NTN    

 

 

 

RRC Parameters (NR)

RRC parameters for 5G NTN highlights the intricate configuration elements necessary for supporting advanced NTN functionalities in the 5G ecosystem. These parameters, defined within the 3GPP technical specifications, encompass essential elements such as NTN-specific configurations, reference locations, timing adjustments, and ephemeris information to facilitate satellite and high-altitude platform integration. The configuration sequences include fields for neighbor cell setup, synchronization validity, polarization, and orbital data, addressing the unique challenges of NTN environments like extended distances, Doppler shifts, and dynamic network topologies. Additionally, enhanced downlink and uplink configurations, HARQ feedback, and scheduling mechanisms ensure robust communication and efficient resource utilization, paving the way for seamless connectivity across terrestrial and non-terrestrial domains. These parameters collectively enable UEs to adapt to diverse operational scenarios, ensuring reliable and efficient communication in NTN-enabled 5G deployments.

Highlights

  • NTN Configuration: Provides the foundational parameters for configuring non-terrestrial networks (NTN). It includes synchronization validity to ensure time alignment between satellite and terrestrial systems, polarization settings (RHCP, LHCP, linear) for signal integrity, and ephemeris data to track satellite positions.
  • Neighbor Cell Configurations: Specifies the setup for neighboring NTN cells, including parameters such as carrier frequencies and physical cell IDs, to ensure seamless handover and connectivity between cells in the NTN network.
  • Timing Adjustments: Introduces K_mac as a scheduling offset for aligning downlink and uplink frame timings. The TAInfo-r17 provides details for timing advance, accounting for the large distances inherent in NTN communication.
  • Ephemeris Information: Supports tracking of satellite positions and movements, including orbital parameters and position-velocity data. This enables dynamic adjustment of communication paths and ensures reliable network operation.
  • Distance Thresholds: Defines the maximum allowable distance for effective communication within NTN. This ensures the network can manage link budgets and latency effectively over vast distances.
  • HARQ Feedback: Implements configurable downlink HARQ feedback mechanisms. This includes specific parameters to control and disable HARQ processes, supporting efficient error correction and retransmission handling.
    • downlinkHARQ-FeedbackDisabled-r17
    • nrofHARQ-ProcessesForPDSCH
    • nrofHARQ-ProcessesForPDSCH-v1700
    • DL-DataToUL-ACK-r17
    • DL-DataToUL-ACK-v1700
    • DL-DataToUL-ACK-DCI-1-2-r17
  • Adaptability for Diverse Scenarios: Ensures robust connectivity across various network domains. Includes parameters for NTN configuration, polarization, and ephemeris information to support diverse NTN deployment scenarios.
    • ntn-Config-r17
    • ntn-PolarizationDL-r17
    • ntn-PolarizationUL-r17
    • ephemerisInfo-r17
  • Advanced Resource Utilization: Facilitates efficient use of network resources through features like code block group transmission, ensuring optimal handling of transport blocks and resource allocation.
    • PDSCH-CodeBlockGroupTransmission
    • PDSCH-CodeBlockGroupTransmissionList-r16
    • codeBlockGroupFlushIndicator

RRC Parameters

SIB19-r17 ::= SEQUENCE {

   ntn-Config-r17                           NTN-Config-r17 OPTIONAL, -- Need R

   t-Service-r17                            INTEGER (0..549755813887) OPTIONAL, -- Need R

   referenceLocation-r17                 ReferenceLocation-r17 OPTIONAL, -- Need R

   distanceThresh-r17                     INTEGER(0..65525) OPTIONAL, -- Need R

   ntn-NeighCellConfigList-r17           NTN-NeighCellConfigList-r17 OPTIONAL, -- Need R

   lateNonCriticalExtension               OCTET STRING OPTIONAL,

   ...

}

 

NTN-NeighCellConfigList-r17 ::= SEQUENCE (SIZE(1..maxCellNTN-r17)) OF NTN-NeighCellConfig-r17

 

NTN-NeighCellConfig-r17 ::= SEQUENCE {

   ntn-Config-r17                        NTN-Config-r17 OPTIONAL, -- Need R

   carrierFreq-r17                       ARFCN-ValueNR OPTIONAL, -- Need R

   physCellId-r17                        PhysCellId OPTIONAL -- Need R

}

 

DownlinkConfigCommon ::= SEQUENCE {

    frequencyInfoDL                               FrequencyInfoDL OPTIONAL, -- Cond InterFreqHOAndServCellAdd

    initialDownlinkBWP                             BWP-DownlinkCommon OPTIONAL, -- Cond ServCellAdd

    ...,

    [[

    ntn-Config-r17                                 NTN-Config-r17 OPTIONAL, -- Need R

    initialDownlinkBWP-RedCap-r17            BWP-DownlinkCommon OPTIONAL -- Need R

    ]]

