Technology

Dueling NAVs in 802.11ax

Wi-Fi radios use two methods of carrier sense to determine if the RF medium is busy and possibly defer transmissions. The clear channel assessment (CCA) is a physical carrier sense mechanism which works together with MAC layer virtual carrier sense. Virtual carrier sense uses a timer mechanism known as the network allocation vector (NAV). In previous […]

What is PoE (Power Over Ethernet) Budgeting?

Chris and I talk about PoE (power over ethernet) budgeting in this latest video.

How Does BSS Coloring Work in 802.11ax?

A basic service set (BSS) is the cornerstone topology of any 802.11 network. The communicating devices that make up a BSS consist of one AP radio with one or more client stations. In the last blog, we discussed how BSS color is a numerical identifier of a BSS. BSS color, also known as BSS coloring, […]

What is BSS Color in 802.11ax?

As we discussed in the last few blogs, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) dictates half-duplex communications, and it says only one radio can transmit on the same channel at any given time. An 802.11 radio will defer transmissions if it hears the PHY preamble transmissions of any other 802.11 radio. Unnecessary medium contention […]

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 […]

Cone vs Beach Ball – When to Choose an Access Point with an External Antenna 

In the world of wireless access points, one size does not fit all. There are choices to be made in ensuring that you have the best technology fit for the requirements of each situation and one of the key considerations is whether to use an Access Point with an internal or external antenna. So how do […]