GSM Location Update Procedure - EventHelix.com
GSM Location Update Procedure - EventHelix.com
GSM Location Update Procedure - EventHelix.com
- No tags were found...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Location</strong> <strong>Update</strong> (<strong>GSM</strong> <strong>Location</strong> <strong>Update</strong> <strong>Procedure</strong>)Subscribers<strong>GSM</strong> Network<strong>GSM</strong> Mobiles Maryland <strong>Location</strong> Area Maryland<strong>GSM</strong>Equipment<strong>GSM</strong>DatabasesOther <strong>GSM</strong> <strong>GSM</strong> Rockville Bethesda MarylandMobile Mobile Cell Cell MSC VLRVirginia<strong>Location</strong>AreaHLR Vienna Cell VirginiaBSCMAP/G SEND PARAMETERSMaryland TMSIVirginia <strong>GSM</strong>EquipmentMAP/G SEND PARAMETERS RESULT<strong>Update</strong> the currentlyserving MSC address tothe new MSCMAP/D CANCEL LOCATIONDelete the record for theold subscriber.MAP/D CANCEL LOCATION RESULTIMSIMAP/D UPDATE LOCATIONVirginiaMSC VLRCompare the oldlocation area withthe new locationareaMAP/D INSERT SUBSCRIBER DATAKc, RAND, SRESCreate a record forthe new visitingsubscriber andstore the (Kc,RAND, SRES)tuplesMAP/D INSERT SUBSCRIBER DATA RESULTEventStudio System Designer 612-Jun-14 22:48 (Page 3)The MSC finds that the oldlocation area was handled by adifferent MSC. Thus the MSCneeds to contact the HLR.The Virginia MSC VLR does notfind the TMSI in its database. Ituses the old <strong>Location</strong> AreaIndicator (LAI) to obtain theaddress of the old MSC VLR. Arequest is sent to the old MSCVLR, requesting the IMSI(International Mobile SubscriberIdentity) of the subscriber.The Maryland MSC VLRprovides the IMSIcorresponding to the TMSI. Notethat the IMSI could have beenobtained from the mobile. Thatis not a preferred option as the<strong>Location</strong> Updating Request issent in clear so it could be usedto determine the associationbetween the IMSI and TMSI.The MSC sends an updatelocation message to the HLR.This message is needed for tworeasons: (1) The HLR needs toupdate its record to point to thenew MSC when queried forlocation. (2) The new MSC doesnot have information about thissubscriber.At this point, the HLR updatesits records to indicate that thesubscriber is now present in alocation area served by theVirginia MSC VLR.Pass information about the newsubscriber to the new MSC. Themessage contains the a 64-bitciphering key used as a SessionKey (Kc), a 128-bit randomchallenge (RAND) and a 32-bitSigned Response (SRES). Theseparameters will be used in theauthentication process.Subscriber information isupdated in the new MSC.The new MSC replies back.Ask the Old MSC to delete therecord for this subscriber.The old subscriber's record isdeleted. The TMSI assigned tothe mobile is also released.The Old MSC replies back to theHLR.
Change language