5G Uplink lower then 4G + 5G UL (PDCP)

5G NR
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Hello experts,

What could be possible reason of low uplink in 5G assuming radio conditions are perfect including RSRP/SINR and UL flow is also over both 4G and 5G leg.

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  1. In FDD scenario 5G Has higher throughput in DL and in UL, as more resources are available.
  2. In TDD scenario maximum Uplink theoretical throughput is low In general - less resources available for Uplink.
    Some of Major Factors Impacting Uplink Throughput as below:
    2a. Duplex Mode → TDD Configuration (Using Same Frequency band for UL/DL in different time).
    2b. Downlink and Uplink Slot Ratio:
    Slot pattern has a direct impact on throughput, as it defines how many and which slots will be used for DL/UL data, SSBs and PRACH etc.
    Example: 5G TDD Slot configuration (8:2 [8_2_DDDDDDDSUU]) => More Resources for Downlink and Less for Uplink.
    2c. MIMO Supports (Downlink Vs Uplink): Higher MIMO Capability in Downlink in comparison with Uplink
    DL: SU supports a maximum of 8 layers while the MU supports a maximum of 4 layers.
    UL: SU/MU supports a maximum of 4 layers.
  1. Low UL thrp is due to low data demand.
  2. In 3x , UL leg will stay on NR until good UL SINR else will switch to 4G. UE max tx power is 23 dbm and 5G is totally UL limited due to this. Simply you can enjoy good ul thrp around 300-400 m radius of the site else it will be 4G experience.
  3. Testing should be done for UL & DL leg switching and Aggregation ( MCG+SCG) thresholds and observe where you can get best thrp in OSS and field
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