Bluetooth and Wi-Fi: What's the Difference?
Bluetooth and Wi-Fi, as wireless technologies have similarities, but the differences are significant.
The term “wireless” has been in use for more than a century. It first referred to communication without telegraph wires and was adopted as the term for what is more commonly known today as radio.
That the two are synonymous was the point Edward C. Hubert emphatically made in “Radio vs. Wireless” back in 1925:
“Wireless means communication without the use of wires other than the aerial; the ether and ground taking the place of wires. Radio means exactly the same thing: it is the same process.”Advertisement
Today when we hear “wireless,” we likely don’t picture a radio. However, radio waves are still key to the way Bluetooth and Wi-Fi operate, enabling your devices to connect to each other or to the internet. (Read also: More Than Moore: 50 Years of Moore's Law.)
The Birth of Bluetooth
An interesting thing about the name “Bluetooth” is that it is far older than wireless technology. The company behind the name explained it was the nickname of King Harald “Bluetooth” Gormsson who united Denmark and Norway back in 958 that highlighted the color of his dead tooth.
In 1996 Jim Kardach from Intel suggested that name to reference the unification concept: “King Harald Bluetooth…was famous for uniting Scandinavia just as we intended to unite the PC and cellular industries with a short-range wireless link.” While it wasn’t intended to be the final version of the name, it ended up sticking.
Among the names they were considering were variations on PAN for personal area network. The person in there refers to the distance with the range of a person. That’s why the signal won’t usually extend beyond 30 feet.
The distance between Bluetooth devices is often much smaller, as in the case of using a wireless keyboard within a couple of feet of your computer or a wireless headset near your phone. To put it in technical terms:
“Bluetooth operates in the 2400-2483.5 MHz range within the ISM 2.4 GHz frequency band. Data is split into packets and exchanged through one of 79 designated Bluetooth channels (each of which have 1 MHz in bandwidth).”
The BLE version
As with all technology, Bluetooth did not remain static. The original form that some may call Bluetooth classic was reinvented more than once, most significantly in 2011 when it released version 4.0 AKA Bluetooth Low Energy (BLE), which leads some to refer to the other version as Bluetooth Classic (BC).
The way BLE achieves a reduction in energy consumption is by staying in sleep mode until roused by activation through a connection. The amount of energy saved as a result is quite impressive.
According to The Droids on Droids, an Android blog, it can achieve “as much as 100x lower power consumption” than its classic counterpart. That’s because where BC consumes a full watt, BLE only consumer 0.1-0.5 watts of energy.
The blog explains the way it works:
“The data is sent in small (20 bytes) packages, but the range can be even more than 100 meters (330 feet) and the minimum latency between unconnected state to data transfer can be counted in a handful of milliseconds, while in BT Classic it’s about 100 ms.”
As a result, all it takes to power basic BLE devices is a very small battery. A small 1,000 mAh coin cell battery can keep it going for up to two years, according to the blog.
Why Bluetooth Classic is Still in Demand
Given the impressive efficiency of BLE, one may think that it has completely supplanted the classic version. But that is not the case, because the low energy version is not up to providing uninterrupted transmission that we have come to expect from our computer and smartphone tasks.
People are willing to sacrifice battery power for “for continuous two-way data transfer with high Application throughput (up to 2.1 Mbps),” the blog explained. That’s why the Bluetooth that enables “streaming audio and video, or mice and other devices that need a continuous, broadband link” is the classic version.
From PAN to LAN with Wi-Fi
Like Bluetooth, Wi-Fi works off a radio frequency. But it is not limited to the short distances and data loads of PAN; it enables LAN (local area network). In that network, Wi-Fi-enabled devices can connect so long as they are within range of the signal, which can extend to 300 feet.
Wi-Fi is a trademark name used to refer to devices that employ IEEE 802.11 standards. Product manufacturers must complete Wi-Fi interoperability certification testing, as conducted by the Wi-Fi Alliance, in order to label devices as Wi-Fi devices.
First introduced in 1994, Wi-Fi can work off 2.4, 3.6, and 5 GHz with a bandwidth of 11 Mbps, and latency of 150 ms. Typical Wi-Fi is used to allow access to the internet, so that a home, office, library, or hotel can have several devices pick up on the service without being plugged in.
That form of connection is what makes the Internet of Things (IoT) possible, to have smart homes, devices, and appliances that can be accessed over the internet from anywhere. The downside is that it also can create a point of vulnerability that leads to the phenomenon of being hacked though an aquarium and the like. (Read also: 6 Myths About Hacking That May Surprise You.)
Wi-Fi Direct: Like Bluetooth But Different
Despite its association with getting connected online, Wi-Fi can now be used to connect devices directly to each through what is known as Wi-Fi Direct, which is more comparable to Bluetooth in functionality than standard Wi-Fi.
As the official site explains:
Wi-Fi Direct devices can connect anywhere, anytime—even when there is no access to a Wi-Fi network nearby. Wi-Fi Direct devices emit a signal to other devices in the area, letting them know a connection can be made. Users can view available devices and request a connection or may receive an invitation to connect to another device. When two or more Wi-Fi Direct-certified devices connect directly, they form a Wi-Fi Direct group using Wi-Fi Protected Setup™.
Wi-Fi Direct connections are faster than Wi-Fi connections made over the internet because they only entail a single-hop rather than two—one to the router and another to the intended device. It’s like taking a direct flight without having to hop over to the airline’s hub to then hop out again to your destination. (Read also: Is Wi-Fi Interference Causing Unseen Problems in Your Enterprise Network?)
While that sounds just like Bluetooth’s function, the difference is that you get much faster speed with Wi-Fi direct. Bluetooth can’t accommodate more than 50 Mbits/s, and Wi-Fi direct can achieve speeds of 2Gbits/s. That’s the kind of speed you need for optimized experiences of video games, smart TVs, as well as high-resolution images and videos and richer-sounding music.
But faster speeds do come at a cost, and for Wi-Fi direct, that means a lot more energy consumption -- as much as 20 watts in contrast to BLE’s consumption of 0.01 watts. That is a consideration when it comes to limited battery power on mobile devices.
The Answer: All of the Above
The various forms of Bluetooth and Wi-Fi are not mutually exclusive. Most of us are using all of them.
The different forms of connectivity coexist in our offices, cars, homes, and libraries. They help provide the type of connection we need with the range and level of power required to make our interfaces seamless as we shift from our computers to our smartphones, tablets, and smart devices.