mmWave: Enabling 10-Gigabit Backhaul for Superior Network Performance

With the rapid advancements in communication technologies, the demand for data, faster internet speed, and reliable service is growing, especially in popular attractions, business districts, transportation systems, and large-scale event venues. The current network infrastructure is facing considerable challenges in maintaining its performance.

Millimeter wave (mmWave) technology offers a key solution for future high-density communication scenarios and varied service requirements. Specifically, it enables "10-gigabit backhaul"—the transmission of substantial data from end devices to the core network—thanks to its abundant bandwidth resources and outstanding data transmission rates. These features complement the current 5G spectrum, reduce network congestion in densely populated places, and enhance overall efficiency and service quality, providing customers with a smoother and faster internet experience.

How mmWave Empowers 10-Gigabit Backhaul

The extensive frequency resources and substantial bandwidth capacity of mmWave position it as a fundamental technology for achieving 5G's "10-gigabit speed." Compared to conventional sub-6 GHz bands, mmWave provides significantly more spectrum (Fig. 1). For example, by using continuous 800 MHz spectrum in the 26 GHz band, along with multi-carrier aggregation technology, mmWave provides highly efficient data transmission. According to 3GPP specifications, utilizing advanced antenna design and radio-frequency processing, a single mmWave device can achieve peak throughput of over 7 Gbps.

In September 2024, ZTE partnered with China Unicom and Qualcomm to conduct a high- and low-frequency new radio-dual connectivity (NR-DC) speed test on smartphones, attaining a peak downlink rate of 9.3 Gbps on a single device and a cell-level peak capacity surpassing 30 Gbps. This accomplishment established a new benchmark for ultra-high-speed network performance.

 With its high frequency and short wavelength properties, mmWave is highly compatible with beamforming technology. Beamforming enhances signal strength in targeted directions while reducing interference in non-targeted regions, making mmWave systems ideal for implementation in high-density areas, such as popular attractions, central business districts (CBDs), stadiums, and metro lines.

Currently, ZTE's mmWave AAU equipment comprises 1,536 antenna elements, and can be further scaled for greater beamforming gain. This technology significantly enhances both uplink and downlink performance.

10-Gigabit Backhaul Scenarios and Use Cases

In high-traffic hotspots, heavy user data traffic during peak hours put considerable pressure on network resources. Implementing 5G mmWave in these areas with its “10-gigabit backhaul” capabilities enables accurate data offloading and reduces network congestion. Outdoor hotspot areas include public squares, stadiums, and main avenues, while indoor hotspots consist of transportation hubs, business buildings, and shopping malls.

Empowering Metro Systems with Faster Internet and Smart Operations

In major cities like Beijing, Shanghai, and Guangzhou, metros account for about 70% of public transportation usage. For instance, the metro lines in Shanghai span approximately 936.17 km, serving around 13 million passengers daily. Passengers require stable, high-speed internet access during their average 40-minute commutes for social interaction and entertainment. However, while outdoor 5G coverage exceeds 95%, metro systems remain less connected, with only 20% coverage. A key limitation is the existing cables that support frequencies between 800 MHz and 2.3 GHz, while 5G requires higher bands like 2.6 GHz and 3.5 GHz. Additionally, space constraints in tunnels, power supply limitations, and the need to upgrade existing infrastructure further slow down deployment.

ZTE has introduced the "Smart 5G-Powered Metro" solution to address these challenges: mmWave AAUs are installed in tunnels for 10-gigabit backhaul, and a complete 5G micro-station (QCell) system is deployed on each train. This solution meets passenger internet demands and supports the digital and intelligent transformation of metro system.

• In the tunnel: mmWave 10-gigabit backhaul. mmWave provides up to 15 Gbps in downlink backhaul, supporting seamless HD video streaming for over 1,800 passengers simultaneously. The integration of beamforming significantly decreases the need for AAU output power within the tunnel, hence reducing total energy usage. In the Shanghai Metro Line 4 project, the total power consumption of 5G system was reduced by 78%, saving 3.7 million kWh of electricity annually.

• Inside train carriages: 5G QCell for enhanced passenger experience. The 5G Qcell system aboard the train minimizes spatial limitations, where installing new 5G cables in tunnels is restricted or unfeasible, while also resolving signal loss problems induced by the train's metal body and Doppler shifts from high-speed travel. The maximum per-user throughput in the carriage can increase from 600 Mbps to 2.1 Gbps.

Supporting a 100,000-Person Music Festival  

Thailand's "Big Mountain Music Festival" is a popular music event in Southeast Asia, drawing over 100,000 visitors annually. As attendance grew, network connectivity issues—particularly during peak periods—became more evident, resulting in network congestion and reduced audience satisfaction. To enhance network quality and customer satisfaction, mmWave sites were deployed at a 1.5 km line-of-sight (LoS) from the festival grounds, achieving a cell-level peak rate of 22 Gbps and offering ultra-fast, low-latency connectivity throughout the event.

During the festival, the backhaul site accommodated over 3,600 concurrent users at peak times, generating total data traffic of nearly 2,400 GB. Participants could share images and videos on social media at any time. Social media engagement surged by 300%, and audience satisfaction with network performance far exceeded that that of previous years.

mmWave technology is ushering in a new age of communications, offering substantial benefits in crowded attractions, commercial zones, metro transit systems, as well as for live streaming and virtual reality applications. As technology advances, mmWave will facilitate the development of a more intelligent and efficient society, providing unparalleled connectivity for users.