Impact of 6 GHz Band on Wireless Technology

The 6 GHz band has been opened for unlicensed use in the United States, creating new opportunities for wireless technology, particularly with Wi-Fi 6E. This change allows multiple devices to connect without a specific license, which can lead to much better performance. However, there are concerns about how these new technologies will affect existing services that use this frequency, such as fixed microwave links and other incumbent services.

#Background on 6 GHz Use

In 2020, the Federal Communications Commission (FCC) set rules for using the 6 GHz band for unlicensed wireless devices. This was primarily to address the growing demand for wireless bandwidth due to more devices and applications online. Most of the existing usage of wireless spectrum comes from Wi-Fi, which accounts for about 60% of wireless traffic. By making the 6 GHz band available, the FCC aims to ease congestion in the already crowded 2.4 GHz and 5 GHz bands.

The 6 GHz band is divided into four segments, known as U-NII bands. The rules for using this band include two main types: Low Power Indoor (LPI) and Standard Power (SP). LPI devices can operate indoors without needing a control system, while SP devices can operate anywhere but must use a control system to avoid interfering with existing services.

#The Importance of Real-World Measurements

As more Wi-Fi 6E access points (APs) are deployed, understanding their real-world impact on existing users becomes crucial. Most of the research has focused on theoretical models and simulations, resulting in gaps in knowledge regarding actual Interference risks. To fill this gap, extensive real-world measurements were conducted at the University of Michigan, where there is a large deployment of Wi-Fi 6E APs.

#Extensive Measurement Campaign

The measurement campaign was comprehensive and looked at various scenarios to assess the interference potential from a dense indoor Wi-Fi 6E network. This involved monitoring conditions while walking, driving, and even using drones to gather data on received Signal Strength, how buildings block signals, and overall channel usage.

#Outdoor Signal Strength

The team measured the signal strength from various access points and found that the median signal strength outdoors ranged from -75 dBm to -85 dBm. They also noted significant building entry loss when signals passed through windows, especially double-pane low-emission ones, which created a loss of around 12 dB to 16 dB.

Despite having many Wi-Fi 6E APs deployed indoors, only a small percentage of their signals were detected outside. This indicates that the interference risk to fixed links from these indoor deployments is relatively low.

#Use of Drones

Drones played a critical role in this measurement campaign. By flying at different altitudes near buildings, the team could capture how signals varied with height. The results showed that the higher the drone flew, the weaker the signal received, which further indicates reduced interference potential for outdoor fixed links.

#Results and Analysis

The overall findings from this research indicate that while there are many indoor access points, the actual risk of interference to outdoor services is lower than expected. Many signals do not make it outside due to building materials and design. Furthermore, the limited number of signals observed outdoors suggests that the crowded indoor environment is less likely to impact outdoor services significantly.

#Implications for Future Technologies

The findings have important implications for future developments in wireless technology, especially with features like client-to-client (C2C) communication. This feature could allow devices to communicate directly, bypassing the need for data to go through an access point. However, establishing the right threshold for enabling signals is vital to ensure that it doesn’t lead to unintended interference between outdoor devices.

#Challenges and Future Research

While the findings are promising, there are still challenges ahead. More extensive research is needed to confirm these results and establish the best practices for future Wi-Fi deployments. In particular, understanding how to balance increased use of the 6 GHz band while protecting existing users will be crucial.

Future studies might consider working closely with operators of fixed links, to gather more detailed data on how new wireless technologies might affect their operations. Also, continuous monitoring as more devices come online will be necessary to adapt regulations and practices as needed.

#Conclusion

The shift to using the 6 GHz band for unlicensed wireless usage opens exciting possibilities for the future of Wi-Fi and other wireless technologies. The extensive measurement campaign at the University of Michigan has provided valuable insights into the real-world impacts of deploying numerous Wi-Fi 6E access points indoors. The results show that while interference potential exists, it is currently low.

Future efforts should focus on fine-tuning these technologies to ensure they coexist harmoniously with existing services, ultimately leading to improved wireless performance for everyone.