For example, if you buy a cordless mouse, the first time you turn it on, you pair it to the device you plan to use it with.
You might turn the mouse on, then go to the Bluetooth settings on your computer to pair the device once you see its name in a list of nearby Bluetooth accessories. A computer can handle many Bluetooth connections at once by design. You may want to use a cordless mouse, keyboard and headphones. The makers of those accessories, however, are going to limit connections to one at a time.
You want your keyboard to type only on your computer, or your headphones to listen specifically to your phone. Some allow the user to pair the device with multiple computers, tablets or phones, but they may only be allowed to connect with one at a time. It all depends on what the manufacturer decided was sensible for their product. Some devices require a code for security while being paired with another device.
This is an example of authentication and it ensures that the device you are setting up that trusted relationship with is the one you think it is, rather than another device somewhere else in the environment. For example, many cars let you take calls without taking your hands off the steering wheel. The first time you want to use this facility, you will have to pair your phone and the car's audio system using the car's entertainment display and your smartphone together.
The car gives you a number to type in. Your phone lets you know a device wants to pair using a numeric code. You enter the code off the entertainment display to confirm that this is an authorized pairing. After that, you can use the hands-free phone system without ever needing to pair again.
The user also has control over a device's visibility to other Bluetooth devices. On a computer or smartphone, for example, you can also simply switch the device's Bluetooth mode to "nondiscoverable" or simply disable Bluetooth until you need it again. Sign up for our Newsletter! Mobile Newsletter banner close.
Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. How Bluetooth Works. Although Bluetooth technology has become synonymous with headphones, it's used for all kinds of wireless devices. How much data will be sent at a time? For instance, serial ports send data 1 bit at a time, while parallel ports send several bits at once. How will they speak to each other?
All of the parties in an electronic discussion need to know what the bits mean and whether the message they receive is the same message that was sent. Create your free account or Sign in to continue. See Subscription Options. Go Paperless with Digital. We go straight to the source and get Bluetooth executive director Michael Foley to wirelessly transmit an answer to this query. Get smart. Sign Up. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber?
Create Account See Subscription Options. Continue reading with a Scientific American subscription. However, the lower the frequency the lower the data rate it can support. As a result, selecting a radio spectrum comes with tradeoffs between range and data rate. In addition, the 2. The physical layer PHY of a wireless technology defines the modulation scheme and other techniques it uses to send data over a specific radio frequency RF band.
This includes the number of channels available, how effectively those channels are utilized, the use of error correction, the guards in place to counter interference, and much more. If you compare RF communication to verbal communication, you can think of the PHY as defining the speed and clarity of your speech. Both impact the range at which you can be heard. Receiver sensitivity is the measure of the minimum signal strength a receiver can interpret. Think of receiver sensitivity as a measure of how well you can hear or the quietest sound you can hear and understand.
However, Bluetooth implementations typically achieve much higher receiver sensitivity levels. Choosing a transmit power level is a design tradeoff between range and power consumption. The higher the transmit power, the more likely the signal can be heard at longer distances and the longer the effective range. However, increasing the transmit power increases the power consumption of your device. Think of transmit power like the volume of your voice.
The louder you speak, the farther away someone can hear you but the more energy it takes. The antenna converts electrical energy from the transmitter into electromagnetic energy or radio waves and vice-versa for the receiver. Antenna location, package size, and design can greatly impact how effective the signal is transmitted and received.
And types and sizes of antenna and their efficiency in converting electrical to electromagnetic energy and focusing the direction of the energy can vary greatly.
The effective antenna gain is relevant for both the transmitting and receiving antenna. The directional influence of an antenna is similar to speaking or listening through a cone to focus the energy of the sound.
Antenna design is as much an art as it is a science. Path loss is the reduction in signal strength that occurs as a radio wave propagates through the air. Path loss, or path attenuation, occurs naturally over distance and is impacted by the environment in which the signal is being transmitted. Obstacles between the transmitter and the receiver can deteriorate the signal. What's going on here? If you guessed that the stranger was talking to someone else via a wireless headset hooked up to the smartphone in his pocket, you're correct!
Is this magic? It's Bluetooth! Bluetooth is a global wireless communication technology originally invented by engineers at Swedish company Ericsson in Today, no single company owns the Bluetooth technology.
Instead, a group of companies called the Bluetooth Special Interest Group work together to advance the technology. Bluetooth technology allows a wide variety of devices and services to connect to each other wirelessly, silently, and automatically. Bluetooth-capable devices include smartphones, audio speakers, automobiles , medical devices, computers, and even toothbrushes, to name just a few.
Exactly how do such different devices communicate wirelessly and so effortlessly? Bluetooth connectivity requires both hardware and software components. To send and receive Bluetooth communications, a device must have a special microchip that contains an antenna. It must also have companion software that can process the signals. When you connect two Bluetooth devices, they form a personal area network, also known as a piconet.
Once that connection is made, the devices communicate automatically without needing human input. To communicate wirelessly, the devices exchange data via low-power, short-range radio waves in the industrial , scientific, and medical ISM band at 2.
Since Bluetooth devices send low-power signals only about 1 milliwatt , the technology does not use much battery power. However, these weak signals limit the range of Bluetooth devices to about 30 feet.
Despite their weakness, Bluetooth signals don't require line of sight between devices. The radio waves will travel through walls easily, and their low power helps to reduce the chance of interference from other technologies that use radio waves, such as baby monitors and garage door openers. Bluetooth technology features several other advanced techniques to avoid interference and maintain strong wireless communication. For example, a technique known as spread- spectrum frequency hopping allows a device to transmit on any one of 79 different, randomly-chosen frequencies while also changing frequencies up to 1, times per second!
What does that mean practically? Bluetooth technology can connect up to eight devices at the same time within the same foot radius without any of the devices interfering with each other. That's quite impressive, given that there are currently billions of devices around the world equipped with Bluetooth technology. We hope you enjoyed today's wireless Wonder of the Day! Be sure to check out the following activities with a friend or family member:.
Fantastic website, I appreciate the hard work and commitment y'all put into the website. Really great information. We hope this Wonder helped explain that a little better, Eva! Every device is different, though! Hi, nyla! What was your favorite part? Thanks for joining the discussion and leaving a comment! Hi, Katherine! We're glad you liked this Wonder and learned a lot of new information.
It's interesting to learn how Bluetooth technology works. It was a very informative Wonder, for sure!
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