Bottleneck?

RE: Bottleneck?

djqtsg — Thu, 29 Sep 2016 04:01:59 GMT

By saying "The packets are still ACK-ed on the link layer, so you should not have any data loss", do you mean Notification?

Why so many posts I've read say otherwise, i.e., no Ack for Notification? Or what they mean is Ack from application level?

RE: Bottleneck?

KPE — Wed, 13 Nov 2013 16:04:59 GMT

The payload is the size of the packet that I'm sending. The Interval's represents the interval setup on each end, the MCP (PC) and BLE Stack (nRF51822). The timer is the application timer interval, used for sending the packets, also on the nRF51822. The example is located in the SDK, and I've modified it to make the test (it's not available anymore, as I use to only have one project for all my research - and it was not under source control at the time). It is located here: Nordic\nrf51822\Board\nrf6310\ble\ble_app_hts

RE: Bottleneck?

athar — Wed, 13 Nov 2013 12:22:29 GMT

From which example you find the columns parameters payload byte,timer etc? Where to find HTS example?

RE: Bottleneck?

Bastiaan — Thu, 31 Oct 2013 11:47:18 GMT

May we know how many packets can the PCA10000 dongle with MCP as central support per connection interval.

thank you

RE: Bottleneck?

Guest — Thu, 31 Oct 2013 11:47:18 GMT

May we know how many packets can the PCA10000 dongle with MCP as central support per connection interval.

thank you

RE: Bottleneck?

KPE — Tue, 08 Oct 2013 09:25:41 GMT

Man - this is just what I needed to hear - a perfect and elegant solution!

Do you ever get credited for the fantastic work you guys are doing here :D

RE: Bottleneck?

Ole Morten — Tue, 08 Oct 2013 07:58:13 GMT

Since you are allowed to have only one Indication pending confirmation at any time, this will limit your throughput significantly. If there isn't any particular reason for your use of indications, I'd strongly recommend you to instead use notifications. The packets are still ACK-ed on the link layer, so you should not have any data loss, the only difference is whether or not the packet is received and acknowledged by the application on the other end.

With notifications, you will be able to transmit up to 6 packets per connection interval, and hence you will see a much higher data throughput. The softdevice keeps a buffer of packets, so you need to find a way to manage this buffer. Two suggestions are given in the "Introduction to S110 SoftDevice" document, available in the SDK documentation folder or online here.

However, be aware that MCP won't be able to keep up with 6 packets per interval, so you will still not see 128 kbps with this. To get maximum throughput you have to use a Central device which allows both 7.5 ms connection interval and can do 6 packets per interval. You should also note that this high throughput will severely limit the application processing time available on the nRF51822, as given in table 11 in the S110 SoftDevice Specification.