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Why OFDMA is the Secret Sauce for Wi-Fi 6

At the Wireless LAN Professionals Conference, David Coleman (Senior Technical Evangelist) spoke about Wi-Fi 6, and why OFDMA is the most important aspect of the new standard. Watch the video below to learn more about Wi-Fi 6 (802.11ax), how it works, and why it’s important. Key Takeaways What is Multi-User (MU) in Wi-Fi 6? Transmissions […]

What is UL-OFDMA Random Access (UORA)? – Part 2

In our last Wi-Fi 6 blog, we discussed a method in which clients can allocate resource units for uplink transmissions instead of the AP making the decision 802.11ax provides for an optional UL-OFDMA random access (UORA) method. A random-access method is favorable in conditions where the AP is unaware of traffic buffered on the clients. […]

What is UL-OFDMA Random Access (UORA)?

As you have learned in previous blogs, an 802.11ax access point uses OFDMA technology to partition a channel into smaller sub-channels called resource units (RUs) so that simultaneous multiple-user transmissions can occur. The AP mandates the RU allocation for multiple clients for both downlink and uplink OFDMA. In simpler words, the AP is in charge of how RU […]

Uplink Orthogonal Division Multiple Access (UL-OFDMA) in 802.11ax

As we discussed in a previous blog, an 802.11ax AP must contend for the medium and win a transmit opportunity (TXOP) before multi-user (MU) communications can occur. Once the 802.11ax AP wins a TXOP, it can then coordinate uplink transmissions from 802.11ax clients that support UL-OFDMA. UL-OFDMA is more complex than DL-OFDMA and may require the […]

How Does DL-OFDMA Work in 802.11ax?

You should always remember that multi-user OFDMA communication is only for 802.11 data frame exchanges between an 802.11ax AP and multiple 802.11ax clients. For backward compatibility, management and control frames will still be sent using single-user OFDM. In a previous blog, we mentioned that a series of frame exchanges are used for both DL-OFDMA and […]

What are OFDMA Trigger Frames?

In previous blogs, you have learned that an 802.11ax access point uses OFDMA technology to partition a channel into smaller sub-channels called resource units (RUs) so that simultaneous multiple-user transmissions can occur. The AP mandates the RU allocation of a 20 MHz for multiple clients for both downlink and uplink OFDMA. When referencing downlink and uplink OFDMA […]

OFDM and OFDMA Subcarriers – What Are the Differences?

As we continue our 802.11ax blog series, let’s discuss both OFDM and OFDMA technologies used for Wi-Fi communications. 802.11a/g/n/ac radios currently use Orthogonal Frequency Division Multiplexing (OFDM) for single-user transmissions on an 802.11 frequency. 802.11ax radios can utilize Orthogonal frequency-division multiple access (OFDMA) which is a multi-user version of the OFDM digital-modulation technology. OFDMA subdivides a channel […]

How Does an 802.11ax AP Allocate OFDMA Resource Units?

In the previous blog, you learned that 802.11ax access point uses OFDMA technology to partition a channel into smaller sub-channels called resource units (RUs) so that simultaneous multiple-user transmissions can occur. The AP mandates the RU allocation of a 20 MHz for multiple clients for both downlink and uplink OFDMA. RU allocation information is communicated to […]

What are OFDMA Resource Units in 802.11ax?

In our last 802.11ax blog, we discussed how OFDMA is the main 802.11ax enhancement that offers the biggest bang for the buck. Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of OFDM digital-modulation technology. OFDMA subdivides a channel into smaller frequency allocations. By subdividing the channel, parallel transmissions of small frames to multiple clients can […]

The Main Ingredient of 802.11ax: OFDMA

In previous blogs, we have discussed many 802.11ax PHY and MAC enhancements including BSS color, spatial reuse, Multi-TID AMPDU, 20 MHz-only clients and more. However, we have not yet dedicated a lot of blog discussion about the main 802.11ax enhancement that offers the biggest bang for the buck: OFDMA. 802.11a/g/n/ac radios currently use Orthogonal Frequency […]