GSM Location Update

GSM LOCATION UPDATE MS

NEW VLR

HLR

Location Update request Send Authentication Information

Triplets (RAND, SERS, Kc)

Update location request

Insert Subscriber Data

Insert Subscriber Data Ack Cancel Location

Cancel Location Ack

Update location request Ack Update location request Ack

OLD VLR

Description of GSM LU: •

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Mobile Set containing the IMSI ( E.212 - International Mobile Subscriber Identity) Identity) of the subscriber and send it to New VLR. New VLR will perform the IMSI analysis and send the SAI (Send Authentication Information) to HLR. SAI message Containing MGT (E.214 - Mobile Global Title) which will go on Numbering Plan -7. HLR will send the triplets [Chipping Key (Kc), Signed Response (SERS), Random Value (RAND) ] to New VLR. New VLR will verify the triplets with MS generated triplets. After After verification new VLR will send the update location request request to HLR. Update location message will go on NP =7.

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HLR will send the ISD (Insert Subscriber Data) to new VLR.

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New VLR will send the ISD acknowledgement to HLR.

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HLR will send the cancel location request to old VLR.

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Old VLR will send the cancel location acknowledgement to HLR.

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HLR will send the Location Update acknowledgement to New VLR.

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New VLR will send the Location Update acknowledgement to MS and MS will latched on to new VLR.

GPRS LOCATION UPDATE MS

SGSN

HLR / AUC

GPRS Attach Request Send Authentication Information

Triplets ( Kc, RAND, SERS)

Update Location request

Insert Subscriber Data

Insert Subscriber Data Acknowledgement

Update Location Acknowledgement

GPRS Attach Request Complete

Description Of GPRS LU •

MS sends the GPRS attach message to SGSN.

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SGSN( Service GPRS Support Node) will send the SAI to HLR.

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HLR will send the Triplets ( Kc, SERS, RAND) to SGSN.

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SGSN will verify the triplets with the MS generated triplets.

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SGSN will send the Update Location Request to HLR.

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HLR will send the ISD to SGSN.

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SGSN will send the ISD acknowledgement to HLR.

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HLR will send the Update Location Acknowledgement to SGSN.

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SGSN will send the GPRS attach response to MS.

SMS CALL FLOW

MS1

MSC1 + VLR 

MS2

MSC2 + VLR 

SMSgwy + SMSC

HLR 

Submit SM Forward MO SM  Ack   Ack  Send routing info Routing info Forward MT SM Deliver SM  Ack   Ack  Delivery acknowledgement

Description Of SMS Flow •

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MS-1 will send the submit SM to VLR -1.  VLR -1 will send the forward MO SM message to SMSC ( Short Message Service Center). SMSC will send the acknowledgment to VLR -1.  VLR -1 will send the acknowledgement to MS -1.

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SMSC will send the SRI (Send routing Info) to HLR.

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HLR will send the SRI acknowledgement to SMSC.

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SMSC will send the Forward MT SM message to VLR -2.

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 VLR -2 will send the deliver SM message message to MS -2.

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MS -2 will send the acknowledgement to VLR-2.

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 VLR -2 will send the acknowledgement to SMSC.

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SMSC will send the delivery acknowledgement to MS -1.

MOBILE ORIGINATED CALL