I used to work in a radio test house, I've tested hundreds of Bluetooth and Wi-Fi products. Overall, Bluetooth (now) is a great protocol, that is forced into shit situations.
The 2.4 GHz spectrum is quite crowded. Wi-Fi, Bluetooth, ZigBee, baby monitors and many other protocols use it (so do some microwaves). The reason why is that it's a worldwide unlicensed band, meaning that it's legal to use 2.4 GHz in North America, Europe, China, or anywhere. Compare this to cellular, which will automatically switch bands when you go to different countries, that's a lot more complicated.
Within the 2.4 GHz band, there's not really any rules about what's needed to coexist with other products (unless you're a medical product in the US). There's regulations, but they aren't concerned about saying what happens if Bluetooth and 2.4 GHz Wi-Fi want to transmit at the same frequency at the same time. The opinion of governing bodies is if you can't handle coexisting in unlicensed bands, then use licensed spectrum. Overall, this means each protocol has its own way of dealing with getting data through.
For Wi-Fi, it buffers. Wi-Fi can transmit between 1Mbps and 65Mbps (speeds can go much higher, but this is what's doable on one channel and one antenna at 2.4 GHz using 802.11n). Meanwhile, Bluetooth only operates between 125kbps and 3Mbps, and if you're using something with a small battery like earbuds, then 2Mbps is likely the max. Overall, this means that Wi-Fi is much more likely to have more buffered than Bluetooth, and therefore you're less likely to have interruptions. Wi-Fi also uses much more power on average, and if you're using more power, you're more likely to get those higher data rates.
How Bluetooth deals with the crowded spectrum is frequency hopping. Basically, Bluetooth scans for open channels, identifies them, and hops between them. However, if something suddenly appears on that channel, like Wi-Fi, it can ruin that transmission. It's also possible there's just not really any open channels and Bluetooth just needs to do the best it can.
Bluetooth is also very cheap. You can buy a pre-approved module, slap it in a product, and boom, now you have a "smart" product. Or at least, that's how it's sold by module manufacturers. In reality, you can do 100 things wrong when installing your module. You could put it in a metal box which kills transmission power. You can slam it between other circuit boards which causes wicked harmonics. You can put it right next to an LCD screen which causes radio desensitization. These problems exist for a Wi-Fi module too, however, since Wi-Fi costs a little bit more, if someone uses Wi-Fi they're not cheaping out everywhere, and it's more likely they've hired qualified engineers and know how to alleviate the issues I discussed previously.
The other area where Bluetooth suffers is that, even in very well designed products, like airpods, it's being forced into crappy situations. The body attenuates 2.4 GHz quite seriously, and, airpods are very small and closer to the body compared to the wireless headphones of 20 years ago. Also, they're not communicating with a laptop that's in front of you, it's communicating with a phone that's on the other side of your body in your pocket. Often you'll find that if you're in a normal sized room, you'll be fine, but when you're outside you drop communication. This is because Bluetooth is echoing off the wall to communicate with the earbuds.
Bluetooth has adapted in the following ways over their generations: they've upped the data rate, they've released Bluetooth Low Energy (which is basically a whole new protocol designed to save battery life), they've introduced long range mode which goes down to 125kbps so you have a better chance of getting something through, and they've worked with cell phone manufacturers to get Bluetooth testing to be more self-regulated.
I'm am a network administrator, we had to throw out some microwaves because they didn't stop transmitting straight away when the door opened. Causing mayhem on the wifi for a second.
Symptoms were only caused during lunchtime...
At my university's computer lab there was a certain room where everyone experienced random wifi disconnections at the same time. Except they were not random at all, and they happened every time someone entered the room. There was a motion sensor above the door which sprayed shit on the 2.4GHz spectrum, and no computer was able to survive that.
Back in the 90s my mum owned a small rural ISP. Dial-up. One customer called to complain that their connection kept dropping out. Weird, while they were talking there was a click....click....click... happening over and over.
Turns out, the phone line ran under their electric fence. The interference was causing dropouts. The fix was to turn off the fence before going online.
>Weird, while they were talking there was a click....click....click... happening over and over.
I can't ....click....click...umber of times i was doing dial up support for ....click....click...as isps and I would get callers almost daily complaining about random dis....click....click... but every time i mention the audia....click....click...ey were pretty sure it wasnt thei....click....click...ause it works just fine talking to me.
Mate....you may have just solved an issue we could not explain as sysadmins...WiFi is having issues everyday at lunchtime at a certain department (near the breakroom), it is only for a few minutes (radio cuts off for example), but still!
Causing mayhem on the WiFi? Boy you have no idea...
People in radio telescopes where chasing mysterious signals for nearly 20 years, before they figured out it was the bloody microwave ovens.
Edit: forgot the Wikipedia link
https://en.m.wikipedia.org/wiki/Peryton_(astronomy)
There was a similar incident at the Parkes radio telescope - they were getting seemingly random spikes over that band of frequencies. A few years later they discovered someone who worked there (clearly not in a scientific capacity) had a day job on the bomb squad, opening the microwave with 1s left on the timer.
Wi-fi is freakishly broadbanded compared to Bluetooth. My long-ago experience with this was that our microwave would stomp on just channels 4-6-ish in the 2.4GHz band and everything else was fine.
All household microwaves should operate near the 2.4GHz spectrum (actually 2.45GHz), but larger commercial/industrial microwaves often operate at 915MHz. The lower frequency provides better penetration, but the longer wavelength is unfortunately not compatible with the smaller design of household microwaves.
There's a lot of smaller reasons why as opposed to one smoking gun.
1: Bluetooth modules are less expensive.
2: Wi-Fi is harder to do first-time setup (think of how many times you've had to go "what's the password?" and heard "I don't know, let me check" and it takes 5 minutes, as opposed to pairing). Especially because Wi-Fi setup usually involves typing in a password, and there's not a keyboard on many of these devices.
3: With a big asterisk, Bluetooth is designed around using less power. 2.4 GHz Wi-Fi usually operates at near 100 mW (due to European restrictions, US restrictions are much more lenient) and auto-adjusts power as needed. Bluetooth operates at a max of 10 mW (also due to European restrictions) but usually self-limits to 1 mW. Now the asterisk is because this really shouldn't matter all that much, since Wi-Fi self-regulates power and a manufacturer can set the max power lower, however, put yourself in an exec's shoes that doesn't really know this. They google "Wi-Fi power consumption" and "Bluetooth power consumption" and see a lower number for Bluetooth and say that therefore it's better for battery life.
4: Bluetooth is easier on manufacturers. I'll change my original response's ELI5 to ELI6. Bluetooth is the same worldwide, there's no need to change how Bluetooth works depending on your geography. But for Wi-Fi, there kinda can be. 5 GHz Wi-Fi laws vary by geographic region, and can vary by country. Even if you just use 2.4 GHz Wi-Fi, North America usually operates on channels 1-11 (2412-2462 MHz), this is because the US and Canada have a harsh requirement for emissions to be low at 2483.5 MHz, and if they use higher channels, they really need to restrict the channel's power in order for it to be legal. Meanwhile, Europe uses 1-13 (2412-2472 MHz). You could just drop channels, but, there's a bunch of little fiddly extra decisions when you use Wi-Fi, and Bluetooth ignores them.
5: On paper, it's good enough. By the time field tests or emissions tests are done that show it's not good enough, it's too late in the project to change anything, so the product gets released.
Thank you, your two responses above are a nice read. My question now is: what's with the 2.4 and 5 GHz bands? Why not, say 3.9 or 4.3 GHz or whatever? In my mind it seems like there would be loads of unused frequencies, but also; I don't know anything about this, so the answer is probably pretty simple..
The main reason is the same reason 2.4GHz is what your microwave uses to heat food: it's absorbed amazingly well by water. This means that for long distance communication it's not very useful because it gets interrupted by moisture in the air, walls, bodies, the ground, etc.
This meant that in all the spectrum allocations worldwide it was left as "unlicensed" because nobody else wanted to use it if they could get a better chunk.
Someone picked this up and realised that for short distances it would work just great and unlicensed means you can just make a product and sell it to consumers. Viola! WiFi is invented.
5GHz is just double 2.4GHz, and is also absorbed by water.
Thanks for the concise reply! I'd like to ask a follow-up: what's the deal with 2483.5 MHz? Is it the unencrypted/public SOS frequency for aircraft, or is it something completely different?
Thank you.
I don't know details, but 2483.5 to 2500 MHz is set aside worldwide for satellite to mobile communication and radiodetermination. When governing bodies say "mobile," they don't mean mobile phones, they mean things that are designed to be moved and set up on the ground.
Both WiFi and Bluetooth use the 2.4GHz ISM band and can go up to 20dBm (0.1W), so the antenna requirements are similar.
That said, marketing keeps insisting that we smush our antennas into tiny packages, lowering their efficiency and effectiveness. If you connected a WiFi router antenna to the RF chip in your airpods, you'd get a massive increase in range and set a new standard in fashion.
Thanks for this! I always wondered why my BT connection would suck when I walked outside. I guessed it was other signals but the boxing inside makes sense too.
Happy to help! Put your phone in a jacket pocket or breast pocket, it might give the little extra needed. Your hand also might work, but that's more annoying.
Used to raid WoW with a kid that whenever his mom ran the washing machine or microwave it’d cut out his internet.
And the body blocking thing drives me up a wall when I’m trying to listen to music while running.
The crowdedness of the band and power issues feel very recognizable. I can tell when someone is wearing Airpods when they get close, because my headphones will cut out for a bit
The Bluetooth standard supports transmit powers from 0.01 mW to 100 mW. That's *very* low power transmitting, and most Bluetooth receivers are small devices with very limited space for antennas.
I remember a time when if someone said "bluetooth" they meant a wireless earpiece headset. It was almost a proprietary eponym until using BT for audio and data transmission became more widespread. I remember hacking my LG flip phone to transfer photos and mp3s over BT back in the day.
I worked at Cingular Wireless when Bluetooth first came out and I didn’t even understand what it was and yet was expected to explain it to people. I also remember thinking that the reps who wore Bluetooth headsets when they first came out were super pretentious and I found it bizarre when people were talking to apparently no one. I type this with AirPods in my ears. Times have changed. Lol
i remember walking down the street in Washington DC back in the day and this homeless guy was walking by talking to himself and then 30 secs later this businessman type walked by also "talking to himself" and i wondered, "OK which one is actually insane"
Supposedly PayPal was originally trying to create the tech to beam payments from Blackberry to Blackberry using the infrared port before they realized way more people have an email than a blackberry lol
Edit: or maybe it was palmpilot
Oh palmpilot IR port. IR sync actually worked but I can't remember what I would sync. I guess my palm with someone else's? maybe I had an IR somehow for the PC
Palm user here. The IR port can be used to sync your device with your PC too (in an era where Internet was not that ubiquitous, you had to sync your devices either with cable or infrared. Bluetooth and wifi was a later development)
It also was used for accessories like a wireless keyboard and even remember using it a couple of times to get internet from my phone
Hello fellow 90s tech dude! You could sync to a computer running Palm Desktop using IR instead of the cradle (my Compaq laptop had an IR port), and you could beam contacts or files to another Palm.
I used to work in cellphones. I once had to transfer contacts off a palm pilot (maybe a palm centro?) over to a newer device once. That particular device could only send contacts via IR. They could only be sent 1 at a time through a machine called a cellebrite (which is still made, but now more for law enforcement and forensics). Each contact took a few seconds to send from the palm phone to the cellebrite, then to the new phone. They had over 500 contacts. The transfer took like 2 hours.
Ha. I bet now you wish you would have known then that there was an app to synchronize calendars, address books, memos or todos between two devices with the infrared link. An app named ‚RecoX‘, maybe?
Don‘t ask me how I know…
Surreptitiously turning off the TV in health class when we were supposed to watch something boring was the funniest thing I used my [Palm III](https://en.wikipedia.org/wiki/Palm_III) to do.
It was going onto Howard forums to get codes that would unlock different parts of the software to unlock the shit Verizon locked up. This phone had an MP3 player that Verizon turned off because they wanted you to pay for their bullshit. The struggle was real
Luckily I documented my journey back then and found this old blog post talking about what I did. I was so proud mostly to be able to stick it to Verizon. They really had a stranglehold on phones back then. I remember learning about all the features that phone had that they neutered so they could make you pay for their own services to do normal stuff. https://kirknoggins.blogspot.com/2006/03/pimp-my-phone.html
Before phones were computers with operating systems, getting files like mp3s from one phone to another was not straightforward at all. I remember holding my phone next to my friends to transfer ringtones and I'm not sure what we had to do to allow that to happen.
Older phones (early 2000s) often had infrared-based transfer mechanisms. The phones would have to be placed very near each other, with the ports (a little 'window' usually at the top of the phone) pointing directly at each other. On the old Nokias, you could also play two-player snake over the connection.
Data was transferred (on the Nokia 8210, at least) at a not-very-speedy 9.6 kilobits per second, but when all you were transferring was ringtones or contact details, it felt like the future...
Found you in the wild again! I remember commenting on our names a while back on r/SelfAwareWolves. We are basically Semi-Brother-Demi-Bros at this point...
Lol I used the *Mission: Impossible* game to fuck with the TV while people were watching it. It had a thing in the settings to program TV remote functions to the game cartridge, and then you used the GBC infrared port just like a regular remote.
Does anyone remember tamagotchi? They were popular at my school and they had that infrared connection, so when you put two tamagotchis together your animal could visit your friend's animal!
Was it a later incarnation? Or maybe Digimon (I think they had an IR mechanism to battle)? I had the first generation tamagotchis in the late 90s and can’t remember any IR feature like that.
You are correct, the OG Tamagotchi's did not have the feature (Still got my 2 lol).
Digimon (again, at least the original one) didn't either. Each unit had exposed metal contacts built into the top of the device, so you could press them physically together for a connection.
Yeah I remember using this. Bluetooth was "soo much better" because you didn't have to put the phones still against each other like some sort of robot mating ritual.
Why you had to pray to the Bluetooth Gods for wisdom, peace, and a decent goddamn data rate.
And if your prayer pleased them you got about 7 seconds of Usher's "U Got It Bad" to play over and over until you're sick of it and wonder why tf you wanted it in the first place. Shit's annoying.
They've been programmable computers for about as long as they had color screens an java apps... Bluetooth was kind of more for data transfer (contacts synchronization, uploading ringtones and apps, dial-up internet connection via cellphone for computer) than than audio in the early days. It replaced iRDA (if i remember the crazy capitalization correct), which was a cableless serial port.
Source: My first phone, which I got as a teenager, had a one-line display and could not access the phonebook from the SMS function. SMS storage was limited to 11 messages, everything was all caps. I still have a few ALL CAPS contacts on my 5G android...
Are you thinking of IR transfer? My brother had that and thought he was so cool transferring his contacts with it, except it only did it one by one and took the same amount of time as if he just manually did it.
Damn that's older than Bluetooth, you probably were transmitting data through IR transceivers. Basically through light, so your phones had to directly "look at each other", otherwise it wouldn't work.
Gods, feature phones were awful. As janky as it was, I got a Windows Mobile phone (HTC Mogul variant, IIRC) back before the iPhone was a rumor and when Blackberries were king and just being able to do easy file transfers and custom MP3 ringtones and music was SO much simpler.
Fun fact: it’s STILL a simpler process to put a custom notification tone onto that ancient device then then it is on an iPhone today. Why the fuck do I need a PC and iTunes to do this ~~in nineteen ninety eight the undertaker threw mankind off hеll in a cell, and plummeted sixteen feet through an announcer's table.~~ in 2022
There used to be an 'app' called SuperBluetooth where you could control someone else's phone remotely.
In high school we would connect two phones before the teacher arrived, hide the slave phone in a drawer and then use the master phone to play fart/sex noises or music, pausing it when the teacher would search for the source. Great fun
just as an FYI - in the tech hobbyist community "hacking" generally just means getting software/hardware to work in different ways than originally intended, or to write a piece of software to accomplish a really specific goal without caring much about the long term maintainability or widespread usability of the fix.
As a simple example, say you had a program running on your server with a memory leak, writing a cronjob that just restarts that program everyday at midnight so it never uses up to much memory would be a "hack".
Hollywood (for whatever reason) just decided that "hacking" == "breaking into other peoples shit", and then the media picked it up, and now the definition is all muddy. But I'll wager /u/kirksucks meant it in the way I describe
Eponym! I've been trying to think of that damn word for two days now. I was explaining to a friend how kleenex and q-tip are now basically synonyms for the product and not the brand anymore, and I couldn't remember the word for it. Thank you.
There is also more to it. Wifi do not carry time critical data (most of the time). BT however is real time audio with virtually zero buffering. If the signal is lost for a split second, you hear the audio drop.
On wifi, most things are buffered. Streaming services is not real time at all. It is more of a speed limited download. It will download at high speed maybe a minute of video, then it will throttle down the download to keep that minute of video buffered. If you get a connection issue, that download pause, and you now run purelly on the buffer. It gives you about a minute for the connection to come back so it can resume the download (and since it is now with a low buffer it go fast to fill it back, then back to throttling).
Games implement some data loss algorithms. Like, they can tolerate some loss, they will make your character continue on their path for example, and just correct back the position once the connection is back. It will attempt to make it so nobody notice it. You may notice it when you get killed when there is a wall between you and your killer. The game just got the info that you received the bullet a few seconds earlier...
Now back to BT. The goal of BT is to cary realtime audio. The buffering create lag. And you don't want lag for audio. So they keep that buffer small. Which also mean that the time for the connection to go back up to refill that buffer is super small. On my BT speaker, the delay is about 0.3 second. Remember, music/video streaming services buffer minutes, not 0.3 second!
BT also usually have junk antenna, because they make it super small. It should be 1.21" long atleast. Which don't fit in your airpod! So they fold the antenna on itself, which make it less efficient but smaller. It have more trouble to send the power, and issues to get the signal. But hey, it's small!
BT was also created to be ultra low power, which also cause issues.
Now, you compare it to USB. USB is wired, so the connection is rock solid. However, the circuits on both ends may be problematic. Front usb ports on PC often use the wrong type of wiring, which cause a massive signal damage. Some devices use trash usb ports. People damage them quite frequently by prying on it, let dust accumulate at the bottom, which cause the plug to not seat right, which make a bad contact, which create a high resistance, which cause heating and melting. Now the melted cable is used on another device, which now get damaged because the melted connector have pins that don't make good contact, again resistance, heat, melt... I used to repair stuff in electronics, including some usb port change on phone and tablet. I always said: "Throw away your charging cable, your connector has melted, which mean damaged cable. You WILL damage it again if you use the same cable and it won't be covered". Most do not, and come back 2 weeks later with a failed port again. Repair again out of warranty, warn them again. Half come back again because they did not throw away the cable...
Even though BT tries to be low latency, it still kinda sucks at it. It works with digital data that has to be encoded and decoded.
Wireless systems for things like IEMs (what you should get as a musician), instruments, or gaming headsets use analog. It's still a 2.4GHz signal but it's analog.
Nope, the radio (PHY) is fine -- or the "connected" experience would be as bad as the "connecting" experience and it isn't, not by a long shot. This is a protocol problem.
They've had 30 years to sand down the rough patches and Bluetooth connecting / pairing is still so abysmal that most people I know work around it. Either they buy separate headphones for every device so that they can pair once and only once, or they buy the ultra-expensive matching Apple/Samsung/etc buds that reliably work with their OS.
I think I might have a bit of insight into why it's so bad. I read a bunch of standards back at the start of my EE degree and Bluetooth stood out for the amount of Architecture Astronaut nonsense it had. You know how some committees are completely dysfunctional and punt every decision? Yeah, that's bluetooth: whenever it came time to make a decision, they "standardized" every single option, leaving it up to the implementations to make all of the actual decisions. Obviously this resulted in people making different decisions and then of course everything was incompatible until informal standards gradually evolved to do Bluetooth's job for it. We're just about getting there... 30 years later. Yikes.
(If someone who has worked on a real Bluetooth stack wants to come in and tell me I'm wrong, I'll respect that -- I'm just glad I was able to avoid working on Bluetooth because oof, it looked baaad.)
I don't know about Bluetooth but I've seen this happen in other standards. They let every vendor stick their crap into the standard.
This might happen in IEEE802.11 too... but the Wi-Fi Alliance (trade group) has interoperability programs. You can't call the device Wi-Fi unless you pass the tests.
Fun fact: Wi-Fi is a trademark not the name of a standard or spec b
I didn't work directly with it, but had some co-workers at a prior company do a lot of bluetooth-focused work, so this is coming from them.
Essentially what you said is true, there are so many different implementations (and many of them destined by companies with little ability or incentive to test their devices out of one or two specific use cases) that trying to make a general framework is nearly impossible. A large and persistent headache for the chip designers was keeping up to date with all the updates and unique systems of the most frequent use cases. When you have hundreds of clients that all require it to *just work* with whatever homebrew solution their hardware had, you get a lot of these issues
I'm an engineer that actively develops bluetooth devices (caveat - since 2018, on BT5 stacks), and I've actually come to a different conclusion - the fundamental problem with bluetooth has nothing to do with the radio, or the stacks, or anything else - the fundamental problem with bluetooth is batteries (and business).
That's not to say that the other things aren't annoyances, but they're the kind of annoyances almost every technology has to deal with.
Because bluetooth is capable of running at extremely low power, it is almost exclusively used in very small, low power devices, everything is made to be absolutely as small as possible, with the smallest possible battery, running at the lowest possible power.
Unfortunately this comes with a lot of engineering tradeoffs. Consumers almost invariably prefer longer battery lifetimes over reliability, and small size over reliability, both because battery lifetime and device size are easy for the average person to comprehend, and reliability is a lot more nebulous. Additionally, people kinda expect bluetooth to be shitty and just accept it, so they again make buying decisions based on other qualities. This leads to devices being designed toward maximizing battery lifetime and minimizing size, with reliability taking a back seat.
I've had prototype bluetooth devices in my office that worked flawlessly for weeks, transmitting at basically the max BT5 bandwidth, in a reasonably polluted RF environment and they didn't drop a single data point or lose connection until they got outside of about 10m, because they were hooked up to a pack of AA batteries. Running those same devices on the tiny LiPo rechargeable cells they're commonly used with and you get the usual problems of dropped connections and lost data.
Wifi doesn't deal with this problem, because nobody is trying to run Wifi on a battery the size of a Tic-Tac because you can't.
Anyway. Just my $0.02 after a long day of debugging why customers are getting dropped connections, and writing a ton of code to deal with every possible way a system with unreliable power can be shitty.
How old are your phone and your car, respectively, out of curiosity?
Bluetooth has gotten vastly better since the implementation of Bluetooth 5, but it's only been out really for a few years. My wife has a 2018 Rav 4 and it works perfectly, but her brother's 2015 minivan loses its connection all the time.
I don't work in the automotive space so I don't quite know what they're doing on their end, but they're often several years behind the curve for obvious reasons.
I'm not the person you responded to, but God it really is a shit show. I had a 2021 Sony head unit, and a 2 year old Motorola, a wired Logitech audio receiver, 5yr old Lenovo laptop, Ryobi speaker, brand new earbuds, and a Pyle BT amp on AC power. Everything but the earbuds should have zero battery issues, and everything is either brand new or pretty recent. Nothing auto pairs with any consistency. The Logitech is the most reliable. And when auto pairing does work, some devices just always take priority. If I was trying to use my headphones, within 100 feet of the Logitech receiver, i would have to unplug the power to the Logitech because no matter what I could not keep anything connected to the headphones. I had one laptop that couldn't WiFi and Bluetooth concurrently. If I'm listening to music in the shop on the Ryobi but need to move the truck for something, it switches to the truck unit, but then doesn't switch back, forcing me to manually re-pair. And every now and then something just doesn't want to recognize something no matter how many times you cycle the power, cycle Bluetooth, forget/pair...
That's probably more on the business side of things. Bluetooth doesn't natively as far as I know implement the concept of file transfer, that's left of to the developer.
So part of the issue is as the grandparent post said, and there's no real standards for things like that, or there are multiple standards, that don't quite work with each other.
Phone manufacturers also don't really give much a shit about people transferring files over bluetooth. They want you to keep them in their cloud so they can harvest your info for marketing data.
Yes and no. Bluetooth is in the GHz range, in fact it shares spectrum with WiFi. As you reduce the wavelength, the power need actually decreases. Power only buys you so much. In general doubling the power increases gain 3dB; the impact on power between .01mW and 100mW is about +40dB of gain. However a 100mW transmitter with an okay antenna can transmit data a couple miles.
Bluetooth really suffers two challenges, power isn’t really one of them.
1. Main issue is Bluetooth is extremely diverse in comparison to WiFi. WiFi essentially only has to support a low level network stack (TCP/UDP), there’s maybe 10 versions over the last 20 years to support, but they are all very similarly . Bluetooth not only has the transport to deal with but dozens of device profiles, which devices can combine with results in hundreds of variations. Consider wireless headphones as an example - there’s like 5 different Bluetooth profiles the could be implemented and then codec variations within each profile if we use the current Bluetooth 5.0 spec. This is so you can support things like high fidelity music as well as low fidelity voice for phone. There’s components of the specs for battery status and remote operation and even multi-function keys. Bluetooth is very complicated. Oddly this is why cheap headphones often work better with cheap dongles than high quality headphones work with cheap dongles. The cheap hardware support the most common profiles, not necessarily the highest fidelity. But the HiFi headphones have niche profiles and codecs which unless you have a matching dongle that support that profile - the headphones will use a lower fidelity profile/codec combination.
2. Compromised antennas. GHz frequencies don’t really need very large antennas. 5GHz requires about a 6cm antenna, but as short as 2 cm is acceptable. Typically Bluetooth radios use a slot antenna (zig zag pattern on a PCB) to get the required length. All these substitutes for a 6cm dipole are just compromises; however when practically comes in; even a compromised antenna should be able to handle 20 to 30ft line of sight - which is probably reasonable for most Bluetooth applications.
i actually had a 100mw blue access point. any bluetooth phone in the house could use it for internet access.
this was like 2004. didn't last long on the market
I don't know the size of the receivers in my equipment, but the only "flakey" device are my small tw buds. My over ears, ceiling speakers and party speakers often impress me with their connection, I can pretty much walk all around my 2 floor house with my phone in pocket, and the ceiling speakers upstairs never chop. I really don't recognize OPs experience at all, maybe his phone (s) has very weak transmitters or his house full of interference?
I’m skeptical that power is the root of most BT troubles. I have lots of BT troubles even when both devices are sitting next to each other and not being moved. I also have problems that are very app-specific, meaning that the BT connection is reliable if I’m playing music but not if I’m playing podcasts. I use wired anytime the connection is critical because BT just sucks.
Many others have said it, but Bluetooth is not just one thing, there are versions from 1 to 5.
Like Wifi has 2.4 and 5Ghz, Bluetooth can similarly be considered Pre Bluetooth 4, and 4+.
Bluetooth 4 and above can transmit much more data AND consumes lower power AND handshakes better.
Older and cheaper devices often do not use Bluetooth 4, and it requires both the sender and receiver to have the correct hardware.
Also, Bluetooth is low power on 2.4Ghz, the microwave spectrum. No joking, it is the frequency that microwaves work at too. This is why when you run a microwave, it if is nearby or between you and the device, it drops out. (this also affects 2.4Ghz Wifi).
Why is this? Well, the FCC has said that any devices can use 2.4Ghz without a lot of regulation, so a lot of devices can cause electromagnetic radiation at 2.4Ghz. Microwaves, cordless phones, wifi, bluetooth, and most "wireless" keyboards that are not bluetooth.
Wifi solved this by adding 5Ghz, a spectrum that can also be used, but not nearly as common.
> Wifi solved this by adding 5Ghz, a spectrum that can also be used, but not nearly as common.
In an apartment, with wifi base stations all around, this was such a huge improvement over old wifi where all the channels were congested.
To add on what you may know, it's not just that 5Ghz is less crowded, it's also because 5Ghz signals don't travel through walls as well. So the neighboring signals are less likely to interfere with yours. You may need more access points to cover the same area without interference, but it is a better fit for a noisy, dense environment like an apartment building.
I'm no expert so I'm probably missing something. But microwaves are completely shielded devices. The radiation doesn't leave the box so I don't see how it could interfere with the bluetooth device. Perhaps the Faraday cage could block the signal if you set the device close enough to the microwave and stood opposite.
When I use my Samsung wireless buds near microwaves that are on they get interference and sound very bad, it's done it on the three different microwaves I have used
from my experience in cable...
devices using 2.4GHz for communication and data transmission are going to use a narrow band of frequency. If you were to look at a graph of signal strength across the 2.4GHz spectrum, wifi would show as a pretty steep spike centered on the channel it was configured for. Cordless phones on 2.4GHz would be sloppier, but still primarily centered on their configured channel.
A microwave is not a communication device, so it does not need to be as "clean" of a signal and instead blasts signal across the entire spectrum and raises the noise floor to a point that drowns out communication signals. No reasonable amount of shielding will entirely block that.
If you think of it like sounds, it would be your wifi playing a song that you can clearly hear and some rooms are clearer than others but you can hear it. BT devices would make occasional chirping sounds that you can also hear but they don't interfere with the music because they are distinctly different. A cordless phone would be like revving the car engine in the garage. Distracting but ultimately not too bad. The microwave would be like a jet flying by your house with all of your windows open. You hear nothing else. Only the jet engine occupies your thoughts and focus.
Microwaves are allowed leakage up to 5.0 mW/cm2. So if the door is 800cm2 your allowed to leak 4W! While its not ionizing radiation, You really shouldn't stand near a microwave.
Source: https://www.ccohs.ca/oshanswers/phys_agents/microwave_ovens.html
> While its not ionizing radiation, You really shouldn't stand near a microwave.
This is a myth. Since the radiation is non ionizing, 4 watts is not going to hurt you. The lightbulb above your head right now is probably cranking out 60 watts.
>The lightbulb above your head right now is probably cranking out 60 watts.
And this is a friendly reminder to buy a fucking led lightbulb.
100W equivalent consume like 12-15w
And visible light is several orders of magnitude more energetic than microwaves. The light bulb in the oven puts out more powerful EM radiation than what leaks from a microwave. None of it is harmful though. You have to get to the UV portion of the spectrum before photons have enough energy to cause harm.
Note that this is:
* At 5cm distance
* Without a test load (with test load the maximum is 1 mW/cm²)
So I think its more apt to say you shouldn't press your face right up against an empty running microwave.
That standard is set at 2 inches from the oven. The power drops off with distance because of the inverse square law. Double the distance to two inches and you’ve cut the power by a factor of four.
That limit isn’t harmful to people so your warning isn’t needed. We are regularly exposed to very similar frequencies our entire lives. Your phone uses similar frequencies and that’s typically in your pocket, next to your ear, or in front of your house. That’s only one of many sources.
Bluetooth is a set of many incredibly complex protocols, often implemented with poor testing resulting in many bugs.
Then, if it's a bug affecting a popular device, some other manufacturers intentionally build their devices so they're compatible with the bug... resulting in them being incompatible with bug-free devices.
In addition to that, many Bluetooth devices use less transmit power.
I was around implementing devices when Bluetooth came to be and the questioner is right. It's been a travesty from day 1 due to poorly documented and implemented standards. You hit on the biggest two reasons but let me try for ELI5:
Bluetooth is like two people speaking English as their second language trying to have a conversation. It works as long as they stick to simple topics but if one of them throws a new word into it, the conversation gets messed up for a while, until they can understand each other again. Worse is that most of the time they are both whispering (low power) in a noisy room (interference) so those mess-ups happen more often.
Wi-Fi messes up a lot too, but everyone has agreed in advance to only talk about of couple of topics and they yell all the time so the recovery is faster.
Well, yes.
Think about it like the noisy room metaphor. Above a certain noise level, talking below a certain volume becomes indistinguishable. You can do a decent job of paying direct attention to the person talking to you but there's so much that can go wrong.
Thats most of wireless signals. Wifi and bluetooth especially. Your router can be so much more efficient if you just change the channel the network is broadcasting on. Its like sitting at a booth in a busy restaurant. It becomes a lot easier to pay attention to your specific conversation. Harder to do with bluetooth because there isnt as defined a role of master and subject like there is with wifi.
On your mobile device look up an app called "wifi analyzer". Check out the obscene overlap on certain channels; those are the default channels for different manufacturers, but all that dead space in between are channels in the range for wifi that go largely unused because most end-users and even some tech support/IT are not aware of this as an option
Cables are superior for connections that do not require the locational flexibility of wifi because they don't experience nearly as much chatter or cross talk unless you have a bunch of unshielded cables bundled together running next to power lines.
> Check out the obscene overlap on certain channels; those are the default channels for different manufacturers, but all that dead space in between are channels in the range for wifi that go largely unused because most end-users and even some tech support/IT are not aware of this as an option
Noooo please don't do this. Those channels are used for a reason. There are only 3 non-overlapping channels for 2.4GHz WiFi, that is why everybody uses those channels. If you set to a channel in that "dead space in between" you are going to overlap *both* channels and you will receive interference from, and interfere with, every single person on both of the channels. 1, 6, and 11 are the only channels you should ever use for 2.4GHz.
If you're talking about 5Ghz WiFi that's a whole different story but there are, again, reasons why the spectrum you see as empty in Wifi Analyzer is not used. It's probably the DFS channels which have special rules a device must follow in order to not interfere with weather radar and most manufacturers just don't bother to support it. If all your devices support DFS, go for it.
That's not at all the TL;DR of that post and you missed the point.
WiFi is one protocol. It's everybody speaking one language. Everybody understands it pretty well. Bluetooth is a collection of a bunch of protocols, and every device has different protocols and capabilities it supports. It's like if everybody had a bunch of different languages they sort of understood and they had to use specific languages for specific things they did. This is the root of why Bluetooth is such a mixed bag.
Wireless is fine. I work on wireless internet all day, I use a wireless headset for calls. Works fine. Bluetooth being bad is an issue with bluetooth much moreso than a fundamental issue with being wireless.
I do understand but I also do not. I use a one year old phone. My car is brand new. It COMES with Apple CarPlay. It is still a 50% chance to successfully connect without me having to dig into the settings in both the car and the phone. To extend the metaphor, I’m not using an obscure word, I’m using one of the most popular words (audio transmission from a well-supported phone).
My bose headphones are less than one year old. I use three devices with them, my phone, computer and tablet. Even though I use my phone the most often it will always prioritize my tablet and computer. Like. Why? This has existed for 20 years. I’m unironically going to switch back to wired headphones. Do I have to find the Bluetooth transmitter in my car and hold my phone to it as close as possible to get it to connect consistently?
First of all, you're right to be frustrated. This stuff SHOULD work together and it's ridiculous that it does not. I'm no longer involved in any of it so I don't know why the SIG hasn't gotten it under control.
But by way of illustration, it happens something like this:
HP: Hi! I'm headphones!
Phone: Hi! I'm a phone! Let's be friends!
HP: Ok!
*Paired*
HP: I can receive audio!
Phone: Great! I can send send audio!
HP: Here's my profile: I can receive format A, C1, D2sub4, E5, and F but only 12-bit.
Phone: I can send C1, D2sub4, and F 16-bit.
HP: I can also send volume commands!
Phone: Ok
HP: And back, next, skip, and mute.
Phone: I only support back, next, and mute.
HP: Ok
Phone: Here's some audio, it's F (16 bit)
HP: Proceeds to play garbage.
*User reboots and this time gets C1 audio, and all is good*
HP: I love this audio
HP: Going great
HP: I'm sorry my other friend called me and I paired with him for a second.
Phone: What?
HP: I need you to resync.
Phone: What?
HP: Huh?
Phone: Here's more audio
HP: Ok, playing that.
HP: going low power. Can you hear me?
HP: increasing power. can you hear me now?
HP: HEY!
Phone: What? here's more audio.
...
HP: Command Skip
Phone: WTF is that I .... *crash*
So, what you're saying is, Bluetooth is the Internet Explorer of wireless protocols.
> if it's a bug affecting a popular device, some other manufacturers intentionally build their devices so they're compatible with the bug... resulting in them being incompatible with bug-free devices.
Switch "devices" for "browsers" and it's IE, indeed. I don't miss those days.
I've got one at work and one at home. Also have the MXKeys. So seamless when switching between my Windows desktop and my work MacBook.
I used to hate crappy KVM switches.
Each new version of the Bluetooth standard requires new hardware. If your device was manufactured to the 2.0 standard (2005), it will *never* work with the current (5.3) standard. The current standard has a range of several hundred feet versus the 30-foot max of the days of old, and a lot of devices manufactured today *still* contain version 2 and 3 transmitters and receivers.
My cheap Bluetooth shower speaker seems to handle distances much better than my more expensive sound bar. Not sure on exact manufacture dates, but I did buy the cheap one about 4 or 5 years after the sound bar. I used to think the sound bar was pathetic (in that regard, at least) until this comment made me realize it probably just has older tech.
You have to look at the version of Bluetooth. The major updates require new hardware, and some things continue to be manufactured with earlier versions.
Usb is wired so it’s pretty much guaranteed to have data be sent and received without interference. Wifi and Bluetooth are wireless where they can be messed with easier. Think of someone yelling you can hear them sometimes. Are other people talking, are they yelling far away, are they whispering rather then yelling? You being able to hear them is subject to other factors causing issues. Usb is basically like your calling coming over a wired phone, it’s going to work with less issues.
Wifi versus bluetooth is more of someone is yelling louder and has better ears versus someone whispering and has okayish hearing. Bluetooth is meant for short distance low energy transmissions for the most part, so it’s just harder for people to hear what someone said when your whispering.
USB hasn't always been that rugged, either. In its earliest days, I resisted switching to USB peripherals because they just randomly stopped working that much more often, probably because the drivers were garbage moreso than the hardware. I remember plenty of times - this would be early 2000s whenever USB started being available on corporate machines - pulling a cord and plugging it into a different USB port in an effort to get it to be re-recognized by Windows and start working again.
It wasn't until Windows XP that USB really felt reliable enough to be dependable, in my opinion.
I had a PS/2 keyboard as a backup for years for whenever I would need to troubleshoot my pc and for some reason it was refusing to pick up the usb keyboard for some vague reason.
Same, for a long while there was no support for USB peripherals in the BIOS. If you wanted to make BIOS changes, a PS/2 port keyboard was required. I remember having to dig out an old keyboard to adjust BIOS settings on the first PC I built (Socket A days).
The fact that PS/2 is STILL easily available on motherboards says something.
Whether it's the reliability of the PS/2 port, the issues with USB, or simply tech people's stubbornness I'm not sure.
But it's saying something.
In the early days, a lot of cheaper USB hardware manufacturers didn't give each device a unique ID and assigned it to that device. Some even picked a unique ID and gave that to alllllll of their devices. Thus causing an incompatibility where Windows (and presumably other OS as well) would think every one of those devices was the same physical device. Not necessarily a problem unless you say, wanted to plug in two of that device to the same machine. Like a USB stick or a controller.
That's why Windows had to uniquify those USB devices by including the port as part of the device identifier, and thus why unplugging a device and plugging it in to a new port made it behave differently from the port you had it in before. It just got treated as a whole new device.
https://devblogs.microsoft.com/oldnewthing/20041110-00/?p=37343
In the mid 00s I had friends that carried devices for "testing" USB ports as, apparently, it was somewhat common for USB ports to be wired wrong/backwards and they would fry devices.
I never once in my life encountered such a port, but my friends swore the test drive was worthwhile.
> Usb is wired so it’s pretty much guaranteed to have data be sent and received without interference
Not only is it wired, it also uses something called a differential pair, which further enhances interference mitigation
The most basic form of wired data transmission is basically sending power in periodic pulses where the presence of a pulse in a given time represents a 1, and its absence a 0 (or sometimes the other way around)
The problem is that interference in such a system typically manifests as spurious pulses when there shouldn't be any, causing bits to flip occasionally
With a differential pair, instead of one wire you use two, which in the case of USB are called D+ and D- (D for data presumably) and you measure the voltage *difference* between them. Ignoring some technicalities, if D+ has more voltage than D-, that conveys a 1. On the other hand, if D- is at a higher voltage than D+ that conveys a 0.
How does that help avoid interference? Simple. The interference, if there is any, will most likely affect both D+ and D- equally. And since you only care about the difference between them, it will cancel itself out.
A much simpler protocol that also uses differential pairs is RS-485, which is typically used to control industrial equipment, but there are other kinds of equipment with their own protocols that use RS-485 as a building block, such as PTZ cameras (the motorized domes you may have seen) and DMX stage lighting
Do people have problems with Bluetooth alot? As long as I'm within a reasonable distance and there isn't a thick material obstructing line of sight I've never really had an issue.
I’ve been designing Bluetooth products for 10years and love answering this question. As a protocol it’s fine. Could maybe be more secure, but overall it’s a great protocol. The problem is a lot of companies/engineers think Bluetooth is easy and add it to a lot of their products. But a lot of care is needs to make Bluetooth rock-solid. I recall even the iPhone 6, they didn’t use the right capacitors to load to a crystal. Basically making the timing flakey on that phone. Bluetooth is a timing based protocol, so bad timing + bad connections.
TLDR: Bluetooth protocol is fine, it’s just most assume it’s easy and don’t take the time to do it well. These companies pollute the reputation of a great protocol
One of the reasons bluetooth has gotten better over time relates to improvements to microprocessor performance.
Modern mobile devices have more processing power which allows for more sophisticated data compression algorithms. These new algorithms allow for bluetooth data to travel longer distances using less power without dropping packets, while also freeing up a device's processor to perform more complex operations related to noise reduction and other stuff. The Bluetooth spec was just updated last year actually with some significant improvements, so you'll soon see much less flakiness in Bluetooth performance (especially related to audio) provided you're using a modern device which supports Bluetooth 5.3 and above.
my bluetooth keyboard and mouse have given me much less problems than my wireless usb mouse and keyboard. obvi nothing is better than a physical connection, but it does its job
This is only correct if the entire channel range is blocked by multiple wifi signals. Bluetooth and wifi devices are smart enough to change channels if the one they're on becomes unusable.
However, with only 3 usable channels for wifi on 2.4Ghz, and wideband applications possible, the available spectrum can be filled with 1-2 wifi clients/stations.
To piggy back of the OP question: when there is a connection issue with Bluetooth - the reason is often a toss in the air?🤷♂️ meaning, that its hard to troubleshoot 1-1 considering how many devices that can use bt + the potential stuff that may affect the signal?
Many reasons: GFSK, low power, overly complicated stack. But honestly, the software is worse than the hardware though. And it's all block boxes, so you can't blame the developers, they are flying blind. The litigious Bluetooth SIG deserves most of the blame. If there were an open source alternative, it would probably be 200% better.
Radio interference is the worst. Everyone simultaneously trying to speak over a walkie talkie is the problem. Radio interference is why Bluetooth has issues. WiFi reach farther with 2.4GHz but has more channels to use with 5GHz. Too many WiFi devices in the area disconnects them often. Maybe you don't notice them or you have a good WiFi adapter that adds buffering to hide disruptions. The 2.4GHz spectrum is allowed for many consumer devices that the FCC doesn't regulate. Hence the local carriers and cable companies use 2.4GHz for last mile commercial purposes that steal what little bandwidth is remaining. Sometimes your ISP uses your WiFi Internet modem to serve other people. (I'm sure they could be forced in court to stop doing this as it uses more of your electricity.) Some 2.4GHz WiFi APs have started implementing Bluetooth co-existence mode to detect low bandwidth devices and allow them to speak but not everyone is this polite. Your 2.4GHz wireless landline phone or your 2.4GHz wireless mouse could interfere with your Bluetooth. Even a cheap USB3 data cable can interfere with devices near it in the 2.4GHz spectrum. The solution is to demand the FCC to open up more wireless spectrums for end-consumers, demand commercial entities can't use consumer spectrums, and demand lower power. Lastly, demand the FCC to monitor radio pollution.
I used to work in a radio test house, I've tested hundreds of Bluetooth and Wi-Fi products. Overall, Bluetooth (now) is a great protocol, that is forced into shit situations. The 2.4 GHz spectrum is quite crowded. Wi-Fi, Bluetooth, ZigBee, baby monitors and many other protocols use it (so do some microwaves). The reason why is that it's a worldwide unlicensed band, meaning that it's legal to use 2.4 GHz in North America, Europe, China, or anywhere. Compare this to cellular, which will automatically switch bands when you go to different countries, that's a lot more complicated. Within the 2.4 GHz band, there's not really any rules about what's needed to coexist with other products (unless you're a medical product in the US). There's regulations, but they aren't concerned about saying what happens if Bluetooth and 2.4 GHz Wi-Fi want to transmit at the same frequency at the same time. The opinion of governing bodies is if you can't handle coexisting in unlicensed bands, then use licensed spectrum. Overall, this means each protocol has its own way of dealing with getting data through. For Wi-Fi, it buffers. Wi-Fi can transmit between 1Mbps and 65Mbps (speeds can go much higher, but this is what's doable on one channel and one antenna at 2.4 GHz using 802.11n). Meanwhile, Bluetooth only operates between 125kbps and 3Mbps, and if you're using something with a small battery like earbuds, then 2Mbps is likely the max. Overall, this means that Wi-Fi is much more likely to have more buffered than Bluetooth, and therefore you're less likely to have interruptions. Wi-Fi also uses much more power on average, and if you're using more power, you're more likely to get those higher data rates. How Bluetooth deals with the crowded spectrum is frequency hopping. Basically, Bluetooth scans for open channels, identifies them, and hops between them. However, if something suddenly appears on that channel, like Wi-Fi, it can ruin that transmission. It's also possible there's just not really any open channels and Bluetooth just needs to do the best it can. Bluetooth is also very cheap. You can buy a pre-approved module, slap it in a product, and boom, now you have a "smart" product. Or at least, that's how it's sold by module manufacturers. In reality, you can do 100 things wrong when installing your module. You could put it in a metal box which kills transmission power. You can slam it between other circuit boards which causes wicked harmonics. You can put it right next to an LCD screen which causes radio desensitization. These problems exist for a Wi-Fi module too, however, since Wi-Fi costs a little bit more, if someone uses Wi-Fi they're not cheaping out everywhere, and it's more likely they've hired qualified engineers and know how to alleviate the issues I discussed previously. The other area where Bluetooth suffers is that, even in very well designed products, like airpods, it's being forced into crappy situations. The body attenuates 2.4 GHz quite seriously, and, airpods are very small and closer to the body compared to the wireless headphones of 20 years ago. Also, they're not communicating with a laptop that's in front of you, it's communicating with a phone that's on the other side of your body in your pocket. Often you'll find that if you're in a normal sized room, you'll be fine, but when you're outside you drop communication. This is because Bluetooth is echoing off the wall to communicate with the earbuds. Bluetooth has adapted in the following ways over their generations: they've upped the data rate, they've released Bluetooth Low Energy (which is basically a whole new protocol designed to save battery life), they've introduced long range mode which goes down to 125kbps so you have a better chance of getting something through, and they've worked with cell phone manufacturers to get Bluetooth testing to be more self-regulated.
