nabil el haddani 2010-01-13, 01:05 AM Hi experts, I'm working on SHO overhead optimisation on UMTS900 and UMTS2100 layers; I have a lot of cells with excessive SHO overhead; For rural sites, i can apply more downtilt to reduce the SHO area; for urban and dense urban sites i have the same problem but i can't downtilt because the tilt is already 8, 9 or 10, i thought about reducing the Active set size to 2 but it's not good idea cuz i will l oose SHO gain.. Can anyone light my way with some good ideas in order to optimise to the normal range which is 30%-40% and share some experience related to this task. Br Nabil desi_larka 2010-01-13, 04:35 AM Nabil i am assuming u have the right sorts of neighbours defined. there are a few ways to acheive this You could increase your threshold for adding which would avoid weak radio legs, you could change hystersis which would also do similar thing. There are also priorities defined for the neighbous so you could do that. BTW having more than 3 RL would it give you much SHO gain anyways ? i doubt it nabil el haddani 2010-01-13, 04:56 AM Thanks for your answer, i already tried that but in vain! Do u know how to implement prorities for neighbours with NSN vendor? I know that in ZTE but NSN i should dig i n Br, Nabil wolverine 2010-01-13, 05:08 AM Have you examined the possibility of reducing the power of t he pilot channel (CPICH)? This is usually the second step if downtilting doesn't work/isn't possible. nabil el haddani 2010-01-13, 05:17 AM It's a risky solution man :) roamR 2010-01-13, 02:20 PM How high is the a ntenna height for urban area and dense urban implemented? Physical changes such as lowering the antenna height also might help. gprastomo 2010-01-13, 05:27 PM Hi,
Reducing the SHO, its better to apply to antenna downtilt for the cells which we dont want to serve, or if you want to make it difficult SHO for specific neighbour you can apply Cell Individual Offset or EcNo Offset for that neighbour. br nabil el haddani 2010-01-14, 07:02 PM Hi guys, I realised that mostly all U900 cells have SHO overhead higher than 50%; seems global problem. Anyone have an idea. Thank u guys gprastomo 2010-01-14, 07:22 PM Do you work on U900-2100 SHO or separately ? nabil el haddani 2010-01-14, 08:00 PM I'm working on U9-U21 together, what's the effect? fangruan2201 2010-01-14, 08:09 PM Hi experts, I'm working on SHO overhead optimisation on UMTS900 and UMTS2100 layers; I have a lot of cells with excessive SHO overhead; For rural sites, i can apply more downtilt to reduce the SHO area; for urban and dense urban sites i have the same problem but i can't downtilt because the tilt is already 8, 9 or 10, i thought about reducing the Active set size to 2 but it's not good idea cuz i will l oose SHO gain.. Can anyone light my way with some good ideas in order to optimise to the normal range which is 30%-40% and share some experience related to this task. Br Nabil Friend! If the statistics u got are from OMC, I doubt it is the counter problem? Tto confirm u can analyse the logfiles? Export the active set size statisctics then calculate the average: Eg: Number of Components in Active Set Count Percentage
1 222
2
444
3 111
Then the SHO overhead = (1*222 + 2*444+3*111)/(222+444+111) ~1-2 is fine! nabil el haddani 2010-01-14, 08:10 PM Hi gprastomo, plz find enclosed the xls file with SHO overhead statistics for RT and NRT services, it's filtered on SHO overh more than 50%, you can see that's it's general issue for U9 cells (like 143YEW1), but not for U21 (with YEU naming). You can find also ADJS for neighbours and also gsm timing advance to have an idea about the overshooting sites in 900 band. Thanks for ure help
@fangruan2201: i already did this exercise, it gives the same results with high SHO overhead!! Br, Nabil gprastomo 2010-01-14, 08:25 PM Hi gprastomo, plz find enclosed the xls file with SHO overhead statistics for RT and NRT services, it's filtered on SHO overh more than 50%, you can see that's it's general issue for U9 cells (like 143YEW1), but not for U21 (with YEU naming). You can find also ADJS for neighbours and also gsm timing advance to have an idea about the overshooting sites in 900 band. Thanks for ure help
@fangruan2201: i already did this exercise, it gives the same results with high SHO overhead!! Br, Nabil Dear Friend, based on my general analysis, it should be like this (This case almost the same with GSM and DCS layer). U900 will have better coverage than U2100, so the SHO OH have higher than U2100. What i want to know is : 1. Both of them implemented on the same antenna or not ?
