Maximum troughput with 3 peripherals and one central

[Constantin]

Hi,

I am planning two have the following network:

1 central communicating with 3 peripherals

One of the peripherals will be a smart device (iOS or Android). What would be the maximum through put. From my understanding the minimum connection interval is 7.5 ms and the nRF52 is capable of sending 6 packages in between this interval. But does this mean for three peripherals that the central can send 2 packages two each peripheral in between one interval?

iOS only supports intervals down to 30 ms. This would mean that if an iOS device is inside the network the throughput will reduce by factor 4?

And last questions doe a package send always mean both ways? So the central sends one package and the peripheral answers?

Thanks for your help.

[endnode]

Surprisingly nRF52832 is BT5 as well and even more surprisingly BT5 doesn't make larger throughput through more PDUs/MTUs but through data rate. And because both nRF52832 and nRF52840 support 2Mbps they will have basically equal maximum theoretical throughput.

Now as you use nRF52832 I suppose you are talking about S132 V3 stack (note that there are other Open Source options which can provide different maximums!) and it has indeed detailed section about theoretical maximum throughput in its specification here. If you want to convert these back to PDU/MTU numbers per interval in relation to connection interval used and number of parallel GAP Central links then read this and this blog post as well as this section from SD specification.

[endnode]

... full Scheduling section from S132 Soft Device specification (especially last section 16.10). I would actually write the FW and do the test if you are really so much interested into detailed bandwidth.

To the BT5.0 remark: it sounds completely incorrect, at least in the way you wrote it ("The only change for BT 5.0 will be the amount of bytes per package which can be sent."). Already BT4.2 has various extensions like Connection Interval, PDU and ATT_MTU. The only added feature in BT5.0 is 2Mbps airspeed option, it gives you larger bandwidth if you can leverage it.