思科802.11ax 无线网络设计白皮书

Technical white paper

Cisco public

IEEE 802.11ax: The Sixth

Generation of Wi-Fi

© 2018 Cisco and/or its affiliates. All rights reserved.

1 Executive summary

Wireless is evolving, driven by more devices, more connections, and more bandwidth-hungry applications. Future

networks will need more wireless capacity and reliability. That’s where the sixth generation of Wi-Fi comes in.

The emerging IEEE 802.11ax standard is the latest step in a journey of nonstop innovation. It builds on the

IEEE 802.11ax lets access points support more clients in dense environments and provide a better experience

for typical wireless LAN networks. It also powers more predictable performance for advanced applications such

as 4K video, Ultra HD, wireless office, and Internet of Things (IoT). Flexible wake-up time scheduling lets client

devices sleep much longer than with 802.11ac, and wake up to less contention, extending the battery life of smart

phones, IoT, and other devices.

IEEE 802.11ax achieves these benefits by pushing on three different dimensions:

• Denser modulation using 1024 Quadrature Amplitude Modulation (QAM), enabling a more-than-35-percent

speed burst

• Orthogonal Frequency Division Multiple Access (OFDMA)-based scheduling to reduce overhead and latency

• Robust high-efficiency signaling for better operation at a significantly lower Received Signal Strength

adding standards-based sounding and beamforming, and enabling new use cases and business models for

indoor and outdoor coverage.

Technical white paper

Cisco public

© 2018 Cisco and/or its affiliates. All rights reserved.

IEEE 802.11ax will enhance existing 802.11a/g/11n/11ac deployments even

if they are not fully upgraded to 802.11ax immediately. Its OFDMA-based

channel access is fully backward-compatible with traditional EDCA/CSMA,

and Cisco® access points will use each scheme optimally. Secondly,

802.11a/g/11n/11ac monitoring and wireless intrusion protection systems

(Wireless Intrusion Protection Switching [WIPS]) can continue to decode most

management frames such as beacon and probe request/response frames,

even when sent in the new 802.11ax packet format.

technology, unlocking real benefits for enterprise and service provider

organizations as time moves forward.

2 Market dynamics

Examination of the previous 802.11-based networks shows that each

generation delivered increasing throughput and coverage to users to

support the expansion and densification of enterprise networks. However,

considering future wireless networks indicates that the next generation

needs not only to support this ongoing expansion but also to offer a greater

level of service to existing networks. In particular, there is a growing need

to support 4K/8K video; augmented and virtual reality (AR/VR); and IoT for

speeds and economics. For the future (2020+ it is clear that even the newest

cellular technology (5G) will require significant Wi-Fi capacity supportive of

carrier-grade voice and video services that are best delivered with 802.11ax

and its cellular-like scheduling capability (Figure 1).

3.1 Drivers for 802.11ax

3.2 How does 802.11ax go

while reducing

scheduling

3.4 How did the IEEE make

802.11ax more robust?

3.5 Technology overview

5.1 Compatibility

5.2 When to upgrade to

8 02.11a x ?

6 Summary

Technical white paper

Cisco public

© 2018 Cisco and/or its affiliates. All rights reserved.

Figure 1. Mobile ooad trac trend (Cisco Virtual Networking Index [VNI])

0%

An important trend, Internet of Things (IoT) presents a significant challenge to enterprises: how to securely and easily

capabilities such as low power and determinism are expected to accelerate this adoption (refer to Figure 2).

Figure 2. IoT trends (Cisco VNI)