LTE Accessibility KPI and Counters Mapping.​

1. RRC Setup Success Rate (Service)

The RRC (Radio Resource Control) setup procedure in LTE is initiated for various reasons, identified by the establishmentCause field in the RRCConnectionRequest message. These reasons include:

  • emergency
  • highPriorityAccess
  • mt-Access (mobile terminating access)
  • mo-Signaling (mobile originating signaling)
  • mo-Data (mobile originating data)
  • delayTolerantAccess-v1020

The UE (User Equipment) sets the establishmentCause and this is received by the eNodeB (Evolved Node B). For KPI (Key Performance Indicator) purposes, causes other than mo-Signaling are categorized as service-related, while mo-Signaling is categorized as signal-related.

RRC Setup Success Rate (Service)

The RRC Setup Success Rate (Service) KPI evaluates the success rate of RRC setups with service-related causes in a specific cell or cluster.

RRC_SSRService=RRC_ConnectionSuccessServiceRRC_ConnectionSuccessAttempt×100

RRC Setup Success Rate (Signal)

This KPI evaluates the RRC setup success rate specifically for the signal-related cause (mo-Signaling) in a cell or cluster.

These two KPIs help in assessing the performance of the RRC setup process by distinguishing between service-related and signal-related causes, providing valuable insights for network optimization.

RRC_SSRSignal=RRC_ConnectionSuccessSignalRRC_ConnectionSuccessSignal×100

2. Counter Mapping for RRC SSR.

Counter Mapping for RRC SSR.
Counter Mapping for RRC SSR.

LTE-SAE QoS Class Identifier

In LTE, there are nine QCIs (QoS Class Identifiers) defined by 3GPP TS 23.203. Each QCI has its own QoS requirements, and each E-RAB (Evolved Radio Access Bearer) is assigned a QCI attribute.

QCIResource type.PriorityPacket delay budget (ms).Packet error loss rate.Example services.
1GBR210010−2Conversational voice.
2GBR415010−3Conversational video (live streaming)
3GBR530010−6Non-conversational video
(buffered streaming).
4GBR35010−3Real time gaming.
5Non-GBR110010−6IMS signalling.
6Non-GBR710010−3Voice, video (live streaming), interactive gaming.
7Non-GBR630010−6Video (buffered streaming).
8Non-GBR830010−6TCP-based (e.g. WWW, e-mail) chat, FTP, p2p file sharing, progressive video, etc.
9Non-GBR930010−6

3. ERAB Setup Success Rate.

VoIP ERAB Setup Success Rate: This KPI measures the success rate of ERAB setups for VoIP services (QCI 1) in a specific cell or cluster. The formula for calculating this KPI is:

VoIP_ERAB_SSR =VoIP_ERAB_SetupSuccessVoIP_ERAB_SetupAttempt×100%

ERAB Setup Success Rate (All): This KPI measures the success rate of ERAB setups for all services, including VoIP, in a specific cell or cluster. The formula for this KPI is:

ERAB_SSR(All) =ERAB_SetupSuccessERAB_SetupAttempt×100%

ERAB Setup Success Rate

4. Counter Mapping for ERAB SSR.

Counter Mapping for ERAB SSR
Counter Mapping for ERAB SSR
Counter Mapping for ERAB SSR

Call Setup Success Rate.

VoIP Call Setup Success Rate (VoIP CSSR): This KPI evaluates the success rate of the entire call setup procedure for VoIP services (QCI 1) in a cell or cluster. This procedure includes three main phases: RRC setup, S1 signaling connection establishment, and VoIP E-RAB setup. The formula for calculating VoIP CSSR is:

VoIP_CSSR=RRC_ConnectionSuccessService RRC_ConnectionAttemptService×S1SIGConnectionEstablishSuccessS1SIGConnectionEstablishAttempt×VoIP_ERAB_SetupSuccessVoIP_ERAB_SetupAttempt×100

Call Setup Success Rate (All): This KPI measures the call setup success rate for all services, including VoIP, in a cell or cluster. It also includes the three main phases: RRC setup, S1 signaling connection establishment, and service E-RAB setup. The formula for calculating CSSR (All)

CSSR(All)=RRC_ConnectionSuccessService RRC_ConnectionAttemptService×S1SIGConnectionEstablishSuccessS1SIGConnectionEstablishAttempt×ERAB_SetupSuccessERAB_SetupAttempt×100

These KPIs are critical for evaluating and optimizing the performance and reliability of LTE networks, ensuring high-quality service for end users.

Counter Mapping for CSSR.

Counter Mapping for CSSR.
Counter Mapping for CSSR.
Counter Mapping for CSSR.

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