Bluetooth vs. Infrared: What’s the Difference?

Bluetooth vs. Infrared: 5 Must-Know Facts

• Bluetooth uses radio waves to transmit data, while infrared uses infrared light.
• Infrared sensors require a line of sight to a connected device and have a limited operating range.
• Bluetooth 5.0 introduced a long-range mode that allows devices to interface up to 1 km apart.
• Infrared sensors are still used in modern technology that requires simple but efficient data transfer, like remote controls.
• Both infrared and Bluetooth are technologies overseen by governing bodies rather than owned by a specific entity.

With more companies forgoing analog inputs where they can, wireless technology has never been more ubiquitous. Peripheral equipment uses several types of wireless technologies to interface with the technology we use daily. Bluetooth and infrared technologies are just a few ways we can wirelessly interact with peripheral technologies.

But, what’s the difference between them? Let’s take a look at the two technologies and dive deep into what sets them apart.

Bluetooth vs. Infrared: A Side-by-Side Comparison

Bluetooth vs. Infrared: What’s the Difference?

Both Bluetooth and infrared transmission are used to transfer data between two devices. In this sense, they are similar. However, the two technologies use different methods of determining whether two devices can connect and interface.

Infrared Transmission: How Does it Work?

To start, we’ll define what infrared actually is. The term ‘infrared’ generally refers to the infrared light spectrum, a type of red light beyond the scope of visible light. Infrared light is higher on the spectrum than the light visible to the human eye. Infrared wavelengths fall between 700 and 1,400 nanometers, a range known in science as the “near infrared” range.

However, it’s not invisible to infrared sensors. These sensors can detect the pulses of infrared light transmitted by devices. The most notable example of infrared transmission is a television remote, which interfaces with the TV using infrared light to control the TV using inputs from the remote.

Infrared devices use the infrared data protocol to transmit data from one device to another. Before the introduction of more modern technologies, this protocol was used for almost everything wireless, from game systems like the Gameboy Advance SP, which shipped certain games with a detachable infrared sensor that allowed players to play together and share data, to PDAs which used infrared technology to interface with devices like printers.

One major downside to infrared technology is the distance limits. Since the wavelengths of light change over time, by the time an infrared signal reaches a sensor, the sensor may not be able to pick up the signal. This limitation is why the remote stops working if you move too far from your TV.

Since infrared sensors pick up and transmit data using light, it’s possible to replace infrared sources with candles. People used this common tactic during the Wii era if their sensor bar broke.

Since the Wii and Wii U’s Sensor Bars were not actual sensors—they were the beacon that connected to the sensor in the controller to transmit motion and position data to the console—you could actually replace the sensor bar by fixing two candles either above or below your television and achieve the same effect.

Bluetooth: How Does It Work?

Bluetooth uses radio waves instead of light waves to transmit data from one device to another. These radio waves are similar to Wi-Fi or cellular transmission. Still, they are much weaker, so they don’t get tangled up during transmission.

Bluetooth uses 79 different radio wave frequencies to interface with other devices. These waves are processed by a 2.4GHz band similar to the one used by Wi-Fi signals. Unfortunately, not all devices come equipped with these bands. People building a computer must purchase an internal sensor or an external dongle to use Bluetooth with their new computer—something many budget computer builders forgo.

Since the technology produces weaker waves than other transmission types, the process requires less power. It is particularly useful for battery-powered devices with limited power resources to transmit data.

However, because these radio waves are weaker, the transmission can only be done over a short distance. In addition, similar to light waves, the wavelengths change over time as the signal moves through the air, making it difficult for the sensor to pick up and process the information being transmitted.

Most Bluetooth-enabled devices are designed for short-range transmissions, like earbuds, game controllers, and sending data from one device to another nearby device.

Line of Sight and Device Position

The primary difference between Bluetooth and infrared technology is the way the two devices interface with each other. Mainly, infrared technology is referred to as a “line-of-sight” technology.

This means that an infrared sensor has a positional detector that can only detect things in front of it, and something that moves out of this line of sight will disconnect. Bluetooth is not position-related. You can move 360° around a Bluetooth sensor, and the sensor will still connect.

Bluetooth not using a line-of-sight sensor makes it more effective for people using devices that won’t constantly fall perfectly in front of the host device, like headphones or Bluetooth mice. However, since infrared is a little cheaper to produce, it makes sense to continue using infrared technology in devices that will fall into sight of the host device, like TV remotes.

Since infrared transmission is position-based, it’s becoming less popular, and more companies are turning to Bluetooth. However, Bluetooth is a controlled technology that the Bluetooth Special Interests Group manages, meaning some companies may forgo Bluetooth technology to cut costs and avoid paying for the rights to use Bluetooth technology.

A historical example of this is Nintendo’s Wii U console, which used infrared transmission through a sensor and two clusters of infrared LEDs at either end of the “sensor bar.” Despite the name, the sensor bar did not actually contain any sensors. Instead, the sensor was in the controller, and the sensor bar was primarily a beacon for the controllers to help them transmit motion data from the controller to the console.

Energy Consumption

Neither Bluetooth nor infrared is exceptionally high on the energy consumption scale. However, there have been more innovations to Bluetooth’s technologies. The use of Bluetooth in cellphones and other wireless devices makes Bluetooth’s power consumption mean that the technology must be light enough to run effectively on battery-powered devices without draining the device’s battery processing the signals.

In addition, Bluetooth has introduced Bluetooth Low Energy mode, which features even lower energy consumption than Classic Bluetooth connections. One thing to note is that BLE devices are not compatible with Classic Bluetooth devices. You cannot hook up a BLE-only device with a Classic beacon.

