Low RACH sucess rate in Ericsson

4G LTE
1

Dear Experts,
There is very low RACH success rate in LTE Ericsson as compared to Nokia & Huawei.
Can anyone multivendor expert explain the reason?

Regards
Sachin

2

Hello, i got this from ChatGPT, for reference: (Experts can confirm)

The reason for a lower Random Access Channel (RACH) success rate in LTE Ericsson networks compared to Nokia and Huawei could stem from various factors. Here are a few possibilities:

1. Parameter Configuration: Each vendor might have default parameter settings that differ slightly, and optimizing these settings is crucial for network performance. It’s possible that Ericsson’s default settings or the settings configured for a particular network are not as well tuned for RACH success rate as those of Nokia or Huawei.
2. Interference Management: Interference from neighboring cells or external sources can significantly impact RACH success rates. Ericsson’s interference management algorithms or techniques might not be as effective in mitigating interference compared to Nokia or Huawei.
3. RACH Procedure Handling: The way Ericsson handles the RACH procedure, including contention resolution and access grant mechanisms, might not be as efficient as those of its competitors. This could lead to higher contention and lower success rates.
4. Load Balancing Algorithms: The load balancing algorithms used by Ericsson might not distribute traffic optimally among cells, leading to congestion in certain areas and lower RACH success rates.
5. Hardware or Software Issues: There could be specific hardware or software issues in Ericsson’s LTE equipment affecting RACH performance. These issues might require software updates or hardware adjustments to resolve.
6. Environmental Factors: Environmental factors such as geography, population density, and spectrum allocation can also play a role. Ericsson networks might be deployed in areas with more challenging conditions for RACH success, such as high-density urban areas or regions with limited spectrum availability.

To pinpoint the exact reason for the lower RACH success rate in LTE Ericsson networks, a detailed analysis of network configurations, performance metrics, and field measurements would be necessary. This analysis would likely involve network engineers familiar with LTE technologies and experience working with Ericsson, Nokia, and Huawei equipment.

3

Have you checked CBRA counters.? What does exactly contribute to CBRA degradation?

4

Hello, friends!

How can I improve the RACH success rate on Ericsson LTE?

Currently, my success rate is only 50%

5

I think RSI optimization needs to be done.

6

Check the RSI configuration of the cluster.

You can also tune RACH-related parameters for optimization.

7

For contention-based random access (CBRA), the Msg1 counters include ghost preambles (caused by noise or real UEs from other cells). As a result, any success ratio based on these counters may appear relatively low.

Also, make sure to check your KPI formulas.

8

Have you checked the main cause of failures?

9

Please verify the following:

  1. Root Sequence Index (RSI) Planning – Ensure that the planning is correct and that there is no repetition in the next two tiers.
  2. Parameter: preambleInitialReceivedTargetPower – The default value is -100 dBm. You may consider increasing it if necessary.
  3. RA Failures – Check the counters:
    (a) EUtranCellFDD.pmRaFailCbraMsg1DiscOoc
    (b) EUtranCellFDD.pmRaFailCfraMsg1DiscOoc
  4. TA Distribution – Analyze where the traffic is predominantly coming from: is it near the cell center or at the cell edge?

And answer this :point_down: