michael_cooney
Senior Editor

Wi-Fi 7 brings enterprise-caliber predictability to wireless networks, says Cisco CTO

Analysis
Oct 08, 20247 mins
Network SecurityNetwork SwitchesNetworking

Wi-Fi 7 enterprise readiness hinges on ‘deterministic’ features, including the ability to schedule traffic, handle contention, and manage interference.

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The ability to more effectively control wireless networks will go a long way toward making Wi-Fi 7 a viable upgrade for current over-the-air networks and, in some cases, even hard-wired environments.

The evolution of Wi-Fi 7 has included more than a decade of spectrum changes and standards updates. Now it’s exciting to see Wi-Fi 7’s “deterministic” features come to fruition, because that means Wi-Fi can be used for next-generation networking requirements, including distributed data centers, SD-WAN and more, said Matt MacPherson, wireless CTO at Cisco. 

“One of the stigmas around Wi-Fi is it’s a best-effort technology, and I think there’s some truth to that. Now, as we start to go to more predictable wireless, or what I’ve been calling determinism, there are two things that you have to be able to do: You need a more capable stack, and you need a stack that can schedule traffic,” MacPherson said.

Wi-Fi 7 can schedule traffic based on a policy. It also can address contention, which occurs when multiple devices try to transmit data over the same network segment at the same time, which can lead to collisions, require data to be resent, and cause delays, MacPherson said.

And it can manage interference. When too many devices try to get on the network at the same time, it doesn’t matter how good your stack is, or how good your policies are. “If you’re getting broadsided by interference, you’re going to increase your error rates,” MacPherson said. Errors require retransmission, and “retransmission means it once again becomes unpredictable.”

Wi-Fi 7 is changing the game. “Wi-Fi 7 can do this level of determinism,” MacPherson said. With greater predictability, enterprises can run high-priority applications on the same network that business applications are running on, while maintaining Wi-Fi 7’s characteristic low latency and high reliability, MacPherson said.

Wi-Fi 7 features and capabilities

Wi-Fi 6E adoption is still growing, but industry watchers predict Wi-Fi 7 will eclipse previous generations in 2025. 

Wi-Fi 7 is expected to reduce latency, increase network capacity, boost efficiency, and support more connected devices. Also known as 802.11be Extremely High Throughput (EHT), Wi-Fi 7 is promised to deliver peak data rates of more than 40Gbps, making it significantly faster than previous generations.

A key feature of Wi-Fi 7 is multi-link operation (MLO), which lets devices simultaneously send and receive data across different frequency bands and channels, enhancing the efficiency of wireless connections. Additional features such as encryption and authentication further strengthen Wi-Fi security.

There are a number of core Wi-Fi 7 features that will improve determinism and QoS delivery, MacPherson said. Those include:

  • Wi-Fi multimedia: This feature defines the ability to prioritize voice and video over “best effort” and background traffic. 
  • Triggered uplink access: This feature optimizes the Wi-Fi 6 definition to accommodate latency-sensitive streams and deliver QoS requirements. The idea is that when a wireless device or station has data to deliver, the wireless access point can schedule a slot on the network for transmission.
  • Stream classification service: This capability defines how to intelligently categorize and make sure the bandwidth is available for different types of data traffic based on their characteristics and priorities. The idea is to prioritize time-sensitive or mission-critical data, such as real-time video streaming or voice calls.
  • Restricted target wait time: This feature defines how to slot or schedule traffic to avoid collisions.
  • Puncturing: Defined in the Wi-Fi 6 spec as an optional implementation, puncturing is now mandatory in Wi-Fi 7. It’s a technique used to adjust wireless modulation to adapt to channel conditions such as such as signal-to-noise ratio (SNR) and interference levels. The idea is to reduce the number of errors and boost QoS.

Triggered uplink access, in an oversimplified way, is basically letting a device say, “Hey, I have traffic to send. If I don’t send this traffic, my queues are going to back up,” MacPherson said. “So, the device tells the network. And remember, in Wi-Fi 6 we could schedule from the network, but Wi-Fi 7 actually lets a device communicate to the network what it needs.”

With the stream classification service, the communicating device tells the network, “Hey, I’ve got this prioritization I need for this upstream traffic, but when the traffic comes back, I need you to properly prioritize that as well,” MacPherson said. “So, the station is basically saying when you see this traffic, apply this QoS to it.”

These stack enhancements essentially let devices and the network better collaborate, “and if they’re collaborating, then the network can work to actually meet the service level that the device needs for the applications it’s running, and meet the policy that it has set on that access network,” MacPherson said.

Mission-critical Wi-Fi requirements will vary by industry and application – and Wi-Fi 7’s deterministic capabilities will give enterprises the tools to prioritize what matters in their environments.

“What we want to do is to be able to prioritize traffic based on need,” MacPherson said.

“If you’re a warehouse and you’re moving robots around like Amazon, what you’re prioritizing is probably going to be different than if you’re in an elementary school and you’re doing training videos. So, it’s very important that an IT department be able to specify what is mission critical to them. And that’s really what’s happening as we do the scheduling and policy and these sorts of new capabilities that are part of Wi-Fi 7,” MacPherson said.

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