RE: For what all application can BLE OTS be used in nRF52840

SG1 — Wed, 17 Jan 2024 06:06:57 GMT

Thankyou Edvin for the reply.

RE: For what all application can BLE OTS be used in nRF52840

Edvin — Tue, 16 Jan 2024 10:32:45 GMT

Hello,

A1) Technically, yes.

A2) It needs to be handled in the application layer.

A3) To be honest, I have not tested this sample, but it should be a simple matter to count the amount of sent/received bytes per second (add an app_timer and count how many bytes you receive per second).

Technically, you may see a slight increase, but I think this is negligible, compared to using GATT. However, I am not sure how this needs to be implemented on the mobile/central side of the application. It may vary from phone to phone whether this is possible or not. So in short, I would recommend that you use GATT, which is commonly used, and you know that it works on all phones.

All this being said, OTS is not standardized on BLE. So this example is just a suggestion on how to do it. Regardless of whether you are using GATT or not, you would still need to implement the logic in the application of the central/mobile. I believe L2CAP was better than BLE in terms of speed when BLE was new, but since then there have been a lot of features added to BLE, which makes L2CAP redundant. So I would recommend that you just use a BLE service, such as the NUS to transfer the data. You would need to split up the object in chunks, and reassemble them on the other side, (which you would also have to do in the ble_app_ots application). With the "new" features in BLE, such as increased MTU, High speed BLE (2MBPS physical radio), longer connection event length, and so on, you can get close to the theoretical maximum of 1.3MBPS of payload throughput.

If you are interested, you can test the attached application, which will show the throughput between two DKs (or one peripheral running on a DK and the central being a mobile phone). Note that I only tested the pca10056->ses projects.

If you connect using a mobile phone as a central, using e.g. the nRF Connect app, remember to enable notifications before starting to transmit data.

On the peripheral and central device, press button 4 to start transmitting data, and monitor the throughput in the RTT log.

Best regards,

Edvin