how can I improve throughput for ble link?

RE: how can I improve throughput for ble link?

Ben.Qin — Wed, 22 Oct 2014 02:55:51 GMT

Thank you all. I tried several phones and pads, and I eventually found a result as I expected on a phone, transmitting more than 240 packets per second. So I guess different centrals make difference.

RE: how can I improve throughput for ble link?

Stefan Birnir Sverrisson — Mon, 13 Oct 2014 13:05:32 GMT

Yes, you are using notifications, so that should be optimal.

RE: how can I improve throughput for ble link?

Ben.Qin — Fri, 10 Oct 2014 07:23:11 GMT

@Stefan Birnir Sverrisson, I read the blog post, a very good article. I checked the configuration in my project, snippet memset(&hvx_params, 0, sizeof(hvx_params)); hvx_params.handle = p_nus->rx_handles.value_handle; hvx_params.p_data = p_data; hvx_params.p_len = &len; hvx_params.type = BLE_GATT_HVX_NOTIFICATION; making clear the server(nrf51822) should work in notification mode, not indications mode, right? If so, I don't suppose I should have done something wrong to configure the packets type.

RE: how can I improve throughput for ble link?

Stefan Birnir Sverrisson — Thu, 09 Oct 2014 10:33:08 GMT

Perhaps this blog post will give you some hints on the subject.

Update 13.10.2014 Try the throughput test example which is linked to in the blog post. The Nexus 7 might not be able to receive more than 1 packet per connection interval, and that might be the problem, but the best way to find out is to sniff the on air traffic to see what is actually going on.

For best throughput, make sure you have selected 7.5ms connection interval in the nRF51 application.

RE: how can I improve throughput for ble link?

Ben.Qin — Wed, 08 Oct 2014 02:56:58 GMT

@Asbjørn, thank you for your answers. I'll upload the data caught by sniffer, expecting it brings something useful. I don't know whether the app on android slows down the speed. Can the sniffer play as a central to catch data? lbs-throughput.pcapng nus_thoughput.pcapng

RE: how can I improve throughput for ble link?

Asbjørn — Mon, 06 Oct 2014 13:49:23 GMT

I'm a bit confused, do you see twice the amount of data going through with the example I linked to compared to the UART example that you had been playing with?

The type of service shouldn't matter as long as you achieve the same connection parameters and setup. By double speed, you mean double the amount of packages going through?

RE: how can I improve throughput for ble link?

Ben.Qin — Sat, 27 Sep 2014 02:07:51 GMT

There is a demo app on android catching the data from peripheral. Each data packet contains a sequence number. The received data sequenced without any missing. About 100 packets were received per second. So I thought the speed is about 16Kbps. Of cause I had read the example @Asbjørn pointed out. I hadn't found any distinguish difference. From the sniffer data, it owns a double speed to my nus project's. Should the service kinds make it different?

RE: how can I improve throughput for ble link?

Asbjørn — Fri, 26 Sep 2014 11:54:00 GMT

The throughput is dependent on the connection parameters as you say, but these can only be requested from the peripheral and will be set by the central.

How do you measure the throughput? Have you used a sniffer to check the amount of packages being sent across air? Have you had a look at this example?