- This topic has 38 replies, 1 voice, and was last updated 8 years, 4 months ago by korgi.
16th December 2009 at 10:14 #60226FresherGuest
Can the mobile be ristricted for access in n/w using TA settings? Pls help16th December 2009 at 10:18 #60227AliAsgherGuest
Yes dear. TA restrictions are usually implemented on border cells alongwith other modifications to restrict network coverage.16th December 2009 at 12:41 #60228fresherGuest
Thanks Aliasgher but can u explain in detail how settings are done ,what parameters involve16th December 2009 at 15:40 #60229PixGuest
parameter in alcatel is called :
RACH TA Filter17th December 2009 at 07:41 #60230AliAsgherGuest
In Ericsson, “MAXTA” is the hard limit.
In Huawei, “Max TA”. Also there are some reserved parameters in case of BSC3200 which needs to be set and a hidden parameter for BSC6000 which should be set for proper call disconnections on high ta.
The procedure to limit a cell by TA will be to simply reduce the MAXTA. Whenever a BTS will detect a MS transmitted burst with TA limit greater than this value, it will not entertain the request.
For Ericsson, this will increase your RACH failure rate (RACCFA will be pegged). (For Huawei, it apparantly seems that this is not counted for RACH failures)
Why is the param called RACH TA Filt? Do you have seperate TA for RACH and TCH???? 🙂
Regards,17th December 2009 at 08:31 #60231BijoyGuest
I think “TALIM” is the soft limit.
Maybe the parameter Pix mentioned is for RACH only.Maybe there are other parameters for HO like TALIM in Ericsson.17th December 2009 at 08:35 #60232AliAsgherGuest
Yes TALIM is indeed the soft limit in Ericsson.
Yes may be there are separate limits, but soft limits are always less than the hard limit. So if a TA is applied to RACH then it must be applicable to calls too. Thats why I thought naming it RACH limit is somewhat strange.
I think the alcatel enthusiast Pix can explain this in detail.
Regards,17th December 2009 at 19:29 #60233PixGuest
In alcatel (WOOOOWWWW YEAH !) there is a TA filter applied on channel resquests.
If TA(chan.req) > RACH TA FILTER, the channel request is not processed
during a call : the TA cannot be used to detect a “call drop”. The only application of TA is to detect a HO. If the TA > U_TIME_ADVANCE, then a neighbour cell is chosen.
If there is no neighbour, the call is kept in the current cell. A high TA is not a reason for a call drop (at least, not in alcatel)
Soft, Hard… Whatever, in Alcatel, it’s just the truth.18th December 2009 at 04:40 #60234AliAsgherGuest
Dear “Pix the Holy Saint”,
Oh yes, Saints operate Alcatel equipment. All truth 😀
The concept of “U_TIME_ADVANCE” is what we say a soft TA limit.18th December 2009 at 06:56 #60235PixGuest
I’m not good with “concepts”, I work only with algorithms, parameters and numbers.
Your “hard” blocking is limiting the TCH & the RACH ?? Any burst could be filtered out by the MAXTA ? So someone during a call, as soon as the burst TCH is further than MAXTA, would get a Call Drop ?
That sounds very strange to me, it actualy sounds so strange that I just can’t believe you… Are you sure the MAXTA works only on the Access Bursts ? Not all the bursts ?
-pix the bursts buster18th December 2009 at 08:21 #60236AliAsgherGuest
There are two limits namely TALIM and MAXTA.
Usually we will put TALIM less than MAXTA. Assume TALIM = 10, MAXTA = 12. This means that as soon as limit 10 is reached an emergency handover will be triggered. But if there are no servers etc and the call continues upto 12 TA, it will be dropped.
MAXTA is also the limit used to filter RACH requests and will fail a request if its TA is greater.
It will be a pity if there is no such hard limit for TCH TA call drop in Alcatel. Even Huawei has got one 🙂 But perhaps when optimizers look into starry night for solutions then this happens. 🙂 🙂 🙂
Regards,18th December 2009 at 08:55 #60237fresherGuest
Hi Aliasgher,is parameter Talim MAX TA present in huawei.if no pls let me know about huawei parameter.u replied( hidden parameter for BSC6000 which should be set for proper call disconnections on high ta.) which r those hidden parameter .can u help me to know18th December 2009 at 09:11 #60238AliAsgherGuest
I have currently got the knowledge about BSC3200 where Reserved Parameter no. 5 should be modified to 65503. I know for a fact that there is something similar for BSC6000 too, but unfortunately I dont have the exact parameter.
Maybe a Huawei expert can help us here.
P.S. Bijoy please if your can shed some light on this.
Regards,18th December 2009 at 11:27 #60239BijoyGuest
In Huawei,there are many access paramters based on TA.
1.MAX TA—Similar to MAX TA of ericsson
2.TA threshold.—-similar to TALIM in Ericsson.
But there is another parameter “TA emergency HO threshold” in case of concentric cells.
TA emergency HO threshold should be > TA threshold.
There are various other access parameters in Huawei based on TA.
I didn’t came across any reserved parameter for BSC6000.However,i was unfortunate as i didnt worked on BSC3200(i think its the newest version)
Bijoy18th December 2009 at 11:45 #60240AliAsgherGuest
Here lies a problem.
In Huawei Max TA is not similar to Ericsson due to the fact that in Ericsson a call will be disconnected if its TA > MAXTA. But in Huawei an on-going call will not be terminated. (Unless it is BSC32 with Reserved Parameter 5 = 65503).
To make calls drop due to Max TA in BSC6000, there is another parameter which I have not got the exact documentation.
BSC32 was the previous (old) version.