The 6 GHz network: Bigger channels, stronger signal, faster data
The future of Wi-Fi looks extremely promising. The Federal Communications Commission made an order to allow a large range of spectrum, about 1,200 MHz in the 5.925 GHz to 7.125 GHz (6 GHz) band, for unlicensed use. The news of the additional spectrum provides a significant boost for Wi-Fi-based innovation, including augmented reality, virtual reality, the Internet of Things (IoT), and low-latency applications.
Although the majority of mobile data traffic is being carried on Wi-Fi today, there is only 80 MHz of spectrum in the 2.4 GHz band and 580 MHz in the 5 GHz band, a total of 660 MHz for unlicensed Wi-Fi purposes.
The effort to bring 6 GHz to Wi-Fi is backed by tech giants such as Facebook, Apple, Broadcom, Intel, the Wireless Internet Service Providers Association, and others. As a collective group, the members of the unlicensed spectrum community agree that opening the 6 GHz band for Wi-Fi will usher in a wave of innovation in new consumer experiences and revolutionize the economy.
Aruba Networks assembled in-depth research and documentation from its testing of viable unlicensed use of the 6 GHz band. Its research included identifying the coexistence of fixed satellite services and Wi-Fi, testing transmit power and received signal in the Sunnyvale, California, area, and submitting details of those efforts to the FCC to accelerate the rulemaking process.
The Wi-Fi Alliance has announced a new certification for the interoperability of 6 GHz-capable devices, called Wi-Fi 6E, an extension of Wi-Fi 6. Certification will be available early next year. As of today, there are no 6 GHz devices or access points available, but the market may begin to see traction in 2021.
Given that Wi-Fi is projected to grow into a $15.6 billion business and current resources are finite, new spectrum is required. The additional 1,200 MHz of spectrum provides a path to realizing the gigabit capabilities promised with 802.11ac in 2013. Today, 5 GHz does the heavy lifting, carrying about 60 to 80 percent of mobile data traffic. The strain is beginning to take its toll, however, meaning the industry needs to set its sights on the future of Wi-Fi and the use cases that will depend on it.
Is 6 GHz a solution aimed for laptops, computers, and devices or innovations in applications? All of the above. To fully utilize applications in the 6 GHz band, devices must be able to operate in the new frequency, which they currently cannot do.
What this means
Wi-Fi has seen explosive growth since 802.11n, which was more than 10 years ago, in addition to the growth of IoT devices over the past few years. More devices continue to operate in existing unlicensed frequencies without added frequency to meet the capacity and demand.
As a result, the 2.4 GHz band has seen a negative impact from non-wireless interference, making the band less desirable for Wi-Fi use. IoT devices, for the most part, have been kept on the 2.4 GHz band because of the low-cost hardware. IoT may occupy the 5 GHz band once 6 GHz becomes widely available.
In the 5 GHz band, the industry has been fortunate to have 24 non-overlapping channels (20 MHz wide). Later amendments to the wireless standard allowed channel bonding for higher throughput but at the cost of reduced non-overlapping channels. Many environments were not able to use 80 MHz-wide channels due to less channel reuse and neighboring Wi-Fi networks using the same frequencies. Reliable wireless networks have been limited to 20 MHz- or 40 MHz-channel widths.
These problems have been getting worse over time, as Wi-Fi usage has grown. And then the pandemic hit, and the amount of data on Wi-Fi networks skyrocketed, as applications related to e-learning, telemedicine, and telecommuting were rushed into service. The case for increasing wireless bandwidth and capacity has never been greater.
With 6 GHz on the horizon, everyone is eyeing the 1,200 MHz of spectrum. The shift toward additional channels provided by 6 GHz will allow more utilization of 40 MHz and 80 MHz channels. To get an idea of the potential benefits, compare 80 MHz channel width availability to 5 GHz. Currently, 5 GHz provides six non-overlapping 80 MHz channels. With 6 GHz, there is a 133 percent increase of channels to 14 non-overlapping channels. Wi-Fi 6 now provides 160 MHz-channel widths, to accommodate especially data-hungry applications. The 6 GHz band will allow for seven non-overlapping channels.
The new spectrum brings greenfield deployments, leaving the legacy devices behind. No one wants to carry over the same challenges encountered with the 2.4 GHz and 5 GHz band. Legacy wireless and security protocols will be deprecated, and the adoption of Wi-Fi 6 and next-generation security of WPA3 mandated.
A migration plan to 6 GHz is a must. A large majority of deployments will undergo a transition phase, mixing both 5 GHz and 6 GHz equipment. Moving into the new spectrum will require a refresh of equipment. Today's access points and devices are not capable of operating at 6 GHz, which requires a new radio. These new devices, operating in the new spectrum, require FCC certification and should have Wi-Fi 6E certification.
During the transition to 6 GHz, expect to see tri-band access points, supporting 2.4 GHz, 5 GHz, and 6 GHz. Some of these access points will be tri-radio devices supporting concurrent operation in all three bands. The increased radio complexity and aggregate performance of these 6 GHz-capable devices will drive increased power consumption. Not all existing switching infrastructure can support the Power over Ethernet requirements of some of these access points, but new PoE standards, such as 802.3bt, have emerged to raise power levels.
