SgNB addition reguest rejections with cause: no radio resource available

5G NR
,
1

Hi Experts.
Anyone had issue with SgNB addition reguest rejections with cause: no radio resource available?
Sounds like AC issue but only one user is trying to attach.

2

Check pucchs and srs resources.
And number of connected users on sgNB cell.
Those settings maybe as low as 1.

1 Like
3

Check below reason

  1. The transmission on the Transport resource not available (5G side is faulty:X2-U link or S1-U link Alarm)
  2. The gNB ID is duplicate
  3. No available SRS resources are available (5G gNB)
4

Hi All.

In our 5G NSA network we have defined L800 FDD cells as anchor of 5G TDD N77 band .

And it is observed sgNB addition rejections from sgNB to MenB increased with RNL cause “No radio resource available, NRRA”

I checked AC parameter dimensioning (NSA users capacity, pucch capacity, non GBR bearers, CP-UE… etc) and found all OK.

Any idea to check this accessibility issue?

5

Check UE Admission Control: Check if the admission control parameters are preventing the addition of new UEs.

This includes:

Maximum number of UEs per gNB.

  • GBR and non-GBR bearer limits.
  • Number of UEs allowed for CP-UE (Control Plane).
  • Number of UEs allowed for UP-UE (User Plane).

Parameters to check:

  1. Maximum connected UEs allowed per gNB.
  2. Maximum non-GBR bearers per gNB.
  3. GBR/non-GBR bearer thresholds (if configured).
  4. Admission Control Threshold (for specific QoS requirements).
6

Thanks dear.

AC checks already done earlier and all fine (no issues).

Will check QoS settings and let you know

By the way issue observed in only one FDD carrier B20 with one particular 5G carrier N77 while others FDD/5G layers not reporting this issue.