5 ms·

They do agree on an awful lot of stuff, but the tools provided by the Bluetooth guys aged very poorly (i.e. their tools for generating GATT interfaces as C code

They do agree on an awful lot of stuff, but the tools provided by the Bluetooth guys aged very poorly (i.e. their tools for generating GATT interfaces as C code is absolute garbage, full of holes and has a built-in buffer overflow capability). The one thing nobody seems to do is stick to the standards provided, because they simply aren't broad enough for the creative stuff that people do with Bluetooth and Bluetooth LE. Most of us working in this space have some cack-handed way to advertise data without connecting because (for example) most of the connections to Bluetooth LE devices involve you having to do device discovery, even if you are connecting to 500 of the same damn device. Also, the bluetooth library in Android started out terrible and didn't improve despite being replaced, the Bluetooth chips in most cheap phones are also rubbish and fail when you exceed their undocumented number of connections, often requiring a reboot of the device etc. In short: You can sheet a lot of the problems back to an ill thought out spec and bluetooth chips in things like phones that just plain suck. Things like RF interference - I just don't know. Sometimes there is just a heap more bluetooth traffic around than anybody knows about. Packet sniffers are relatively cheap, it's interesting to fire one up in a busy office and see how many bluetooth packet collisions there are (hint: it's a lot). Blame RF storms or whatever but it's more likely to be something advertising a lot and spamming the spectrum.

toxik 4y ago
Something I’ve noticed is that Bluetooth breaks down around major construction sites, like infrastructure projects. It’s very strange, I wonder if they have some kind of high power BT transmitters for some reason.
- consp 4y ago
  Any high power 2.4ghz transmitter will destroy Bluetooth communication, this is all in the same 2.45ghz ISM band. I guess they use some devices communicating on that band.
  - dcx 4y ago
    They certainly do - walkie-talkies! Edit: Yes, they do exist - you can google this. But on reflection, a commenter below is probably right that it's more likely wireless security cameras, given typical site requirements (range, penetration depth)
    - gorgoiler 4y ago
      Handhelds are usually UHF - in the 446MHz range. Do you know of personal radios that operate in the 2.4GHz unlicensed spectrum?
      - tekknik 4y ago
        Drones (FPV), baby monitors to name two. I’m sure there’s more.
    - gruez 4y ago
      I don't think they use the 2.4 GHz band. https://en.wikipedia.org/wiki/General_Mobile_Radio_Service https://en.wikipedia.org/wiki/General_Mobile_Radio_Service
- mschuster91 4y ago
  On construction sites, I'd suspect that the problem is an awful lot of EM noise from machinery that should have been replaced or at least maintained decades ago, like mechanic spark generators/distributors from simple combustion motors or brushed electric motors (e.g. in drills). Additionally, remote controls for cranes, concrete pumps and other machinery may be the cause, depending on the frequency bands these use. Here in Germany, it's all 433/869 MHz from what I remember from sites I worked at, but no idea about the US.
  - toxik 4y ago
    It may be motor noise but anecdotal evidence suggests that it happens even when the machines are off, eg on national holidays. Some kind of transmitter seems likely though. I know one construction site had analog video signals in the 2.4 Ghz range for their surveillance cameras. I accidentally found out when I did a range sweep on a video receiver for other reasons. PS I am in northern Europe, not the US.
seanalltogether 4y ago
> The one thing nobody seems to do is stick to the standards provided, because they simply aren't broad enough for the creative stuff that people do with Bluetooth and Bluetooth LE. Yeah, I've been working with BLE now for clients for 3 years, it seems like most people think of their devices as little CRUD servers (unless you're doing genuine pairing with constant data streams). BLE would be much better using a simple REST model than the GATT table model. > Also, the bluetooth library in Android started out terrible and didn't improve despite being replaced One thing I'll give Apple credit for is having a very solid bluetooth stack. We've had only a handful of BLE connection failures on our testers apples devices over the past 3 years, whereas on android test devices we get at least one connection failure DAILY that interrupts test cases from running. Furthermore Android devices just reach a point of critical failure where you need to just restart the device to resume BLE.

toxik 4y ago

Something I’ve noticed is that Bluetooth breaks down around major construction sites, like infrastructure projects. It’s very strange, I wonder if they have some kind of high power BT transmitters for some reason.

consp 4y ago
Any high power 2.4ghz transmitter will destroy Bluetooth communication, this is all in the same 2.45ghz ISM band. I guess they use some devices communicating on that band.
- dcx 4y ago
  They certainly do - walkie-talkies! Edit: Yes, they do exist - you can google this. But on reflection, a commenter below is probably right that it's more likely wireless security cameras, given typical site requirements (range, penetration depth)
  - gorgoiler 4y ago
    Handhelds are usually UHF - in the 446MHz range. Do you know of personal radios that operate in the 2.4GHz unlicensed spectrum?
    - tekknik 4y ago
      Drones (FPV), baby monitors to name two. I’m sure there’s more.
  - gruez 4y ago
    I don't think they use the 2.4 GHz band. https://en.wikipedia.org/wiki/General_Mobile_Radio_Service https://en.wikipedia.org/wiki/General_Mobile_Radio_Service
mschuster91 4y ago
On construction sites, I'd suspect that the problem is an awful lot of EM noise from machinery that should have been replaced or at least maintained decades ago, like mechanic spark generators/distributors from simple combustion motors or brushed electric motors (e.g. in drills). Additionally, remote controls for cranes, concrete pumps and other machinery may be the cause, depending on the frequency bands these use. Here in Germany, it's all 433/869 MHz from what I remember from sites I worked at, but no idea about the US.
- toxik 4y ago
  It may be motor noise but anecdotal evidence suggests that it happens even when the machines are off, eg on national holidays. Some kind of transmitter seems likely though. I know one construction site had analog video signals in the 2.4 Ghz range for their surveillance cameras. I accidentally found out when I did a range sweep on a video receiver for other reasons. PS I am in northern Europe, not the US.

seanalltogether 4y ago

> The one thing nobody seems to do is stick to the standards provided, because they simply aren't broad enough for the creative stuff that people do with Bluetooth and Bluetooth LE. Yeah, I've been working with BLE now for clients for 3 years, it seems like most people think of their devices as little CRUD servers (unless you're doing genuine pairing with constant data streams). BLE would be much better using a simple REST model than the GATT table model. > Also, the bluetooth library in Android started out terrible and didn't improve despite being replaced One thing I'll give Apple credit for is having a very solid bluetooth stack. We've had only a handful of BLE connection failures on our testers apples devices over the past 3 years, whereas on android test devices we get at least one connection failure DAILY that interrupts test cases from running. Furthermore Android devices just reach a point of critical failure where you need to just restart the device to resume BLE.