Abstract
A user equipment (UE) transmits a buffer status report (BSR) on a contention-based physical uplink shared channel (CB-PUSCH) and counts consecutive failed attempts, a failure being the absence of a PDCCH addressed to its C-RNTI within a contention resolution time. The failure counter persists across BSR triggers. Attempts the UE cannot perform, such as after a listen-before-talk failure, increment a skip counter. Fallback occurs when the failure counter reaches an RRC-configured maximum, when the skip counter reaches its limit, or when the remaining delay budget is too short for another attempt. The UE sends a scheduling request (SR) on PUCCH if a valid SR occasion falls within a configured wait bound, and otherwise performs random access. A prohibit timer doubling with each consecutive fallback episode bars CB-PUSCH use. A late uplink grant cancels a pending fallback. Fallback reports let the network node override the maximum attempt count.
Creative Commons License
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Recommended Citation
Anonymous, "Attempt-counter-based fallback from CB-PUSCH BSR to SR or random access", Technical Disclosure Commons, ()
https://www.tdcommons.org/dpubs_series/12963