B  Information flows for Lawful Interception invocation of GSN Packet Data services  Word‑p. 300

B.0  General |R12|

The following figures show the information flows for the invocation of Lawful Interception for Packet Data and typical scenarios. The figures show some of the basic signalling messages of the target Packet Data communication and the events on the X2 and X3 interfaces. The dotted lines indicate signalling depending on whether CC and/or IRI information has been requested. The Gateway 3G GGSN may setup/release packet tunnels and send IRI information depending on national requirements.

The use of the Gateway 3G GGSN for interception is a national option.

B.1  Mobile Station Attach

Figure B.1 shows the interception of a basic Mobile Station Attach where the mobile (A) is the target for interception.

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Figure B.1: Interception of mobile originated Mobile Station Attachment

B.2  Mobile Initiated Mobile Station Detach  Word‑p. 301

Figure B.2 shows the interception of a Mobile Initiated Mobile Station Detach where the originating mobile (A) is the target for interception.

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Figure B.2: Interception of mobile originated Mobile Station Detachment

B.3  Network initiated Mobile Station Detach

Figure B.3 shows the interception of a network initiated (by 3G SGSN or HLR) Mobile Station Detach where the mobile (A) is the target for interception.

Figure B.3: Interception of network initiated Mobile Station Detach

B.4  Intra 3G GSN Routing Area Update  Word‑p. 302

Figure B.4 shows the interception of an Intra Routing Area Update where the mobile (A) is the target for interception. The sequence is the same for the combined RA / LA Update procedure but additional signalling is performed between the current 3G SGSN and the prior 3G SGSN before the Routing Area Update Accept message is sent to the MS.

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Figure B.4: Interception of an Intra Routing Area Update

B.5  Inter 3G GSN Routing Area Update

Figure B.5 shows the interception of an Inter Routing Area Update where the mobile (A) is the target for interception. The sequence is the same for the combined RA / LA Update procedure but additional signalling is performed between the 3G GSN, HLR and the old 3G GSN before the Routing Area Update Accept message is sent to the MS. In case of PDP context not being active less signalling is required.

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Figure B.5: Interception of an Inter Routing Area Update

B.6  PDP Context Activation  Word‑p. 303

Figure B.6 shows the interception of a PDP Context activation where the mobile (A) is the target for interception. The sequence for a network initiated PDP Context activation is analogous but is preceded by the 3G GSN sending a Request PDP Context Activation to the MS.

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Figure B.6: Interception of a PDP Context Activation

B.7  Start of interception with PDP context active

A tunnel is established to DF3 and an event is sent to DF2.

B.8  MS initiated PDP Context Deactivation  Word‑p. 304

Figure B.7 shows the interception of a MS initiated PDP Context deactivation where the mobile (A) is the target for interception.

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Figure B.7: Interception of a PDP Context Deactivation

B.9  Network initiated PDP Context Deactivation

Figure B.8 shows the interception of a Network initiated PDP Context deactivation where the mobile (A) is the target for interception. The 3G GGSN may send, (depending on national requirements) the PDP Context deactivation and release the Packet Data tunnel after the Delete PDP Context Response has been sent or received, (signalling between the 3G SGSN and the 3G GGSN is not shown here).

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Figure B.8: Interception of a Network initiated PDP Context Deactivation

B.10  SMS  Word‑p. 305

Figures B.9a and B.9b show the interception of a Mobile-terminated SMS. Figures B.10a and B.10b show the interception of a Mobile-originated SMS. In all the scenarios, the mobile subscriber (A) is the target for interception.

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Figure B.9a: MT-SMS interception after 3G SGSN receives notification of SMS delivery to MS(A)

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Figure B.9b: MT-SMS interception after 3G SGSN receives SMS from SMSC

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Figure B.10a: MO-SMS interception after 3G SGSN receives notification of SMS delivery from SMSC

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Figure B.10b: MO-SMS interception after 3G SGSN receives SMS from MS(A)

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