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’s The Biggest Cause Of Co-Channel Interference?

In my last blog, What is a Clear Channel Assessment?, we discussed the difference between the signal detect (SD) threshold and the energy detect (ED) thresholds used by Wi-Fi radios to determine if the RF medium is busy. The ED threshold is used to detect any non-Wi-Fi transmissions while the SD the threshold is used to […]

What is a Clear Channel Assessment (CCA)?

The CSMA/CA protocol utilizes a line of defense to ensure that any Wi-Fi radio does not transmit while another is already transmitting on the same channel. The 802.11-2016 standard defines a physical carrier sense mechanism to determine if the radio frequency (RF) medium is busy. Physical carrier sense is performed constantly by all Wi-Fi radios […]

802.11ax and Medium Contention

As many of you might already know, a key efficiency enhancement for 802.11ax will be the use of OFDMA by Wi-Fi radios. Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the OFDM digital-modulation technology and is used in other wireless technologies such as LTE. OFDMA subdivides a channel into smaller frequency allocations, called […]

What’s the Maximum Number of Devices For A Wi-Fi Access Point?

Chris and I discuss how many devices a single access point can provide access to along with design and configuration best practices for enterprise Wi-Fi.

How Do 20 MHz-Only Clients Operate In 802.11ax?

Much of the 802.11ax draft amendment has been written with Internet of Things (IoT) devices in mind. The radio chipsets used for IoT devices generally need to be low-cost and consume very little power. Traditionally, Bluetooth and Zigbee chipsets have been cheaper to manufacture for IoT devices than Wi-Fi radio radios. However, 802.11ax lays the […]

What Does Multi-User (MU) Mean?

The term multi-user (MU) simply means that transmissions between an AP and multiple clients can occur at the same time dependent on the supported technology. However, the MU terminology can be very confusing when discussing 802.11ax. MU capabilities exist for both OFDMA and MU-MIMO. 802.11ax defines the use of two multi-user technologies, OFDMA and MU-MIMO. But please […]

802.11ax Frame Aggregation Enhancements

The primary goal of both 802.11n and 802.11ac was to provide high throughput and bigger data rates. However, frame aggregation is one key aspect of 802.11n/ac that did enhance airtime efficiency. Frame aggregation is a method of combining multiple frames into a single frame transmission. Fixed MAC layer overhead and medium contention overhead are reduced, […]

Why is Upgrading Wi-Fi Clients/Devices Important?

Chris and I discuss the importance of upgrading end user devices when upgrading your enterprise WLAN network in a recent video.

Enterprise Wi-Fi Configuration Bells and Whistles

In this video,  Chris Harkins, Sr. Technical Instructor and I talk about configuration features like Load Balancing and when (or when not) to use them.

How Many SSIDs Should An Enterprise Wi-Fi Network Have?

David Coleman, CWNE#4 and Sr. Product Evangelist, and Chris Harkins, Sr. Technical Instructor discuss best practives on SSID design. If you’ve ever wondered why you shouldn’t use 16 SSIDs, be sure to watch this video.