*What Are the Technical Differences Between Bluetooth and Wi-Fi? | Re/code
Too Embarrassed to Ask: Wi-Fi v. Bluetooth
A few weeks ago, a very smart friend asked me how she might play music from
her iPhone through an external speaker to entertain about 40 people at an
event, without using any cables. I suggested a Bluetooth speaker, and showed
her how it worked. But she still wondered if this was a reliable solution,
because she didn’t know if the location of the event had a Wi-Fi network.
As I tried to explain that Wi-Fi was irrelevant in this case, it occurred to
me that a lot of people may be too embarrassed to ask what the difference is
between the two widely used forms of wireless data transmission. So here
Both Wi-Fi and Bluetooth are found in almost every laptop, tablet and
smartphone. But they’re very different, and generally used for different
things. They can be on and active at the same time, doing these different
things, or you can use each one separately.
Wi-Fi, which originally meant “wireless fidelity,” is primarily about
connecting one or many devices to the Internet, or creating a local wireless
network that can link multiple devices. It depends on a central base station
(or multiple stations) that sends out a network signal strong enough and
wide enough to cover, say, an office or home, a coffee shop or even an
By far the most typical Wi-Fi scenario for consumers is the wireless router
installed by an Internet provider in a home. It sends out what might be
thought of as invisible Internet “rays” around the house that can be tapped
into by any laptops, smartphones or tablets within their range to get
Here’s what you need to know: Bluetooth is a short-range wireless solution
for pairing one device with another; Wi-Fi has greater range and works with
Bluetooth is much shorter-range, usually around 30 feet in my experience. It
rarely involves getting onto the Internet, and doesn’t depend on any central
device like a router. It is almost always used to connect two devices
together in some useful way.
One example is that wireless speaker and smartphone my friend wanted to use.
The phone and speaker talk directly to each other over Bluetooth, which
beams the music from the phone to the speaker without the need for any third
device or wide network. That’s why it doesn’t matter whether there’s Wi-Fi
in the room.
Other common examples of Bluetooth scenarios are wireless headsets for
making phone calls, or wireless keyboards and mice for computers and
tablets. If you’ve purchased a brand-new car in the past few years, you
likely had the option of getting Bluetooth installed in your vehicle.
Because Bluetooth is a direct device-to-device technology and used for so
many different things, it typically requires that you first “pair” the two
devices being linked. This usually involves typing a number generated by one
into the other. Wi-Fi has no such pairing requirement, though you’ll need a
password to access a private Wi-Fi network.
Sometimes the two wireless systems can be used in ways that appear more
typical of the other. For instance, if your laptop lacks an Internet
connection but your smartphone has one, you can “tether” the two together to
get the laptop online. And on some phones, a Bluetooth connection is one of
several ways to perform that tethering. In this case, Bluetooth plays a rare
role in Internet connectivity.
Wi-Fi can also act like Bluetooth, connecting two devices directly over a
short range. A version called Wi-Fi Direct does this. It can transfer photos
and files between nearby devices, just like Bluetooth.
*Bluetooth Radiation – just how dangerous is it?
Posted first on August 24 2010 and updated March 2015. Burrell
Bluetooth is the name of a wireless technology that uses pulsed radio
frequency signals. Anybody that has been following my website will have just
felt their ears prick up as I said the word “pulsed”. Not good.
Here is what Dr. Andrew Goldsworthy has to say about pulsed radiation:
“Pulses carried by microwaves are particularly dangerous. This is because
their very short wavelength allows the transmission of pulses with extremely
rapid rise and fall times, and it is the rate of change of the fields
(rather than their total energy) that does most of the biological damage”
Because when we talk about pulsed radio frequency signals we are of course
talking about radiation, or in this case Bluetooth radiation. Read on..
Bluetooth is now used extensively in today’s world, in cell phone headsets,
computer accessories such as keyboards, printers, personal digital
assistants (PDAs), personal media players, GPS, gaming equipement, and also
various medical health and wellness devices.
This Bluetooth technology is used for more and more personal and commercial
applications. The Bluetooth Special Interest Group now lists over 6000
products that utilize Bluetooth technology.
All the more reason that we should be really clear as to what the potential
dangers are with Bluetooth radiation.
Is All Bluetooth The Same?
Bluetooth transmits at frequency levels in the 2.4 GHz band.
bluetooth radiation There are three power classes and it’s these
power classes which are your best indicator as to what level of Bluetooth
radiation you’re exposing yourself to :
Class 1 transmitters – are the most powerful, have a range of 100 meters and
peak transmission power of 100 mW (milliwatt)
Class 2 transmitters – are usually found in mobile devices and they have a
range of 10 meters and operate at 2.5 mW peak transmission power
Class 3 transmitters – these are the weakest and operate in a range of less
than 10 meters and have a peak transmission power of 1 mW
So the first thing to do is to check what class of transmitter your
Bluetooth headphone is. You should find this information in the
manufacturers specification. I say ‘should’ because it seems some
manufacturers deem in unnecessary to share this information. That’s why I’ve
done some research on this and listed at the bottom of the page a selection
of the ‘lower EMF’ Bluetooth devices that are on the market.
