David Coleman

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David Coleman is a wireless mobility consultant, public speaker, and trainer. For the last twenty years, David has instructed IT professionals from around the globe in enterprise WLAN design, WLAN security, WLAN administration and WLAN troubleshooting. In his spare time, David writes white papers, blogs, and books about enterprise Wi-Fi networking. David is the co-author of Sybex Publishing’s Certified Wireless Network Administrator (CWNA) Study Guide and numerous other books about Wi-Fi. David is the Senior Product Evangelist for Aerohive Networks and is CWNE #4.

What is Operating Mode Indication (OMI)?

In previous blogs, we have discussed both downlink OFDMA as well as uplink OFDMA for true multi-user communications between and 802.11ax AP and Wi-Fi 6 clients. In either case, that 802.11ax access point wins a transmit opportunity (TXOP) and is in control of the medium. During the TXOP, the AP uses OFDMA technology to partition a […]

Aerohive Network’s Ruchi Sharma Achieves CWNE Certification

It gives me great pleasure to announce that we have a new CWNE working here at Aerohive. This employee joins a growing list of Aerohive CWNEs, all of whom are named at the bottom of this post. CWNP, founded in 1999, is the IT industry standard for vendor-neutral enterprise Wi-Fi certification and training. IT professionals in over 150 […]

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 […]

Unsolicited Buffer Status Reports in 802.11ax and Wi-Fi 6

In a previous blog, we focused on the delivery of buffer status reports (BSRs) from Wi-Fi 6 clients using an explicit process that requires polling from the AP. To summarize the solicited UL-OFDMA frame exchange we discussed, the following three trigger frames might be used: Trigger 1: BSRP to solicit buffer status reports from the clients […]

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 […]

Uplink OFDMA is not PCF

In the previous blog, we discussed DL-OFDMA and the 802.11 frame exchanges between an 802.11ax AP and multiple 802.11ax clients for multi-user downlink transmissions. In future blogs, we will discuss the necessary UL-OFDMA frame exchanges to achieve synchronized multi-user uplink transmissions. However, there is already some confusion between UL-OFDMA and some legacy RF medium access methods. […]

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 Cloud Configuration Groups used for?

In an earlier blog, we announced Cloud Configuration Groups, a new HiveManager configuration and network device management feature. Cloud Config Groups is a new form of device classification that adds more flexibility when configuring network policies with HiveManager. Cloud Config Groups solves the management challenge of implementing template-based network policies for network devices that require […]

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 […]