Ambient Internet of Things index split agreed at RAN1 #126-bis

This is Release 20 Ambient Internet of Things work under agenda item 9.3.3. Broadcast information has a first part and a remaining part in this work. Qualcomm links the index range to modification periods and paging monitoring cycles, using the remaining part's periodicity as its step.

The chair notes agree that X index bits go in a four-bit field in the first part. Remaining Y bits go in the remaining part of broadcast information. The agreement leaves "the value of Y" and the total number of bits X+Y for further study.

Source: R1-2607286, Ad-Hoc Chair (NTT DOCOMO, INC.), 3GPP TSG RAN WG1 #126-bis, chair notes, agenda item 9.3.3.

Qualcomm proposed to "consider down-selection of Alt.2 and Alt.3", narrowing consideration to those two alternatives. Lenovo proposed deprioritizing Alt.2, which places the index in the remaining part. vivo argued Alt.3 avoids blind detection of the remaining part after the first part. Our reading: blind detection means checking for the remaining part without knowing whether it is present. China Mobile proposed a maximum index value no smaller than modification periodicity divided by Psync, a term used in its contribution. Our reading: the agreement specifies a split without identifying it as either Alt.2 or Alt.3.

Source: R1-2608615, Qualcomm, 3GPP TSG RAN WG1 #126-bis. © Qualcomm.