How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

Sukriti — Thu, 27 Jul 2023 03:19:45 GMT

Hi Zhang,

Thank you so much for the help. I saw the screenshot of the spec that you've attached. The behaviour makes better sense now. The Controller indeed seems to be handling one sync create command at a time. I hope Simon will also have something insightful to share based on the inputs from the developers. I will also post an update here if I observe something new worth sharing.

Best regards

Sukriti

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

zhangpc — Thu, 27 Jul 2023 02:45:20 GMT

Hello Sukriti,

I find some rules in BLE Core_v5.1, it indicates that the hci create sync command is pending until the establishment of a sync event occurs, the sync timeout or the cancel sync command is sent.

Best wishes,

zhangpc

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

zhangpc — Wed, 26 Jul 2023 05:15:50 GMT

At present, I have modified the relevant functions in scan.c to avoid waiting for the current sync operation, but I found that bt_hci_cmd_send_sync will return an EIO error code, so I suspect that the current BLE controller does not support continuously creating multiple sync tasks.

By the way, I believe that supporting the creation of multiple syncs simultaneously is the foundation of AoA productization.

Best regards,

zhangpc

Attach some logs

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

Sukriti — Tue, 25 Jul 2023 13:22:45 GMT

Hi Zhang,

I'm facing a similar problem. Were you able to find a solution? If yes, it'd be great if you could give me some insight on the same 🙂

Best regards

Sukriti

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

zhangpc — Tue, 25 Jul 2023 07:08:43 GMT

Thank you for your continuous support. Let's wait for the developer's reply.

Best regards,

zhangpc

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

Simonr — Tue, 25 Jul 2023 06:57:14 GMT

I've asked our developers if they have any clever ideas on how to increase efficiency in the synchronization step here. However, due to the summer vacation period we are currently understaffed, so delayed replies must be expected. I am sorry about any inconvenience this might cause.

Best regards,

Simon

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

zhangpc — Fri, 21 Jul 2023 03:11:42 GMT

Maybe I did not describe my problem clearly. At present, I have realized the synchronization of multiple tags and can obtain CTE packets, but their synchronization process is one after another, and there is no way to achieve the function of establishing synchronization with multiple tags at the same time. I think this has to do with the logic of the function implementation in the scan.c component, which leads to very inefficient synchronization.So how can you improve the efficiency of the synchronization process?

Thanks for your kind attention and look forward your reply.

Best regards,

zhangpc

RE: How to achieve multiple sync simultaneously in connectionless periodic advertising synchronization?

Simonr — Thu, 20 Jul 2023 13:04:38 GMT

Due to the summer vacation period we are currently understaffed, so delayed replies must be expected. I am sorry about any inconvenience this might cause.

To have multiple transmitters be able to sync with multiple devices, you need to distinguish the provided IQ reports by the sync_handle for example:

Best regards,

Simon