streaming data over BLE (nRF8001) high throughput / bandwidth solution

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

TIE Fighter — Tue, 20 Aug 2013 12:41:43 GMT

Hi,

100Kbits of data/sec from the master to the nRF51822 (slave) should be possible with the nRF51822 when using a 8.75 to 10ms connection interval. 100Kbits of data/sec from the nRF51822(slave) to the master should be possible with the nRF51822 when using a 8.75 to 10ms connection interval.

The nRF8001 has about 20bytes per connection interval at 7.5ms from nRF8001 to master and has about 60 to 80 bytes per connection interval from master to slave.

You should examine the nRF51822 for this application. The bandwidth however is a combination of both the master and the slave so you may get lower or higher bandwidth based on your master. So you would need to test this with the specific master that you plan to use.

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

Pablo Garcia — Tue, 13 Aug 2013 13:21:26 GMT

My mistake, I forgot, sorry. Solved !

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

Ole Morten — Tue, 13 Aug 2013 08:26:33 GMT

Good that it's clear! If you found the answer useful, I'd be happy if you could click the "Accept as answer" button below it. :-)

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

Pablo Garcia — Mon, 12 Aug 2013 13:14:43 GMT

OK, very clear now. Dongle is not an option in our case. Perhaps the best move for us it to fall back to Classic Bluetooth.

Thank you !

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

Ole Morten — Mon, 12 Aug 2013 13:09:55 GMT

The nRF8001 isn't able to transmit more than one packet of 20 bytes per connection interval. It is capable of receiving some more, probably 3-4 such packets, but anyway, the bandwidth will be way lower than your requirement.

The nRF51822 with the S110 will be able to transmit more, up to 128 kbit per second both ways, but this is most definitely stretching it. This is for example dependent on the Central being able to do 6 packets per connection interval with an interval of 7.5 ms, and not all Centrals can or will do that (for example iOS, which limits the interval to 30 ms).

As Marc says, BLE isn't a high-throughput or real-time protocol, so you might be better of considering other protocols. If you can live with having a dongle, using Gazell, our proprietary protocol, could be an option. This should at least give you 300-400 kbit/s.

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

Pablo Garcia — Mon, 12 Aug 2013 07:06:54 GMT

By continous stream of data, I mean around 100Kbits/sec.

I have read the documentation of BT 4.0 and, apparently, the limit is higher than that... but in forums people say that it also depends on the particular implementation of the stack of each manufacturer.

Given my bandwidth requirements... what BLE mode should I use? or... I am forced to switch to bluetooth classic?

Is there any reference design?

Thanks for your reply, Marc.

RE: streaming data over BLE (nRF8001) high throughput / bandwidth solution

Marc Nicholas — Sun, 11 Aug 2013 23:32:42 GMT

Profiles are built on top of GATT. Which is built on top of GAP. Changing profiles won't affect anything -- they're all intrinsically using the same mechanisms.

You mention "high throughput/bandwitdh" and real-time streaming. While BLE is low latency, it is not oriented towards high throughput or real-time (i.e. synchronous) communication. There is, however, another standard that is called Bluetooth Classic ;)

Maybe provide some more definition and constraints around what you're trying to achieve?

-m