RAN2 agrees single on-duration per monitoring cycle for ambient IoT

The meeting report, marked revised at RAN2 #135-bis, records this agreement: "the monitoring cycle contains a single on-duration". It places the start of that on-duration against a reference time in each monitoring cycle. The reference time is determined relative to a synchronization signal or broadcast information. The start's possible offset and the exact reference-time relation remain for further study. Our reading: An on-duration is the part of a monitoring cycle when the device listens for paging.

Source: R2-2607785, Session Chair (MedaTek), 3GPP TSG RAN WG2 #135-bis, meeting report, agenda item 8.2.4.

OPPO proposed multiple paging monitoring windows within one paging cycle to reduce collisions. Its proposal says "Different device group can monitor the corresponding paging duration". Our reading: A single on-duration per monitoring cycle sits uneasily with multiple windows per paging cycle. Our reading: The texts do not establish whether those cycles cover the same period. No decision on OPPO's Proposal 3 is recorded under this agenda item.

Source: R2-2606952, OPPO, 3GPP TSG RAN WG2 #135-bis. © OPPO.

In a separate paper, Huawei, with HiSilicon, China Telecom, ZTE, vivo and NEC, raised a different concern. They warned that subsequent paging outside on-duration could mean "the network may fail to find the device within certain service cycles". Their warning concerns initial paging sent within on-duration while subsequent paging messages are not restricted to it. The paper also warns of more service failures or longer access delays.

Source: R2-2606775, Huawei (with HiSilicon, China Telecom, ZTE, vivo, NEC), 3GPP TSG RAN WG2 #135-bis. © Huawei, HiSilicon, China Telecom, ZTE, vivo, NEC.