- This topic has 9 replies, 1 voice, and was last updated 12 years, 7 months ago by ali abbas.
6th July 2008 at 11:59 #53005jackGuest
can any body help me to explain why the ciphering is activated the SDCCH Drop reduce vise versa that I expected it must be increase .6th July 2008 at 19:38 #53006peyoGuest
i’ve no idea at this time but it’s very interesting. which bss and nss vendors are you using? which ciphering algorithms are you using (sorted by order if several used)?
When you say that it reduced sd_drop can you give figures or percentage?7th July 2008 at 05:40 #53007jackGuest
vendor is Huawei
and SDCCH drop reduce around 24%.algorith is A5/112th July 2008 at 05:02 #53008PanGuest
I am thinking that it is because when network does not provide A5/1 ciphering algorithm, then it is mandatory to insert RR_Classmark_enquiry transaction in Location_Updating procedure (In MM_LU_request there is Classmark_1 information element which contains only A5/1 support indication). Hence SDCCH load is increased.
When A5/1 ciphering algorithm is provided in your network then it is not needs for Classmark_2 information element which contains A5/2 support indication also.12th July 2008 at 06:02 #53009jackGuest
what does this message mean (RR_Classmark_enquiry transaction in Location_Updating procedure) I need more explanation .
BR15th July 2008 at 09:16 #53010PanGuest
CLASSMARK ENQUIRY message (gsm 04.008) is used in Classmark interrogation procedure (if the information initially sent by the mobile station is not sufficient for network decision (e.g. when A5/1 ciphering not active in network): network want to know A5/2 is supported in MS or not)
On receipt of the CLASSMARK ENQUIRY message the mobile station sends a CLASSMARK CHANGE message to the network on the main DCCH. This message contains the mobile station classmark 2 information element.16th July 2008 at 05:39 #53011jackGuest
Why network want to know i mobile support A5/2 if network already all ciphering algorithm is Deactive17th July 2008 at 03:21 #53012PanGuest
my assumtion was that before activation A5/1 algorithm there is A5/2 algorithm provided in your network only. But really your network does not provided any algorithm before A5/1 activation, doesn’t it?19th July 2008 at 05:42 #53013jackGuest
yes there wan no Ciphering29th August 2008 at 15:33 #53014ali abbasGuest
what is meant by Ciphering on/off.Which algorithm is used for this.