To improve Uplink Channel Quality, you mentioned some optimization terms. Could you throw some light on the below topics, how it works: A) *IRC-Intereference Rejection Combining (Enhanced Rec Algo)* B) *Uplink Coordinated Multipt.*
Great and good explanation. Normaly,this MME Abnormal release counter can not added on the E-RAB Drop formula, right? Since it's not really a drop perceived from Customer but can be improved separetly?
Hi Ali, just a quick question in case of re-establishment on a different enodeB. How this new eNodeB will fetch old UE context from old enodeB? Will send message to all its 850-60 enodeB neighbors and one will eventually reply with old UE context? What is this message name on X2?
No, the UE includes the source cell PCI information in RRC Reestablishment so based on this, the target eNB can find the source eNB. And then it can initiate RLF indication to that source eNB over X2.
Hi Ali, Good Noon, Need your suggestion in understanding how Enb can keep exact record of Voice Drops happening at UE To elaborate- While we are doing KPI validation, we are seeing high no, of ERAB drops getting pegged in Enb than in DT Tool during Drive test. UE detect RLF and indicated to Enb. Enb waits for 3 Sec (RLF Timer) and upon expiry of the same, start the process of UE CONTEXT RELEASE with MME and after receiving the response from MME , it increments ERAB drop count, while the call is not actually dropped, UE will keep on sending Service Request to resume Radio connection post detecting RLF and Enb will act on this request by passing SERVICE request to MME and established Bearers. In this process before the call is actually dropped at UE, Enb will keep on accepting Service Request and increments ERAB drop multiple times and DT toll will increment fewer drops only. Can u please help me in this
Actually these are implementation specific details that I usually try to avoid going into. But some vendors have internal timers to peg drops for Voice. But if the eNB is pegging drop multiple time for same call session , that sounds like a bug.
Hi Can you confirm from which point X2RelocTimer starts from because in figure it is from the time when RRC Reconfiguration Complete message timer expires and it is not transmitted Secondly is it a combination of T304 , T301 & T311 or is it a separate timer altogether
@@OurTechPlanet But whenever SCTP congestion was there ERAB stp SR RNL failure kpi got affected not TNL kpi. Whether transmission media can affect RNL as well?
Hello! Could you please tell how can we analyze ERAB drop case in actix analyzer or tems discovery, I have not found ERAB drop counter name in both. Thankyou!
You do not see that ERAB drops in Drive Test tools because the ERAB drops are pegged on S1 interface. On DT tools, you are only looking at Uu interface. However, in most of the DT Tools, there are events which are generated to show RLFs which are actually drops.
I guess there is one mistake in the flow, UeCtxt Rel request will go from target enB to source enB to release it, not to MME. in this case I guess it should be from enB2 to enB1.
No, the whole concept of this kind of drop is that the target eNB initiates a new connection to MME. Thus MME sends a UE Context release to source eNB which is why it is pegged under MME drop.
Thank you so much Sir for wonderful explanation .If possible need to make a video on how to improve volte drop reason for drops How to do parking on cmx log file
In eNodeb Initiated DL RLC Drops, there will be no RRC Re-Establishment Request because UL RLC Threshold is not breached? Also can you tell what is the X2 Reloc Overall Timer parameter name in Huawei? How would be target eNb know which eNodeB X2 Link to send "Context Request over X2" over or it sends to all X2 Links?
For eNB initiated DL RLC Drops, the UE might not know that it has experienced RLF so usually no RRC Reestablishment is seen. For UL RLC issue, the UE is itself counting that so it will know when UL RLC retransmissions exceed the threshold and thus, it will trigger RRC Reestablishment
During RRC Reestablishment, the UE sends the last source cell's PCI and its context information. This helps the new eNB to identify the original source cell.
For LTE KPIs, Call Flows & Optimization, check out the complete playlist below :)
🌐LTE KPI Optimization
💡ruclips.net/p/PL4OXTttOk9WiA1ogmEIBYmFO_K2EhgLln
hi, all videos are very good, please add more topics for detailed VoLTE optimization
@@syedhunainabbas Thanks, will work on it soon.
RLC Drops-->
0:34 RLC Re-transmission threshold
4:27 RLC poll timers
4:55 DL channel quality
*Handover Drops(eNB initiated)--> 5:27
*UL RLC Drops(MME initiated)--> 9:14
*Poor Quality Drops(MME Initiated)--> 15:12
Handover Drops(MME Initiated)--> 20:08
Single UE repeated drops-->23:19
Thanks again!!!!
brother that is parameter or Features?
@@sanaullahdaud8304 These are just topics covered in this session
For LTE KPIs , can you please let me know about the ERAB.Congestion.QCI1, it will be helpful in counter validation .
Will work on that soon.
To improve Uplink Channel Quality, you mentioned some optimization terms. Could you throw some light on the below topics, how it works:
A) *IRC-Intereference Rejection Combining (Enhanced Rec Algo)*
B) *Uplink Coordinated Multipt.*
Sure, I can put them in my list and create a session for these too.
