What is Bluetooth?

Bluetooth

Is there anything worse than wires? If you've ever hooked up a computer and half a dozen peripherals (add-ons), a digital television and a DVD player, or run your own telephone extensions through the house, you'll know just what a pain all those cables can be. Wouldn't it be nice if there were a way of bringing electronic gadgets together so they could share whatever signals they need without any wires at all? 

Bluetooth! It's a simple way for cellphones, printers, PCs, digital cameras, and other gadgets to link together over relatively short distances using wireless (radio wave) technology. The curious name comes from Harald Bluetooth, a Danish king who united the Scandinavians in the 10th century. Will Bluetooth unite the electronic world the same way? Let's take a closer look!!

What is Bluetooth?

A Bluetooth device uses radio waves instead of wires or cables to connect to a phone or computer. A Bluetooth product, like a headset or watch, contains a tiny computer chip with a Bluetooth radio and software that makes it easy to connect. When two Bluetooth devices want to talk to each other, they need to pair. Communication between Bluetooth devices happens over short-range, ad hoc networks known as piconets.

 A piconet is a network of devices connected using Bluetooth technology. When a network is established, one device takes the role of the master while all the other devices act as slaves. Piconets are established dynamically and automatically as Bluetooth devices enter and leave radio proximity.

fig:piconet and scatternet

Bluetooth is a similar radio-wave technology, but it's mainly designed for communicating over short distances less than about 10m or 30ft. Typically, you might use it to download photos from a digital camera to a PC, to hook up a wireless mouse to a laptop, to link a hands-free headset to your cellphone so you can talk and drive safely at the same time, and so on. Electronic gadgets that work this way have built-in radio antennas (transmitters and receivers) so they can simultaneously send and receive wireless signals to other Bluetooth gadgets.

Older gadgets can be converted to work with Bluetooth using plug-in adapters. The power of the transmitter governs the range over which a Bluetooth device can operate and, generally, devices are said to fall into one of three classes:

class 1 are the most powerful and can operate up to 100m (330ft),

class 2 (the most common kind) operate up to 10m (33ft)

class 3 are the least powerful and don't go much beyond 1m (3.3ft).

 

How does Bluetooth work?

Bluetooth sends and receives radio waves in a band of 79 different frequencies (channels) centered on 2.45 GHz, set apart from radio, television, and cellphones, and reserved for use by industrial, scientific, and medical gadgets. Don't worry: you're not going to interfere with someone's life-support machine by using Bluetooth in your home, because the low power of your transmitters won't carry your signals that far! Bluetooth's short-range transmitters are one of its biggest plus points. They use virtually no power and, because they don't travel far, are theoretically more secure than wireless networks that operate over longer ranges, such as Wi-Fi.

Bluetooth devices automatically detect and connect to one another and up to eight of them can communicate at any one time. They don't interfere with one another because each pair of devices uses a different one of the 79 available channels. If two devices want to talk, they pick a channel randomly and, if that's already taken, randomly switch to one of the others (a technique known as spread-spectrum frequency hopping).

 To minimize the risks of interference from other electrical appliances (and also to improve security), pairs of devices constantly shift the frequency they're using—thousands of times a second.

When a group of two or more Bluetooth devices are sharing information together, they form a kind of ad-hoc, mini computer network called a piconet. Other devices can join or leave an existing piconet at any time. One device (known as the master) acts as the overall controller of the network, while the others (known as slaves) obey its instructions. Two or more separate piconets can also join up and share information forming what's called a scatternet.

Is Bluetooth secure?

Wireless is always less secure than wired communication. Remember how old spy films used to show secret agents tapping into telephone wires to overhear people's conversations? Cracking wired communication is relatively difficult. Eavesdropping on wireless is obviously much easier because information is zapping back and forth through the open air. All you have to do is be in range of a wireless transmitter to pick up its signals. Wireless Internet networks are encrypted (use scrambled communications) to get around this problem.

How secure is Bluetooth?

 Like Wi-Fi, communications are encrypted too and there are numerous other security features. You can restrict certain devices so they can talk only to certain other, trusted devices—for example, allowing your cellphone to be operated only by your Bluetooth hands-free headset and no-one else's. This is called device-level security. You can also restrict the things that different Bluetooth gadgets can do with other devices using what's called service-level security.

