5G/NR  -  NTN

 

 

 

 

 

NTN (Non Terestrial Network)

 

The basic idea of NTN is obvious. It is to deliver 5G/NR service via space (satellite) or air (airborne platform) as illlustrated below.

 

 

 

Why NTN ?

 

The motivation is obvious as well. If it is realized as expected, it would be able to deliver the 5G service to those places where it is technically very difficult or cost too much to deliver with terrestrial network. Some examples of those places would be a remote area like deep forest that would be too costly with terestrial delivery, or far islands or ship that would be technically almost forbidden in terrestrial connection.

 

NOTE : The illustration shown above is consolidated representation of various deployment options described in various TRs in the reference section. If you want to get a little bit detailed diagram for each of the deployment plan separately, you may refer to 3GPP TR 38.821 V16.1.0

 

I found another well summarized illustration from this paper as shown below. It shows various different use cases and potential ground-to-airborne connection mechansm.

 

 

 

 

Challenges  

 

I personally am so eager to see this realized because one of those areas shown above is my dream place -:), but there would be many challenges to be overcome. Followings are a short list of those challenges. (NOTE : To foresee on those challenges, I think it would be helpful to investigate on the challenges that the satellite communication systems being depolyed and tested now (as of Feb 2021) and SpaceX Starlink can be a good example since there are so much informations are available. Even though it is not easy to find the details on challenges on the fancy looking system, it would be more helpful as an engineer to look for the challenges and see how those challenges gets resolved).

 

Latency : One obvious challenge that everybody can easily guess would be the long latency caused by pure physics. There is long distance between ground station/user terminal and the satellite. The speed of light is finite. So it would take a considerable amount of time (delay) for the radio wave to reach the user device. Of course, this latency would very depending on the altitude of the satellite. If the satellite is deployed on GEO(Geostationary Orbit), the delay would be huge. If they are deployed in LEO(Low Earth Orbit), the delay would be low (in some case it can be even shorter than what you experience with WiFi delivered by ground connection), but it would require huge cost to cover the wide area with LEO like StarLink.

 

Demand on Ground Stations : Even though we can put the radio part (e.g, gNB, Relay etc) up in the space, the core network is (should be) on the ground. It mean that the satellite or airborne platform should be connected to ground station at some point. The question is how far it can get connected to the ground station. Obviously there would be a certain limit in distances in which a satellite can reach a ground station. As a result, we would need a lot of ground station as well as satellite if we want to cover wide area. In some cases, it will be very challenging to set a ground station. For example, if we need a satellite covering far in the oscien, how can we setup a ground station that can cover those satellites ? One possible solution for this situation is to make some satellites to get access to the core network indirectly via another sattelite instead of ground station. In order to do this, we would need to make relay networks or mesh networks among the satellites. Of course, theoretically this is possible and most of satellite communication systems put this into account from the design phase. But it would not be easy for implementation in reality (NOTE : This is one of the challenges that Starlink faces at early phase and as of Feb 2021 the communication between satellites is not supported) 

 

Antenna Technology : Intuitively and by experience, we would easily guess that Antenna technology would ge a critical component for this kind of communication system. First how small we can make it ? We may tolerate the necessity of using a large sized dish antenna (i mean large size in comparison to mobile phone antenna), but everybody would like to have a smaller dishes in various reasons. Next, how to change the direction of antenna radiation pattern pointing in line of sight to a satellite ? Two options are considered for this. The first option is to put some mechanical component so that it can change the direction of the dish mechanically (like the dishes used in Starlink system). But it would be difficult to change the direction of the antenna fast enough to handle mobility situation. The second option would be to use phase array antenna by which we can change the direction of radiation pattern electronically. Technically this would be much better than the mechanical method, but cost would be a big issue.

 

Large Doppler Shift :  Usually sattelites and airborne platform in this communication system moves very fast whereas most of user terminal is stationary or moves slowly. It implies there would be huge differences in terms of relative speed between satellites and user terminals. In turn, it mean there would be large doppler shift experienced by the reciever.

