- This topic has 35 replies, 1 voice, and was last updated 4 years, 11 months ago by Sud.
23rd July 2009 at 07:06 #58109ArpanGuest
what are the radio parameters that needs to be set while enabling “directed retry”?
Also, can anybody explain the same specifically for ZTE System.
Arpan23rd July 2009 at 08:03 #58110AbdelGuest
co-incidence, i was just right now configuring directed retry on a ZTE BSS to relieve the congestion. What version of ZTE BSS are you using? If the version is 2.95 or later then you can activate it through the radio resource management interface. Right click the cell parameters and go to Service Process Additional Params and check the parameter drind(directed retry indication). From the performance i can see that it is working although SDCCH handover is disabled.23rd July 2009 at 08:22 #58111ArpanGuest
for directed retry there is no need to enable SDCCH handover cuz SCCH HANDOVER IS from SDCCH To another SDCCH while directed retry is SDCCH to TCH.23rd July 2009 at 09:11 #58112AbdelGuest
Yes ur right i forgot sdcch HO is sdcch to sdcch while dr is sddch to tch.24th July 2009 at 17:53 #58113ArpanGuest
We are using 2.95 (V2) and iBSC version. “Enable Directed retry Indication” parameter is jst for enabling/disabling. Is there any other parameters to defining thresholds or criteria to decide when/where to handover????
Arpan25th July 2009 at 06:56 #58114AbdelGuest
Hi Arpan ,
wow the IBSC is the one that has the IP interface you can connect ur BTS trhough the internet, it is one of the latest ZTE BSCs, well I am using the 2.95 Version but the hardeware is the old BSC V2 with has TIC cards as the E1 interface I assume the OMM interface is the same, I activated the DR and added the DR indices in my performance to see how well it is working and so for it is so succesful it is working on all the sites with a congestion. I just put the tick over the checkbox on all my sites nothing else.25th July 2009 at 07:48 #58115AbdelGuest
Als the queueing feature enables the subscribers to put in a queue for a few miliseconds until a TCH is available it is also used to relief congestion. Do you use this feature too? do u know whether this feature is recommended or, the default value in ZTE is no , i was wondering the effect of this feature it will ofcourse increase the setup time but the good thing is it reduce the congestion ratio.25th July 2009 at 13:57 #58116Fresh OptGuest
What is difference between Directed Retry and Forced Directed Retry in Alcatel.
Thanks, waiting for your reply.25th July 2009 at 14:13 #58117AbdelGuest
In ZTE BSC I didn’t see the forced directed retry, so i think this feature is not available in zte bsc, but we have forced Handover.
I know Directed retry can be either from MS to BSC(MOC)or BSC to MS(MTC), but what about Queueing is it MOC, MTC OR BOTH??
anybody knows how the queueing works, i read is it a good parameter for congestion relieft but i can not find additional details.25th July 2009 at 16:30 #58118PanGuest
Dear, Abdel! the Queuing works for MOC and for MTC both and for handover also. MSC indicates in Assighnment Request (TCH assighnment) to BSC that queueing is allowed. When there is no idle TCH on radiointerface then Ass Request shall be put in a queue and BSC shall send the Queuing Indication message to MSC and start timer. After succesful TCH allocation within period defined by timer, Assighnment Complete is transfered from BSC to MSC. If implementation dependent queuing timer expires then BSC sends Clear Request to MSC and removes Assignment Request from queue.
B.R.25th July 2009 at 18:24 #58119AbdelGuest
Dear Pan ,
I thought Queueing is activated on cell level not on MSC, may be we are talking about two different types of queueing the one u mentioned looks like a queueing that is activated on the MSC side since you said the MSC indicates to the BSC that queueing is allowed.26th July 2009 at 00:17 #58120PixGuest
Pan is right, again (booo-o-ooring)
MSC allows the queuing of a TCH request
the BSC will actually DO it.
2 activation parameters:
MSC parameter to allow TCH queue
BSC parameter to perform TCH queue
if MSC doesn’t authorize the TCH queue, then you might have a BSC parameter called “Queue Anyway”, which will trick the MSC : the TCH queue is performed anyway, but without informing the MSC 🙂 The time of queuing should be shorter than the time that the MSC is waiting for the response from BSC 🙂
TCH queue contains 2 main parameters:
– T11 (queue duration)
– BTS Q LENGTH (number of tch requests that can be queued for one cell)
Finally, you’re right about DR :
there are thresholds about rxlev and capacity in the neirhbour.
DR must be enabled in ALL the cells, along with FORCED DR. They are mandatory mechanism to share the load among cells (IMO).27th July 2009 at 09:47 #58121PanGuest
Dear, Abdel! I was the same man who pushed queue button in our MSC when queuing feature was introducing in our network:)27th July 2009 at 18:54 #58122AbdelGuest
Pan, I trust u that u did, well I am working currently on a zte msc and i checked inside out and this feature is not available so i am gonna test the queueing without msc activation and see how it works, so how about ur network did u activate the queueing at the congested cells only or to all the cells, cuz these this feature will do its work when there are no TCHs available , i see it beneficial to active on all cells.
I tried to search some info at the internet on queuing so most of them ended up in the IEEE digital library they claim they have 2 million technical articals but it requires a username which can only be logged in by IEEE memberships, they say it costs 140 bucks per year to join them. so i am interested to join it what do u think pan? and then get access to this nice gsm and UMTS articlels? from the abstract the really looked good but may be some of these articals are too technical i am not sure.27th July 2009 at 19:17 #58123PixGuest
I have access to IEEE, and it’s really good. It’s a lot of field experiments and thesis about a lot of stuff. If you see one/two articles that interest you, let me know, i can send it to you.