What about Bluetooth radiation?
The radiation from your Bluetooth earpiece will zap you just the same
because Class 1 Bluetooth headsets can expose you to the similar radiation
levels to your cell phone if they’re operated in close proximity to the
What Does Bluetooth Version Mean?
Don’t confuse Bluetooth version and Bluetooth Class. When looking at
Bluetooth devices you’ll often see terms like “Bluetooth V2.1 compliant” or
“Bluetooth version 3.0”. This tells you the Bluetooth software the device
uses but Bluetooth version has nothing to do with Bluetooth class.
Bluetooth versions are all about offering enhanced data speeds. These data
speeds are improving all the time as the technology evolves. Bluetooth
version 1.0, the earliest Bluetooth version, offers a data transmission rate
of 721 kbit/s. Version 3.0 HS offers a transmission rate of 24 Mbit/s.
There’s no correlation between Bluetooth version and Class.
Is a Bluetooth version with a lower transmission rate safer? It’s possible
but we don’t know. There are no studies on this so we’re pretty much in the
What Does Science Say About Bluetooth Radiation?
The science on this issue can seem confusing. The problem is there is a huge
amount of funding bias and outright manipulation of the science in order to
publish studies which show favorable results. The cellphone industry is
ready to spend a considerable amount of money to protect its interests.
Various studies support (American Cancer Society 2008, Martinez & Burdalow
2009) the view that Bluetooth headsets when used in conjunction with
cellphones decrease the overall levels of SAR exposure to the head. Whereas
other studies show a diversity of hazards from these exposures.
study found that , “men who keep cell phones in a trouser pocket
in the talk mode while using a Bluetooth device may experience decreased
fertility”. High-frequency electromagnetic fields can lead to a significant
increase in blood pressure and affect biological processes in the body just
the same as cell phones. Just two hours of exposure to high-frequency EMFs
from a cell phone or Bluetooth headset, can cause irreparable DNA damage.
This study is entitled: “Cell Phone Use Could Damage Semen – Renal and
View the complete study here:
Does Bluetooth drastically cut down on radiation as compared to having the
cell phone near my ear?
Yes, Bluetooth does drastically cut down radiation exposure compared to
having the cell phone next to your ear, if you could be sure that you were
only exposing yourself to Bluetooth radiation. The problem is that when you
use a Bluetooth headset that the transmission strength from the cell phone
itself is not decreased. If for instance you are putting the phone in your
pocket or clipping it to your belt then you are at the same time exposing
your internal organs to radiation.
The Swiss Federal Office of public health recommends that cell phones should
not be carried in a front trouser pocket when making calls and that it may
be safest to hold the phone away from the body to reduce radiation. Studies
(Whittow 2008) have also found that metallic objects situated near your
waistline, such as coins, a belt buckle, rings, keys etc increased the
Specific Absorption Rate (SAR) in the body at different frequencies.
Specific Absorption Rate (SAR) is the rate at which your body absorbs cell
Read more at this link:
“Can We Rely on SAR to Protect Us From Cell Phone Radiation?
Bluetooth devices do not require measuring and reporting of the
SAR (Specific Absorbtion Rates) values. So we’re kept
completely in the dark as to possible radiation absorption levels.
Does the radiation transmit up the headphone cable that’s physically plugged
into the phone?
Yes, it can. The headphone can act as a sort of antenna for your cell phone
giving the radiation a fast route into your brain. The science is sketchy on
this but in my view, having tried wired headphones, they are not the
solution to reducing your radiation exposure. This is now widely accepted
and yet wired headphones continue to be sold by the boatload to the
population at large.
To overcome the antenna effect of wired headphones use an
airtube hands-free kit.
Do you have a chart or is there an article you can direct me to that
contrasts/compares methods of getting the most sound to your ears with the
least amount of radiation?
I don’t know of any comparative resource on this topic but to answer your
question, “what’s the best way to reduce radiation when listening to
streaming audio on a cell phone?”. Remember: distance is your friend.
In other words, avoid holding your cell phone next to your ear at all costs.
If you do need to hold a cell phone next to your ear a
Pong case can reduce your exposure.
Read more here:
Do cell chips offer protection from cell phone radiation?
I’ve tried cell phone chips, diodes and neutralizers from many different
suppliers. None of the devices I’ve tried worked. In some cases using these
devices can be more dangerous than not using them.
