Time of the advertisement and scan

[lgs]

Hi Team,

I have a few questions about the transceive process of BLE Mesh5.0 based on nRF52840 chips.

1. Can they do advertisement and scan operations simultaneously?

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

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

With best  regards,

Gaosheng

[Elfving]

Hello again!

lgs said:

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

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

lgs said:

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

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

[lgs]

Elfving said:

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

Precisely, the time is spent on sending advertisements.

[Elfving]

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

[lgs]

Morning Elfving,

Do three channels mean one packet need send three times?

Gaosheng

[Elfving]

Good afternoon!

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

Regards,

Elfving