 

Large Delay Spread : In this kind of communication system, the physical distance between the transmitter and the reciever tend to be very far (e.g, ranging from several hundreds of kilometers(LEO) to 36,000 kilometers (GEO)). This would lead to large delay spread.

 

Competition to other technolgies  : Simply put, in terms of business point of view, would it be lucrative enough to invest huge money to compete against existing satellite communication system like Starlink or Kuiper ? (NOTE : There is a company called ASTspaceMobile that claim to provide SpaceMobile service with just a few hundreds LEO satellites for regular mobile phone. But almost no technical details are known as of now (Mar 2021)).

 

 

 

Delay Requirements

 

The total Delay Requirement specified in TS 22.261 is roughly the following value + 5 ms (delay caused by 5G protocol)

 

< 22.261 (Rel 18) - Table 7.4.1-1: UE to satellite propagation delay >

NOTE :  Even the smallest propagation is greater than the max delay that can be covered by TA field of RAR.(Around 2 ms is covered by RAR TA in SCS 15Khz, 1 ms in SCS 30Khz).

 

 

 

Performance Requirements

 

 

< 22.261 (Rel 18) - Table 7.4.2-1: Performance requirements for satellite access >

 

 

 

How 3GPP is updated to get around the problems and meet the requirements listed above ?

 

To cope with the issues and to meet the requirement mentioned above, some new features are introduced in 3GPP release 17. In summary, those new features can be summarized as below.

  • Handling Timing Offset for Long Delay :  Additional Timing Address Information elements (ta-Info-r17) are added in SIB 19.
  • Handling the long delay for HARQ due to long distance between UE and gNB : a New Information Elements (DL-DataToUL-ACK-v1700 ) is added to specify long enough K1 value.
  • Indicating the Position and Motion of the Satellite : For this purpose, a new Information Elements (ephemerisInfo-r17 ) is added and broadcast in SIB 19.

 

 

 

Examples

 

 

Example 01 :  NB IoT

: This is a sample log from Amarisoft Callbox with NTN for LTE NB IoT.  This example is done with a simulated environement for the following setup.

 

 

Step

Direction

Message / Procedure

1

UE <-- NW

MIB

2

UE <-- NW

SIB1

3

UE <-- NW

SIB2

4

UE <-- NW

SIB31

5

UE --> NW

PRACH

6

UE <-- NW

RAR

7

UE --> NW

RRC Connection Request

8

UE <-- NW

RRC Connection Setup

9

UE --> NW

TA_REPORT (MAC CE)

10

UE --> NW

RRC Connection Setup Complete

11

UE <--> NW

< Authentication and Security >

12

UE <-- NW

K_OFFSET (MAC CE)

13

UE <-- NW

UE Capability Enquiry

14

UE --> NW

UE Capability Information

15

UE <-- NW

Rrc Connection Reonfiguration

16

UE --> NW

TA_REPORT (MAC CE)

17

UE --> NW

Rrc Connection Reonfiguration Complete

18

UE <--> NW

< Attach Complete >

 