However, some Bluetooth devices use a technology known as Bluetooth Smart Ready, which has compatibility with Bluetooth Low Energy and Classic Bluetooth.

Number of Devices Connected

Another difference between infrared and Bluetooth connections is that infrared tends to be a one-to-one connection. In contrast, Bluetooth devices can connect to multiple devices. However, it is possible to use multiple devices with infrared technology, as shown by the Wii and Wii U, which both allow couch co-op and split-screen play, requiring more than one controller to be connected to the system.

Typically, people recommend using a Bluetooth device if you’re planning to use more than one peripheral device. However, while multi-connection infrared devices exist, they’re rare—rarer now that Bluetooth is replacing the technology, so they’re not typical. In addition, they can be prohibitively expensive to purchase or produce.

Bluetooth allows multiple connections through a process known as “frequency hopping.” Frequency hopping is when a device connects to one of the 79 frequencies that Bluetooth is compatible with, then changes its frequency every few microseconds. Changing the frequencies often allows multiple devices to be connected as each has a different frequency pattern and typically won’t overlap with another frequency pattern for more than a microsecond.

Practical Applications

While we’ve already mentioned them, the TV remote and PDA are the most accessible use of infrared technology in daily life. However, PDAs are much less common with the advent of smartphones, which combine most of the PDA’s features with that of a cellphone.

Infrared technology is mainly used for objects that are going to be stationary, as these objects allow a more stable infrared connection. Nowadays, infrared technology is mainly used for heat-sensing devices like thermal and night vision cameras.

Infrared cameras use the infrared light emitted by heat-producing objects to capture images in the dark or show the heat signature of an object. These have been used in home security and to provide information to study the heat signatures of human beings and how they are related to various illnesses.

On the other hand, Bluetooth technology has become nearly synonymous with wireless technology. Bluetooth is used for everything wireless, from speakers to data transfer; you can find Bluetooth sensors in most devices that interface wirelessly with other devices.

Bluetooth is used in almost all consumer technology to some extent. For example, computer manufacturers use Bluetooth sensors and chipsets in their desktop and laptop computers to allow them to interface with Bluetooth peripherals. Likewise, headphone manufacturers use Bluetooth chipsets to allow their headsets to connect to devices wirelessly, replacing the easily damaged cables that are used to connect to your phone.

Security

You’ll want to look at Bluetooth when securely connecting to a device. Unfortunately, infrared sensors don’t have a connection security protocol. Since infrared transmission detects light and decodes the transmitted information, it has no notable security features.

On the other hand, Bluetooth has security protocols, and devices can only accept connections from “trusted” instruments that the user self-designates. This protocol allows you to securely transfer data from one device to another and keep your history to yourself and out of the hands of hackers. You can even set up a password that must be entered to connect with a device, keeping your data safe behind a wall.

Transmission Range

Both Bluetooth and infrared are designed to be used for short-range transmission. However, Bluetooth has a slightly longer range of use, sitting about nine meters before the system starts to have trouble connecting. Infrared connections only go up to about five meters before disconnecting due to proximity issues.

Bluetooth is recommended for people using their devices at a longer range as its range of use is considerably bigger than infrared.

Long-range Bluetooth devices exist, but the technology is nowhere near accessible to the consumer. Consumer electronics generally have a Bluetooth range of 5–9 meters, or about 30 feet. Bluetooth 5.0 introduced a long-range mode that claims to offer ranges up to 1 kilometer while still using Bluetooth Low Energy.

Transmission Stability

Infrared connections are notoriously unstable. Going back to your TV remote, which almost universally uses infrared connections, you press buttons on your remote, and jack squat happens on your TV because infrared connections are so unstable.

Bluetooth uses radio waves that can pass through many obstacles; even most walls can’t stop a radio wave. This, combined with the long connection range and 360° radius, make Bluetooth a much more stable connection between two devices.

Governing Authority

No one owns Bluetooth and infrared technologies. Unlike intellectual properties, which are, well, property, Bluetooth and infrared technologies aren’t owned. However, their use in consumer products is strictly overseen by their governing bodies, the Bluetooth Special Interests Group and the Infrared Data Association. These governing bodies control what devices are allowed to use Bluetooth or infrared technologies.

These bodies also control and develop the technologies and data protocols used by devices that incorporate their technologies. This ensures that the devices using their technologies are of suitably high quality and are using the technology correctly.

Data Transfer Efficiency

Both systems transfer data very efficiently, but the type of data they can transmit is different. In the modern day, infrared technology is rarely used actually to transfer files and data. Instead, most infrared technology uses remote controls and small-scale data transfers. Large-scale transfers are generally done through a wired connection or a wireless cloud.

Bluetooth connections quickly become a preferred file transfer method when transferring files wirelessly. The stability of the connection and ease of use make it an ideal setup for wireless data transfer. Unfortunately, infrared can’t compare to the speed and stability of Bluetooth in this market, mainly because infrared light experiences interference from minor environmental changes.

Having your connection interrupted when transferring data could result in corruption of the data, and infrared’s notoriously finicky line-of-sight requirements make it a dangerous game to play with your data.

Final Thoughts

Infrared and Bluetooth technologies are both essential pillars of wireless connectivity. While they may be different in both theory and application, they both represent some of the most efficient wireless data transfer methods the world currently has available.

Bluetooth is undoubtedly receiving more innovation, but that doesn’t mean infrared is outdated technology. On the contrary, many industries, including tech and medical, use infrared technology daily to improve work environments and perform tasks wirelessly.

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