When enterprises upgrade to Wi-Fi 6, soon to be ratified as a standard, they will realize the Wi-Fi efficiencies that can be utilized in 6 GHz—essentially free of interference from existing devices. The benefits include lower latency for mission-critical applications in higher density environments.
Will users see upwards of 1 Gbps Wi-Fi throughput? It's too early to tell. Wi-Fi 6 will help increase efficiency and lower latency to achieve higher speeds. Wi-Fi 6 also borrows the orthogonal frequency-division multiple access (OFDMA) feature from cellular technologies, which takes advantage of servicing multiple users on sub-channels transmitted simultaneously.
Rules to abide
The 6 GHz spectrum is occupied by currently operating incumbents, so some regulation and standards work is necessary to protect them from interference. These incumbents, such as utilities, common carriers, public safety services, and fixed satellite services, are in locations where big dishes exist.
To play nicely and avoid interference, devices and access points must support the following standards:
- Low Power Indoor (LPI)
- Power Spectral Density (PSD)
- Automated Frequency Coordination (AFC)
LPI and PSD are rules for restricting the power output of indoor 6 GHz devices, to limit interference with each other or with licensed outdoor use. AFC is for outdoor 6 GHz devices and consults with a database based on the FCC's Universal Licensing System so that 6 GHz access points can avoid interfering with licensed applications.
The four classes of power for access points are:
- Standard power at 36 dBm (with AFC)
- LPI at 5 dBm per MHz across 1,200 MHz (no EIRP)
- Very low power AP (proposed by the FCC)
- Client devices 6 dB below AP
Of the three, LPI and PSD will be implemented first, indicating how the transmit power will be distributed within the frequency.
This may lead people to believe it would require a denser access point deployment. But for wireless networks that are correctly architected for today's technologies, there may not be a significant change in the number of access points deployed when 6 GHz is added.
In today's 5 GHz world, access points are limited to 30 dBm. In 6 GHz, under LPI and PSD, the new limitation will be 18 dBm, which protects the incumbents operating in 6 GHz.
AFC will be implemented in another phase of 6 GHz, similar to how 802.11ac was deployed in two phases. This requires that additional infrastructure be in place for the frequency coordination that the access points must follow, in the case of nearby incumbent transmissions. A database would be available to each access point, and a central coordinator will notify nearby access points to move to a new frequency due to incumbent use. The database will be managed by AFC operators.
All eyes on the U.S.
The world is watching how the FCC navigates this new arena for Wi-Fi. Europe is moving forward to allow unlicensed use in a portion of the 6 GHz frequency. South Korea is moving at a quick pace to allow the same usage for Wi-Fi, with the country's Ministry of Science and ICT moving toward proposing a new regulation allowing the unlicensed use of 6 GHz.
The U.S. has taken a lead in the adoption of 6 GHz, and other countries will follow the same path once vendors and manufacturers begin releasing products.
What about the alternatives?
At what point does an organization start considering alternatives to Wi-Fi? While 5G is making strides in the industry and trials are underway, nothing is mainstream yet. 5G technology doesn't have the global proliferation compared with Wi-Fi, which is largely used in enterprises and residential networks. Wi-Fi has been a big, fertile area for innovation and at a lower cost.
Citizens Broadband Radio Service (CBRS) is also making its way into the playing field. Apple's latest mobile devices support the CBRS frequencies, but the installed base is still small. The benefit is in creating a private mobile network with less interference from the unlicensed spectrum. CBRS operates on licensed frequency, an appealing characteristic for many critical business applications.
A consideration for CBRS and 5G is the procurement of equipment in addition to a Wi-Fi installed base. Wi-Fi is already in many environments where cellular is not.
6 GHz Wi-Fi will have the advantage of environments with existing infrastructure. Wi-Fi radios are installed in almost every network-capable device. Wi-Fi growth continues to take over the market.
Phil Solis, a research director at IDC, told Wi-Fi NOW that the "overall Wi-Fi chipset market is expected to continue on a growth trajectory of 5 to 7 percent per year while Wi-Fi 6 proceeds to chew big bites out of the legacy Wi-Fi 5 market."
6 GHz will unlock the true potential of Wi-Fi, allowing Wi-Fi operators to increase bandwidth and throughput by finally implementing features that exist in the wireless standards, such as wider channel configuration. Higher bandwidth usage will create room for more innovation over Wi-Fi at a lower cost compared with the alternatives.
6 GHz is set to be the biggest change to Wi-Fi in the past 10 years.
6 GHz Wi-Fi: Lessons for leaders
- Applications that are impractical using current technology will be practical with Wi-Fi 6E.
- A migration plan involving wireless network engineers is a must for proper exploitation of 6 GHz.
- 6 GHz is supplemental spectrum, not a replacement for 2.4 GHz and 5 GHz.
- Listen to an interview with Aruba Networks' Chuck Lukaszewski on aspects of 6 GHz Wi-Fi
- 5 highlights in the future of Wi-Fi
- WPA3: How and why the Wi-Fi standard matters
- Stadium technology turns the game around
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Wi-Fi congestion has been increasing for some time, but when the pandemic hit, the amount of data on Wi-Fi networks skyrocketed, making matters worse. The case for increasing wireless bandwidth and capacity has never been greater.
This article/content was written by the individual writer identified and does not necessarily reflect the view of Hewlett Packard Enterprise Company.