[2] SIB 1

    {

      message c1: systemInformationBlockType1-r13: {

        hyperSFN-MSB-r13 '01'H,

        cellAccessRelatedInfo-r13 {

          plmn-IdentityList-r13 {

            {

              plmn-Identity-r13 {

                mcc {

                  0,

                  0,

                  1

                },

                mnc {

                  0,

                  1

                }

              },

              cellReservedForOperatorUse-r13 notReserved

            }

          },

          trackingAreaCode-r13 '0002'H,

          cellIdentity-r13 '1A2D102'H,

          cellBarred-r13 barred,

          intraFreqReselection-r13 allowed

        },

        cellSelectionInfo-r13 {

          q-RxLevMin-r13 -70,

          q-QualMin-r13 -34

        },

        p-Max-r13 10,

        freqBandIndicator-r13 7,

        schedulingInfoList-r13 {

          {

            si-Periodicity-r13 rf128,

            si-RepetitionPattern-r13 every2ndRF,

            sib-MappingInfo-r13 {

            },

            si-TB-r13 b208

          },

          {

            si-Periodicity-r13 rf64,

            si-RepetitionPattern-r13 every4thRF,

            sib-MappingInfo-r13 {

            },

            si-TB-r13 b256

          }

        },

        si-WindowLength-r13 ms160,

        systemInfoValueTagList-r13 {

          0,

          0

        },

        nonCriticalExtension {

          nonCriticalExtension {

            nonCriticalExtension {

              nonCriticalExtension {

                schedulingInfoList-v1530 {

                  {

                  },

                  {

                    sib-MappingInfo-v1530 {

                      sibType31-NB-r17

                    }

                  }

                },

                nonCriticalExtension {

                  nonCriticalExtension {

                    cellAccessRelatedInfo-NTN-r17 {

                      cellBarred-NTN-r17 notBarred

                    }

                  }

                }

              }

            }

          }

        }

      }

    }

 

 

[3] SIB 2

    {

      message c1: systemInformation-r13: {

        criticalExtensions systemInformation-r13: {

          sib-TypeAndInfo-r13 {

            sib2-r13: {

              radioResourceConfigCommon-r13 {

                rach-ConfigCommon-r13 {

                  preambleTransMax-CE-r13 n10,

                  powerRampingParameters-r13 {

                    powerRampingStep dB2,

                    preambleInitialReceivedTargetPower dBm-104

                  },

                  rach-InfoList-r13 {

                    {

                      ra-ResponseWindowSize-r13 pp5,

                      mac-ContentionResolutionTimer-r13 pp32

                    }

                  }

                },

                bcch-Config-r13 {

                  modificationPeriodCoeff-r13 n64

                },

                pcch-Config-r13 {

                  defaultPagingCycle-r13 rf128,

                  nB-r13 oneT,

                  npdcch-NumRepetitionPaging-r13 r1

                },

                nprach-Config-r13 {

                  nprach-CP-Length-r13 us66dot7,

                  nprach-ParametersList-r13 {

                    {

                      nprach-Periodicity-r13 ms80,

                      nprach-StartTime-r13 ms32,

                      nprach-SubcarrierOffset-r13 n0,

                      nprach-NumSubcarriers-r13 n12,

                      nprach-SubcarrierMSG3-RangeStart-r13 twoThird,

                      maxNumPreambleAttemptCE-r13 n10,

                      numRepetitionsPerPreambleAttempt-r13 n1,

                      npdcch-NumRepetitions-RA-r13 r8,

                      npdcch-StartSF-CSS-RA-r13 v4,

                      npdcch-Offset-RA-r13 zero

                    }

                  }

                },

                npdsch-ConfigCommon-r13 {

                  nrs-Power-r13 -15

                },

                npusch-ConfigCommon-r13 {

                  ack-NACK-NumRepetitions-Msg4-r13 {

                    r1

                  },

                  dmrs-Config-r13 {

                    threeTone-CyclicShift-r13 0,

                    sixTone-CyclicShift-r13 0

                  },

                  ul-ReferenceSignalsNPUSCH-r13 {

                    groupHoppingEnabled-r13 FALSE,

                    groupAssignmentNPUSCH-r13 0

                  }

                },

                uplinkPowerControlCommon-r13 {

                  p0-NominalNPUSCH-r13 -80,

                  alpha-r13 al1,

                  deltaPreambleMsg3-r13 0

                },

                ntn-ConfigCommon-r17 {

                  ta-Report-r17 enabled,

                  t318-r17 ms2000

                }

              },

              ue-TimersAndConstants-r13 {

                t300-r13 ms2500,

                t301-r13 ms2500,

                t310-r13 ms200,

                n310-r13 n6,

                t311-r13 ms10000,

                n311-r13 n5

              },

              freqInfo-r13 {

                additionalSpectrumEmission-r13 1

              },

              timeAlignmentTimerCommon-r13 infinity

            }

          }

        }

      }

    }

 

 

[4] SIB 31

    {

      message c1: systemInformation-r13: {

        criticalExtensions systemInformation-r13: {

          sib-TypeAndInfo-r13 {

            sib31-v1700: {

              servingSatelliteInfo-r17 {

                ephemerisInfo-r17 orbitalParameters: {

                  semiMajorAxis-r17 8394210402,

                  eccentricity-r17 0,

                  periapsis-r17 0,

                  longitude-r17 242097885,

                  inclination-r17 0,

                  anomaly-r17 193139

                },

                nta-CommonParameters-17 {

                  nta-Common-r17 7776350

                },

                ul-SyncValidityDuration-r17 s240,

                k-Offset-r17 1023

              }

            }

          }

        }

      }

    }

 

