High repetition rate of RRC Attempts in 3G

[etdoja]

Hi,

what can affect a very high repetion rate of RRC attempts in E******* 3G network?

In E******* there are tow different raw counter to count the number of RRC attempts - pmTotNoRrcReq and pmTotNoRrcConnectReq.

In addition to pmTotNoRrcConnectReq, the counter pmTotNoRrcReq includes all repetition attempts, that were recived by the nodeb, but are alöready manageged by the system.

So what can be reasons for send repetitions of the mobiles, thats leads to different values here?

Let me know
Thx etdoja

[etdoja]

98 reads!!! Thx for the great interest. Unfortunately nobody want's to answer this question. Pls share your ideas about that with me. No idea is stupid and can help me to solve this problem.

Thx in advance

[khurrambilal01]

Hi,

what can affect a very high repetion rate of RRC attempts in E******* 3G network?

In E******* there are tow different raw counter to count the number of RRC attempts - pmTotNoRrcReq and pmTotNoRrcConnectReq.

In addition to pmTotNoRrcConnectReq, the counter pmTotNoRrcReq includes all repetition attempts, that were recived by the nodeb, but are alöready manageged by the system.

So what can be reasons for send repetitions of the mobiles, thats leads to different values here?

Let me know
Thx etdoja

Please check your initial RACH power set, If it is set to too low value there would be alot of RRC repetitions,
Secondly what about your UL? Is it clean or has high RTWP? this can also cause high number of RRC re-attempts.

Sometimes there are such devices in our network which are malfunctioning, these devices don't follow 3GPP Standard specifications, when RRC attempt is send by these UEs, Network assigns them resources but instead of sending network the response of the assignment these devices keep on generating new RRC requests. We have identified some devices in our network using trace.

[fon909]

Hi,

If this RRC re-attempts has increased all of a sudden then you may want to check the following;

1. MP load of the corresponding RNC.
2. MultiCast, BroadCast issues at SGSN.
3. Check if some parameter tuning done at Router End.

[etdoja]

Hi,

the problem with the high repetation rate is not only in one nodeb, it's seems more a generell problem of our network. What I found out is, that the repetation rate seems to be lower in areas with a correct (higher) tilt, then in urban areas, where coverage
is more in focus. Therefore your idea with the initial RACH power set is logical to me. I'll check it out. What are your parameter settings for that?
The UL of cause also can be a problem, but more in specific sites, than in generell. I also have to keep in mind. Thx

[etdoja]

Hi,

If this RRC re-attempts has increased all of a sudden then you may want to check the following;

1. MP load of the corresponding RNC.
2. MultiCast, BroadCast issues at SGSN.
3. Check if some parameter tuning done at Router End.

Yeah you are right. We have seen this in the past in our network, when in MP Load of the RNC was to high. You can see this failure picture cleary in the E/// counter, but this are retransmissions, that are counted in pmTotNoRrcReq and pmTotNoRrcConnectReq and are splitted up after pmTotNoRrcConnectReq and after "Load Control procedure".

My problem is more related to the behaviour of the devices, I guess!?

But again thx for your post.