E-RAB Setup Success Rate (VoIP)

Description

The E-RAB Setup Success Rate (VoIP) KPI indicates the E-RAB setup success rate of the voice over IP (VoIP) services in a cell or radio network.
According to 3GPP TS 36.300 and 3GPP TS 36.413, the counters related to this KPI are measured when the eNodeB receives an E-RAB Setup Request message or an Initial Context Setup Request message from the mobility management entity (MME), as shown in Figure 1 andFigure 2. The E-RAB is part of the Evolved Packet Service (EPS) bearer. According to 3GPP TS 23.401, an E-RAB is one or more Service Data Flows between UE and an EPC. The E-RAB identity remains unique for the UE even if the UE-associated logical S1-connection (S1 bearer) is released during periods of user inactivity. The E-RAB consists of both the E-RAB radio bearer (between the eNodeB and the UE, which is the same as the radio bearer defined in the EPS bearer) and the corresponding S1 bearer (between the eNodeB and the MME).

Figure 1 and Figure 2 show two scenarios: MME-initiated E-RAB setup (Scenario A) and UE-triggered E-RAB setup (Scenario B). Scenario B is triggered by the radio bearer setup. Initial Context Setup Request messages are exchanged between the eNodeB and the MME. If the E-RAB Setup Request message or Initial Context Setup Request message requires multiple E-RAB setups at the same time, specific counters are incremented for each E-RAB.

Definition

The E-RAB Setup Success Rate (VoIP) KPI is defined in Table 1. Note that the number of E-RAB connection setup attempts (VoIP) and the number of successful E-RAB setup connections (VoIP) are collected based on the descriptions in section Description.

Table 1 E-RAB Setup Success Rate (VoIP)

Name	E-RAB Setup Success Rate (VoIP)
Object	Cell or radio network
Formula	VoIPERABS_SR = (VoIPERABSetupSucces/VoIPERABSetupAttempt) x 100%
Associated Counters	E-RAB Setup Success Rate (VoIP) =(L.E-RAB.SuccEst.QCI.1/L.E-RAB.AttEst.QCI.1) x 100%
Unit/Range	Percentage (%)
Note	None