Wi-Fi’s Continuing Evolution: 6GHz Band and AFC

OCTOBER, 2022


Wi-Fi in 6GHz Band


With more than 15 billion devices compatible with Wi-Fi technology, Wi-Fi has proven to be one of the successful technologies over the past 2 decades. The availability of Wi-Fi is accessible almost everywhere and the need for high-speed connectivity is growing. The sixth generation of Wi-Fi, known as Wi-Fi 6, can support up to 9.6 Gbps transmission speed and 160 MHz wide channels to provide more bandwidth, so even more high-speed devices and applications can be used simultaneously. However, as applications such as cloud media streaming services and IoT devices are placing increasing demands on bandwidth, signal stability and performance, Wi-Fi congestion is becoming a serious problem. In order to continue to support low-latency, high-bandwidth applications, Wi-Fi 6E, an extension of the current Wi-Fi 6 standard, was introduced. Wi-Fi 6E not only includes all the features in Wi-Fi 6 like OFDMA, WPA3, and Target Wake Time (TWT) but also offers open more capacity by supporting the 6 GHz band, which allows more wide channels, and less interference from microwaves, etc. With new features introduced in Wi-Fi 6E, companies can easily support multi-gigabit speeds applications.


Traditionally, Wi-Fi uses two bands: 2.4 GHz and 5 GHz. Since the majority of devices are connected via these two bands, users often experience congestion. On the other hand, Wi-Fi 6E provides newly-available unlicensed radio spectrum in the 6 GHz band with 7 extra 160 MHz channels. The main advantage of 6Ghz should not be how fast data can be delivered; rather, this new band quadruples the total frequency space available for Wi-Fi use. Even though 5 GHz Wi-Fi speed can reach a theoretical top speed at 9.6 Gbps, limited spectrum with millions of devices connected will cause them to all be competing with each other. 6 GHz Wi-Fi operates from 5925 MHz to 7125 MHz range covering total of 1200 MHz bandwidth and offers 14 new 80 MHz and 7 new 160 MHz channels which drastically increase the available channels and minimizes congestions.


While 6 GHz can bring low latency and high throughput, there are certain rules of operation in this unlicensed band. Access points (APs) and clients (phone, computer, etc.) need to follow power level limits in order to avoid potential interference with existing 6 GHz incumbents like fixed satellites, fixed microwave services, broadcast auxiliary services and cable TV relay services. Thus, there are new rules created by regulators to govern the 6 GHz band: standard power APs and low power indoor (LPI) APs. First of all, standard power APs will primarily be used to support outdoor communications within the part of 6 GHz, specifically U-NII-5 and U-NII-7 bands. The maximum EIRP for standard power AP is 36 dBm which can support greater distances.


Automated Frequency Coordination (AFC)


Since 6 GHz Wi-Fi may interfering with incumbent fixed services, standard power AP must consult a database to ensure non-interference using automatic frequency coordination (AFC) systems. AFC systems is a geolocation database that controls real-time frequency assignments to protect established incumbent operations from RF interference. During installation, standard power APs will communicate with AFCs to obtain a list of prohibited frequencies on which they cannot transmit and through the geolocation provided by the standard power AP, it can identify nearby incumbent 6 GHz operations and check for possible interference. When interference with incumbent activities is predicted, the AP’s operations will be limited or not allowed.​


Alternatively, the FCC has authorized indoor APs to fully use the entire 6 GHz band. Compared with standard-power APs, the maximum EIRP allowed in low power indoor AP is 30 dBm and clients’ connection is limited to EIRP 24 dBm. Additionally, low power indoor AP requires integrated antennas such that users cannot replace them with higher gain antennas which may cause unexpected interference with existing 6 GHz operations. Indoor APs should contain “Indoor Only” label and cannot have a weatherized enclosure to avoid end users placing the AP outside.


To facilitate the standard-power APs requirement of checking with AFC systems, numerous large organizations like Cisco, Broadcom, Google, Meta, etc. are bidding to the FCC to become AFC operators as there are huge potential business opportunities to run the AFC system. Furthermore, there are variety of protocols being worked on by these companies which may impact device hardware manufacturing. On top of the uncertainties of AFC plans, telecommunications analysis Dell’Oro Group pointed out that hardware like integrated circuits for Wi-Fi has experienced shortages in 2021~2022 which impacted Wi-Fi 6E availability and adoption. While there are still products like Google Pixel 6 Pro and Samsung Galaxy S22 Ultra that support Wi-Fi 6E, as do some high-end enterprise grade Access Points, the level of availability is still very limited and costly. As a result, Wi-Fi 6E may end up having a very limited lifespan.

Should I wait for Wi-Fi 7?


The low demand for Wi-Fi 6E is expected to persist due to the limited device support, especially when the iPhone 14 series launched recently in September 2022 also forgoes 6E support. Additionally, major Wi-Fi chipset vendors like Broadcom, Qualcomm, Mediatek and Intel have announced Wi-Fi 7 solutions and major brands are expected to make product announcements at the coming Consumer Electronics Show (CES) in January 2023.


“Wi-Fi 7 is going to be the big upgrade,” Dell’Oro said. If supply constraints ease in next year and new generation of Wi-Fi is available, Wi-Fi 6E might end up being ignore and left out. Since Wi-Fi 7 is upcoming next near, in the next article, we will be discussing the new powerful, revolutionary wireless fidelity – Wi-Fi 7.