}

 

NTN-Config-r17 ::= SEQUENCE {

    epochTime-r17                               EpochTime-r17 OPTIONAL, -- Need R

    ntn-UlSyncValidityDuration-r17          ENUMERATED{ s5, s10, s15, s20, s25, s30, s35,

                                                                    s40, s45, s50, s55, s60, s120, s180, s240} OPTIONAL, -- Need R

    cellSpecificKoffset-r17                      INTEGER(0..1023) OPTIONAL, -- Need R

    kmac-r17                                       INTEGER(0..512) OPTIONAL, -- Need R

    ta-Info-r17                                    TAInfo-r17 OPTIONAL, -- Need R

    ntn-PolarizationDL-r17                      ENUMERATED {rhcp,lhcp,linear} OPTIONAL, -- Need R

    ntn-PolarizationUL-r17                      ENUMERATED {rhcp,lhcp,linear} OPTIONAL, -- Need R

    ephemerisInfo-r17                            EphemerisInfo-r17 OPTIONAL, -- Need R

    ...

}

kmac :K_mac is a scheduling offset provided by network if downlink and uplink frame timing are not aligned at gNB. It is needed for UE action and assumption on downlink configuration indicated by a MAC-CE command in PDSCH [see TS 38.2xy]. If the field is absent UE assumes value 0. For the reference subcarrier spacing value for the unit of K_mac in FR1, a value of 15 kHz is used. The unit of K_mac is number of slots for a given subcarrier spacing.

 

EpochTime-r17 ::= SEQUENCE {

    sfn-r17                                           INTEGER(0..1023),

    subFrameNR-r17                               INTEGER(0..9)

}

 

TAInfo-r17 ::= SEQUENCE {

    ta-Common-r17                                INTEGER(0..66485757),

    ta-CommonDrift-r17                          INTEGER(-261935..261935) OPTIONAL, -- Need R

    ta-CommonDriftVariant-r17                 INTEGER(0..29470) OPTIONAL -- Need R

}

 

EphemerisInfo-r17 ::= CHOICE {

    positionVelocity-r17                          PositionVelocity-r17,

    orbital-r17                                       Orbital-r17

}

 

PositionVelocity-r17 ::= SEQUENCE {

    positionX-r17                                  PositionStateVector-r17,

    positionY-r17                                  PositionStateVector-r17,

    positionZ-r17                                  PositionStateVector-r17,

    velocityVX-r17                                VelocityStateVector-r17,

    velocityVY-r17                                VelocityStateVector-r17,

    velocityVZ-r17                                VelocityStateVector-r17

}

 

Orbital-r17 ::= SEQUENCE {

    semiMajorAxis-r17                            INTEGER (0..8589934591),

    eccentricityE-r17                             INTEGER (0..524287),

    periapsis-r17                                   INTEGER (0..16777215),

    longitude-r17                                  INTEGER (0..2097151),

    inclinationI-r17                                INTEGER (-524288..524287),

    meanAnomalyM-r17                          INTEGER (0..16777215)

}

 

PositionStateVector-r17 ::=                   INTEGER (-3355432..33554431)

VelocityStateVector-r17 ::=                   INTEGER (-131072..131071)

 

PUCCH-Config ::= SEQUENCE {

   ...

   secondTPCFieldDCI-1-1-r17        ENUMERATED {enabled} OPTIONAL, -- Need R

   secondTPCFieldDCI-1-2-r17        ENUMERATED {enabled} OPTIONAL, -- Need R

   dl-DataToUL-ACK-r17              SetupRelease { DL-DataToUL-ACK-r17 } OPTIONAL, -- Need M

   dl-DataToUL-ACK-DCI-1-2-r17      SetupRelease { DL-DataToUL-ACK-DCI-1-2-r17} OPTIONAL,--Need M

   ul-AccessConfigListDCI-1-1-r17   SetupRelease { UL-AccessConfigListDCI-1-1-r17 } OPTIONAL,

                                                        --Need M

   ...

   schedulingRequestResourceToAddModListExt-v1700     SEQUENCE (SIZE (1..maxNrofSR-Resources))

                                                        OF SchedulingRequestResourceConfigExt-v1700

                                                        OPTIONAL, -- Need N

   dmrs-BundlingPUCCH-Config-r17    SetupRelease { DMRS-BundlingPUCCH-Config-r17 }

                                                        OPTIONAL, -- Need M

   dl-DataToUL-ACK-v1700            SetupRelease { DL-DataToUL-ACK-v1700 } OPTIONAL, -- Need M

   dl-DataToUL-ACK-MulticastDCI-Format4-1-r17      SetupRelease

                                                     { DL-DataToUL-ACK-MulticastDCI-Format4-1-r17 }

}

 

DL-DataToUL-ACK-r17 ::= SEQUENCE (SIZE (1..8)) OF INTEGER (-1..127)

