Millimeter wave refers to electromagnetic waves with frequencies between 30GHz and 300GHz. Its wavelength is extremely short, ranging from 1mm to 10mm, and it possesses extremely high bandwidth resources, capable of supporting data transmission rates of several Gbps per second or even higher. This characteristic makes it one of the core supporting technologies for 5G to achieve its goals of ultra-high speeds, low latency, and massive connectivity. As a key breakthrough in modern communications, millimeter wave technology has profoundly impacted the evolution of 5G networks and the popularization of fixed wireless access (FWA) services.
FWA (Fixed Wireless Access) technology uses wireless communication networks to provide fixed broadband access services to homes or businesses. Simply put, it replaces traditional fiber optic or cable networks with wireless technology, transforming the "last mile" of internet connectivity from "wired" to "wireless," enabling high-speed internet access. In rural and remote areas, where complex geographical conditions, dispersed populations, and the high cost of laying fiber optic cables are paramount, FWA is a highly cost-effective solution. The high bandwidth of millimeter waves enables FWA to provide stable gigabit-class internet speeds, meeting the bandwidth-demanding needs of high-definition video, cloud gaming, and remote work, truly replacing wired networks with wireless.
In practical applications, millimeter wave FWA has been extensively implemented in many countries and regions. In China, telecom operators are also piloting 5G millimeter wave FWA in selected rural areas, combining it with sub-6GHz networks to achieve a balance between wide coverage and high speeds. These practices not only validate the feasibility of the technology but also demonstrate its enormous potential in narrowing the urban-rural digital divide and promoting rural revitalization. Farmers can use high-speed networks for live streaming, smart agricultural monitoring, remote education, and healthcare, significantly improving production efficiency and quality of life.
However, the most prominent issue with millimeter wave applications in 5G and FWA is its limited propagation characteristics: millimeter wave signals have a short wavelength and weak penetration, making them easily obscured by buildings, trees, rain, fog, and even people, resulting in a limited coverage range of only a few hundred meters. This requires the use of ultra-dense networking (UDN) and the deployment of a large number of micro base stations, increasing construction and operation and maintenance costs. Furthermore, power consumption and heat dissipation issues are prominent in terminal devices, especially in scenarios where outdoor CPE operates for extended periods of time, where stability still needs to be optimized. Furthermore, global standardization of millimeter-wave frequency bands has yet to be fully unified, and spectrum strategies adopted by different countries and regions vary, hindering the versatility and scalability of equipment.
To address these challenges, the industry is implementing various technical optimizations. Beamforming and Massive MIMO technologies are widely used, enhancing coverage range and interference mitigation by focusing signals in a targeted manner. Intelligent Reflecting Surfaces (RIS), relay technologies, and multi-connectivity solutions are also under research to improve signal penetration and network resilience. Simultaneously, chip manufacturers are continuously advancing the integration and cost-effectiveness of millimeter-wave RF front-ends, driving CPE devices towards miniaturization and low power consumption.
In the future, millimeter-wave technology will continue to play a key role in the evolution to 5G Advanced (5.5G) and 6G. With the introduction of AI algorithms, networks will possess more intelligent beam management and resource scheduling capabilities, further enhancing the practicality and cost-effectiveness of millimeter-wave technology. In FWA scenarios, millimeter wave is expected to deeply integrate with technologies such as Sub-6 GHz and Wi-Fi 6/7, building a multi-layered, coordinated wireless access network that delivers seamless coverage and an ultimate user experience. It is foreseeable that millimeter wave will not only be an accelerator for 5G speed increases, but also a key engine driving FWA mainstream and achieving universal digital access.