6.8 Reliability KPI

28.5543GPP5G end to end Key Performance Indicators (KPI)Management and orchestrationRelease 18TS

6.8.1 Definition

Reliability is defined (see TS 22.261 [13] clause 3.1) in the context of network layer packet transmissions, as the percentage value of the packets successfully delivered to a given system entity within the time constraint required by the targeted service out of all the packets transmitted.

6.8.1.1 Packet transmission reliability KPI in DL on Uu

a) DLRelPSR_Uu

b) This KPI describes the Reliability based on Packet Success Rate(PSR) Percentage between gNB and UE. It is used to evaluate the Uu interface reliability contribution to the total network downlink reliability. It is the percentage of RLC SDU packets which are successfully received in UE out of the total RLC SDU packets transmitted by gNB. It is a measure of the DL packet delivery success i.e. PSR% over Uu interface. It is a percentage value (%). This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in NR option 3) and per S-NSSAI.

c) Below is the equation for downlink Reliability in RAN based on PSR percentage between gNB and UE.

DLRelPSR_Uu = × 100 , where N(T1,drbid) & Dloss(T1,drbid) are as defined in TS 38.314.

or optionally DLRelPSR_Uu.QoS = × 100, where QoS

identifies the target QoS quality of service class.

or optionally DLRelPSR_Uu.SNSSAI = × 100,

where SNSSAI identifies the S-NSSAI.

d) NRCellDU

6.8.1.2 Packet transmission reliability KPI in UL on Uu

a) ULRelPSR_Uu

b) This KPI describes the Reliability based on Packet Success Rate Percentage between UE and gNB. It is used to evaluate the Uu interface reliability contribution to the total network uplink reliability. It is the percentage of PDCP SDU packets which are successfully received in gNB out of the total PDCP SDU packets transmitted by UE. It is a measure of the UL packet delivery success i.e. PSR% over Uu interface. It is a percentage value (%). This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in NR option 3) and per S-NSSAI.

c) ULRelPSR_Uu = DRB.PacketSuccessRateUlgNBUu × 100 , where DRB_PacketSuccessRateUlgNBUu is as defined in TS 28.552 [6].

or optionally ULRelPSR_Uu.QoS = DRB.PacketSuccessRateUlgNBUu.QOS × 100, where QoS identifies the target QoS quality of service class.

or optionally ULRelPSR_Uu.SNSSAI = DRB.PacketSuccessRateUlgNBUu.SNSSAI × 100, where SNSSAI identifies the S-NSSAI.

d) NRCellCU

6.8.1.3 Packet transmission reliability KPI in DL on N3

a) DLRelPSR_N3

b) This KPI describes the Reliability based on Packet Success Rate(PSR) Percentage between UPF and gNB. It is used to evaluate the N3 interface reliability contribution to the total network downlink reliability. It is the percentage of GTP data PDUs which are successfully received by gNB out of the total GTP data PDUs transmitted by UPF over N3 interface. It is a measure of the DL packet delivery success i.e. PSR% over N3 interface. It is a percentage value (%). This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in NR option 3) and per S-NSSAI.

c) DLRelPSR_N3 =

where GTP.OutDataPktN3UPF, GTP.InDataPktPacketLossN3gNB are as defined in TS 28.552

or optionally,

DLRelPSR_N3.QoS =

where QoS identifies the target QoS quality of service class.

or optionally,

DLRelPSR_N3.SNSSAI =

where SNSSAI identifies the S-NSSAI.

d) UPFFunction, GNBCUUPFunction

6.8.1.4 Packet transmission reliability KPI in UL on N3

a) ULRelPSR_N3

b) This KPI describes the Reliability based on Packet Success Rate(PSR) Percentage between gNB and UPF. It is used to evaluate the N3 interface reliability contribution to the total network uplink reliability. It is the percentage of GTP data PDUs which are successfully received by UPF out of the total GTP data PDUs transmitted by gNB over N3 interface. It is a measure of the UL packet delivery success i.e. PSR% over N3 interface. It is a percentage value (%). This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in NR option 3) and per S-NSSAI.

c) ULRelPSR_N3 =

where GTP.InDataPktN3UPF , GTP.InDataPktPacketLossN3UPF are as defined in TS 28.552

or optionally,

ULRelPSR_N3.QoS =

where QoS identifies the target QoS quality of service class.

or optionally,

ULRelPSR_N3.SNSSAI =

where SNSSAI identifies the S-NSSAI.

d) UPFFunction