- This topic has 14 replies, 1 voice, and was last updated 11 years, 5 months ago by Pix.
26th October 2009 at 13:48 #59301UrgentGuest
Alcatel B9, 900 with 1*1 Frequency plan with Nemo Drive test tool; Network with allot of drops with the same reason!bad level at the serving cell and good level at the neighbors without making HO even the difference become more than 30 dB and the quality jump from 0 to 6 or 7 suddenly, mobile send allot of Uplink measurement reports without getting any response from system until the drop happen after RLT become out!
help be appreciated,26th October 2009 at 17:54 #59302PixGuest
What is your RF Load ?
Please search for previous posts related to “RF Load”
pix27th October 2009 at 08:38 #59303UrgentGuest
RF Load was 16%; and due to drop we adjusted TRX Config. to S333 then RF Load became 9%,
Regards27th October 2009 at 21:26 #59304PixGuest
Even with low RF load, you are seeing bad rxqual ? Are you sure your antenna design is well done ? Are there a lot of cells overlapping each others ?
You said you don’t see a HO while the difference in levels are > 30dB. Possible reasons are :
– target cell is congested
– HO might not take place because cells are in different bands / layers
– the HO parameters (thresholds, traffic load, etc) might not be tuned properly
UL measurement reports are sent every 0.48s during call 🙂 that’s normal.
no response = no HO command… but that might be normal : the HO is not triggered or the target cell is too congested. Check your qos stats (HO requests, HO allocated, HO success, per adjacency)
pix28th October 2009 at 08:46 #59305UrgentGuest
Your time really appreciated,
No overlapping issue; Network controlled by redirection and physical adjustment plan before new frequency plan,
No congestion; Network with very low traffic,
different bands/layers: DT was locked on 900 even the network is dual,
appreciated if you tell me how I have to check the HO commanded as you suggested and can you suggest no of BSS parameters at alcatel relative? I’m with Huawei experience therefore,
Cheers28th October 2009 at 09:49 #59306PixGuest
Can you check your QoS stats ?
Go in “adjacency” in RNO, and check the QoS indicators “BASIC MATRIX” : HO REQUEST, HO ALLOCATED and HO SUCCESS.
Focus on the cells you have seen during your drive test.
Check these indicators for all adjacencies (outgoing and incoming) around the cells you tested. Could you please chare the values here ?
Pix28th October 2009 at 17:25 #59307UrgentGuest
You don’t think there is problem in BSS parameter setting? may be there is is an of penalty HO setting,
No HO from cell A to cell B at the same site even the lev diffrence become 60dBs (-110 at A and -50 at B) until the RLT become o then drop and the problem at more than 60% of the network; really I’m surprising!
I got PING_PONG_HCP is 15dB and T_HCP is 0 at 40% of the network and 10 seconds at other 60%; do you think it’s effect?
appreciated if you help,
Thanks for your time,
Regrads28th October 2009 at 17:27 #59308UrgentGuest
I will try to check the points that you already mentined and inform you soon; I’m with the operator site and there is no RNO! but I will try my best,
Regards29th October 2009 at 11:10 #59309PixGuest
Ok, i understand your problem. Put clearly, it means that there is no “power budget HO” between the 2 cells. Possible causes :
– probably different layers or different bands (mini, micro, umbrella, indoor ? 900 / 1800 ?)
– or the target cell is congested or in high load (…and traffic HO is enabled with high Delta Inc HO)
I have a strong suspicion on the different bands/layers.
The ping pong hcp is just 15dB, so it will not prevent HO at 60dB difference 🙂 And ping pong HCP is used only at the 2nd HO, returning into the previous cell…
What are the layer type of each cell ?
If the DT is locked on 900, the target cell is not 1800, is it ?
pix30th October 2009 at 11:10 #59310UrgentGuest
I checked the cell type are single for the whole GSM cell; is it that parameter for cell layer?
Drive test locked on GSM (one band); and no congestion,
Target cell is 900 as well; other cell at the same site,
and I agree with you; there was no another HO; call generation on A,
Your time really appreciated,
Thanks30th October 2009 at 16:21 #59311PixGuest
“and I agree with you; there was no another HO; call generation on A”
I don’t understand this part.
Regarding your problem, you will need to check your stats, for both directions. There might be some adjacency “bug”, I experienced this once already. Try deleting both cells and recreate them from scratch ?
When coming from another cell, can you HO to that particular cell ?30th October 2009 at 17:01 #59312UrgentGuest
I meant that there was no another HO in order think to fix the problem by that parameter,
and for deleting and recreate; I think is not easy for operation; more than 50% of Network,
Thanks30th October 2009 at 22:36 #59313PixGuest
50% ??? Check your QoS ! It’s a very serious issue, don’t tell me that nobody at RNO side can support you on this 🙂 The full radio team should be working on this issue, shouldn’t they ?2nd November 2009 at 12:32 #59314UrgentGuest
we did new FP at a part of the Network (Little far from the main) from SFH to BBH as a trail; the problem fixed with BBH,
do you think Alcatel equipments have problem with SFH? is it possible?
sorry to say that; I heard and I wanted to be sure,
Regards3rd November 2009 at 16:01 #59315PixGuest
No problem with SFH and ALU equipment !
Don’t you see any other improvement on TCH drop rate, Call Setup Success Rate or even the causes of HO ?
If not, then I would assume that activating the new FP did actually re-initialize the BSC database… Like a huge system reboot 😉