BLE PHY and connection time.

[Ziyao Zhou]

Hi

Whether the physical layer (PHY) of BLE affects the time from advertising and scan response to connection establishment?

[Turbo J]

I believe it does. And this answer is also missing about as much detail as your question itself...

[Edvin]

Hello,

Yes. It requires some more context. Are you seeing a difference? Or do you want to reduce the connection time? Are the devices far apart? Typically 1MBPS is being used for advertising. Unless your devices are very far apart, there is not really any reasons to change the PHY. There are other parameters you could change to minimize the connection time, such as the advertising interval and scan window.

Best regards,

Edvin

[Ziyao Zhou]

Hi Edvin and Turbo,

If I use certain advertising interval and scan window, when the PHY is higher (2M), the speed will be faster than 1M or LR right?

[Turbo J]

Wrong.

As far as I understand BTLE, the advertisement and connection establish procedures run at 1M by default.

The upgrade to 2M happens after the connection was established, and both devices need to agree to the upgrade procedure.

Don't ask me about coded Phy, I have no idea.

[Edvin]

No, increasing to 2MBPS will not speed up the connection process. increasing the advertising interval and scan window will decrease the time it takes to connect.

Do you have some more context? Do you have a peripheral and a central that takes a long time to enter into a connection? Are they located close to one another? Do you control both devices (meaning they are both DKs and you have built the code for them)? Or are one of them 3rd party (like a phone or some other product)? 

BR,

Edvin