ARP ( Allocation and Retention Priority) in LTE
ARP parameter in Qos profile define the the relative importance of a bearer(requested) compared to other existing bearers for the allocation or retention in the network.
ARP consists of three parameters :
Priority level(1-15): Defines the importance of a bearer in relation to other bearers.
Pre-emption Capability: Defines the capability of the requested bearer to Pre-empt (remove) the existing bearers having low priority in the network.
i.e Capability to delete the other bearers.
Pre-emption Vulnerability: Defines the capability of a bearer to get Pre-emt or deleted by other high priority bearers.
I.e Capability to get deleted by other bearers.
Use case:
Suppose a Network is configured with a threshold to support 1000 number of bearers and a request received for the creation of one more bearer when there are already 1000 bearers exist in the network.Then network decides whether to accept the new bearer creation request or not based upon the ARP value of the requested bearer ie. Priority Level is high and Pre-emption Capability is ENABLED.
Based upon that network initiate existing bearer deletion(one or more) that are having low Priority Level and Pre-emption Vulnerability ENABLED to give services to the requested high Priority bearer.
Note: This is product specific implementation to select the algorithm to select and delete the existing bearers based upon priority.
