I have a bunch of questions about Bluetooth 5.0, a very interesting technology for smart home. E.g. like this article tells:
The Bluetooth 5 spec allows low-energy transmissions to sacrifice data rate for more range. A lot more range: up to four times the range of Bluetooth 4.2 LE, for a maximum of around 800 feet.
There are some 5.0 dongles on the market right now, but for most of them there are nearly no technical specs rather than “Bluetooth 5.0”. I think to use them as BLE, I’d expect that least the following features are listed:
Some information about the range or “BLE Long Range” support? For lower Bluetooth versions, there were dongles with low and with long range available, this was distinguished by “Class 1”, “Class 2”, … like in this table: https://en.wikipedia.org/wiki/Bluetooth#Uses. For BT 5.0, no such table / information seem to exist.
I didn’t find any dongle which mentioned all these features. Does somebody know such a dongle or has even successfully tested it? (maybe also tests with the Raspberry-integrated BT 5.0 chip?)
The only page I found which shows a little bit more detailed supported Bluetooth features is this one: https://www.silabs.com/wireless/bluetooth
But these are only chips, no dongles. And the dongles do not mention which chip they use, at least not the ones that I know. Anyhow, the silabs page shows that there is a big diversity about the actual features that a chip / stick labeled with “Bluetooth 5.0” supports.
The Bluetooth specification got a complete jungle, when I see a “Bluetooth 5.0” label, I have completely no idea what they mean and which Bluetooth 5.0 features are included.
More questions I’m wondering about what are the prerequisites that the extended range is working:
Do both BT devices need support for Bluetooth 5.0 BLE long range or is the dongle enough?
Does the software stack has to do something for long ranges to work or does it automatilly happen with existing software for the BLE 4.x stack?
Maybe some of you have more knowledge about Bluetooth and can bring some light into the dark…
It’s a pure guess (I didn’t bother checking back with the standards) but BT was or is supposed to introduce mesh networking like ZigBee and ZWave already do. Maybe that’s how they reach that claimed extended range.
Range is related to link budget, which is the difference between transmission power and receiver sensitivity. Higher link budget (from higher transmission power or better receiver sensitivity or both), normally means better range. But this all depends upon environment.
The link budget (i.e. range) in BLE is from a new Coded PHY layer, which enables more sensitive receivers, by changing to the transmission technique (not transmission power) and has to be supported by both devices. This is controlled by the higher layers of the BT stack (e.g. BlueZ, Windows, etc), so just a controller or “dongle” support alone will not be enough to use it.
Also notice that there is no claim of longer range AND simultaneous higher data rates, for the same transmission power - as is normal for radio technologies you get one or the other, not both
The class 1 / 2 etc that is in “normal” or “classic” Bluetooth is the transmission power (and not applicable to BLE).
Separately BLE also has mesh. Mesh, in general, not just BLE, can add range by having additional “hops”/relays between the source and sink of the data, as well as potentially more robustness with multiple routes.
Thanks @ThinkSteve. To summarize what I learned so far:
Both BLE devices communicating which each other have to support “link budget” on the hardware and software side to enable the longer range (with lower data rates at the same time)
Class 1 / 2 /3 is not applicable to BLE
Bluetooth Mesh can extend the range (actually, I did know that before, but it seems like Bluetooth Mesh did not reach the market at all yet. There are near to 0 devices supporting it afaik and this doesn’t seem to change in the near future.).
Anyhow, this results in new questions for me:
How do I recognize whether a device and/or the software supports “link budget”. I never saw this term anywhere on products. If “Bluetooth 5.0” and “BLE” support is stated, does this necessarily include link budget capability?
Does this mean all Bluetooth transmitters with “Bluetooth 5.0” / “link budget” have more or less the same range?
At which layer are the routes managed? E.g. Bluez?