Wi-Fi 8 is coming — and it’s going to make AI a lot faster

While it seems like Wi-Fi 7 was just released (it was actually officially released in Jan. 2024), work is already underway on its successor Wi-Fi 8.

In fact, Broadcom just announced the industry’s first Wi-Fi 8 silicon as an early entrant ahead of the specifications being finalized. Formally known as IEEE 802.11bn, Wi-Fi 8 is not expected to be finalized until 2028, though that isn’t slowing down the pace of technology development.

Unlike previous generations of Wi-Fi that competed on peak throughput numbers, Wi-Fi 8 prioritizes consistent performance under challenging conditions. The specification introduces coordinated multi-access point features, dynamic spectrum management, and hardware-accelerated telemetry designed for AI workloads at the network edge.

The 802.11bn specification also marks a departure from single-feature Wi-Fi generations. Previous standards centered on one major capability: OFDMA for Wi-Fi 6, 6 GHz spectrum for Wi-Fi 6E, 320 MHz channels for Wi-Fi 7. Wi-Fi 8 instead bundles multiple coordinated technologies to address median and tail latency performance.

“Wi-Fi 8 is entirely different, where you don’t have just one anchor feature,” Christopher Szymanski, director, product marketing at Broadcom, explained to Network World. “Here you see a variety of features that come together collectively work so well in creating a much better user experience.”

Ultra High Reliability architecture

A core part of the Wi-Fi 8 architecture is an approach known as Ultra High Reliability (UHR). This architectural philosophy targets the 99th percentile user experience rather than best-case scenarios. The innovation addresses AI application requirements that demand symmetric bandwidth, consistent sub-5-millisecond latency and reliable uplink performance.

Traditional Wi-Fi optimizes for 90/10 download-to-upload ratios. AI applications push toward 50/50 symmetry. Voice assistants, edge AI processing and sensor data all require consistent uplink capacity.

“AI traffic looks different,” Szymanski explained. “It’s increasingly symmetric, with heavy uplink demands from these edge devices. These devices are pushing all this data to the cloud or locally with on prem. That calls for smarter resource management.”

Coordinated Multi-AP Operation comes to Wi-Fi 8

Wi-Fi 8 introduces inter-access point coordination as a core innovation. Multiple APs communicate and collaborate rather than operating independently. This represents a significant architectural change from autonomous AP operation. Enterprise deployments gain prioritized packet handling across the infrastructure. APs label and process voice and video traffic cooperatively. The system ensures latency-sensitive applications receive resources even during congestion. 

The coordination is enabled with a series of capabilities including:

• Coordinated Spatial Reuse (Co-SR) allows access points to negotiate transmit power dynamically. When one AP detects that a client has strong signal strength, it informs neighboring APs. Those neighbors can increase power for their own clients without causing interference. The coordination prevents the hidden node problem while maximizing spatial reuse.
• Coordinated Beamforming (Co-BF) extends this concept to directional transmission. Access points share client location information and coordinate beam patterns. Multiple APs can simultaneously serve different clients in the same coverage area by steering beams away from each other’s clients.

“It’s going to feel like you have one cohesive network, rather than having four or three overlapping mesh networks,” Szymanski said.

Dynamic spectrum access innovation

Wi-Fi 8 introduces three related features that fundamentally change how devices access available spectrum. These three features work together to maximize spectrum efficiency. Broadcom’s apartment density simulations showed 200% median throughput improvement and 6x lower latency at the 99th percentile compared to Wi-Fi 7.

Non-Primary Channel Access (NPCA) breaks the primary channel requirement. Current Wi-Fi requires the primary channel to be clear before using any spectrum. A device with 160 MHz capability cannot use the secondary 80 MHz if the primary 80 MHz is busy.

NPCA allows devices to transmit on secondary channels without waiting for primary channel availability. This fills spectrum that would otherwise remain unused.

“Not everybody’s transmitting at the same bandwidth,” Szymanski explained. “You have IoT devices that are much narrower bandwidth, or you have a laptop that might be a 320 megahertz capable device. Right now, that spectrum would lie fallow. With non primary channel access, you can fill up the whole medium.”

