Ever wondered what ANT is, and how it works? Coming from an engineering background, I get that question a lot. The question usually pops up when friends have a connection issue, or when they want to know if a heart rate monitor strap is compatible with a different sports watch. So I thought I would put together a quick column about ANT with a multisport focus in mind. So here goes:
First of all, what is ANT? ANT is an acronym for “Advanced and Adaptive Network Technology.” This isn’t very helpful, but let me take a swag at a description. ANT is a protocol that uses the same frequencies as WiFi and Bluetooth, namely 2.4 GHz. The data transfer rate is much slower than WiFi and Bluetooth, but it doesn’t really need to transmit as much data as your home WiFi. It is very low power, and the transmitters and receivers can run on a watch battery for a long time, typically a few years or longer. The working distance is typically less than five feet.
There are two version of sensors. The first sensors to be produced were just called ANT sensors (no +). ANT sensors would not necessarily work with other competitors products, so if you bought a heart rate monitor watch from a manufacturer, you would probably need to use their heart rate monitor strap that came with the watch.
The next generation of sensors were called ANT+ sensors. This new generation of devices used the new ANT+ protocol. With ANT+, all manufacturers agree to follow the same specification, so that heart rate monitors, heart rate chest straps, power meters, ect., are all theoretically interoperable. This allows the power meter designed by one manufacturer to work with the bike computer of another manufacturer. Also, heart rate monitor straps could be interchangeable.
With ANT+, manufacturers typically supply a USB dongle that allows users to download data from most ANT+ watches and bike computers. Of course, you will need some software that is compatible with your device. Te software typically displays your workout data, most times in graphical form. We will be covering some of this software in future columns. I have taken a few pictures of an ANT+ development kit that I have, to five you an idea around the size of the hardware.
Here is a picture of a working ANT+ module. The complete ANT+ module is shown on the circuit board. The gold strip at the top of the board is actually the antenna, so you can see how small these complete receivers can get. The hardware can get even smaller, which is what allows it to fit into a watch, and still be small and thin.
Take your ANT+ heart rate strap with you, and you should be able to connect to the equipment.
There are also many manufacturers that make ANT+ adapters for the iPhone and Android Phones. Garmin, CycleOps, Wahoo Fitness and Nike are a few of them. I will be covering these devices in a future column. There are even phones that have ANT+ receivers built in.
A few questions that everyone wants to know are,
“Which manufacturers use the new ANT+ specification?” Garmin, Suunto, Finis, Timex and Wahoo Fitness all use the ANT+ protocol.
“Does WiFi and Bluetooth cause interference to ANT+?” ANT+ can change frequencies on the fly to avoid interference in a typical location.
“How many ANT+ systems have been sold?” There are over 16 million sport, fitness and health monitoring devices in the field.
“How do I know if my device works with another manufacturers hardware?” Here is a website that can help you get an answer to your question. You can check by manufacturer and see what other hardware is compatible. It is now complete, but it is a good starting location. It is
If you can’t find the information here, check with the manufacturer.
If you have ANT+ questions, leave me a comment or send me an email and I will try to get them answered.