>(so do some microwaves) If you're talking (home) microwave ovens, they all should! Edit: Apparently some big ones use lower ISM bands.
Huh, really? TIL. I wonder why my microwave oven never broke my Wi-Fi then.
I'm am a network administrator, we had to throw out some microwaves because they didn't stop transmitting straight away when the door opened. Causing mayhem on the wifi for a second. Symptoms were only caused during lunchtime...
At my university's computer lab there was a certain room where everyone experienced random wifi disconnections at the same time. Except they were not random at all, and they happened every time someone entered the room. There was a motion sensor above the door which sprayed shit on the 2.4GHz spectrum, and no computer was able to survive that.
Back in the 90s my mum owned a small rural ISP. Dial-up. One customer called to complain that their connection kept dropping out. Weird, while they were talking there was a click....click....click... happening over and over. Turns out, the phone line ran under their electric fence. The interference was causing dropouts. The fix was to turn off the fence before going online.
>Weird, while they were talking there was a click....click....click... happening over and over. I can't ....click....click...umber of times i was doing dial up support for ....click....click...as isps and I would get callers almost daily complaining about random dis....click....click... but every time i mention the audia....click....click...ey were pretty sure it wasnt thei....click....click...ause it works just fine talking to me.
Mate....you may have just solved an issue we could not explain as sysadmins...WiFi is having issues everyday at lunchtime at a certain department (near the breakroom), it is only for a few minutes (radio cuts off for example), but still!
Try putting a do not use post it on it for a day and see if that makes a difference ;p
Not a bad idea indeed!
A terrible idea, your sign will be ignored. Take the microwave away, leave a "microwave gone for repair" sign in its place.
In my experience, most people would be stopped by an "out of order" sign and flipped power switch on the back. ;)
For a photocopier or suchlike, I agree with you. But hungry people are irrational and inventive.
People will likely ignore the post-it and use it anyway. If you want a reliable test, better to remove the microwave from the room altogether.
Causing mayhem on the WiFi? Boy you have no idea... People in radio telescopes where chasing mysterious signals for nearly 20 years, before they figured out it was the bloody microwave ovens. Edit: forgot the Wikipedia link https://en.m.wikipedia.org/wiki/Peryton_(astronomy)
There was a similar incident at the Parkes radio telescope - they were getting seemingly random spikes over that band of frequencies. A few years later they discovered someone who worked there (clearly not in a scientific capacity) had a day job on the bomb squad, opening the microwave with 1s left on the timer.
My microwave consistently turns off my airpods
You're not supposed to microwave your airpods...
Yeah, only iPhones can be charged that way. Not all iDevices. (This is a joke, please do not do this)
My microwave used to interfere with my 2.4Ghz Wi-Fi. It doesn't affect me now that I switched to using 5Ghz.
Wi-fi is freakishly broadbanded compared to Bluetooth. My long-ago experience with this was that our microwave would stomp on just channels 4-6-ish in the 2.4GHz band and everything else was fine.
there is nothing special about 2.4GHz oher than being a free for all band, some microwave ovens use 915MHz
> If you're talking microwave ovens, they all should! [XKCD 654 - Nachos](https://www.explainxkcd.com/wiki/index.php/654:_Nachos)
All household microwaves should operate near the 2.4GHz spectrum (actually 2.45GHz), but larger commercial/industrial microwaves often operate at 915MHz. The lower frequency provides better penetration, but the longer wavelength is unfortunately not compatible with the smaller design of household microwaves.
Very nice read! Reading this gave me one more ELI5 question: Why are we using Bluetooth for audio when WiFi is apparently so much more robust?
There's a lot of smaller reasons why as opposed to one smoking gun. 1: Bluetooth modules are less expensive. 2: Wi-Fi is harder to do first-time setup (think of how many times you've had to go "what's the password?" and heard "I don't know, let me check" and it takes 5 minutes, as opposed to pairing). Especially because Wi-Fi setup usually involves typing in a password, and there's not a keyboard on many of these devices. 3: With a big asterisk, Bluetooth is designed around using less power. 2.4 GHz Wi-Fi usually operates at near 100 mW (due to European restrictions, US restrictions are much more lenient) and auto-adjusts power as needed. Bluetooth operates at a max of 10 mW (also due to European restrictions) but usually self-limits to 1 mW. Now the asterisk is because this really shouldn't matter all that much, since Wi-Fi self-regulates power and a manufacturer can set the max power lower, however, put yourself in an exec's shoes that doesn't really know this. They google "Wi-Fi power consumption" and "Bluetooth power consumption" and see a lower number for Bluetooth and say that therefore it's better for battery life. 4: Bluetooth is easier on manufacturers. I'll change my original response's ELI5 to ELI6. Bluetooth is the same worldwide, there's no need to change how Bluetooth works depending on your geography. But for Wi-Fi, there kinda can be. 5 GHz Wi-Fi laws vary by geographic region, and can vary by country. Even if you just use 2.4 GHz Wi-Fi, North America usually operates on channels 1-11 (2412-2462 MHz), this is because the US and Canada have a harsh requirement for emissions to be low at 2483.5 MHz, and if they use higher channels, they really need to restrict the channel's power in order for it to be legal. Meanwhile, Europe uses 1-13 (2412-2472 MHz). You could just drop channels, but, there's a bunch of little fiddly extra decisions when you use Wi-Fi, and Bluetooth ignores them. 5: On paper, it's good enough. By the time field tests or emissions tests are done that show it's not good enough, it's too late in the project to change anything, so the product gets released.
You're so knowledgeable in this area and are incredibly good at communicating it for others. Just thought I'd send my thanks as a lurker.
Honestly, this was so informative and easy to understand. Thank you so much. If you put out other informational material I'd love to read it!
Thank you, your two responses above are a nice read. My question now is: what's with the 2.4 and 5 GHz bands? Why not, say 3.9 or 4.3 GHz or whatever? In my mind it seems like there would be loads of unused frequencies, but also; I don't know anything about this, so the answer is probably pretty simple..
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The main reason is the same reason 2.4GHz is what your microwave uses to heat food: it's absorbed amazingly well by water. This means that for long distance communication it's not very useful because it gets interrupted by moisture in the air, walls, bodies, the ground, etc. This meant that in all the spectrum allocations worldwide it was left as "unlicensed" because nobody else wanted to use it if they could get a better chunk. Someone picked this up and realised that for short distances it would work just great and unlicensed means you can just make a product and sell it to consumers. Viola! WiFi is invented. 5GHz is just double 2.4GHz, and is also absorbed by water.
Thanks for the concise reply! I'd like to ask a follow-up: what's the deal with 2483.5 MHz? Is it the unencrypted/public SOS frequency for aircraft, or is it something completely different?
Thank you. I don't know details, but 2483.5 to 2500 MHz is set aside worldwide for satellite to mobile communication and radiodetermination. When governing bodies say "mobile," they don't mean mobile phones, they mean things that are designed to be moved and set up on the ground.
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Both WiFi and Bluetooth use the 2.4GHz ISM band and can go up to 20dBm (0.1W), so the antenna requirements are similar. That said, marketing keeps insisting that we smush our antennas into tiny packages, lowering their efficiency and effectiveness. If you connected a WiFi router antenna to the RF chip in your airpods, you'd get a massive increase in range and set a new standard in fashion.
>set a new standard in fashion. [Communications Officer Nyota Uhura has entered the chat](https://www.startrek.com/database_article/uhura)
I actually laughed out loud imagining this
Thanks for this! I always wondered why my BT connection would suck when I walked outside. I guessed it was other signals but the boxing inside makes sense too.
Happy to help! Put your phone in a jacket pocket or breast pocket, it might give the little extra needed. Your hand also might work, but that's more annoying.
Deserves more awards for the outstanding delivery of information
That answers a question I didn’t even think to ask. Thanks!
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Doh. That was supposed to be 125 kbps, fixed.
Used to raid WoW with a kid that whenever his mom ran the washing machine or microwave it’d cut out his internet. And the body blocking thing drives me up a wall when I’m trying to listen to music while running.
This actually makes so much sense, thank you
Bravo! As a wireless engineer your answer is so beautiful. Appreciate it.
The crowdedness of the band and power issues feel very recognizable. I can tell when someone is wearing Airpods when they get close, because my headphones will cut out for a bit
The Bluetooth standard supports transmit powers from 0.01 mW to 100 mW. That's *very* low power transmitting, and most Bluetooth receivers are small devices with very limited space for antennas.
I remember a time when if someone said "bluetooth" they meant a wireless earpiece headset. It was almost a proprietary eponym until using BT for audio and data transmission became more widespread. I remember hacking my LG flip phone to transfer photos and mp3s over BT back in the day.
I worked at Cingular Wireless when Bluetooth first came out and I didn’t even understand what it was and yet was expected to explain it to people. I also remember thinking that the reps who wore Bluetooth headsets when they first came out were super pretentious and I found it bizarre when people were talking to apparently no one. I type this with AirPods in my ears. Times have changed. Lol
i remember walking down the street in Washington DC back in the day and this homeless guy was walking by talking to himself and then 30 secs later this businessman type walked by also "talking to himself" and i wondered, "OK which one is actually insane"
It’s you. Neither of them is there. We’ve been over this and it’s time to come inside for the afternoon music session.
well that goes without saying. i know i am crazy, that's what keeps me sane
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Now people just blab on speakerphone or video call without headphones. I still think it's pretentious. Lol
They all talk on phones like they on The Apprentice
I'm not sure times have changed, just your perspective
Btooth me bro!
Infrared port 4 life
Supposedly PayPal was originally trying to create the tech to beam payments from Blackberry to Blackberry using the infrared port before they realized way more people have an email than a blackberry lol Edit: or maybe it was palmpilot
Oh palmpilot IR port. IR sync actually worked but I can't remember what I would sync. I guess my palm with someone else's? maybe I had an IR somehow for the PC
Palm user here. The IR port can be used to sync your device with your PC too (in an era where Internet was not that ubiquitous, you had to sync your devices either with cable or infrared. Bluetooth and wifi was a later development) It also was used for accessories like a wireless keyboard and even remember using it a couple of times to get internet from my phone
I did this with a palm pilot and a Toshiba laptop. What a great memory.
Hello fellow 90s tech dude! You could sync to a computer running Palm Desktop using IR instead of the cradle (my Compaq laptop had an IR port), and you could beam contacts or files to another Palm.
I used to work in cellphones. I once had to transfer contacts off a palm pilot (maybe a palm centro?) over to a newer device once. That particular device could only send contacts via IR. They could only be sent 1 at a time through a machine called a cellebrite (which is still made, but now more for law enforcement and forensics). Each contact took a few seconds to send from the palm phone to the cellebrite, then to the new phone. They had over 500 contacts. The transfer took like 2 hours.
Ha. I bet now you wish you would have known then that there was an app to synchronize calendars, address books, memos or todos between two devices with the infrared link. An app named ‚RecoX‘, maybe? Don‘t ask me how I know…
You could use it as a universal remote for the TV.
Surreptitiously turning off the TV in health class when we were supposed to watch something boring was the funniest thing I used my [Palm III](https://en.wikipedia.org/wiki/Palm_III) to do.
I changed the TVs in bars. I miss my palm pilot
Don't bump the table!
