[{"name":"R5-240162","title":"Discussion on NGSO test model","source":"MediaTek Inc.","contact":"Daiwei Zhou","contact-id":72872,"tdoctype":"discussion","for":"Endorsement","abstract":"During the discussion of [1] in RAN5 #101 meeting, there was no consensus achieved on NGSO test model. An action point AP#101.03 was raised to investigate to decide on choosing dynamic\/static\/mixed signalling test environments for NGSO NTN testing.\n\n2.\tDiscussion\nThe dynamic\/static\/mixed signalling test environments for NGSO (LEO with a typical orbit height 600 km) testing are:\n1.\tDynamic: the NGSO satellite is moving on its orbit and the broadcasted SIB31-NB is updated according to its position and velocity within the satellite visible window (about 8 minutes for LEO 600 km).\n2.\tStatic: the NGSO satellite is static, and the broadcasted SIB31-NB has same message content. As this is not the realistic NGSO scenario, UE uses constant Doppler\/delay to keep DL\/UL synchronous with eNB, and UE also needs to deactivate prediction of satellite trajectory as mentioned in [2].\n3.\tMixed: During the satellite visible window, the NGSO satellite is moving on its orbit and the broadcasted SIB31-NB is updated according to its position and velocity, then after the visible window the satellite keeps static at its last location and the SIB31-NB becomes unchanged. As this is not the realistic NGSO scenario, after the satellite visible window UE shall use constant Doppler\/delay and needs to deactivate prediction of satellite trajectory as does in Static model.\n\nCurrently the NGSO satellite propagator model for TE to emulate channel model with Doppler and delay shifts are not defined by 3GPP. This also impacts the UE to correctly compensate the Doppler and delay in uplink transmission. The lack of propagator model will restrict the usage of dynamic signalling test environment as well as the mixed.\n\nBased on above analysis, we can have following proposals for NGSO test model:\nProposal #1: RAN5 to approve the usage of static as default signalling test environment for IoT NTN specific cases and applicable NB-IoT legacy cases.\n\nWhen static signalling test environment is used, the ephemeris information of NGSO needs to be specified, such as dedicate satellite stateVectors to be defined for the serving and neighbour cells, that means there is no need to define a full table of ephemeris information. And the UE pre-configuration of these cases shall be updated to the trajectory prediction mode to be deactivated in UE side. RAN5 CRs [3] [4] are submitted to address this approach during this meeting.\n\nProposal #2: RAN5 to approve the CRs [3] [4] to update ephemeris information of NGSO and to update the UE pre-configuration for static signalling test environment.\n\n3.\tProposal\/Way Forward\nIn the contribution, we investigate the possible dynamic\/static\/mixed signalling test environments for NGSO NTN testing with following proposal:\nProposal #1: RAN5 to approve the usage of static as default signalling test environment for IoT NTN specific cases and applicable NB-IoT legacy cases.\n\nProposal #2: RAN5 to approve the CRs [3] [4] to update ephemeris information of NGSO and to update the UE pre-configuration for static signalling test environment.","secretary_remarks":"","agenda_item_sort_order":755,"ainumber":"6.3.14.5","ainame":"Discussion Papers \/ Work Plan \/ TC lists","tdoc_agenda_sort_order":1620,"status":"noted","reservation_date":"2024-01-02 06:31:40","uploaded":"2024-02-06 09:20:23","revisionof":"","revisedto":"","release":"","crspec":"","crspecversion":"","workitem":[{"winame":"LTE_NBIOT_eMTC_NTN_plus_EPS-UEConTest"}],"crnumber":"","crrevision":"","crcategory":"","tsg_crp":"","lsreplyto":"","lsto":"","Cc":"","lsoriginalls":"","lsreply":"","link":"https:\/\/www.3gpp.org\/ftp\/tsg_ran\/WG5_Test_ex-T1\/TSGR5__102_Athens\/Docs\/R5-240162.zip","group":"R5","meeting":"R5-102","year":2024,"uicc_affected":"","me_affected":"","ran_affected":"","cn_affected":"","clauses_affected":"","crsinpack":null,"crsinpacknumber":0}]