Problem in UE / gNB / eNB that can affect Throughput?

Hi Experts.

What could be a problem in UE and gNB / eNB (cell side) that can cause and affect / defect the performance of the network in terms of Throughput for DL and UL?

Lets cover please the major problems that could happen


Major problems in UE and gNB / eNB impacting network Throughput:

DL (Downlink):


  1. Weak signal strength: Low signal strength at the UE can lead to poor decoding and reduced throughput. This can be caused by distance from the gNB, antenna problems, or interference.
  2. Buffer overflow: If the UE’s buffer becomes overloaded, it can drop packets, leading to decreased throughput. This can happen when the UE receives data faster than it can process it or when the data rate exceeds the available bandwidth.
  3. Hardware limitations: Older UE devices may not have the necessary processing power or memory to handle high data rates, resulting in throughput limitations.
  4. Software bugs: Software bugs in the UE’s operating system or radio access network (RAN) software can also impact throughput.

gNB / eNB:

  1. Congestion: When a large number of UEs are connected to a gNB, the network can become congested, leading to reduced throughput for all users.
  2. Insufficient resources: If the gNB does not have enough resources (e.g., bandwidth, processing power) to support the connected UEs, throughput will suffer.
  3. Incorrect configuration: Improper configuration of the gNB’s parameters can also lead to throughput problems.
  4. Backhaul limitations: The backhaul network connecting the gNB to the core network can be a bottleneck, limiting throughput if it is not adequately provisioned.

UL (Uplink):


  1. Limited transmit power: UEs have limited transmit power, which can restrict the maximum achievable uplink data rate.
  2. Interference: Interference from other UEs or other sources can significantly reduce throughput in the uplink.
  3. HARQ failures: Hybrid Automatic Repeat Request (HARQ) is a mechanism used to retransmit data packets that are not received correctly. Frequent HARQ failures can significantly impact uplink throughput.
  4. Excessive scheduling delays: Delays in scheduling uplink transmissions can lead to reduced throughput, especially for real-time applications.


  1. Limited scheduling resources: The gNB has limited resources available for scheduling uplink transmissions. This can lead to bottlenecks and reduced throughput when there are many UEs competing for uplink resources.
  2. Incorrect uplink power control: Improper uplink power control can lead to wasted power and reduced throughput.
  3. Inter-cell interference: Interference from neighboring cells can significantly impact uplink throughput.
  4. Backhaul limitations: Similar to the downlink, the backhaul network can also be a bottleneck for uplink traffic, limiting throughput.


Some general issues can impact both downlink and uplink throughput:

  1. Inter-frequency interference: Interference from other frequencies used by the network can degrade performance.
  2. Handovers: Frequent handovers between cells can cause interruptions in data transmission and reduce throughput.
  3. Mobility: Moving UEs can experience signal fluctuations and reduced throughput.
1 Like