eRAN Performance KPI Overview (Accesibility)

Accessibility KPI

1. RRC Setup Success Rate
2. E-RAB Setup Success Rate
3. Call Setup Success Rate 

RRC Setup Success Rate

The RRC connection setup procedure is triggered by various different causes as identified by the “establishmentCause” field in RRCConnectionRequest message: emergency, highPriorityAccess, mt (Mobile terminating)-Access, mo (Mobile Originating)-Signaling, and mo-Data. The UE sets the establishmentCause in accordance with the information received from upper layers. Causes except mo-signaling are categorized as service-related ones. The mo-signaling cause is a signaling-related cause

This KPI evaluates the RRC setup success rate in a cell or cluster involved.

According to Reference, the RRC connection setup procedure is triggered by various different causes as identified by the “establishmentCause” field in RRCConnectionRequest message: emergency, highPriorityAccess, mt-Access (Mobile terminating), mo-Signaling (Mobile Originating), and mo-Data. The UE sets the establishmentCause in accordance with the information received from upper layers. Causes except mo-signaling are categorized as service-related ones. The mo-signaling cause is a signaling-related cause.

Assosiate Counter

The counters measure the number of RRC connection setup requests for different causes in a cell. The RRC Connection Request message is the first RRC signaling message sent from the UE to the eNodeB. The corresponding counter are incremented by 1 each time the eNodeB receives an RRC Connection Request message from the UE. Note: The L.RRC.ConnReq.Att counter is incremented by 1 when the eNodeB receives the message for the first time. The counter will not be incremented repeatedly, if the eNodeB receives the message for multiple times.

RRC Setup Failure Reason

Possible reason:

• Resource allocation failure (admission failure)
• No response from UE ( Poor coverage or terminal problem)

E-RAB Success Rate (Radio Access Bearer)

Type of bearers

• Default bear: With default QCI which is specified in HSS
• Dedicate bear: With dedicated QCI which is negotiated by PDN-GW and PCRF

An E-RAB is the access layer bearer for carrying service data of users. The E-RAB setup success rate in a cell directly represents the capability of the cell to provide E-RAB connection setups for users

E-RAB Setup Success Rate (VoIP)

VoIP is related with QCI 1 bearer

This KPI is used to evaluate the E-RAB setup success rate of the VoIP service in a cell or a cluster.

LTE-SAE QoS Class Identifier

E-RAB Setup Success Rate (All Service)

This KPI is used to evaluate the E-RAB setup success rate of all services (including VoIP) in a cell or a cluster.

Associated Counters – Initial E-RAB Setup


Associated Counters – Dedicated E-RAB Setup




Call Setup Success Rate

Call Setup Success Rate
 
 
Counters For S1 Dedicated Signaling Setup

• As shown at point A,the L.S1Sig.ConnEst.Att counter is incremented by one each time the eNodeB sends an INITIAL UE MESSAGE to the MME.
• As shown at point B, the L.S1Sig.ConnEst.Succ counter is incremented by one each time the eNodeB receives the first S1 interface message from the MME after sending an INITIAL UE MESSAGE to the MME.