Connection about GATT

[FACE@shibuya]

I have a question about for LE.
In my understanding, BT connection must confirm each profile, and it is able to connect same profile that each products have.
For example, In case of BT classic products,
If One product has A2DP, HSP, and RCP, Another product has only HSP, both productions connect the HSP.
However, in my understanding, BT LE have only GATT.
Smart glass of BT LE, smart watch of BT LE, hearing aid of BT LE, can there device connect to each device of BT LE ?

Or,

Dose BT LE have some profile like BT classic?

Is it coorect in my understanding?

[Menon]

Hello,

What you wrote or understood about Bluetooth Classic and BLE is correct.

Dose BT LE have some profile like BT classic?

For BLE, while it does have defined profiles, they are more abstract compared to Bluetooth Classic. BLE profiles are essentially collections of services and characteristics. Unlike Bluetooth Classic, BLE devices don’t connect based on profiles. Instead, they connect based on the specific services and characteristics they support, which aren’t strict connection requirements like they are in Bluetooth Classic.

However, in my understanding, BT LE have only GATT.

Yes, this is true. BLE does have profiles (e.g., Heart Rate Profile, Battery Profile), but these are essentially collections of standard services and characteristics, not connection requirements like in Bluetooth Classic. BLE relies on GATT, a protocol where data is organized into services and characteristics, for these profiles. I recommend going through our Bluetooth Low Energy course in Developer Academy, which will give you more insight on this.

Kind Regards,

Abhijith

[FACE@shibuya]

Hi, Abhijith san

Thank you for your reply.

I have one more question.

You said that BLE doesn't have the profile for connection, like Classic.
Cna the BLE device eassily  freely asnd easily connect aother BLE device, unlike classic ? 
The Classic device have the profile for connection, However, BLE doesn't have the profile for connection.so, BLE device have  easily connect to each other due to not the coonection profile like CLassic..
Is it correct ?

best regards,

T.Shibuya

[Menon]

Hello,

FACE@shibuya said:

The Classic device have the profile for connection, However, BLE doesn't have the profile for connection.so, BLE device have  easily connect to each other due to not the coonection profile like CLassic..
Is it correct ?

Not exactly like you explained. Compatibility in BLE is defined by the services and characteristics the devices support, not by a specific "connection profile." Just because two devices use BLE doesn't mean they can understand each other they must have compatible services. BLE connections are not "free and easy" just because there are no connection profiles. Instead, BLE devices still need to have matching services and characteristics. I believe making a connection might be possible but it will be completely meaningless as they cannot communicate.

BLE doesn't have a concept of "general pairing" like Bluetooth Classic does with profiles. The pairing or connection happens when a specific service is needed. Even if the devices can technically connect, if they do not share or recognize compatible services and characteristics, the connection won't be useful.

Kind Regards,

Abhijith

[FACE@shibuya]

Thank you for your advice.

 

I understand about your comment.

I think that you said, “ if you connect the service different BLE product each other, it is no meaning of connection due to the different service.”

 

My question is that “Can each different service BLE products connect ? “

I understand that it is no meaning for each different service to connect.

However, I want to know if each BLE device that have the different service connect at physical layer .

The BT classic device cannot connect the product that each different profile. But BT LE don't have the profile like the classic.

So, I afraid that the BLE connect the product that have each different service. ( I know, it is no meaning of the connection for each different service.)

[Menon]

Hello,

FACE@shibuya said:

My question is that “Can each different service BLE products connect ? “

Technically, a connection can be established. I’ll explain a bit more to make it clearer.

The central device (scanner) can connect to the peripheral (advertiser) as long as the peripheral is in advertising mode and accepts incoming connection requests. For establishing the initial connection, compatible services and characteristics are not required; the connection layer in BLE simply provides a communication link.

Once connected, the central device typically performs a GATT service discovery to identify which services and characteristics are available on the peripheral. If the central device doesn’t recognize or support the discovered services or characteristics, it won’t be able to interact with the data meaningfully.

Hope this clears up your doubt.

Kind regards,
Abhijith