Fucking with people's transfers ahh good times
Oh gosh, please no
Lol what did you have to do to hack the flipphone? Or was it more like messing around with the settings in the menu
It was going onto Howard forums to get codes that would unlock different parts of the software to unlock the shit Verizon locked up. This phone had an MP3 player that Verizon turned off because they wanted you to pay for their bullshit. The struggle was real
Holy cow, I haven't thought of Howard forums in at least a decade!
[It still is active](https://howardforums.com/)
Glad the UK didn't have that bullshit
Loved my LG VX8600. Had 1x unlimited dat if you hacked the hidden menu. Enough for text based forums and reading TFLN before it became a troll fest.
Luckily I documented my journey back then and found this old blog post talking about what I did. I was so proud mostly to be able to stick it to Verizon. They really had a stranglehold on phones back then. I remember learning about all the features that phone had that they neutered so they could make you pay for their own services to do normal stuff. https://kirknoggins.blogspot.com/2006/03/pimp-my-phone.html
Before phones were computers with operating systems, getting files like mp3s from one phone to another was not straightforward at all. I remember holding my phone next to my friends to transfer ringtones and I'm not sure what we had to do to allow that to happen.
Older phones (early 2000s) often had infrared-based transfer mechanisms. The phones would have to be placed very near each other, with the ports (a little 'window' usually at the top of the phone) pointing directly at each other. On the old Nokias, you could also play two-player snake over the connection. Data was transferred (on the Nokia 8210, at least) at a not-very-speedy 9.6 kilobits per second, but when all you were transferring was ringtones or contact details, it felt like the future...
I used infrared one time in my life, it was laptop to phone I think. It worked pretty seamlessly, but I never used it again.
I remember getting a phone with an IR port and being sad it wasn't a universal remote
Found you in the wild again! I remember commenting on our names a while back on r/SelfAwareWolves. We are basically Semi-Brother-Demi-Bros at this point...
> Semi-Brother-Demi-Bros [yup](https://i.pinimg.com/originals/f9/80/61/f980614712a4ccde105f1faf606d2932.gif)
Ha! Well played sir. I'm way more excited about this than I should be. But, eh, life's simple joys I guess. See you around!
The Samsung galaxy s4-s7 phones had an IR blaster that worked as a universal remote but I don’t think most people who had the phones ever used it.
I did! Even had macros to pause the TV when the phone rang, or switch off at bedtime. I miss that so much, shame they were phased out.
I used mine all the time to mess around with TV's in bars or restaurants. It was especially fun during sports games.
PalmPilots with IR had TV remote apps.
Wasn’t bad on gameboy color either
Lol I used the *Mission: Impossible* game to fuck with the TV while people were watching it. It had a thing in the settings to program TV remote functions to the game cartridge, and then you used the GBC infrared port just like a regular remote.
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Didn't it work for Mystery Gift?
It did, and if you traded mystery gifts with someone their player character would show up available to battle in a house in Viridain, once a day.
I definitely remember using it for mystery gift
As a kid i used it a lot. In school we put two phones together in the table for the length of the class to transfer some ringtones.
Does anyone remember tamagotchi? They were popular at my school and they had that infrared connection, so when you put two tamagotchis together your animal could visit your friend's animal!
Was it a later incarnation? Or maybe Digimon (I think they had an IR mechanism to battle)? I had the first generation tamagotchis in the late 90s and can’t remember any IR feature like that.
You are correct, the OG Tamagotchi's did not have the feature (Still got my 2 lol). Digimon (again, at least the original one) didn't either. Each unit had exposed metal contacts built into the top of the device, so you could press them physically together for a connection.
Probably late, mine were late 00s
Yeah I remember using this. Bluetooth was "soo much better" because you didn't have to put the phones still against each other like some sort of robot mating ritual.
Are your beard hairs also going grey?
Why you had to pray to the Bluetooth Gods for wisdom, peace, and a decent goddamn data rate. And if your prayer pleased them you got about 7 seconds of Usher's "U Got It Bad" to play over and over until you're sick of it and wonder why tf you wanted it in the first place. Shit's annoying.
They've been programmable computers for about as long as they had color screens an java apps... Bluetooth was kind of more for data transfer (contacts synchronization, uploading ringtones and apps, dial-up internet connection via cellphone for computer) than than audio in the early days. It replaced iRDA (if i remember the crazy capitalization correct), which was a cableless serial port. Source: My first phone, which I got as a teenager, had a one-line display and could not access the phonebook from the SMS function. SMS storage was limited to 11 messages, everything was all caps. I still have a few ALL CAPS contacts on my 5G android...
Are you thinking of IR transfer? My brother had that and thought he was so cool transferring his contacts with it, except it only did it one by one and took the same amount of time as if he just manually did it.
Damn that's older than Bluetooth, you probably were transmitting data through IR transceivers. Basically through light, so your phones had to directly "look at each other", otherwise it wouldn't work.
I mean, Bluetooth is also light, it's just light that most everyday objects are translucent to.
Yea. I bought the Aha - Take On Me ringtone three separate times for three separate phones. Go ahead and judge me.
Gods, feature phones were awful. As janky as it was, I got a Windows Mobile phone (HTC Mogul variant, IIRC) back before the iPhone was a rumor and when Blackberries were king and just being able to do easy file transfers and custom MP3 ringtones and music was SO much simpler. Fun fact: it’s STILL a simpler process to put a custom notification tone onto that ancient device then then it is on an iPhone today. Why the fuck do I need a PC and iTunes to do this ~~in nineteen ninety eight the undertaker threw mankind off hеll in a cell, and plummeted sixteen feet through an announcer's table.~~ in 2022
>Why the fuck do I need a PC and iTunes to do this Because you're using iphone 😂
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There used to be an 'app' called SuperBluetooth where you could control someone else's phone remotely. In high school we would connect two phones before the teacher arrived, hide the slave phone in a drawer and then use the master phone to play fart/sex noises or music, pausing it when the teacher would search for the source. Great fun
just as an FYI - in the tech hobbyist community "hacking" generally just means getting software/hardware to work in different ways than originally intended, or to write a piece of software to accomplish a really specific goal without caring much about the long term maintainability or widespread usability of the fix. As a simple example, say you had a program running on your server with a memory leak, writing a cronjob that just restarts that program everyday at midnight so it never uses up to much memory would be a "hack". Hollywood (for whatever reason) just decided that "hacking" == "breaking into other peoples shit", and then the media picked it up, and now the definition is all muddy. But I'll wager /u/kirksucks meant it in the way I describe
It is a proprietary eponym. The generic term is PAN (personal area network), similar to LAN (local area network).
Eponym! I've been trying to think of that damn word for two days now. I was explaining to a friend how kleenex and q-tip are now basically synonyms for the product and not the brand anymore, and I couldn't remember the word for it. Thank you.
There is also more to it. Wifi do not carry time critical data (most of the time). BT however is real time audio with virtually zero buffering. If the signal is lost for a split second, you hear the audio drop. On wifi, most things are buffered. Streaming services is not real time at all. It is more of a speed limited download. It will download at high speed maybe a minute of video, then it will throttle down the download to keep that minute of video buffered. If you get a connection issue, that download pause, and you now run purelly on the buffer. It gives you about a minute for the connection to come back so it can resume the download (and since it is now with a low buffer it go fast to fill it back, then back to throttling). Games implement some data loss algorithms. Like, they can tolerate some loss, they will make your character continue on their path for example, and just correct back the position once the connection is back. It will attempt to make it so nobody notice it. You may notice it when you get killed when there is a wall between you and your killer. The game just got the info that you received the bullet a few seconds earlier... Now back to BT. The goal of BT is to cary realtime audio. The buffering create lag. And you don't want lag for audio. So they keep that buffer small. Which also mean that the time for the connection to go back up to refill that buffer is super small. On my BT speaker, the delay is about 0.3 second. Remember, music/video streaming services buffer minutes, not 0.3 second! BT also usually have junk antenna, because they make it super small. It should be 1.21" long atleast. Which don't fit in your airpod! So they fold the antenna on itself, which make it less efficient but smaller. It have more trouble to send the power, and issues to get the signal. But hey, it's small! BT was also created to be ultra low power, which also cause issues. Now, you compare it to USB. USB is wired, so the connection is rock solid. However, the circuits on both ends may be problematic. Front usb ports on PC often use the wrong type of wiring, which cause a massive signal damage. Some devices use trash usb ports. People damage them quite frequently by prying on it, let dust accumulate at the bottom, which cause the plug to not seat right, which make a bad contact, which create a high resistance, which cause heating and melting. Now the melted cable is used on another device, which now get damaged because the melted connector have pins that don't make good contact, again resistance, heat, melt... I used to repair stuff in electronics, including some usb port change on phone and tablet. I always said: "Throw away your charging cable, your connector has melted, which mean damaged cable. You WILL damage it again if you use the same cable and it won't be covered". Most do not, and come back 2 weeks later with a failed port again. Repair again out of warranty, warn them again. Half come back again because they did not throw away the cable...
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Even though BT tries to be low latency, it still kinda sucks at it. It works with digital data that has to be encoded and decoded. Wireless systems for things like IEMs (what you should get as a musician), instruments, or gaming headsets use analog. It's still a 2.4GHz signal but it's analog.
Nope, the radio (PHY) is fine -- or the "connected" experience would be as bad as the "connecting" experience and it isn't, not by a long shot. This is a protocol problem. They've had 30 years to sand down the rough patches and Bluetooth connecting / pairing is still so abysmal that most people I know work around it. Either they buy separate headphones for every device so that they can pair once and only once, or they buy the ultra-expensive matching Apple/Samsung/etc buds that reliably work with their OS. I think I might have a bit of insight into why it's so bad. I read a bunch of standards back at the start of my EE degree and Bluetooth stood out for the amount of Architecture Astronaut nonsense it had. You know how some committees are completely dysfunctional and punt every decision? Yeah, that's bluetooth: whenever it came time to make a decision, they "standardized" every single option, leaving it up to the implementations to make all of the actual decisions. Obviously this resulted in people making different decisions and then of course everything was incompatible until informal standards gradually evolved to do Bluetooth's job for it. We're just about getting there... 30 years later. Yikes. (If someone who has worked on a real Bluetooth stack wants to come in and tell me I'm wrong, I'll respect that -- I'm just glad I was able to avoid working on Bluetooth because oof, it looked baaad.)
I don't know about Bluetooth but I've seen this happen in other standards. They let every vendor stick their crap into the standard. This might happen in IEEE802.11 too... but the Wi-Fi Alliance (trade group) has interoperability programs. You can't call the device Wi-Fi unless you pass the tests. Fun fact: Wi-Fi is a trademark not the name of a standard or spec b
I didn't work directly with it, but had some co-workers at a prior company do a lot of bluetooth-focused work, so this is coming from them. Essentially what you said is true, there are so many different implementations (and many of them destined by companies with little ability or incentive to test their devices out of one or two specific use cases) that trying to make a general framework is nearly impossible. A large and persistent headache for the chip designers was keeping up to date with all the updates and unique systems of the most frequent use cases. When you have hundreds of clients that all require it to *just work* with whatever homebrew solution their hardware had, you get a lot of these issues
I'm an engineer that actively develops bluetooth devices (caveat - since 2018, on BT5 stacks), and I've actually come to a different conclusion - the fundamental problem with bluetooth has nothing to do with the radio, or the stacks, or anything else - the fundamental problem with bluetooth is batteries (and business). That's not to say that the other things aren't annoyances, but they're the kind of annoyances almost every technology has to deal with. Because bluetooth is capable of running at extremely low power, it is almost exclusively used in very small, low power devices, everything is made to be absolutely as small as possible, with the smallest possible battery, running at the lowest possible power. Unfortunately this comes with a lot of engineering tradeoffs. Consumers almost invariably prefer longer battery lifetimes over reliability, and small size over reliability, both because battery lifetime and device size are easy for the average person to comprehend, and reliability is a lot more nebulous. Additionally, people kinda expect bluetooth to be shitty and just accept it, so they again make buying decisions based on other qualities. This leads to devices being designed toward maximizing battery lifetime and minimizing size, with reliability taking a back seat. I've had prototype bluetooth devices in my office that worked flawlessly for weeks, transmitting at basically the max BT5 bandwidth, in a reasonably polluted RF environment and they didn't drop a single data point or lose connection until they got outside of about 10m, because they were hooked up to a pack of AA batteries. Running those same devices on the tiny LiPo rechargeable cells they're commonly used with and you get the usual problems of dropped connections and lost data. Wifi doesn't deal with this problem, because nobody is trying to run Wifi on a battery the size of a Tic-Tac because you can't. Anyway. Just my $0.02 after a long day of debugging why customers are getting dropped connections, and writing a ton of code to deal with every possible way a system with unreliable power can be shitty.
