How is airtime efficiency measured? How does one increase it, decrease power consumption, and minimize the amount of RF transmitted?

cf. these comments


How is airtime efficiency measured?

Airtime efficiency with regards to 802.11 networking is some measure of how efficient the RF spectrum is utilized. There is no single standard for how to calculate this (i.e. different vendors do it in their own way), but generally speaking it is a measure of what percentage of the "airtime" is actually used to transmit user data.

Things that are often considered to reduce efficiency:

  • slow 802.11 transmissions
  • 802.11 collisions
  • 802.11 transmission failures/retransmissions
  • 802.11 management traffic

How does one increase it,

Again this is a general answer, but in a simple sense by reducing the types of traffic that impact efficiency negatively. Some of the ways you do this are as follows:

  • Increase the average data rate in use
  • Provide sufficient coverage
  • Make good use of channels
  • Remove non-802.11 sources of RF in the same frequencies when possible
  • Reduce the amount of 802.11 management traffic (without negatively impacting the service)

This general list can include dozens of changes to the environment and/or configuration. There are whole books dedicated to the proper planning and operation of 802.11 wireless networks and a large amount of vendor specific documentation, so there is no way to cover the topic in great depth here.

decrease power consumption,

Not exactly clear about what you are asking here, but 802.11 is generally very power efficient. Running the typical microwave oven for a minute or two will use more power (i.e. they generate more RF although it should be mostly contained within the device itself) than an 802.11 radio in a whole day.

minimize the amount of RF transmitted?

Again your request isn't very clear, so jokingly I want to reply that you could always live in a faraday cage? Seriously, RF is all around us every moment of every day. There is no place on earth (or space) you can escape it. Some (not all by any means) of the many devices that operate in the same frequencies as 802.11 include any device capable of using Bluetooth, wireless controllers for video game consoles, wireless keyboards/mice, cordless phones, baby monitors, wireless video cameras, microwave ovens, sensors, two-way radios, and of course 802.11 devices (which includes appliances, vending machines, home automation, etc). That doesn't even touch on naturally occurring sources of RF.

Most of these devices will tend to interoperate well with each other if everything is working correctly and in compliance with regulatory requirements. There really is no reducing the amount of RF transmitted, it simply is a fact of existence in modern civilization.

Reducing the RF transmitted by a single device is largely a matter of utilizing the correct antenna for the coverage you desire and reducing the transmit power of the device(s).


There is no standard definition of airtime efficiency, so you’re free to define it yourself.

For WiFi, there is overhead in the 802.11 protocol, beacons, etc., but you need those to operate a network.

The biggest factor by far that affects efficiency is retransmissions. These are a fact of life over wireless media, but everything you can do to lessen them, such as increasing your S/N ratio will increase your efficiency.

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