 

[5] PRACH

    Message: n_init=8 ta=25 snr=41.3 cfg_id=0 n_rep=1 n_sf=6 n_sc_start=0

 

 

[6] RAR

    Message: RAR: rapid=8

     

    Data:

    rapid=8

      ta=25

      ul_grant:

        sc_spacing=1

        i_sc=0

        i_delay=0

        i_rep=0

        mcs=2

        reserved=0x0

      tc-rnti=0x0101

 

 

[7] Rrc Connection Request

    {

      message c1: rrcConnectionRequest-r13: {

        criticalExtensions rrcConnectionRequest-r13: {

          ue-Identity-r13 randomValue: '2D1318AD6C'H,

          establishmentCause-r13 mo-Signalling,

          multiToneSupport-r13 true,

          earlyContentionResolution-r14 TRUE,

          cqi-NPDCCH-r14 noMeasurements,

          spare '00000000000000000'B

        }

      }

    }

 

 

[8] Rrc Connection Setup

    {

      message c1: rrcConnectionSetup-r13: {

        rrc-TransactionIdentifier 0,

        criticalExtensions c1: rrcConnectionSetup-r13: {

          radioResourceConfigDedicated-r13 {

            srb-ToAddModList-r13 {

              {

                rlc-Config-r13 explicitValue: am: {

                  ul-AM-RLC-r13 {

                    t-PollRetransmit-r13 ms6000,

                    maxRetxThreshold-r13 t32

                  },

                  dl-AM-RLC-r13 {

                  }

                },

                logicalChannelConfig-r13 explicitValue: {

                  priority-r13 1

                }

              }

            },

            mac-MainConfig-r13 explicitValue-r13: {

              ul-SCH-Config-r13 {

                periodicBSR-Timer-r13 pp16,

                retxBSR-Timer-r13 pp64

              },

              timeAlignmentTimerDedicated-r13 infinity

            },

            physicalConfigDedicated-r13 {

              npdcch-ConfigDedicated-r13 {

                npdcch-NumRepetitions-r13 r8,

                npdcch-StartSF-USS-r13 v4,

                npdcch-Offset-USS-r13 zero

              }

            }

          }

        }

      }

    }

 

 

[12] K_OFFSET (MAC CE)

    Message: K_OFFSET=63 LCID:3 len=2 LCID:3 len=41 PAD: len=3

 

 

[13] UE Capability Enquiry

    {

      message c1: ueCapabilityEnquiry-r13: {

        rrc-TransactionIdentifier 0,

        criticalExtensions c1: ueCapabilityEnquiry-r13: {

        }

      }

    }

 

 