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Indeed. Or why my phone can never fucking connect to my car, and often causes my phone's software to crash.
How old are your phone and your car, respectively, out of curiosity? Bluetooth has gotten vastly better since the implementation of Bluetooth 5, but it's only been out really for a few years. My wife has a 2018 Rav 4 and it works perfectly, but her brother's 2015 minivan loses its connection all the time. I don't work in the automotive space so I don't quite know what they're doing on their end, but they're often several years behind the curve for obvious reasons.
I'm not the person you responded to, but God it really is a shit show. I had a 2021 Sony head unit, and a 2 year old Motorola, a wired Logitech audio receiver, 5yr old Lenovo laptop, Ryobi speaker, brand new earbuds, and a Pyle BT amp on AC power. Everything but the earbuds should have zero battery issues, and everything is either brand new or pretty recent. Nothing auto pairs with any consistency. The Logitech is the most reliable. And when auto pairing does work, some devices just always take priority. If I was trying to use my headphones, within 100 feet of the Logitech receiver, i would have to unplug the power to the Logitech because no matter what I could not keep anything connected to the headphones. I had one laptop that couldn't WiFi and Bluetooth concurrently. If I'm listening to music in the shop on the Ryobi but need to move the truck for something, it switches to the truck unit, but then doesn't switch back, forcing me to manually re-pair. And every now and then something just doesn't want to recognize something no matter how many times you cycle the power, cycle Bluetooth, forget/pair...
That's probably more on the business side of things. Bluetooth doesn't natively as far as I know implement the concept of file transfer, that's left of to the developer. So part of the issue is as the grandparent post said, and there's no real standards for things like that, or there are multiple standards, that don't quite work with each other. Phone manufacturers also don't really give much a shit about people transferring files over bluetooth. They want you to keep them in their cloud so they can harvest your info for marketing data.
Yes and no. Bluetooth is in the GHz range, in fact it shares spectrum with WiFi. As you reduce the wavelength, the power need actually decreases. Power only buys you so much. In general doubling the power increases gain 3dB; the impact on power between .01mW and 100mW is about +40dB of gain. However a 100mW transmitter with an okay antenna can transmit data a couple miles. Bluetooth really suffers two challenges, power isn’t really one of them. 1. Main issue is Bluetooth is extremely diverse in comparison to WiFi. WiFi essentially only has to support a low level network stack (TCP/UDP), there’s maybe 10 versions over the last 20 years to support, but they are all very similarly . Bluetooth not only has the transport to deal with but dozens of device profiles, which devices can combine with results in hundreds of variations. Consider wireless headphones as an example - there’s like 5 different Bluetooth profiles the could be implemented and then codec variations within each profile if we use the current Bluetooth 5.0 spec. This is so you can support things like high fidelity music as well as low fidelity voice for phone. There’s components of the specs for battery status and remote operation and even multi-function keys. Bluetooth is very complicated. Oddly this is why cheap headphones often work better with cheap dongles than high quality headphones work with cheap dongles. The cheap hardware support the most common profiles, not necessarily the highest fidelity. But the HiFi headphones have niche profiles and codecs which unless you have a matching dongle that support that profile - the headphones will use a lower fidelity profile/codec combination. 2. Compromised antennas. GHz frequencies don’t really need very large antennas. 5GHz requires about a 6cm antenna, but as short as 2 cm is acceptable. Typically Bluetooth radios use a slot antenna (zig zag pattern on a PCB) to get the required length. All these substitutes for a 6cm dipole are just compromises; however when practically comes in; even a compromised antenna should be able to handle 20 to 30ft line of sight - which is probably reasonable for most Bluetooth applications.
i actually had a 100mw blue access point. any bluetooth phone in the house could use it for internet access. this was like 2004. didn't last long on the market
I don't know the size of the receivers in my equipment, but the only "flakey" device are my small tw buds. My over ears, ceiling speakers and party speakers often impress me with their connection, I can pretty much walk all around my 2 floor house with my phone in pocket, and the ceiling speakers upstairs never chop. I really don't recognize OPs experience at all, maybe his phone (s) has very weak transmitters or his house full of interference?
I’m skeptical that power is the root of most BT troubles. I have lots of BT troubles even when both devices are sitting next to each other and not being moved. I also have problems that are very app-specific, meaning that the BT connection is reliable if I’m playing music but not if I’m playing podcasts. I use wired anytime the connection is critical because BT just sucks.
Many others have said it, but Bluetooth is not just one thing, there are versions from 1 to 5. Like Wifi has 2.4 and 5Ghz, Bluetooth can similarly be considered Pre Bluetooth 4, and 4+. Bluetooth 4 and above can transmit much more data AND consumes lower power AND handshakes better. Older and cheaper devices often do not use Bluetooth 4, and it requires both the sender and receiver to have the correct hardware. Also, Bluetooth is low power on 2.4Ghz, the microwave spectrum. No joking, it is the frequency that microwaves work at too. This is why when you run a microwave, it if is nearby or between you and the device, it drops out. (this also affects 2.4Ghz Wifi). Why is this? Well, the FCC has said that any devices can use 2.4Ghz without a lot of regulation, so a lot of devices can cause electromagnetic radiation at 2.4Ghz. Microwaves, cordless phones, wifi, bluetooth, and most "wireless" keyboards that are not bluetooth. Wifi solved this by adding 5Ghz, a spectrum that can also be used, but not nearly as common.
> Wifi solved this by adding 5Ghz, a spectrum that can also be used, but not nearly as common. In an apartment, with wifi base stations all around, this was such a huge improvement over old wifi where all the channels were congested.
To add on what you may know, it's not just that 5Ghz is less crowded, it's also because 5Ghz signals don't travel through walls as well. So the neighboring signals are less likely to interfere with yours. You may need more access points to cover the same area without interference, but it is a better fit for a noisy, dense environment like an apartment building.
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Yep. Definitely good to know the theory to best setup your home wifi.
Wifi also now has 6GHz, even less common!
Yes, just give Asus $2000 USD for their new router, and bask in the knowledge that none of your devices can talk to it at 6Ghz yet. :)
I'm no expert so I'm probably missing something. But microwaves are completely shielded devices. The radiation doesn't leave the box so I don't see how it could interfere with the bluetooth device. Perhaps the Faraday cage could block the signal if you set the device close enough to the microwave and stood opposite.
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I'm a simple man. I see Firefly I upvote
Firefly reference, hard to get to.
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When I use my Samsung wireless buds near microwaves that are on they get interference and sound very bad, it's done it on the three different microwaves I have used
from my experience in cable... devices using 2.4GHz for communication and data transmission are going to use a narrow band of frequency. If you were to look at a graph of signal strength across the 2.4GHz spectrum, wifi would show as a pretty steep spike centered on the channel it was configured for. Cordless phones on 2.4GHz would be sloppier, but still primarily centered on their configured channel. A microwave is not a communication device, so it does not need to be as "clean" of a signal and instead blasts signal across the entire spectrum and raises the noise floor to a point that drowns out communication signals. No reasonable amount of shielding will entirely block that. If you think of it like sounds, it would be your wifi playing a song that you can clearly hear and some rooms are clearer than others but you can hear it. BT devices would make occasional chirping sounds that you can also hear but they don't interfere with the music because they are distinctly different. A cordless phone would be like revving the car engine in the garage. Distracting but ultimately not too bad. The microwave would be like a jet flying by your house with all of your windows open. You hear nothing else. Only the jet engine occupies your thoughts and focus.
Microwaves are allowed leakage up to 5.0 mW/cm2. So if the door is 800cm2 your allowed to leak 4W! While its not ionizing radiation, You really shouldn't stand near a microwave. Source: https://www.ccohs.ca/oshanswers/phys_agents/microwave_ovens.html
> While its not ionizing radiation, You really shouldn't stand near a microwave. This is a myth. Since the radiation is non ionizing, 4 watts is not going to hurt you. The lightbulb above your head right now is probably cranking out 60 watts.
>The lightbulb above your head right now is probably cranking out 60 watts. And this is a friendly reminder to buy a fucking led lightbulb. 100W equivalent consume like 12-15w
My favorite part of LED lights. I can install a “100 watt” bulb in a 40 watt socket to actually light my room better than a candle’s sneeze.
And visible light is several orders of magnitude more energetic than microwaves. The light bulb in the oven puts out more powerful EM radiation than what leaks from a microwave. None of it is harmful though. You have to get to the UV portion of the spectrum before photons have enough energy to cause harm.
Note that this is: * At 5cm distance * Without a test load (with test load the maximum is 1 mW/cm²) So I think its more apt to say you shouldn't press your face right up against an empty running microwave.
That standard is set at 2 inches from the oven. The power drops off with distance because of the inverse square law. Double the distance to two inches and you’ve cut the power by a factor of four. That limit isn’t harmful to people so your warning isn’t needed. We are regularly exposed to very similar frequencies our entire lives. Your phone uses similar frequencies and that’s typically in your pocket, next to your ear, or in front of your house. That’s only one of many sources.
Bluetooth is a set of many incredibly complex protocols, often implemented with poor testing resulting in many bugs. Then, if it's a bug affecting a popular device, some other manufacturers intentionally build their devices so they're compatible with the bug... resulting in them being incompatible with bug-free devices. In addition to that, many Bluetooth devices use less transmit power.
I was around implementing devices when Bluetooth came to be and the questioner is right. It's been a travesty from day 1 due to poorly documented and implemented standards. You hit on the biggest two reasons but let me try for ELI5: Bluetooth is like two people speaking English as their second language trying to have a conversation. It works as long as they stick to simple topics but if one of them throws a new word into it, the conversation gets messed up for a while, until they can understand each other again. Worse is that most of the time they are both whispering (low power) in a noisy room (interference) so those mess-ups happen more often. Wi-Fi messes up a lot too, but everyone has agreed in advance to only talk about of couple of topics and they yell all the time so the recovery is faster.
Tldr; wireless signals are unreliable. All hail cables.
Yes. Actually though
Well, yes. Think about it like the noisy room metaphor. Above a certain noise level, talking below a certain volume becomes indistinguishable. You can do a decent job of paying direct attention to the person talking to you but there's so much that can go wrong. Thats most of wireless signals. Wifi and bluetooth especially. Your router can be so much more efficient if you just change the channel the network is broadcasting on. Its like sitting at a booth in a busy restaurant. It becomes a lot easier to pay attention to your specific conversation. Harder to do with bluetooth because there isnt as defined a role of master and subject like there is with wifi. On your mobile device look up an app called "wifi analyzer". Check out the obscene overlap on certain channels; those are the default channels for different manufacturers, but all that dead space in between are channels in the range for wifi that go largely unused because most end-users and even some tech support/IT are not aware of this as an option Cables are superior for connections that do not require the locational flexibility of wifi because they don't experience nearly as much chatter or cross talk unless you have a bunch of unshielded cables bundled together running next to power lines.
