Create connection is too slow when BLE mesh enable

RE: Create connection is too slow when BLE mesh enable

AHaug — Wed, 03 Jan 2024 13:22:45 GMT

Hi,

I've been out of office due to the Christmas Holidays so I haven't seen your previous reply before now.

[quote user="delta lucent"]How to fine tune BEACON_THRESHOLD and time_diff?[/quote]

This question does not make sense as the Beacon Threshold is defined from the specification and time_diff is the actual time lapsed since the message has been sent

[quote user="delta lucent"]If I mark that, do we have any risk to ble mesh network?[/quote]

You should be careful with changing things in the stack unless you're very certain that it does not void the specification, which in turn may result in firmware that is unable to be qualified as a Mesh product. You've mentioned this in your previous reply, so I'm just verifying your statement for you.

If you still have it available, I would like to see the entire .pcap from my previous inquiry

Kind regards,
Andreas

RE: Create connection is too slow when BLE mesh enable

lightspring — Wed, 03 Jan 2024 07:01:48 GMT

Hi Ahuag

If I mark that, do we have any risk to ble mesh network?

/*if (time_diff < (120 * MSEC_PER_SEC) &&
(time_diff < BEACON_THRESHOLD(sub) ||
time_since_last_recv < (10 * MSEC_PER_SEC))) {
return false;
}*/

Thank you

RE: Create connection is too slow when BLE mesh enable

lightspring — Thu, 28 Dec 2023 02:00:33 GMT

Hi AHuag

My product don't have open extend advertising, it maybe wireshark ble packet configuration issue.

I found a part of code in zephyr/subsys/bluetooth/mesh/beacon.c

static bool secure_beacon_send(struct bt_mesh_subnet *sub, void *cb_data)

{

......

time_diff = now - sub->beacon_sent;
time_since_last_recv = now - sub->beacon_recv;
if (time_diff < (600 * MSEC_PER_SEC) &&
(time_diff < BEACON_THRESHOLD(sub) ||
time_since_last_recv < (10 * MSEC_PER_SEC))) {
return false;

.....
}

That should be the root cause, it maybe traffic concern to skip new secure beacon send

I mark this part of code, the "create connection" process speed up as my expectation.

But I'm afraid it may cause the new issues , could you have any suggestion about that?

How to fine tune BEACON_THRESHOLD and time_diff?

RE: Create connection is too slow when BLE mesh enable

AHaug — Fri, 22 Dec 2023 15:35:29 GMT

Hi,

Thank you for the snippet of the trace.

Could you provide me with the entire .pcap and not just the snippet?
What you've marked in blue is not the secure beacon as far as I can see. It is just extended BLE advertising.
1. Do you have extended advertisement in your application, or is it your sniffer picking up something else?
It could be that the sniffer does not support the AD data-types that Mesh uses and that the sniffer thinks that theese messages are wrong due to that.
You have some "Empty PDU" packs here indicating that you have a connection running
It could be that there are conflicts with extended advertisement and Mesh i.e that the increase in connection is to be expected due to the amount of radio usage both extended BLE advertisement and Mesh requires

Kind regards,

Andreas

RE: Create connection is too slow when BLE mesh enable

lightspring — Thu, 21 Dec 2023 01:38:35 GMT

Hi Ahaug

I use wireshark to record the timeline , for your reference

This is snapshot of provisioned secure mesh beacon (blue ground part)

In other way, I provide unsecure mesh beacon too

I hope we can speed up connection time of my provisioned device.

Thank you

RE: Create connection is too slow when BLE mesh enable

lightspring — Tue, 19 Dec 2023 07:39:23 GMT

OK , I will provide to you in later days

RE: Create connection is too slow when BLE mesh enable

AHaug — Fri, 15 Dec 2023 15:06:43 GMT

Hi,

[quote user="delta lucent"]Is it because the beacon appears intermittently?[/quote]

That may be the cause, but I will have to double check somethings

Could you provide a sniffer trace where you track the communication and activity for BLE connection?

Kind regards,
Andreas

RE: Create connection is too slow when BLE mesh enable

lightspring — Tue, 12 Dec 2023 08:25:32 GMT

I use nrf connect to scan secured beacon,

I found this beacon is intermittent.

Is it because the beacon appears intermittently?
As a result, the mobile APP cannot quickly establish a connection.

RE: Create connection is too slow when BLE mesh enable

lightspring — Tue, 12 Dec 2023 01:34:21 GMT

Hi AHaug

My project use sensor model and this model has 10 elements

The publishing interval of sensor server is 10 seconds

In this condition, we need to take 3+ secound to establish connection.

But if I remove mesh function from prj.conf, it always take in 1 second.

It is very fast, user can't feel the connection latency.

RE: Create connection is too slow when BLE mesh enable

AHaug — Mon, 11 Dec 2023 14:04:33 GMT

Hi,

Could you state how long time it takes to establish a connection without Mesh as a reference?

Depending on how much activity there are in the Mesh network it may take longer or shorter time to establish the connection.

Kind regards,
Andreas