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Glossary

BSR (Buffer Status Report) in 3GPP: meaning and where it is specified

Published 2026-10-16Updated 2026-10-16

At a glance

Term
BSR
Stands for
Buffer Status Report
Defined in
3GPP TR 21.905 V19.2.0, clause 4
Used in
TS 36.321, TS 36.523-1, TS 38.321

In plain words

In 3GPP TR 21.905, BSR means Buffer Status Report. TS 36.321 describes Buffer Status Report (BSR) MAC control elements, which "Buffer Status Report (BSR) MAC control elements consist of either:" TS 38.321 and TS 36.523-1 also describe BSR MAC control elements, with the latter covering them under conformance requirements.

Source: 3GPP TS 36.321 V19.3.0, clause 6.1.3.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/36_series/36.321/36321-j30.zip

Sources

  1. 3GPP TR 21.905 V19.2.0, clause 4. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/21_series/21.905/21905-j20.zip
  2. 3GPP TS 36.321 V19.3.0, clause 6.1.3.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/36_series/36.321/36321-j30.zip
  3. 3GPP TS 38.321 V17.15.0, clause 6.1.3.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/38_series/38.321/38321-hf0.zip
  4. 3GPP TS 36.523-1 V19.3.0, clause 7.1.4.18.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: https://www.3gpp.org/ftp/Specs/archive/36_series/36.523-1/36523-1-j30.zip

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.