2. The tilt should be different between both of them So this U900 should be treated differently, the parameter should be differ from U2100, we have to match with the objective of implementing this U900 (is is coverage or capacity issue) both of these issue will treated as different strategy. br nabil el haddani 2010-01-14, 08:33 PM To answer your questions: 1. Both of them implemented on the same antenna or not ? we have separated dual antenna one for GSM900/UMTS900 and second one handling DCS/U2100. 2. The tilt should be different between both of them indeed it's different value since it's different antennas. Here we have continuous coverage of U900 so it's for coverage issue, and on the top of this layer we have U2100 layer for capacity issue in the hot spots and high traffic areas. For the paramaters, we have defined different templates/objects for each layer of course. don't hesitate to ask me more questions to have clear idea about my case. Thanks for ure time Br, Nab
So this U900 should be treated differently, the parameter should be differ from U2100, we have to match with the objective of i mplementing this U900 (is is coverage or capacity issue) both of these issue will treated as different strategy gprastomo 2010-01-14, 08:49 PM Hi Boss, What is the value for addition window, deletion and replacement for both band ? br nabil el haddani 2010-01-14, 08:56 PM additions parameters: -for RT :addition window: 4db ; addition time 640 ms -for NRT: addition window : 2.5db, addition time 640ms (for HSDPA it's 100ms). drop parameters: -For RT: drop window :6db; addition time is 1280ms. -For NRT: drop wiondow 4db; addition time is 1280ms(for HSDPA it's 640ms). replacement parameters: for RT, NRT and HS default ones : 2db as replacement window and 100ms as replacement time
Thanks Nabil gprastomo 2010-01-14, 10:27 PM This parameter is quite normal. Do you add the Cell Individual Offset to specific neighbour ? So what we have to do is : 1. identify on which cells the SHO is taking place -> by looking to SHO per adjacencies (which neighbour is the most illogical SHO event) 2. anlysing the pillot pollution area -> from drivetest 3. analysing the cells which has more than 2 average active set size-> from the counter br nabil el haddani 2010-01-14, 11:46 PM For the EcNo offset, how t o choose these specific nighbours to apply an offset on it? by looking to SHO per adjacencies !!? arameter is quite normal. Do you add the Cell Individual Offset to specific neighbour ? So what we have to do is : 1. identify on which cells the SHO is taking place -> by looking to SHO per adjacencies (which neighbour is the most illogical SHO event) 2. anlysing the pillot pollution area -> from drivete nabil el haddani 2010-01-14, 11:46 PM Sorry For the EcNo offset, how t o choose these specific nighbours to apply an offset on it? by looking to SHO per adjacencies !!? gprastomo 2010-01-15, 01:03 AM Hi Boss, From the SHO adjencies report, you can generate the per neighbour performance. You can select which neighbour which has illogical attempt (high attemp from the faraway). Then you can apply CIO (Cell indiividual Offset in Siemens 3G), IntraFreqNcellEcNoOffset on NSN 3G. Positif value will treat the cell as if better than the real value, negative value will act as opposite way. johnsonsem 2011-03-21, 10:45 PM Hi Boss, From the SHO adjencies report, you can generate the per neighbour performance. You can select which neighbour which has illogical attempt (high attemp from the faraway). Then you ca n apply CIO (Cell indiividual Offset in Siemens 3G), IntraFreqNcellEcNoOffset on NSN 3G. Positif value will t reat the cell as if better than the real value, negative value will act as opposite way. Good thread and learn alotz....:D fahmi 2011-04-13, 09:16 PM Hi guys,
I realised that mostly all U900 cells have SHO overhead higher than 50%; seems global problem. Anyone have an idea. Thank u guys Hi nabil, What's new for this problem, does it still persists ? if not, how did you proceed ? BR developingrhythm 2011-04-13, 10:41 PM Just a basic comment. U900 goes a long way and the cell coverage has to be controlled in order to reduce SHO OH. Then what type of vertical BW do you have in your network on U900. A higher vertical BW even with DT will increase the SHO overhead. :) riyantoyadi 2011-04-13, 11:07 PM absolutelly if u900 have more SHO than u21 because of using lower frequency range the coverage bigger than u21. 1. Clearly for rural, it's just make downtilt antenna but hardly if concentration of traffic far away from Node B 2. For Urban/Dense you try to reduce for threshold HO and sharing coverage with the neighbour base on Propagation Delay each cell to t he neighbor Note : to reduce problem U900 on urban/dense, please put antenna height of U21 higher than U900 that make sharing of coverage (possible using different antenna type) adewijaya 2011-04-14, 12:48 AM yes i think is better solution rimoucha 2011-05-10, 10:06 PM Hello, Sorry but I have a question: How to determine the SHO overhead for a cell (vendor is Huawei). Best regards, RFDude_PMA 2011-05-11, 01:12 AM Why do you think is a risky solution to reduce the CPICH? How much do you have it right now? adewijaya 2011-05-11, 01:59 AM this activity for lazy engineer to make optimization, last choice is reduce PCPICH but please do some tilt more better solution in case of signal penetration fahmi
2011-05-11, 02:11 AM this activity for lazy engineer to make optimization, last choice is reduce PCPICH but please do some tilt more better solution in case of signal penetration Yes, but downtilting may affect the G900 coverage. in such a case no soluti on but changing CPICH :rolleyes:. yafawi79 2011-05-11, 03:54 AM Hi nabil what about the SHO qual min? did u try to tune it ?