Dynamic Sub-Channel Operation (DSO) enables access points to identify and avoid congested spectrum in real-time. Rather than staying on a configured channel, APs dynamically shift to clearer frequencies within their operating band. The feature operates on a per-transmission basis.

Dynamic Bandwidth Expansion (DBE) allows real-time channel width changes based on client capability and spectrum conditions. An AP can allocate 320 MHz to a capable laptop while simultaneously serving a 20 MHz smartphone. The bandwidth adjusts dynamically as spectrum availability changes.

Extended range technologies land in Wi-Fi 8

Wi-Fi 8 introduces Extended Long Range (ELR) mode specifically for IoT devices. This feature uses lower data rates with more robust coding to extend coverage. The tradeoff accepts reduced throughput for dramatically improved range.

ELR operates by increasing symbol duration and using lower-order modulation. This improves the link budget for battery-powered sensors, smart home devices and outdoor IoT deployments. Broadcom claims 2x better range in line-of-sight scenarios and 1.5x improvement in non-line-of-sight conditions compared to Wi-Fi 7.

Distributed Resource Units (dRu) complement ELR by allowing non-contiguous spectrum allocation. An IoT device can maintain connectivity using scattered spectrum fragments across the band. This proves particularly valuable in congested environments where clear contiguous spectrum is unavailable.

The specification includes refined Modulation and Coding Schemes (MCS). Wi-Fi 8 adds more granular rate steps between existing MCS levels. This provides smoother transitions as signal conditions change. Devices spend less time at suboptimal rates.

Improved Low-Density Parity Check (LDPC) coding enhances error correction. The better forward error correction allows higher data rates at a given signal-to-noise ratio. This improves performance in noisy RF environments.

Together, these features deliver 50% reduction in active power consumption for battery-operated IoT devices while extending usable range.

Seamless roaming enhancements

Wi-Fi 8 enhances roaming to maintain sub-millisecond handoff latency. The specification includes improved Fast Initial Link Setup (FILS) and introduces coordinated roaming decisions across the infrastructure.

Access points share client context information before handoff. When a device moves, the new AP already knows the client’s capabilities, security credentials and QoS requirements. This eliminates re-authentication delays that cause audio drops and video freezes.

The coordinated approach prevents ping-pong roaming. APs negotiate which one should serve a client based on current load and signal quality rather than signal strength alone. A client won’t repeatedly switch between two APs at a coverage boundary.

“Enhanced roaming means that anywhere you sit in your home or in your network you’re next to an AP,” Szymanski said. “It’s going to provide that sort of unified network experience.”

The improvement particularly benefits voice and video applications. Current Wi-Fi can experience 50-100 millisecond gaps during roaming. Wi-Fi 8 targets single-digit millisecond handoffs.

Broadcom’s Wi-Fi 8 silicon portfolio

As part of its Wi-Fi 8 effort Broadcom announced four chips spanning residential, enterprise and mobile markets.

• BCM6718: A four-stream, 320 MHz tri-band radio for residential gateways and service provider equipment with BroadStream telemetry engine and third-generation DPD front-end modules.
• BCM43840: A four-stream Wi-Fi 8 chip for enterprise access points with advanced location tracking and support for higher client density.
• BCM43820: A two-stream scanning and analytics radio for dedicated monitoring in enterprise deployments, operating independently of data radios.
• BCM43109: A combo chip for mobile devices integrating two-stream 320 MHz Wi-Fi 8, Bluetooth 6.0, Thread v1.4, Zigbee Pro and 802.11az secure ranging.

Broadcom’s Wi-Fi 8 silicon is based on 802.11bn draft 1.5. Szymanski acknowledged the specification remains under IEEE development but expressed confidence in compatibility.

“Draft 1.5 is frozen, but things are still working through the process,” he said. “We have a very high degree of confidence that this will be fully compliant with the bn spec and with the Wi-Fi Alliance certification.”