Criminals get more sophisticated all the time; you've probably heard about bluebugging (people taking over your Bluetooth device without your knowledge), bluejacking (where people send messages to other people's devices, often for advertising purposes), and bluesnarfing (downloading information from someone else's device using a Bluetooth connection) and doubtless there are more ways of hacking into Bluetooth networks still to come. Generally, though, providing you take reasonable and sensible precautions if you use Bluetooth devices in public places, security shouldn't worry you too much.

Is Bluetooth better or worse than Wi-Fi?

People often get confused by Bluetooth and Wi-Fi because, at first sight, they seem to do similar things. In fact, they're very different. Bluetooth is mainly used for linking computers and electronic devices in an ad-hoc way over very short distances, often for only brief or occasional communication using relatively small amounts of data. It's relatively secure, uses little power, connects automatically, and in theory presents little or no health risk. Wi-Fi is designed to shuttle much larger amounts of data between computers and the Internet, often over much greater distances. It can involve more elaborate security and it generally uses much higher power, so arguably presents a slightly greater health risk if used for long periods. Bluetooth and Wi-Fi are complementary technologies, not rivals, and you can easily use both together to make your electronic gadgets work more conveniently for you!

Advantages of Bluetooth

      1. Wireless

      As you probably already know, there are many benefits and advantages to using wireless devices. Along with improving safety as a result of eliminating wires you don't need, wireless also offers you plenty of other advantages. When traveling with your laptop or other wireless devices, you'll no longer have to worry about bringing connection cables.
2. Bluetooth is actually inexpensive
The technology of Bluetooth is cheap for companies to implement, which results in lower costs for the company. These savings are then passed from the company on to you.
3. Bluetooth is automatic
Bluetooth doesn't have you set up a connection or push any buttons. When two or more devices enter a range of up to 30 feet of each other, they will automatically begin to communicate without you having to do anything. 
4. Standardized protocol
Bluetooth is standardized wireless, meaning that a high level of compatibility among devices is guaranteed. Bluetooth will connect devices to each other, even if they aren't the same model.
5. Low interference
Bluetooth devices almost always avoid interference from other wireless devices. Bluetooth uses a technique known as frequency hopping, and also low power wireless signals.
6. Low energy consumption

      As a result of Bluetooth using low power signals, the technology requires very little energy and will use less battery or electrical power as a result. This is an excellent benefit for mobile devices,as Bluetooth won't drain the battery.
7. Sharing voice and data
The standard for Bluetooth will allow compatible devices to share data and voice communications. This is great for mobile phones and headsets, as Bluetooth simplifies driving and talking on your cell phone.
8. Instant PAN (Personal Area Network)
You can connect up to seven Bluetooth devices to each other within a range of up to 30 feet, forming a piconet or PAN. For a single room, you can also set up multiple piconets.
9. Upgradeable
Upgradeable is the standard for Bluetooth. There are newer versions of Bluetooth in the works,
which offer many new advantages and backward compatible with older versions.

Disadvantages of Bluetooth

Bluetooth has several positive features and one would be extremely hard pressed to find downsides when given the current competition. The only real downsides are the data rate and security. Infrared can have data rates of up to 4 MBps, which provides very fast rates for data transfer, while Bluetooth only offers 1 MBps.

For this very reason, infrared has yet to be dispensed with completely and is considered by

many to be the complimentary technology to that of Bluetooth. Infrared has inherent security due to its line of sight. The greater range and radio frequency (RF) of Bluetooth make it much more open to interception and attack. For this reason, security is a very key aspect to the Bluetooth specification

Battery Drain

Bluetooth is an energy-efficient technology. it does slowly drain the battery of your cell phone or other mobile device. When enabled, Bluetooth continually scans for signals, looking for new devices to connect with, but using energy in the process. Check your device's settings and turn Bluetooth off when you're not using it.

Poor Security

Virtually every network technology has some security built into it to prevent hackers from accessing your data without your permission. However, Bluetooth security is weak compared to Wi-Fi and other wireless data standards. A determined attacker can, for example, gain access to your wireless device through a Bluetooth connection, although he or she would have to be nearby for the attempt to work.

Slow Data

All wireless technologies have limits on how fast they can transmit data; generally, faster connections mean higher energy consumption. Because Bluetooth is intended to be very energy-efficient, it sends data relatively slowly. The Bluetooth 4.0 Low Energy standard, at 26 megabits per second, is much faster than Bluetooth used to offer and suitable for occasional syncing and small backup operations. However, Bluetooth is not a substitute for faster technologies such as Wi-Fi and USB.

Although there are very few disadvantages, Bluetooth still remains the best for short range wireless technology. Those who have tried it love it, and they know for a fact that Bluetooth will be around for years to come.