Recently, a fellow drone pilot and I were having a talk about the differences between operating either in 2.4 GHz or 5.8 GHz. We debated which is better and why you might use one over the other.
Now here we are, we’re both experienced drone pilots, and we have both been flying for about the same amount of time, which means many, many years on multiple systems for both of us. As it turned out, he was wrong. I can’t really toot my own horn here or anything. I was wrong as well.
We were both wrong on different aspects of things pertaining to 2.4ghz and 5.8ghz. Now, this got me thinking, how many of us out there only have it half right or half wrong? Do any of us really understand not only the differences between 2.4ghz and 5.8ghz, but what it is?
Well, let’s take a deep dive into it and find out.
What is the difference between 2.4 GHz and 5.8 GHz?
2.4 GHz transmission happens over a more extended range but is slower while anything over 5 GHz reduces coverage but boosts data transmission speed. The higher frequencies of 5.8 GHz reduce the range still.
What are 2.4 GHz and 5.8 GHz frequencies, anyway?
Before we get too far ahead of ourselves, you should know that 2.4 GHz and 5.8 GHz frequencies are both radio frequency bands available in drones.
Yes, that’s right, radio! Here we all thought Video Killed the Radio Star, but who knew?
To be more specific, 2.4 GHz and 5.8 GHz are part of the Wi-Fi frequency radio bands. Did you know Wi-Fi was radio? Now you do!
Did you know the term Wi-Fi or Wireless Fidelity was just part of a marketing strategy that kind of stuck? The term was coined by Interbrand in 1999 to represent IEEE 802.11B Direct Sequence.
Now that really roles off the tongue now, doesn’t it? You can see why they had to come up with something else. In the end, it was Wi-Fi.
Cellular is also in the radio band spectrum and uses radio bands for communication, much like Wi-Fi does.
Bluetooth uses Wi-Fi as well, among many other types of devices such as your key fob for your car and your garage door opener.
Your smartphone uses cellular bands, and your drone, well, it uses Wi-Fi radio bands. All of them are interrelated in a way, as they’re all within the radio spectrum.
The Radio Spectrum
The radio spectrum is a part of the electromagnetic spectrum with frequencies that range from 0 Hz to 3,000 GHz.
Electromagnetic waves in this frequency range, known as radio waves, are widely used in most modern technology today, particularly for telecommunications and wireless purposes.
The only real difference between them is where they are located within the radio spectrum. We use 2.4 GHz and 5.8 GHz bands, whereas cellular uses the bands from 600 MHz to 1900 MHz.
What this means is that you and I, as drone pilots, are constantly bombarded by those invisible radio waves; they surround us everywhere.
Nearly every wireless device on the planet will be using one of these radio bands to operate, with the most being in 2.4 GHz.
For the purposes of drones, we’re interested in the part of the electromagnetic spectrum that deals with radio communications, i.e., radio waves between a receiver and a transceiver.
After all, these are the two components that make flying a drone possible by providing the ability to talk to the craft from a point on the ground. So, we’re solidly within the radio spectrum.
The electromagnetic spectrum contains not only radio but gamma rays and X-rays, UV rays, infrared, and microwave rays too.
This chart shows you the differences.
Here we start getting into the separate radio bands.
Radio bands are a small contiguous section of the radio spectrum frequencies in which channels are used or set aside for some purpose.
Similar services are allocated in bands to prevent interference and allow for efficient use of the radio spectrum.
For example, broadcasting, mobile, or navigation devices will be allocated in a non-overlapping range of frequencies within the 2.4 GHz or 5.8 GHz band. It’s done this way so that one signal doesn’t interfere with or overlap with another signal.
If you’ve ever flown FPV and had your control taken by someone else on your frequency, you’ll know what I mean.
The history of 2.4 GHz and 5.8 GHz
The 2.4 GHz band was established in 1985 by the United Nations, and a group called the ITU (International Telecommunication Union), founded in 1865 in correlation with the US’s FCC and other similar regulating bodies around the world.
It was decided that 2.4 GHz would become an ISM Band, meaning this grouping of frequencies and channels would be used for industrial, medical, and scientific purposes.
There’s some debate today about when the 2.4 GHz band was actually established as an ISM band.
Some say it was in 1947 when the first meeting of the ITU took place. We’re not going to debate that here.
What we know for sure is that in 1985, the 2.4 GHz band was opened to the general public for use as an ISM band.
It also ties in well with the times, as in 1985, we saw more and more devices going wireless.
Think about the cordless phone; it was truly revolutionary at the time and was a big factor in 1985 for these changes as more and more people were buying them.
It was also a time when cellular systems were gaining in popularity. As an example of this, let’s look at the pager. If you don’t know what a pager is, that’s ok. A pager was a carriable device that you could receive a short message or phone number on when someone was trying to reach you.
Today in 2022, that may seem silly, what with nearly everyone having a cell phone. Back then, though, for most people, it was a much more affordable option than an early cell phone.
In 1984 there were 3.2 million pagers worldwide. Just ten years later, by 1994, the number of pager users had increased to 61 million. So, for a while, they were pretty popular. It wasn’t really until cell phones became more affordable in the mid 1990s that the pager sort of faded away.
The regulating bodies such as the ITU recognized a need for an open-source series of RF (radio frequencies) that the general public could have access to and use.
It wasn’t long, though, before the 2.4 GHz band was getting crowded as well, and in 1997, a similar situation presented itself.
This is where we get the 5.8 GHz band as a usable LSM. Prior to this, it was a restricted band.
Once again, although 1997 is when this was implemented, it does seem to have been on the table and discussed in the 1947 meetings that the ITU held.
I have to give those folks credit, they saw the future, and they were right.
As time goes by, we will need more and more RF bands for our technology. How they knew that in 1947, well, that’s a mystery as the devices we have today weren’t even in a conceptual form yet. Heck, the integrated chip would still be 11 years away from being created in 1958.
So that was indeed some foresight they had.
How do 2.4 GHz and 5.8 GHz work?
Once again, as drone pilots, we don’t really have to focus on all the aspects of radio waves and frequencies and the like; we’ll leave that to the Ham Radio Operators out there.
Our focus is on our drones and how they operate. Knowing a little background on a topic never hurts, so here it is.
The 2.4 GHz band which runs from 2.400 GHz to 2.483.5 GHz is an ISM band for general use, as is the 5.8 GHz band, which runs from 5170 MHz to 5835 MHz.
This allows manufacturers such as DJI or Autel to program the controller and craft with these radio bands for use.
Now, today, most if not all drones have dual-band availability.
All this means is that the aircraft and the controller will use the band with the strongest connection, no matter if it is in the 2.4 GHz or 5.8 GHz band.
If you have the drone set to auto or if you fly by the manual option, you will need to select the channel that you want to use.
What our drones also do is jump around from channel to channel seeking out and using the strongest signal within that band.
A channel is the number grouping within a band, so channel 2.461 GHz is an individual channel within the 2.4 GHz band. The same would be true if it was 5.816 GHz would be a channel in the 5.8GHz band.
If you’ve ever watched your transmission page in your flight app, you will have noticed that some channels are red and some are blue.
What this is showing you are the channel strengths and the channel weaknesses. A weak channel won’t maintain a connection as well as a strong channel would.
What’s the difference between 2.5 GHz and 5.8 GHz?
When it comes to using 2.4 GHz or 5.8 GHz, they are not the same, but they are also not all that different from one another.
2.4 GHz offers incredible reliability with a shorter wavelength but also brings less signal penetrating power (less range). However, this can be overcome by using a higher RF power output.
2.4 GHz will put out a signal that has a higher frequency and a narrower, shorter wave pattern, so it’s less directional than say the 5.8 GHz band that is putting out a lower frequency with a wider wave pattern.
That lower-frequency radio wave isn’t really any different than the higher band wave other than the pattern in which they send out. Both will travel at the same speed.
Many people think that the higher the band, the better and faster the reception is. This is a fallacy; all radio waves travel at the same speed.
Radio waves travel at the speed of light or a whopping 186,000 miles per second.
The real difference between the two would be their band waves themselves, which refers to how the signal is sent and received.
2.4 GHz radio waves will travel in a narrower wave and those waves will be further apart. 5.8 GHz waves with their wider band will have a closer wavelength pattern.
Think of throwing a rock in a pond. A small rock will make small waves that radiate out to the pond’s edge, sort of like 2.4 GHz.
Those ripples will radiate out from the source of our rock in a pattern of small spread-out ripples.
If we use a larger rock, like 5.8 GHz, it will produce larger ripples that are closer together than our smaller rock.
Those ripples will naturally radiate out to the edge of the pond as well but will appear to do so more quickly simply because there are more ripples than with the smaller rock.
You’re probably asking yourself that if the 2.4 GHz band is so great, why do we even have the 5.8 GHz band then?
Well, the answer is simple, really. The 2.4 GHz band is used by nearly everyone on this rock. Most if not all wireless devices run on that band.
There will be times that you encounter massive interference from other 2.4 GHz devices.
Metro areas are a prime example of where you may find so much 2.4 GHz traffic that your drone may have a hard time figuring out which is its signal versus some other signal.
In this case, switching to the 5.8 GHz band that isn’t as cluttered with traffic is beneficial. The connection on the higher band won’t have to fight through all that clustering of radio waves.
In the end, the 2.4 GHz band is most likely best for most of your drone flying.
If you find that getting a strong link between the controller and the aircraft in the 2.4 GHz band isn’t working, switching to the 5.8 GHz band should allow for a strong link to be possible.
Which is better, 2.4 GHz or 5.8 GHz?
That’s a loaded question if there ever was one, as it really depends on where you may be flying and what’s around you.
When to Use 5.8 GHz
If you’re in a metro area with lots of interference, operating from the 5.8 GHz will most likely be best.
The downside of that though is you won’t be able to fly out as far and you won’t have as good of a connection if there are obstructions.
When to Use 2.4 GHz
If you’re flying in a rural area with far fewer competing signals, then 2.4 GHz would be your best bet.
The very best way to go and have a good strong connection would be to have the transmission settings set to Auto and Dual Band.
The benefits of operating with these settings are the aircraft and controller will seek out the best connection for you and if need be, will jump from a weakening signal to a stronger one on its own.
Fly Safe, Fly Always, Always Fly Safe!