Connection Interval 's relationship with Data rate and power consumption

[Ziyao Zhou]

Hi

I noticed one ticket says that "the following combination offers low power consumtion and high througput when needed :Short Connection Interval + High Slave Latency + Long supervision timeout "

I try to study this in two nRF54L15 DKs, I will change the connection interval in 

	struct bt_le_conn_param conn_param = {
						.interval_min = 320,
						.interval_max = 320,
						.latency = 0,
						.timeout = 4000,
					
				 };

The result is like， where thee blue curve is throughput. the orange one is power. I notice there is no clear relationship.

Could you kindly give me some evidence that shows Short Connection Interval + High Slave Latency + Long supervision timeout is nice choice?

[Kenneth]

Hi,

In a realistic end product use case it's very likely some kind of interference (e.g. other BLE, classic BT, Wifi, and other 2.4GHz protocol or interference sources (e.g. microwave oven or USB3.0 ports). All these source may cause packet loss, and in BLE if any error is found in the packet, it will wait until next connection interval before retransmitting and continue sending packets. This means that packet loss will have a high impact on the throughput if you use long connection interval, that is why I always recommend having the lowest possible connection interval, because even though under ideal conditions longer connection interval may seem better, in realistic scenarios the short interval will have better stable results.

Kenneth