3GPP Scout / RRC information elements

RRC information element

TCI-State: the RRC information element in TS 38.331

Published 2026-11-05Updated 2026-10-16

At a glance

Specification
3GPP TS 38.331 V19.4.0, clause 6.3.2
Structure
SEQUENCE with 8 fields (3 in Rel-15, 3 in Rel-17, 1 in Rel-18, 1 in Rel-19)
Used in
PDSCH-Config, SRS-Config

In plain words

TCI-State associates one or two downlink reference signals with a quasi-colocation (QCL) type: "The IE TCI-State associates one or two DL reference signals with a corresponding quasi-colocation (QCL) type.". Its tci-StateId field gives the ID number of the TCI state. The SEQUENCE has eight fields: three from Rel-15, three from Rel-17, one from Rel-18, and one from Rel-19. TCI-State is referenced by PDSCH-Config and SRS-Config.

Source: 3GPP TS 38.331 V19.4.0, clause 6.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/38_series/38.331/38331-j40.zip

Sources

  1. 3GPP TS 38.331 V19.4.0, clause 6.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/38_series/38.331/38331-j40.zip
  2. ASN.1 definition in the same clause, counted by 3GPP Scout.

How this page was made

The facts box comes straight from the 3GPP TDoc list and specification archive as indexed by 3GPP Scout. An AI model (GPT-6 Luna) wrote the paragraph and named the source of each sentence. Code checked every quote word for word against the stored source text and every number against the cited source. A second AI model from another company (Claude Opus 5.5) reviewed the paragraph against the same sources. The 3GPP documents themselves govern.