measuring throughput on S130 V2

RE: measuring throughput on S130 V2

Jorge — Mon, 27 Nov 2017 10:48:27 GMT

I achieved 124kbps (full-duplex) using 6pkt/7.5ms with each packet having 20bytes. My problem was I was counting the number of packets wrongly before.

I didn't try below the 7.5ms connection interval since this is outside of the BLE standard spec.

RE: measuring throughput on S130 V2

djqtsg — Mon, 27 Nov 2017 10:33:47 GMT

Hi Jorge,

did u have a conclusion on the throughput thing, which I am very interested to know? recently I did some experiment, in which I could achieve 150kbps: 150 bytes of packets, sending rate is 1pkt/8ms. If I increase sending rate to 1pkt/4ms, I have a lot of lost packets, which I haven't really counted. 150kbps is quite similar to what you achieved. So I want to know you got any further work or results.

RE: measuring throughput on S130 V2

Jorge — Wed, 27 Apr 2016 13:36:55 GMT

I changed from delays to the use of timers to be sure of the time sampling. Now it seems more precise numbers, because I get 386 packets per second on the central and peripheral. Which give me a throughput of 62kbps for each side and 124kbps for both sides (fullduplex) wich is less then the 128kbps expected! Now the numbers feel more real

RE: measuring throughput on S130 V2

Jorge — Tue, 26 Apr 2016 11:17:02 GMT

I receive 991 packets (average) on the peripheral but only get 223 NRF_SUCCESS (average) on the central from the ble_nus_c_string_send. Can't understand the differences in this two numbers. Shouldn't they be the same? I'm only sending 223 packets successfully but receive 991? If anyone can help me understanding this I would appreciate. EDIT: Discover what I was doing wrong

RE: measuring throughput on S130 V2

Jorge — Tue, 19 Apr 2016 12:01:54 GMT

I'm already counting the number of packets that I receive in the central part and those are the ones considered. I try to send every ms a packet to the central but with different times I get different number of packets. I receive 1000 packets in one second, with 7.5 for min and max interval connection, but I think this is not a real number, because it shouldn't let me receive all the packets I send in one second.

EDIT I measured only the when I get NRF_SUCCESS and still got a throughput of 153.27kbps. I think is still a misleading number, but I'll work with it and be cautious!

RE: measuring throughput on S130 V2

Petter Myhre — Tue, 19 Apr 2016 11:48:27 GMT

You are calling ble_nus_string_send() 1000 times in a second. And you assume that you send 20 bytes each time. 20 * 8 *1000 = 160 kbps. Calling ble_nus_string_send() doesn't mean that the packet is actually sent. You need to check the returned error code. I believe most of your calls return NRF_SUCCESS (0x00000000), but some return BLE_ERROR_NO_TX_PACKETS (0x00003004). I would remove the delay and count the number of calls of ble_nus_string_send() that actually returns NRF_SUCCESS.