[14] UE Capability Information

    {

      message c1: ueCapabilityInformation-r13: {

        rrc-TransactionIdentifier 0,

        criticalExtensions ueCapabilityInformation-r13: {

          ue-Capability-r13 {

            accessStratumRelease-r13 rel17,

            ue-Category-NB-r13 nb1,

            multipleDRB-r13 supported,

            pdcp-Parameters-r13 {

              supportedROHC-Profiles-r13 {

                profile0x0002 TRUE,

                profile0x0003 FALSE,

                profile0x0004 TRUE,

                profile0x0006 FALSE,

                profile0x0102 FALSE,

                profile0x0103 FALSE,

                profile0x0104 FALSE

              },

              maxNumberROHC-ContextSessions-r13 cs12

            },

            phyLayerParameters-r13 {

              multiTone-r13 supported

            },

            rf-Parameters-r13 {

              supportedBandList-r13 {

                {

                  band-r13 7,

                  powerClassNB-20dBm-r13 supported

                }

              }

            }

          },

          ue-RadioPagingInfo-r13 {

            ue-Category-NB-r13 nb1

          },

          nonCriticalExtension {

            ue-Capability-ContainerExt-r14 {

              ue-Category-NB-r14 nb2,

              rf-Parameters-v1430 {

              },

              nonCriticalExtension {

                nonCriticalExtension {

                  nonCriticalExtension {

                    rlc-Parameters-r15 {

                      rlc-UM-r15 supported

                    },

                    mac-Parameters-v1530 {

                    },

                    phyLayerParameters-v1530 {

                      nprach-Format2-r15 supported

                    },

                    nonCriticalExtension {

                      nonCriticalExtension {

                        mac-Parameters-v1610 {

                        },

                        measParameters-r16 {

                        },

                        nonCriticalExtension {

                          nonCriticalExtension {

                            phyLayerParameters-v1700 {

                            },

                            ntn-Parameters-r17 {

                              ntn-Connectivity-EPC-r17 supported,

                              ntn-TA-Report-r17 supported

                            }

                          }

                        }

                      }

                    }

                  }

                }

              }

            }

          }

        }

      }

    }

 

 

[15] Rrc Connection Reonfiguration Complete

{

  message c1: rrcConnectionReconfiguration-r13: {

    rrc-TransactionIdentifier 0,

    criticalExtensions c1: rrcConnectionReconfiguration-r13: {

      dedicatedInfoNASList-r13 {

        '278D2415C2010742013E0...'H

      },

      radioResourceConfigDedicated-r13 {

        drb-ToAddModList-r13 {

          {

            eps-BearerIdentity-r13 5,

            drb-Identity-r13 1,

            pdcp-Config-r13 {

              discardTimer-r13 infinity,

              headerCompression-r13 notUsed: NULL

            },

            rlc-Config-r13 am: {

              ul-AM-RLC-r13 {

                t-PollRetransmit-r13 ms6000,

                maxRetxThreshold-r13 t32

              },

              dl-AM-RLC-r13 {

              }

            },

            logicalChannelIdentity-r13 4,

            logicalChannelConfig-r13 {

              priority-r13 13

            }

          }

        },

        mac-MainConfig-r13 explicitValue-r13: {

          timeAlignmentTimerDedicated-r13 infinity,

          offsetThresholdTA-r17 setup: ms1

        }

      }

    }

  }

}

 

 

 

RRC Parameters (NR)

 

 

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. 

 

 

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.

 

 

 

RRC Parameters (LTE)

 

 

SystemInformationBlockType1-v1700-IEs ::= SEQUENCE {

   cellAccessRelatedInfo-NTN-r17 SEQUENCE {

      cellBarred-NTN-r17                 ENUMERATED {barred, notBarred},

      plmn-IdentityList-v1700            PLMN-IdentityList-v1700 OPTIONAL -- Need OR

   } OPTIONAL, -- Need OR

   nonCriticalExtension                  SEQUENCE {} OPTIONAL

}

 

SystemInformationBlockType31-r17 ::= SEQUENCE {

   servingSatelliteInfo-r17            ServingSatelliteInfo-r17,

   lateNonCriticalExtension            OCTET STRING OPTIONAL,

   ...

}

 

ServingSatelliteInfo-r17 ::= SEQUENCE {

   ephemerisInfo-r17 CHOICE {

      stateVectors                     EphemerisStateVectors-r17,

      orbitalParameters                EphemerisOrbitalParameters-r17

   },

   nta-CommonParameters-17 SEQUENCE {

      nta-Common-r17                         INTEGER (0..8316827) OPTIONAL, -- Need OP

      nta-CommonDrift-r17                    INTEGER (-261935..261935) OPTIONAL, -- Need OP

      nta-CommonDriftVariation-r17           INTEGER (0..29479) OPTIONAL -- Need OP

   },

   ul-SyncValidityDuration-r17 ENUMERATED {s5, s10, s15, s20, s25, s30, s35, s40,

                                           s45, s50, s55, s60, s120, s180, s240, s900},

   epochTime-r17 SEQUENCE {

      startSFN-r17                      INTEGER (0..1023),

      startSubFrame-r17                 INTEGER (0..9)

   } OPTIONAL, -- Need OP

   k-Offset-r17                         INTEGER (0..1023),

   k-Mac-r17                            INTEGER (1..512) OPTIONAL, -- Need OP

   ...

