The whole of accessibility on one page: each KPI, the stage it measures, and its counter family in each RAT. Same KPI, different family number — that is the single most useful thing to know when you move between LTE and 5G. Click any family chip for that KPI's counters, failure counters and fix in that RAT.
| KPI | Stage | LTE Family | NR Family | Success formula |
|---|
RRC Establishment is Family 1 on LTE but 5213 on NR; Initial Context is the S1SIG family (27) on LTE but NG_ESTAB (5223) on NR; F1 UE Context exists only on NR (5136/5137, the CU-DU split); Admission is a standalone family on NR (5147/5148) but folded into RRC/E-RAB reject causes on LTE. Learn the stage, then look up the family.Select a KPI and a technology; the explorer shows its family, formula, attempt/success and failure counters for that RAT, computes the success rate from your numbers, and gives the tech-specific fix.
Every accessibility KPI is one gate on the same chain. LTE and NR share the shape; NR inserts the F1 split and swaps EPC/S1 for 5GC/NG.
RRC Resume is the accessibility KPI that saved the attach: instead of a full setup, a UE in RRC_INACTIVE resumes with its context still held in the RAN — cutting the core signalling that a fresh service-request would need. In NR this is a universal state (Family 5217 RRC_CONN_INFO: InactNo*, ConnInactNo*); in classic LTE it exists only for CIoT (Family 471 eMTC / 473 NB-IoT).
rrc-idle-timer = wider fast-resume window = better re-accessibility (at the cost of gNB context memory).| Parameter | Range | Default | Optimization |
|---|---|---|---|
| feature-enabled | disable / enable | disable | Enable INACTIVE (FGR-CC0103) — cuts attach/service-request latency by keeping the context in RAN |
| rrc-inactive-timer | 1 … 7200 s | 10 | CONNECTED→INACTIVE after silence — shorter frees radio; too short churns resume signalling |
| rrc-idle-timer | 1 … 7200 s | 10 | INACTIVE→IDLE — lengthen for chatty apps to keep the fast-resume window open |
| resume-wait-timer | 1 … 10 s | 3 | RAN-paging resume window before releasing the inactive context |
| t319 (UE) | ms100 … ms2000 | ms600 | Supervises RRCResumeRequest — the resume-side timeout |
InterGnb… counters. A high inter-gNB resume/re-estab failure = an Xn / neighbour-relation problem, not radio.Re-establishment is accessibility's safety net: after a radio-link failure or handover failure it continues the connection instead of forcing a fresh attach. NR splits it Intra-gNB vs Inter-gNB and — tellingly — its failure causes are the same suffix family as the setup chain, so the same decoder applies.
| Counter | Meaning |
|---|---|
| IntraGnbReEstabAtt / …Succ | Intra-gNB re-establishment attempts / successes (RRCReestablishmentRequest → Complete) |
| IntraGnbReEstabRrcSetupAtt / …Succ | The fallback path — gNB answered with RRCSetup instead of Reestablishment |
| InterGnbReEstabAtt / …Succ | Inter-gNB re-establishment (context fetched over Xn) |
| …ReEstabFail_{CpFail, E1Fail, F1Fail, NgFail, E1Timeout, F1Timeout, RreTimeout, RrcSetupTimeout, Ignore} | Same domain suffixes as the setup chain — CU-CP · E1 · F1 · AMF/NG · air-timeout — so the same decoder routes the fix |
t310 / t311 govern how fast RLF is declared and how long the UE searches for a re-establishment cell — the same timers that decide retainability. Tune them together: a shorter t310 recovers faster but drops recoverable links; a wider t311 finds a cell deep indoors but delays give-up. A high InterGnbReEstabFail = fix Xn / ANR neighbour relations, not the radio.| LTE suffix | NR suffix | Domain | Owner |
|---|---|---|---|
_CpCcTo / _CpCcFail | _CpFail | Call control / CU-CP | eNB/gNB control health & config |
_UpMac/Rlc/PdcpFail | _MacFail / _RlcFail (DU) | Protocol blocks / DU lower layers | Channel-card / DU hardware |
_RrcSigTo | _RrcTimeout | Air interface | RF / coverage / beam (per-beam 5243 on NR) |
_S1apLinkFail / _S1apSigTo | _NgFail / _NgTimeout | Core (MME / AMF) | S1-MME / NG-C transport & core capacity |
| — (no split) | _E1Fail / _F1Fail (+timeouts) | CU-UP (E1) / DU (F1) | NR internal transport (E1 / fronthaul) |
Reject_CpCapaCacFail | Reject_CacFail / CacFail_* | Admission | Capacity & policy (SW4101… / CC0301…) |
This page is the map; each technology has its own full optimization workspace — studio, diagnostic engine, failure-routing fabric, feature pipeline and parameter master table.
Sources — LTE: Samsung eNB Counter Description (via LTE Samsung KPI.xlsx "eNB Counters"): Fam 1 RRC_ESTAB, 3 RRC_REESTAB, 8/9 ERAB_ESTAB, 27 S1SIG, 59 Random Access Preambles, 211 RACH Usage, 471/473 CIoT RRC Resume, 905 RRC_ESTAB_MSG. NR: Samsung 5G NR Counter Description (via the NR KPI workbook CU-ACPF/DU sheets): 5213 RRC_ESTAB, 5203 RRC_REESTAB, 5217 RRC_CONN_INFO (INACTIVE), 5223 NG_ESTAB, 5136/5137 F1AP_UE_SETUP, 5222/5438 PDU_SESSION, 5147/5148 ADMISSION_CONTROL_FAIL, 5243 NR_PRACH_BEAM, 5225 NGAP_MSG_UE, 5226 RRC_MSG. Features from the 5G RAN Feature Description SVR25B (FGR-CC0102/0103/0107). Formulas per 3GPP TS 36.331/36.413 (LTE) & 38.331/38.413/38.473 (NR). Every counter/family name is verbatim; targets are typical operator values.