​The material contained on this page is informative only. Authoritative compliance information is contained in the applicable Bluetooth specification.


Name: Immediate Alert

Type: org.bluetooth.service.immediate_alertDownload / View

Assigned Number: 0x1802


This service exposes a control point to allow a peer device to cause the device to immediately alert.


The Immediate Alert service is instantiated as a Primary Service. There is only one instance of the Immediate Alert service on a device. There is only one instance of the Alert Level characteristic in an Immediate Alert service. This alert continues until one of following conditions occurs: • An implementation specific timeout • User interaction on this device • A new alert level is written • The physical link is disconnected


If the written alert level is “No Alert”, no alerting is done on this device.

If the written alert level is “Mild Alert”, the device alerts.

If the written alert level is “High Alert”, the device alerts in the strongest possible way.

Service Dependencies

This service has no dependencies on other GATT-based services

GATT Requirements

Sub-Procedure Server Requirement
Write Without Response Mandatory

Transport Dependencies

Transport Supported
Classic true
Low Energy true
High Speed

Error Codes

This service does not define any application error codes that are used in Attribute Protocol.

Service Characteristics

Overview Properties Security Descriptors
Alert Level
The Alert Level characteristic is a control point that allows a peer to command this device to alert to a given level.
Property Requirement
Read Excluded
Write Excluded
WriteWithoutResponse Mandatory
SignedWrite Excluded
Notify Excluded
Indicate Excluded
WritableAuxiliaries Excluded
Broadcast Excluded
None None