Low EMF Bluetooth Headsets
Despite reading all of the above if you’re still committed to using a
Bluetooth headset where does this leave you?
To determine how dangerous a Bluetooth device is, the best information we
have to go on is the power classification, or the Class.
The worst offenders are Class 1 headsets. There are quite a few of these on
the market, for instance the Callpod Dragon is a Class 1 Bluetooth headset
and therefore to be avoided if radiation exposures are your main concern.
In an ideal world you’d use a Class 3 headset, which are the lowest powered
headsets and therefore the safest. Unfortunately because most people’s top
priority is having a good strong signal Class 3 headsets are a relic of the
past. That leaves us with the Class 2s.
The problem is the power classification of a headset takes some rooting out.
The manufacturers are very ‘low profile’ about sharing this information.
I’ve tried contacting a few of them – most of them don’t reply and the one’s
that do often don’t know what I’m talking about.
Nevertheless I’ve rooted some out.
What Class of Earpiece should you buy to minimize your exposure to Bluetooth
If you are decided about using a Bluetooth earpiece then a Class 3
transmitter will expose yourself to the lowest levels of Bluetooth
radiation. Unfortunately I did research Class 3 Bluetooth headsets, I could
find no information about Class 3 Bluetooth earpieces.
So we are left with making a choice between Class 1 and Class 2 earpieces.
Obviously your preference, if you are wanting to minimize your exposure to
Bluetooth radiation is to buy a class 2 Bluetooth earpiece.
5 Best Selling Class 2 Bluetooth Earpieces
The headsets listed below are all Class 2 Bluetooth devices:
Plantronics Voyager PRO Bluetooth Headset
Motorola S305 Bluetooth Stereo Headset
The Bluetooth headsets listed below are all class 1 transmitters (the most
Callpod DragonV2 Bluetooth Headset (Black)
Plantronics CS-55 Dect 6.0 Digital Wireless Office Headset
Callpod Dragon Bluetooth Headset
Are there any studies on Bluetooth Radiation Dangers?
As on the cell phone issue the
cell phone industry have done a very good job of making the science look
inconclusive and confusing. Added to which there have been few studies done
specifically on the issue of Bluetooth radiation.
Are Bluetooth Headsets Really Dangerous?
Yes, Bluetooth radiation dangers are real. I don’t use a Bluetooth headset,
or a cell phone for that matter. But I do occasionally come into contact
with Bluetooth and so can attest to the adverse health effects of Bluetooth
I have a friend who has a car with Bluetooth installed. A few years ago when
I was experiencing fairly extreme electrical sensitivity symptoms, when I
sat in his car with Bluetooth enabled, it would set off exactly the same
symptoms in me as when I used a cell phone.
Bluetooth is particularly dangerous in so far as earpieces and headphones go
because of the proximity to the head of these devices.
Is Bluetooth Radiation More Dangerous Than Cell Phone Radiation?
Yes, I believe it can be. Let me explain.
If you are using a Class 1 Bluetooth earpiece the dangers are very real:
1. Class 1 devices are 40 times more powerful than Class 2 devices. 100 mW
(milliwatt) as opposed to 2.5 mW (milliwatt).
2. When you use a Bluetooth earpiece device you’re exposing yourself to an
additional source of radiation. Your cell phone acts as a relay by emitting
radiation between the cell phone tower and your correspondent. When you add
Bluetooth into the equation your cell phone also emits another form of
radiation, Bluetooth radiation, between your cell phone and your Bluetooth
Your radiation exposure with a Bluetooth headset is the sum of cell phone
radiation plus Bluetooth radiation. So Bluetooth radiation in itself may be
less dangerous than cell phone radiation but when you use a Bluetooth
earpiece you are always exposing yourself to radiation from both devices.
Are There Any Alternatives To Using A Bluetooth Headset?
Besides just using a regular wired headset, yes, there are alternatives to
using a Bluetooth headset:
1. Use an airtube headset. This can be either a
basic airtube headset or a
more sophisticated version with
earbuds made in wood.
These headsets work much like a wired headset except there are no metal
wires to conduct the radiation. Obviously you don’t get the freedom of
movement that you get with a wireless connection, and the sound quality may
not be optimum but if you’re worried about your radiation exposures this is
a good solution.
2. Connect a retro handset to your telephone. The length of the cord means
you are still in close proximity to your cell phone so you will still be
absorbing some radiation. The manufacturers of the
Echo Logico retro handset,
claim that using their handset “reduces absorbed mobile phone radiation by
I recommend steering clear of these devices, but if you still want to
continue using a Bluetooth earpiece make sure you buy a
Class 2 Bluetooth device
(in the absence of Class 3 devices).]]>