What the relation between Immediate Alert Service and Proximity profile in BLE(Bluetooth 4.0)?

Question

I am new to iOS development, and study about Bluetooth Low Energy (BLE, Bluetooth 4.0) for IOS

I have found the information like Proximity profile and it use the Service of Immediate Alert . The description of Proximity profile is like the following:

When a device moves away from a peer device so that the connection is dropped or the path loss increases above a preset level, causing an immediate alert.

The condition-A:Using Proximity profile

The Proximity profile use immediate alert Service to start alert when a device moves away from a peer device.

The condition-B:Without using Proximity profile

I can get the RSSI from the BLE device and use the immediate alert Service to start alert when the RSSI is out of range which I have setting(For example: -75dbm).

The question is like the following:

What the different between condition-A and condition-B ??

Is the Profile just a theory ? and the Service is the real application ?

Answer 1

该配置文件定义了服务的语义，而服务只包含其包含的特征的正式描述，并具有指定的UUID。