RSRP drop when using b78/100MHz

[Kamil Kociszewski]

Hi,

i'm trying to build simulation with b78 and bandwidth 100MHz,
UE movement is not insignificant.

i'm observing signal quality drop,
i tried to debug with trace propagation loss model, but there was no dependence with signal quality drop.

--unstable config--
uint16_t numerologyBwp1 = 1;
double centralFrequencyBand1 = 3.5e9;
double bandwidthBand1 = 100e6;


gNB 3500 id: 1 initialized at azimuth: 30 degrees with frequency: 3500 MHz.
---nr-ue-phy trace--
PHY reconfiguring. Result:
         TxPower: 2 dBm
         NoiseFigure: 5
         TbDecodeLatency: 100 us
         Numerology: 1
         SymbolsPerSlot: 14
         Pattern: F|F|F|F|F|F|F|F|F|F|
Attached to physical channel:
         Channel bandwidth: 2200000 Hz
         Channel central freq: 3.5e+09 Hz
         Num. RB: 5
--simulation trace--
Position of UE with IMSI 1 is 2674.89:2557.72:2 at time 0.1, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.76:2558.02:2 at time 0.2, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -114.444 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2674.64:2558.31:2 at time 0.3, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.51:2558.6:2 at time 0.4, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -113.57 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2674.39:2558.9:2 at time 0.5, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.26:2559.19:2 at time 0.6, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -312.719 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2674.14:2559.48:2 at time 0.7, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.02:2559.78:2 at time 0.8, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -299.943 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0

--stable config--
uint16_t numerologyBwp1 = 0;
double centralFrequencyBand1 = 3.5e9;
double bandwidthBand1 = 20e6;

nr-ue-phy trace
gNB 3500 id: 1 initialized at azimuth: 30 degrees with frequency: 3500 MHz.
---nr-ue-phy trace--
PHY reconfiguring. Result:
         TxPower: 2 dBm
         NoiseFigure: 5
         TbDecodeLatency: 100 us
         Numerology: 0
         SymbolsPerSlot: 14
         Pattern: F|F|F|F|F|F|F|F|F|F|
Attached to physical channel:
         Channel bandwidth: 1100000 Hz
         Channel central freq: 3.5e+09 Hz
         Num. RB: 5

--simulation trace--
Position of UE with IMSI 1 is 2674.89:2557.72:2 at time 0.1, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.76:2558.02:2 at time 0.2, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -110.332 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2674.64:2558.31:2 at time 0.3, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.51:2558.6:2 at time 0.4, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -110.296 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2674.39:2558.9:2 at time 0.5, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.26:2559.19:2 at time 0.6, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -107.773 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2674.14:2559.48:2 at time 0.7, UE connected to Cell: 1
Position of UE with IMSI 1 is 2674.02:2559.78:2 at time 0.8, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -103.33 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2673.89:2560.07:2 at time 0.9, UE connected to Cell: 1
Position of UE with IMSI 1 is 2673.77:2560.36:2 at time 1, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -107.255 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2673.64:2560.66:2 at time 1.1, UE connected to Cell: 1
Position of UE with IMSI 1 is 2673.52:2560.95:2 at time 1.2, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -104.832 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2673.39:2561.24:2 at time 1.3, UE connected to Cell: 1
Position of UE with IMSI 1 is 2673.27:2561.54:2 at time 1.4, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -111.292 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0
Position of UE with IMSI 1 is 2673.14:2561.83:2 at time 1.5, UE connected to Cell: 1
Position of UE with IMSI 1 is 2673.02:2562.12:2 at time 1.6, UE connected to Cell: 1
RSRP Report - Context: /NodeList/1/DeviceList/0/$ns3::NrNetDevice/$ns3::NrUeNetDevice/ComponentCarrierMapUe/0/NrUePhy/ReportUeMeasurements, Cell ID: 1, RNTI: 1, RSRP: -101.83 dBm, RSRQ: 0 dB, InConnectedState: true, BWP ID: 0

[Kent Huns]

Hi Kamil,

I think -300 dBm should be suspected as a “null” rather than a simulated value.
Is this RSRP report working every time even though UE doesn't receive any signal at that time?
It's not uncommon for DL transmissions to stop momentarily due to Tx packet exhaustion or some other latency.

Thanks,

[Gabriel Ferreira]

Kent is right. Probably a modelling issue, since the code was originally intended for FDD, and it is now also in TDD. This is why we did not advertise this feature.
This is just the base porting, to put handover on top, which we are yet to finish. Right now the focus is getting release 4.0 ready.

[Kamil Kociszewski]

Thank you for clarification.