Explore Cisco
How to Buy

Have an account?

  •   Personalized content
  •   Your products and support

Need an account?

Create an account

What Is 802.11ac?

802.11ac is a Wi-Fi standard that delivers higher throughput to WLANs than 802.11n, the preceding Wi-Fi standard. The IEEE introduced 802.11ac in 2013. The Wi-Fi Alliance since renamed 802.11ac as Wi-Fi 5 to place it in context with the following generation, Wi-Fi 6, also known as 802.11ax.

What is 802.11n?

802.11n is a Wi-Fi standard introduced in 2009. In comparison with earlier Wi-Fi standards, it allowed for improved wireless computing, video conferencing, HD streaming, and dynamic web-based apps. But as network traffic and performance demands grew, 802.11n reached its practical capacity.

How does 802.11ac work?

802.11ac uses several new technologies to improve performance over 802.11n:

  • Additional spatial streams: 802.11n used four spatial streams and 40-MHz channel widths to achieve multiple input, multiple output (MIMO). But 802.11ac uses eight spatial streams and channels up to 80 MHz wide. To support MIMO, routers are increasingly designed with multiple antennas.
  • 256 quadrature amplitude modulation (QAM): 802.11ac uses 256 QAM, compared with the 64 QAM of 802.11n. That means 802.11ac squeezes 256 signals onto one frequency, through subtle phasing of the signals. In theory, 802.11ac quadruples the spectral efficiency of 802.11n.
  • Beamforming: This technology sends transmissions directionally rather than transmitting 360 degrees, as most wireless technology did until the arrival of 802.11ac. Beamforming is achieved by use of multiple antennas on the router and by the antennas' physically adjusting themselves for transmission in certain directions.

Is 802.11ac backward- and forward-compatible?

Each new Wi-Fi standard effectively absorbs previous versions. Depending on client hardware or network conditions, 802.11ac operates with 802.11n and any other previous 802 standard when necessary.

This compatibility will extend forward as well: Wi-Fi 6 will be backward-compatible with 802.11ac, with performance conforming to the older standard.

How fast is 802.11ac?

802.11ac transmits at a top speed of 1300 Mbps, almost three times faster than the 450 Mbps of 802.11n.

As with many network performance specs, the actual speed achieved will likely not approach the top theoretical speeds. Variations in hardware, network architecture, applications used, and even the composition of office walls can have huge effects on Wi-Fi performance.

What are advantages of 802.11ac over 802.11n?

With its new 5-GHz spectrum, 802.11ac achieves faster speeds for data throughput and provides more bandwidth for additional computers, wireless devices, and Internet of Things (IoT) devices to come online.

By switching between 2.4-GHz and 5-GHz bands, 802.11ac can dynamically optimize network performance based on network usage. And by using beamforming, 802.11ac results in less interference for transmissions and lower power demands from routers.

How does 802.11ac differ from Wi-Fi 6?

Wi-Fi 6 (802.11ax) represents a significant upgrade over 802.11ac. It provides improvements in all performance specifications and offers additional technologies.

Benefits of 802.11ac

Data network improvements such as the ones that 802.11ac delivers can benefit organizations in multiple ways:

Data speeds

User productivity benefit from 802.11ac's boost in data transmission speeds.


Capacity

802.11ac provides the extra capacity needed for growth in scale or scope of business activity and for increases in numbers of connected devices.


Application response

802.11ac's lower latency means that dynamic web-based applications respond faster, increasing productivity and inviting the use of more web apps.

Beyond 802.11ac: Upgrading to Wi-Fi 6

Wi-Fi 6, also known as 802.11ax, is the successor to 802.11ac. Wi-Fi 6 offers several improvements over its predecessor:

Higher capacity

Network users can attach up to four times more devices than under previous standards, thanks to features such as orthogonal frequency-division multiple access (OFDMA) and multiuser multiple input, multiple output (MU-MIMO). Wi-Fi 6 communicates in parallel with multiple devices; the previous standards communicate with only one device at a time.

The increased device support is essential because the volume of mobile data traffic is expected to grow significantly over the coming years.


Improved power efficiency

Devices that support the Wi-Fi 6 standard consume two-thirds less power. This means that batteries in products such as smartphones, laptops, tablets, and IoT devices can last longer.


Improved security

Wi-Fi Protected Access 3 (WPA3) is certified with Wi-Fi 6 and provides greater value than WPA2 for enterprise Wi-Fi networks. It offers enhanced security for open Wi-Fi networks encryption of unauthenticated traffic, robust password protection against brute-force attacks, and superior data reliability for sensitive information 192-bit encryption.

Increased speed

Wi-Fi 6 offers up to four times the throughput, on average, in congested wireless environments.