}

 

EphemerisStateVectors-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

}

 

PositionStateVector-r17 ::= INTEGER (-33554432..33554431)

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

 

EphemerisOrbitalParameters-r17 ::= SEQUENCE {

   semiMajorAxis-r17                     INTEGER (0..8589934591),

   eccentricity-r17                      INTEGER (0..1048575),

   periapsis-r17                         INTEGER (0..268435455),

   longitude-r17                         INTEGER (0..268435455),

   inclination-r17                       INTEGER (-67108864..67108863),

   anomaly-r17                           INTEGER (0..268435455)

}

 

 

SystemInformationBlockType32-r17 ::= SEQUENCE {

   satelliteInfoList-r17                 SatelliteInfoList-r17 OPTIONAL, -- Need OR

   lateNonCriticalExtension              OCTET STRING OPTIONAL,

   ...

}

 

SatelliteInfoList-r17 ::= SEQUENCE (SIZE (1..maxSat-r17)) OF SatelliteInfo-r17

 

SatelliteInfo-r17 ::= SEQUENCE {

   satelliteId-r17                       INTEGER (0..255),

   serviceInfo-r17 SEQUENCE {

      tle-EphemerisParameters-r17        TLE-EphemerisParameters-r17 OPTIONAL, -- Need OR

      t-ServiceStart-r17                 TimeOffsetUTC-r17 OPTIONAL -- Need OR

   },

   footprintInfo-r17 SEQUENCE {

      referencePoint-r17 SEQUENCE {

         longitude-r17                   INTEGER (-131072..131071),

         latitude-r17                    INTEGER (-131072..131071)

      } OPTIONAL, -- Need OR

   elevationAngles-r17 SEQUENCE {

      elevationAngleRight-r17            INTEGER (-14..14),

      elevationAngleLeft-r17             INTEGER (-14..14) OPTIONAL -- Need OP

   } OPTIONAL, -- Need OR

   radius-r17 INTEGER (1..256) OPTIONAL -- Need OR

   }

}

 

 

 

RRC Parameters (NB IoT)

 

 

SystemInformationBlockType32-NB-r17 ::= SEQUENCE {

   satelliteInfoList-r17                SatelliteInfoList-r17 OPTIONAL, -- Need OR

   lateNonCriticalExtension             OCTET STRING OPTIONAL,

   ...

}

 

 

 

 

 

 

 

YouTube

 

[1] Beginners: Non Terrestrial Networks (NTN)  

[2] R&S Thirty - Five: Non-terrestrial networks NTN

[3] Aerial Access Networks for 6G: From UAV, HAP, to Satellite Communication Networks

[4] Non-Terrestrial Networks (NTN): The Next 20 Years -- Prof. Halim Yanikomeroglu, 04 June 2020

[5] Satellite for 5G

[6] Satellite Cellular Backhaul

[7] WEBINAR | Unified Software Defined Satellite Ground Solution Magic of AI and 5G - SpaceBridge (2022)

 

 

 

3GPP Reference

 

[1] 3GPP TR 38.811 : Study on New Radio (NR) to support non-terrestrial networks

[2] 3GPP TR 38.821 :  Solutions for NR to support non-terrestrial networks (NTN)

[3] 3GPP TR 23.737 - Study on architecture aspects for using satellite access in 5G

[4] RP-193234 : Solutions for NR to support non-terrestrial networks (NTN)

[5] TS 22.261 : Service requirements for the 5G system; Stage 1 (Release 18)

 

 

 

Other References

 

[1] Orbit of a satellite Calculator

[2] LEO Small-Satellite Constellations for 5G and Beyond-5G Communications

[3] Satellite Communications in the New Space Era: A Survey and Future Challenges

[4] Assessing satellite-terrestrial integration opportunities in the 5G environment  

[5] Satellite and Terrestrial Network for 5G

[6] Application of 5G new radio for satellite links with low peak-to-average power ratios

[7] 5G from Space: An Overview of 3GPP Non-Terrestrial Networks