Time of the advertisement and scan

RE: Time of the advertisement and scan

Elfving — Mon, 28 Mar 2022 11:40:15 GMT

Good afternoon!

It sends the same 3 times, to open up for the receiving happening on either of the three channels.

Regards,

Elfving

RE: Time of the advertisement and scan

lgs — Mon, 28 Mar 2022 07:56:07 GMT

Morning Elfving,

Do three channels mean one packet need send three times?

Gaosheng

RE: Time of the advertisement and scan

Elfving — Tue, 22 Mar 2022 09:10:03 GMT

Hello Gaosheng,

Of course! Every advertising interval (20ms here) an advertising packet is being sent out on channel 37,38,39. The next advertising interval this repeats with the next packet.

On the Scanner side, it scans for messages on a frequency every scan window(25ms here). After scan interval(50ms here) it scans again on the next frequency. And so forth.

For a better explanation however, take a look at this youtube video about it.

Regards,

Elfving

RE: Time of the advertisement and scan

lgs — Mon, 21 Mar 2022 13:51:02 GMT

[quote userid="103347" url="~/f/nordic-q-a/85340/time-of-the-advertisement-and-scan/356672#356672"]

Here you can see the relationship between advertising packets and scan window and interval:

[/quote]

Hi Elfving,

Could you explain more about the diagram?

With best regards,

Gaosheng

RE: Time of the advertisement and scan

Elfving — Wed, 16 Mar 2022 12:31:32 GMT

Not long, though it depends on the size of it. For a package of 31 bytes (the maximum) it would approximately be half a ms. I found this previous response about this that explains it rather well.

Regards,

Elfving

RE: Time of the advertisement and scan

lgs — Tue, 15 Mar 2022 12:20:08 GMT

[quote userid="103347" url="~/f/nordic-q-a/85340/time-of-the-advertisement-and-scan/358193#358193"]How long it takes sending the advertisements themselves in other words? Advertisement window is not an expression I am familiar with[/quote]

Precisely, the time is spent on sending advertisements.

RE: Time of the advertisement and scan

Elfving — Tue, 15 Mar 2022 12:13:56 GMT

Hello again!

[quote user="lgs"]

1. Yes I want to know the length of the advertisement window. I want to know how long it will take.

[/quote]

How long it takes sending the advertisements themselves in other words? Advertisement window is not an expression I am familiar with

[quote user="lgs"]

2. Why set the CHANNEL_NUM more than one? is it not enough with one channel? are the channels meaning the different frequencies?

[/quote]

Yes, these are known as channels and refer to different frequencies. 37, 38 and 39 (2402Mhz, 2426Mhz & 2480Mhz) are used for advertising as advertising is bound to happen a lot, and these channels have the least overlap with WiFi. They use multiple channels for redundancy and to allow more traffic.

Regards,

Elfving

RE: Time of the advertisement and scan

lgs — Mon, 14 Mar 2022 09:50:37 GMT

[quote userid="103347" url="~/f/nordic-q-a/85340/time-of-the-advertisement-and-scan/356817#356817"]I am not sure if I understand. Are you wondering about the length of advertisement window?[/quote]

Hi Elfving,

1. Yes I want to know the length of the advertisement window. I want to know how long it will take.

2. Why set the CHANNEL_NUM more than one? is it not enough with one channel? are the channels meaning the different frequencies?

With best regards,

Gaosheng

RE: Time of the advertisement and scan

Elfving — Tue, 08 Mar 2022 10:06:14 GMT

Hello,

[quote user="lgs"]Could you provide which doc you are referenced?[/quote]

Yeah I was referring to Mesh Profile 1.0.1, you can find it here.

[quote user="lgs"]1. I mean the advertisement window. Have the advertisement interval likewise? [/quote]

I am not sure if I understand. Are you wondering about the length of advertisement window?

[quote user="lgs"]2. Is the alternating appear between advertisement and listening?[/quote]

Again I am not completely sure what you are asking, but it does alternate between advertisement and listening. Do you want me to explain the illustration that describes these differences further?

Regards,

Elfving

RE: Time of the advertisement and scan

lgs — Mon, 07 Mar 2022 22:22:37 GMT

[quote userid="103347" url="~/f/nordic-q-a/85340/time-of-the-advertisement-and-scan/356672#356672"]No, which is why they send messages rather infrequently. You can read more about this in section 3.7.4.1. A node should send less than 100 messages in a moving 10-second window, so the message rate is ~10Hz.[/quote]

Hi Elfving,

Could you provide which doc you are referenced?

Best regards,

Gaosheng

RE: Time of the advertisement and scan

lgs — Mon, 07 Mar 2022 15:16:36 GMT

Hi Elfving,

1. I mean the advertisement window. Have the advertisement interval likewise?

[quote userid="103347" url="~/f/nordic-q-a/85340/time-of-the-advertisement-and-scan/356672#356672"]I am a little uncertain about what you are referring to here. The node only advertise when it has something to advertise - either data to send, relay or re-transmit.[/quote]

2. Is the alternating appear between advertisement and listening?

RE: Time of the advertisement and scan

Elfving — Mon, 07 Mar 2022 15:01:38 GMT

Hello Gaosheng!

[quote user=""]

1. Can they do advertisement and scan operations simultaneously?

[/quote]

No, which is why they send messages rather infrequently. You can read more about this in section 3.7.4.1. A node should send less than 100 messages in a moving 10-second window, so the message rate is ~10Hz.

[quote user=""]

2. I know the advertisement interval, but I don't know how long the advertisement process lasts?

[/quote]

I am a little uncertain about what you are referring to here. The node only advertise when it has something to advertise - either data to send, relay or re-transmit.

[quote user=""]

3. What's the difference between scan interval and can window?

[/quote]

Here you can see the relationship between advertising packets and scan window and interval:

Regards,

Elfving

RE: Time of the advertisement and scan

lgs — Mon, 07 Mar 2022 10:40:40 GMT

I hope you can solve the case ASAP😀

RE: Time of the advertisement and scan

lgs — Mon, 07 Mar 2022 08:30:14 GMT

Yes, I am looking forward to it.

RE: Time of the advertisement and scan

Elfving — Thu, 03 Mar 2022 15:26:34 GMT

Hello,

I will have to get back to you on this.

Regards,

Elfving