raghchau 2011-06-15, 09:01 PM In my network, soft handover overhead is very high(58%). Can anyone suggest means to improve this? auto_art 2011-06-15, 09:46 PM In my network, soft handover overhead is very high(58%). Can anyone suggest means to improve this? hi check for pilot pollution also..it not alarming if ur nw doesnt have much traffic..in new launced nw it generaly gives high values due to less traffic raghchau 2011-06-15, 10:06 PM You are right..It is newly launched network but it is i ncreasing gradually. Initially it was 32% but in further 2 months it has increased to 58%. Can you suggest some specific parameters to tune for this.. auto_art 2011-06-15, 10:11 PM You are right..It is newly launched network but it is i ncreasing gradually. Initially it was 32% but in further 2 months it has increased to 58%. Can you suggest some specific parameters to tune for this..
its not much alarming..wait for some let traffic to rise...first... there are not as parameter..noly way to reduce it to tune HO. maasricht 2011-06-15, 10:24 PM Which vendor please specify?
raghchau 2011-06-15, 11:11 PM It is for Huawei system.. adewijaya 2011-06-15, 11:38 PM In my network, soft handover overhead is very high(58%). Can anyone suggest means to improve this? normally is 30%-40% for SHO Overhead, please consider with Time Propagation Delays on that sector and Pillot Polution Pl ot review, too many SHO make system high load on signalling. dimooon11 2011-06-15, 11:40 PM 58% is quite high ratio. first eliminate all overshooting cells from your network - downtilt antenna, only after this you can think about look into parameter tuning, not before Tomas Delgado 2011-06-16, 01:58 AM Mate try this, sometimes it works sometimes not, try with the parameter SHOqualmin and change it from -24 to -20 and see what happens. hesh 2011-06-16, 03:30 AM Mate try this, sometimes it works sometimes not, try with the parameter SHOqualmin and change i t from -24 to -20 and see what happens. Although SHOqualmin is the param you can play with and some more parameters are also there li ke TRIGTIME1A ( you can increase like from 160 to 320) and FILTER COEFFICIANT can be increase (like 2 to 3)but again...this is tradeoff between SHO and Call drop...it could delay the SHO but may increase the Call drop. So better idea is go with Hard optimization(tilt,azimuth change)..and limit the overshooting servers. Hope this could help. Rodbar 2011-06-16, 05:28 AM I think it is not t he time to work with parameters. Is much better to make a physical optimization and then proceed to parameters change. Try to check electrical and mechanical ti lt and azimuths first. Regards, RB raghchau 2011-06-16, 05:48 PM As cluster & market optimizations have already been done,all the physical optimization we made. Now we are planning to run Schema cycle to further reduce pilot pollution i ssues. auto_art 2011-06-16, 06:54 PM As cluster & market optimizations have already been done,all th e physical optimization we made. Now we are planning to run Schema cycle to further reduce pilot pollution i ssues. yeaah schema is good...it surely gonna help u.
plannerguy 2011-06-21, 05:48 PM Hi
1)Pls take the SHO report cell wise and base don same do a drive test in that cluster . 2)Do physicall optimization for site. 3)if it fails go for Parametric optimization. 4)finally go for pillot power decrease(Not recommened , but if now way t hen can be executed) Regards Plannerguy mobilink999 2011-06-21, 05:55 PM I will say not to go Hesh method as this is not very fruitful. Better go for cluster drive and and then selectively reduce overlap area. It will be reflected in SHO factor. Any soft approach is bound to have some trade off.