DL-DataToUL-ACK-v1700 ::= SEQUENCE (SIZE (1..8)) OF INTEGER (16..31)

DL-DataToUL-ACK-DCI-1-2-r17 ::= SEQUENCE (SIZE (1..8)) OF INTEGER (0..127)

UL-AccessConfigListDCI-1-2-r17 ::= SEQUENCE (SIZE (1..16)) OF INTEGER (0..15)

 

NOTE : (Based on 38.331)

DL-DataToUL-ACK-r17, DL-DataToUL-ACK-v1700, DL-DataToUL-ACK-DCI-1-2-r17, UL-AccessConfigListDCI-1-2-r17

    List of timing for given PDSCH to the DL ACK (see TS 38.213, clause 9.1.2). The field dl-DataToUL-ACK applies to DCI format 1_1 and the field dl-DataToUL-ACK-DCI-1-2 applies to DCI format 1_2 (see TS 38.212 clause 7.3.1 and TS 38.213 clause 9.2.3). The dl-DataToUL-ACK-v1700 is applicable for NTN and dl-DataToUL-ACKr17 is applicable for up to 71 GHz. If dl-DataToUL-ACK-r16 or dl DataToUL-ACK-r17 or dl-DataToUL-ACK-v1700 is signalled, UE shall ignore the dl-DataToUL-ACK (withoutsuffix). The value -1 corresponds to "inapplicable value" for the case where the A/N feedback timing is not explicitly included at the time of scheduling PDSCH. The fields dl-DataToUL-ACK-r17 and dl-DataToUL-ACK-DCI-1-2-r17 are only applicable for SCS of 480 kHz or 960 kHz. 

 

ServingCellConfigCommon ::= SEQUENCE {

    ...

    n-TimingAdvanceOffset ENUMERATED { n0, n25600, n39936 } OPTIONAL, -- Need S

    ...

    ntn-Config-r17 NTN-Config-r17 OPTIONAL -- Need R

    ]],

    [[

    ....,

    [[

    ra-ChannelAccess-r17 ENUMERATED {enabled} OPTIONAL -- Cond SharedSpectrum2

    ]]

}

n-TimingAdvanceOffset ; The N_TA-Offset to be applied for all uplink transmissions on this serving cell. If the field is absent, the UE applies the value defined for the duplex mode and frequency range of this serving cell. See TS 38.133-table 7.1.2-2.

 

PDSCH-ServingCellConfig ::= SEQUENCE {

   codeBlockGroupTransmission           SetupRelease { PDSCH-CodeBlockGroupTransmission }

                                                            OPTIONAL, -- Need M

   xOverhead                            ENUMERATED { xOh6, xOh12, xOh18 } OPTIONAL, -- Need S

   nrofHARQ-ProcessesForPDSCH           ENUMERATED {n2, n4, n6, n10, n12, n16} OPTIONAL, -- Need S

   pucch-Cell                           ServCellIndex OPTIONAL, -- Cond SCellAddOnly

   ...,

   [[

   maxMIMO-Layers                       INTEGER (1..8) OPTIONAL, -- Need M

   processingType2Enabled               BOOLEAN OPTIONAL -- Need M

   ]],

   [[

   pdsch-CodeBlockGroupTransmissionList-r16        SetupRelease {

                                                      PDSCH-CodeBlockGroupTransmissionList-r16 }

                                                      OPTIONAL -- Need M

   ]],

   [[

   downlinkHARQ-FeedbackDisabled-r17         SetupRelease { DownlinkHARQ-FeedbackDisabled-r17 }

                                                      OPTIONAL, -- Need M

   nrofHARQ-ProcessesForPDSCH-v1700          ENUMERATED {n32} OPTIONAL -- Need R

   ]]

}

 

PDSCH-CodeBlockGroupTransmission ::= SEQUENCE {

   maxCodeBlockGroupsPerTransportBlock       ENUMERATED {n2, n4, n6, n8},

   codeBlockGroupFlushIndicator              BOOLEAN,

   ...

}

 

PDSCH-CodeBlockGroupTransmissionList-r16 ::= SEQUENCE (SIZE (1..2))

                                                   OF PDSCH-CodeBlockGroupTransmission

DownlinkHARQ-FeedbackDisabled-r17 ::= BIT STRING (SIZE (32))

 

downlinkHARQ-FeedbackDisabled ; Used to disable the DL HARQ feedback, sent in the uplink, per HARQ process ID. The first/leftmost bit corresponds to HARQ process ID 0, the next bit to HARQ process ID 1 and so on. Bits corresponding to HARQ process IDs that are not configured shall be ignored. The bit(s) set to one identify HARQ processes with disabled DL HARQ feedback and the bit(s) set to zero identify HARQ processes with enabled DL HARQ feedback.