Great and good explanation. Normaly,this MME Abnormal release counter can not added on the E-RAB Drop formula, right? Since it's not really a drop perceived from Customer but can be improved separetly?
In nearly all the networks, the MME abnormal releases are added in the Drop Rate :)
I have a doubt, are these timers n310, t310, n311 tunable in sector level or is it site level(3 sectored site)?
Normally, these are tunable at sector level.
this is awesome..... please make video for 5G KPI, counters and optimization parameter with their recommended values
Thanks Varun :)
Hi Ali, just a quick question in case of re-establishment on a different enodeB. How this new eNodeB will fetch old UE context from old enodeB? Will send message to all its 850-60 enodeB neighbors and one will eventually reply with old UE context? What is this message name on X2?
No, the UE includes the source cell PCI information in RRC Reestablishment so based on this, the target eNB can find the source eNB. And then it can initiate RLF indication to that source eNB over X2.
very useful lesson, thank you!
Thanks!
Hi Ali, Good Noon,
Need your suggestion in understanding how Enb can keep exact record of Voice Drops happening at UE
To elaborate- While we are doing KPI validation, we are seeing high no, of ERAB drops getting pegged in Enb than in DT Tool during Drive test.
UE detect RLF and indicated to Enb. Enb waits for 3 Sec (RLF Timer) and upon expiry of the same, start the process of UE CONTEXT RELEASE with MME and after receiving the response from MME , it increments ERAB drop count, while the call is not actually dropped,
UE will keep on sending Service Request to resume Radio connection post detecting RLF and Enb will act on this request by passing SERVICE request to MME and established Bearers. In this process before the call is actually dropped at UE, Enb will keep on accepting Service Request and increments ERAB drop multiple times and DT toll will increment fewer drops only.
Can u please help me in this
Actually these are implementation specific details that I usually try to avoid going into. But some vendors have internal timers to peg drops for Voice. But if the eNB is pegging drop multiple time for same call session , that sounds like a bug.
Great presentation 👏
Thanks!
Good explanation...it has cleared my mind.my level of confusion is dropped
That is great to hear :)
Great & Precise explanation !!!
Thanks :)
Hi
Can you confirm from which point X2RelocTimer starts from because in figure it is from the time when RRC Reconfiguration Complete message timer expires and it is not transmitted
Secondly is it a combination of T304 , T301 & T311 or is it a separate timer altogether
The X2 Reloc timer starts at X2 HO Request Acknowledge and it is a totally separate timer that is maintained at the eNB.
In most of the practical cases in my experience eRAB drops are due to SCTP congestion in the media.
Usually SCTP congestion is rare and that should fall under a transport induced ERAB Drop.
@@OurTechPlanet But whenever SCTP congestion was there ERAB stp SR RNL failure kpi got affected not TNL kpi. Whether transmission media can affect RNL as well?
Awesome bro, Very good, Appreciate
So nice of you! Thanks!
Can you briefly explain the impact of increasing DRX wake up time (increasing ODT & IDT) on ERAB DR
Sure, will discuss it in the DRX session
Hello! Could you please tell how can we analyze ERAB drop case in actix analyzer or tems discovery, I have not found ERAB drop counter name in both.
Thankyou!
You do not see that ERAB drops in Drive Test tools because the ERAB drops are pegged on S1 interface. On DT tools, you are only looking at Uu interface. However, in most of the DT Tools, there are events which are generated to show RLFs which are actually drops.
I guess there is one mistake in the flow, UeCtxt Rel request will go from target enB to source enB to release it, not to MME. in this case I guess it should be from enB2 to enB1.
No, the whole concept of this kind of drop is that the target eNB initiates a new connection to MME. Thus MME sends a UE Context release to source eNB which is why it is pegged under MME drop.
Great information 👍...any video related to 5g interview related questions...optimization related
Not yet, but we have plans to cover these topics as well in near future.
Thank you so much Sir for wonderful explanation .If possible need to make a video on how to improve volte drop reason for drops How to do parking on cmx log file
Thanks! Sure, will add that to my list!
Great explanation. thanks
Glad it was helpful!
Thanks. This a very good for optimizers like me.
You are welcome. That is great to know :)
In eNodeb Initiated DL RLC Drops, there will be no RRC Re-Establishment Request because UL RLC Threshold is not breached?
Also can you tell what is the X2 Reloc Overall Timer parameter name in Huawei?
How would be target eNb know which eNodeB X2 Link to send "Context Request over X2" over or it sends to all X2 Links?
For eNB initiated DL RLC Drops, the UE might not know that it has experienced RLF so usually no RRC Reestablishment is seen. For UL RLC issue, the UE is itself counting that so it will know when UL RLC retransmissions exceed the threshold and thus, it will trigger RRC Reestablishment
During RRC Reestablishment, the UE sends the last source cell's PCI and its context information. This helps the new eNB to identify the original source cell.
and if possible can you tell the name of X2 Reloc Overall Timer parameter name (Huawei)
@@coolmunzir We really try to keep our content vendor agnostic :)
Thank you so much for sharing knowledge very good explanation
You are welcome!
great stuff!
Thanks Pawan! :)