If you’ve been shopping around for a wireless HDMI transmitter, you’ve undoubtedly seen the term “dynamic frequency selection” listed as a feature. But what exactly does this mean? Why are transmitter manufacturers bragging about it? And, more importantly, how can this specific feature help you?
To answer all of these questions, you have to start by understanding how video is transmitted in the first place. When your video has to go from Point A to Point B, it has to get there on a specific frequency. It’s kind of like taking certain roads when you drive home from work.
However, dynamic frequency selection takes things a step further. Some of the frequencies your wireless HDMI transmitter carries may be faster than others. Some may be congested with other traffic or interference, while other frequencies are free and clear. In order to send your video as efficiently as possible, your transmitter will analyze the situation and select the frequency that has the smallest number of hurdles standing in its way. And, since the traffic on these frequencies can change from minute to minute, the decision-making has to be dynamic — meaning that one frequency may work best on Tuesday, but a different frequency may not be the best choice on Wednesday.
Think of it like your rush hour commute. One evening, there may be a huge accident on the expressway, so you decide that it will be faster to take the back roads. But the next day — when there isn’t an accident tying up traffic — the expressway is a much better way to travel because you can drive faster on it, and there are no red lights to worry about. Making those decisions may seem like second nature, but you’re actually doing some dynamic frequency selection of your own!
And, just like your decision to take the back roads one evening seemed like common sense, a good wireless HDMI transmitter will work the same way. It will be smart enough to assess the current frequency situation and pick the best route for your video to take — and it will do all of this in a fraction of a second.
How exactly does it do that?
Your wireless HDMI transmitter obviously doesn’t have a brain and reasoning skills like you do, so instead, it has to use advanced math. Specifically, there are certain algorithms that can tell it which frequencies are good to use right now, and which ones aren’t.
Dynamic frequency selection entered the scene back in 2003, when regulatory agencies started freeing up a bunch of 5 GHz frequencies. Since there were so many new frequencies to choose from, it only made sense to start building transmitters that could take advantage of them! And, since the Federal Communications Commission is thinking about opening up even more 5 GHz frequencies, you really need a transmitter that is smart enough to access all of them.
Dynamic frequency selection can also be a matter of public safety. Because some frequencies are considered to be “primary-use” or “mission-critical” by federal, military, and civilian organizations, your wireless HDMI transmitter will need to recognize whenever they’re in use — so that it doesn’t get in the way of more important information. Remember, residential and commercial transmissions are considered to be the lowest on the food chain, so you’ll be forced to get out of the way when something higher up on the chain comes along.