation.

The white paper describes a future in which AI assists with network planning, operations and maintenance.

One potential application is traffic prediction. Historical traffic patterns can be combined with expected growth to identify links that are likely to require additional capacity. This could allow operators to upgrade connections before congestion begins to affect customer experience.

AI can also support fault diagnosis. Instead of presenting engineers with a large number of individual alarms, an intelligent operations system could correlate events across links and sites, identify the most likely root cause and recommend corrective actions.

Other possibilities include interference analysis, capacity optimisation and automated adjustment of network parameters.

Large language models may eventually provide engineers with a more natural way to interact with operational systems. An engineer could ask about a performance problem or request an explanation of unusual link behaviour, with the system retrieving relevant counters, alarms and configuration data.

These capabilities will depend on data quality. AI cannot compensate for incomplete inventories, inconsistent performance measurements or poorly labelled alarms. Microwave automation will therefore require operators to improve the way network data is collected and structured.

Power saving is also becoming more important

Transport networks contribute to the overall energy consumption of a mobile network, even though radio access equipment normally accounts for the largest share.

The white paper describes power-saving mechanisms at device, link and network levels. These include reducing power consumption during periods of low traffic, adjusting transmission parameters and placing selected components into lower-power states.

Traffic-aware power management is particularly relevant. Backhaul links are usually dimensioned for busy-hour demand, but traffic can fall significantly overnight or during quieter periods.

A system that understands these patterns may be able to reduce energy use without compromising availability or service quality. However, operators will need to ensure that power-saving features can respond quickly when traffic increases and do not introduce excessive delay or instability.

The wider objective is to manage microwave capacity dynamically rather than operating every component at maximum power regardless of demand.

Spectrum policy must keep pace with technology

Many of the proposed capacity improvements depend on spectrum regulation.

Operators need access to appropriate bands, sufficiently wide channels and licensing arrangements that support efficient deployment. Regulators must also consider how new technologies such as full duplex, multiband operation, advanced MIMO and point-to-multipoint systems fit within existing frameworks.

Some spectrum rules were created around traditional fixed point-to-point links. As microwave systems become more flexible, these rules may need to be updated.

The white paper calls for closer cooperation between regulators, standards organisations, operators and equipment suppliers. This will be necessary to ensure that technical innovation can be introduced without creating harmful interference or disadvantaging existing users.

Microwave remains an evolving technology

The expansion of fibre does not mean microwave is becoming obsolete.

Instead, microwave is being pushed into a more demanding role. It must support higher traffic levels, integrate with fibre, operate across multiple frequency bands, use spectrum more efficiently and fit onto increasingly crowded sites.

At the same time, operators expect lower energy consumption, easier maintenance and more automated operations.

Not every technology discussed in Huawei’s white paper will be deployed widely or immediately. Full-duplex microwave, advanced antenna sharing and AI-led autonomous operations will require further development, standardisation and operational experience.

Nevertheless, the overall direction is clear. Microwave backhaul is moving from fixed-capacity radio links towards more adaptive, software-driven transport networks.

For operators extending 5G and preparing for 5G-Advanced, microwave will remain an important part of the connectivity toolkit, particularly wherever fibre alone cannot provide the required combination of cost, speed, resilience and coverage.

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