CATT argues UE CONTEXT RELEASE is not used for UHI at RAN3 #133-bis

RAN3 is the radio access network's Working Group 3. Both CATT contributions discuss self-organising network (SON) enhancement for inter-central-unit (CU) lower-layer triggered mobility (LTM). UE means user equipment, and UHI means UE history information. CATT proposed clarifying, under existing specifications, "whether the new source gNB can send the UE CONTEXT RELEASE message to the initiating node with complete UHI".

Source: R3-263300, CATT, 3GPP TSG RAN WG3 #133. © CATT.

At RAN3 #133-bis, CATT asserted "The UE CONTEXT RELEASE message is not used to carry UHI". Our reading: The initiating node starts the procedure, the candidate is a possible destination, and gNB denotes a base station. Our reading: Old and new source gNBs denote base stations before and after the move. When the initiating node is the candidate, CATT says the release goes to the old source gNB instead. Otherwise, CATT says the initiating node cannot handle a second release without the UE application protocol identifier (AP ID). It had already released that identifier when the first release arrived from the new source.

Source: R3-264160, CATT, 3GPP TSG RAN WG3 #133-bis. © CATT.

Our reading: CATT shifted from requesting clarification to arguing the message is not used for UHI, citing two cases. The RAN3 #133-bis register lists the contribution as available and records no decision. The RAN3 #133 register marks the earlier contribution not treated and records no decision.