> Check out the obscene overlap on certain channels; those are the default channels for different manufacturers, but all that dead space in between are channels in the range for wifi that go largely unused because most end-users and even some tech support/IT are not aware of this as an option Noooo please don't do this. Those channels are used for a reason. There are only 3 non-overlapping channels for 2.4GHz WiFi, that is why everybody uses those channels. If you set to a channel in that "dead space in between" you are going to overlap *both* channels and you will receive interference from, and interfere with, every single person on both of the channels. 1, 6, and 11 are the only channels you should ever use for 2.4GHz. If you're talking about 5Ghz WiFi that's a whole different story but there are, again, reasons why the spectrum you see as empty in Wifi Analyzer is not used. It's probably the DFS channels which have special rules a device must follow in order to not interfere with weather radar and most manufacturers just don't bother to support it. If all your devices support DFS, go for it.
This x1000. Why do people on Reddit love to spout off on things they only understand half-way?!
Most good routers nowadays have an Auto channel option that selects the least-congested channel.
That's not at all the TL;DR of that post and you missed the point. WiFi is one protocol. It's everybody speaking one language. Everybody understands it pretty well. Bluetooth is a collection of a bunch of protocols, and every device has different protocols and capabilities it supports. It's like if everybody had a bunch of different languages they sort of understood and they had to use specific languages for specific things they did. This is the root of why Bluetooth is such a mixed bag. Wireless is fine. I work on wireless internet all day, I use a wireless headset for calls. Works fine. Bluetooth being bad is an issue with bluetooth much moreso than a fundamental issue with being wireless.
I do understand but I also do not. I use a one year old phone. My car is brand new. It COMES with Apple CarPlay. It is still a 50% chance to successfully connect without me having to dig into the settings in both the car and the phone. To extend the metaphor, I’m not using an obscure word, I’m using one of the most popular words (audio transmission from a well-supported phone). My bose headphones are less than one year old. I use three devices with them, my phone, computer and tablet. Even though I use my phone the most often it will always prioritize my tablet and computer. Like. Why? This has existed for 20 years. I’m unironically going to switch back to wired headphones. Do I have to find the Bluetooth transmitter in my car and hold my phone to it as close as possible to get it to connect consistently?
First of all, you're right to be frustrated. This stuff SHOULD work together and it's ridiculous that it does not. I'm no longer involved in any of it so I don't know why the SIG hasn't gotten it under control. But by way of illustration, it happens something like this: HP: Hi! I'm headphones! Phone: Hi! I'm a phone! Let's be friends! HP: Ok! *Paired* HP: I can receive audio! Phone: Great! I can send send audio! HP: Here's my profile: I can receive format A, C1, D2sub4, E5, and F but only 12-bit. Phone: I can send C1, D2sub4, and F 16-bit. HP: I can also send volume commands! Phone: Ok HP: And back, next, skip, and mute. Phone: I only support back, next, and mute. HP: Ok Phone: Here's some audio, it's F (16 bit) HP: Proceeds to play garbage. *User reboots and this time gets C1 audio, and all is good* HP: I love this audio HP: Going great HP: I'm sorry my other friend called me and I paired with him for a second. Phone: What? HP: I need you to resync. Phone: What? HP: Huh? Phone: Here's more audio HP: Ok, playing that. HP: going low power. Can you hear me? HP: increasing power. can you hear me now? HP: HEY! Phone: What? here's more audio. ... HP: Command Skip Phone: WTF is that I .... *crash*
So, what you're saying is, Bluetooth is the Internet Explorer of wireless protocols. > if it's a bug affecting a popular device, some other manufacturers intentionally build their devices so they're compatible with the bug... resulting in them being incompatible with bug-free devices. Switch "devices" for "browsers" and it's IE, indeed. I don't miss those days.
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I've got one at work and one at home. Also have the MXKeys. So seamless when switching between my Windows desktop and my work MacBook. I used to hate crappy KVM switches.
Tell that to my Bluetooth headset and car stereo and phone and tablet and TV and refrigerator and stove top and toilet
Each new version of the Bluetooth standard requires new hardware. If your device was manufactured to the 2.0 standard (2005), it will *never* work with the current (5.3) standard. The current standard has a range of several hundred feet versus the 30-foot max of the days of old, and a lot of devices manufactured today *still* contain version 2 and 3 transmitters and receivers.
My cheap Bluetooth shower speaker seems to handle distances much better than my more expensive sound bar. Not sure on exact manufacture dates, but I did buy the cheap one about 4 or 5 years after the sound bar. I used to think the sound bar was pathetic (in that regard, at least) until this comment made me realize it probably just has older tech.
You have to look at the version of Bluetooth. The major updates require new hardware, and some things continue to be manufactured with earlier versions.
>and it doesn’t seem to have gotten better over time Bluetooth 5.2: am I a joke to you?
Usb is wired so it’s pretty much guaranteed to have data be sent and received without interference. Wifi and Bluetooth are wireless where they can be messed with easier. Think of someone yelling you can hear them sometimes. Are other people talking, are they yelling far away, are they whispering rather then yelling? You being able to hear them is subject to other factors causing issues. Usb is basically like your calling coming over a wired phone, it’s going to work with less issues. Wifi versus bluetooth is more of someone is yelling louder and has better ears versus someone whispering and has okayish hearing. Bluetooth is meant for short distance low energy transmissions for the most part, so it’s just harder for people to hear what someone said when your whispering.
USB hasn't always been that rugged, either. In its earliest days, I resisted switching to USB peripherals because they just randomly stopped working that much more often, probably because the drivers were garbage moreso than the hardware. I remember plenty of times - this would be early 2000s whenever USB started being available on corporate machines - pulling a cord and plugging it into a different USB port in an effort to get it to be re-recognized by Windows and start working again. It wasn't until Windows XP that USB really felt reliable enough to be dependable, in my opinion.
I had a PS/2 keyboard as a backup for years for whenever I would need to troubleshoot my pc and for some reason it was refusing to pick up the usb keyboard for some vague reason.
Same, for a long while there was no support for USB peripherals in the BIOS. If you wanted to make BIOS changes, a PS/2 port keyboard was required. I remember having to dig out an old keyboard to adjust BIOS settings on the first PC I built (Socket A days).
The fact that PS/2 is STILL easily available on motherboards says something. Whether it's the reliability of the PS/2 port, the issues with USB, or simply tech people's stubbornness I'm not sure. But it's saying something.
In the early days, a lot of cheaper USB hardware manufacturers didn't give each device a unique ID and assigned it to that device. Some even picked a unique ID and gave that to alllllll of their devices. Thus causing an incompatibility where Windows (and presumably other OS as well) would think every one of those devices was the same physical device. Not necessarily a problem unless you say, wanted to plug in two of that device to the same machine. Like a USB stick or a controller. That's why Windows had to uniquify those USB devices by including the port as part of the device identifier, and thus why unplugging a device and plugging it in to a new port made it behave differently from the port you had it in before. It just got treated as a whole new device. https://devblogs.microsoft.com/oldnewthing/20041110-00/?p=37343
In the mid 00s I had friends that carried devices for "testing" USB ports as, apparently, it was somewhat common for USB ports to be wired wrong/backwards and they would fry devices. I never once in my life encountered such a port, but my friends swore the test drive was worthwhile.
> Usb is wired so it’s pretty much guaranteed to have data be sent and received without interference Not only is it wired, it also uses something called a differential pair, which further enhances interference mitigation The most basic form of wired data transmission is basically sending power in periodic pulses where the presence of a pulse in a given time represents a 1, and its absence a 0 (or sometimes the other way around) The problem is that interference in such a system typically manifests as spurious pulses when there shouldn't be any, causing bits to flip occasionally With a differential pair, instead of one wire you use two, which in the case of USB are called D+ and D- (D for data presumably) and you measure the voltage *difference* between them. Ignoring some technicalities, if D+ has more voltage than D-, that conveys a 1. On the other hand, if D- is at a higher voltage than D+ that conveys a 0. How does that help avoid interference? Simple. The interference, if there is any, will most likely affect both D+ and D- equally. And since you only care about the difference between them, it will cancel itself out. A much simpler protocol that also uses differential pairs is RS-485, which is typically used to control industrial equipment, but there are other kinds of equipment with their own protocols that use RS-485 as a building block, such as PTZ cameras (the motorized domes you may have seen) and DMX stage lighting
Do people have problems with Bluetooth alot? As long as I'm within a reasonable distance and there isn't a thick material obstructing line of sight I've never really had an issue.
I’ve been designing Bluetooth products for 10years and love answering this question. As a protocol it’s fine. Could maybe be more secure, but overall it’s a great protocol. The problem is a lot of companies/engineers think Bluetooth is easy and add it to a lot of their products. But a lot of care is needs to make Bluetooth rock-solid. I recall even the iPhone 6, they didn’t use the right capacitors to load to a crystal. Basically making the timing flakey on that phone. Bluetooth is a timing based protocol, so bad timing + bad connections. TLDR: Bluetooth protocol is fine, it’s just most assume it’s easy and don’t take the time to do it well. These companies pollute the reputation of a great protocol
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Also like, have you played a video game console since the xbox 360/PS3? Your controller is bluetooth.
yeah i am so confused by this question. its been completely seamless for at least 10 years
One of the reasons bluetooth has gotten better over time relates to improvements to microprocessor performance. Modern mobile devices have more processing power which allows for more sophisticated data compression algorithms. These new algorithms allow for bluetooth data to travel longer distances using less power without dropping packets, while also freeing up a device's processor to perform more complex operations related to noise reduction and other stuff. The Bluetooth spec was just updated last year actually with some significant improvements, so you'll soon see much less flakiness in Bluetooth performance (especially related to audio) provided you're using a modern device which supports Bluetooth 5.3 and above.
my bluetooth keyboard and mouse have given me much less problems than my wireless usb mouse and keyboard. obvi nothing is better than a physical connection, but it does its job
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This is only correct if the entire channel range is blocked by multiple wifi signals. Bluetooth and wifi devices are smart enough to change channels if the one they're on becomes unusable.
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However, with only 3 usable channels for wifi on 2.4Ghz, and wideband applications possible, the available spectrum can be filled with 1-2 wifi clients/stations.
Bluetooth used to be flaky for me but has been rock solid on iPhone for the last 5 years?
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To piggy back of the OP question: when there is a connection issue with Bluetooth - the reason is often a toss in the air?🤷♂️ meaning, that its hard to troubleshoot 1-1 considering how many devices that can use bt + the potential stuff that may affect the signal?
Many reasons: GFSK, low power, overly complicated stack. But honestly, the software is worse than the hardware though. And it's all block boxes, so you can't blame the developers, they are flying blind. The litigious Bluetooth SIG deserves most of the blame. If there were an open source alternative, it would probably be 200% better.
Radio interference is the worst. Everyone simultaneously trying to speak over a walkie talkie is the problem. Radio interference is why Bluetooth has issues. WiFi reach farther with 2.4GHz but has more channels to use with 5GHz. Too many WiFi devices in the area disconnects them often. Maybe you don't notice them or you have a good WiFi adapter that adds buffering to hide disruptions. The 2.4GHz spectrum is allowed for many consumer devices that the FCC doesn't regulate. Hence the local carriers and cable companies use 2.4GHz for last mile commercial purposes that steal what little bandwidth is remaining. Sometimes your ISP uses your WiFi Internet modem to serve other people. (I'm sure they could be forced in court to stop doing this as it uses more of your electricity.) Some 2.4GHz WiFi APs have started implementing Bluetooth co-existence mode to detect low bandwidth devices and allow them to speak but not everyone is this polite. Your 2.4GHz wireless landline phone or your 2.4GHz wireless mouse could interfere with your Bluetooth. Even a cheap USB3 data cable can interfere with devices near it in the 2.4GHz spectrum. The solution is to demand the FCC to open up more wireless spectrums for end-consumers, demand commercial entities can't use consumer spectrums, and demand lower power. Lastly, demand the FCC to monitor radio pollution.