Revision 64d154ce
Added by osmith about 4 years ago
docs/imsi-pseudo-spec.adoc | ||
---|---|---|
118 | 118 |
<<< |
119 | 119 |
== Required Changes |
120 | 120 |
|
121 |
[[hlr-imsi-pseudo-storage]] |
|
121 | 122 |
=== Pseudonymous IMSI Storage in the HLR |
122 | 123 |
|
123 | 124 |
The HLR must store up to two pseudonymous IMSIs (imsi_pseudo) and their related |
... | ... | |
191 | 192 |
=== Process Update_Location_HLR |
192 | 193 |
|
193 | 194 |
All IMSI Pseudonymization related changes to Process Update_Location_HLR |
194 |
(3GPP TS 29.002) are optional. All deviations from the existing specification
|
|
195 |
that are outlined in this section are expected to be enabled or disabled
|
|
196 |
entirely where IMSI pseudonymization is implemented.
|
|
195 |
(3GPP TS 29.002) are optional. Deviations from the existing specification that
|
|
196 |
are outlined in this section are expected to be enabled or disabled entirely
|
|
197 |
where IMSI pseudonymization is implemented. |
|
197 | 198 |
|
198 | 199 |
[[figure-imsi-pseudo]] |
199 | 200 |
.Process Update_Location_HLR with IMSI pseudonymization changes |
... | ... | |
206 | 207 |
MSC => HLR [label="Update Location Request"]; |
207 | 208 |
|
208 | 209 |
--- [label="If new pseudonymous IMSI was used: deallocate and cancel old pseudonymous IMSI"]; |
209 |
HLR box HLR [label="Deallocate old pseudonymous IMSI"];
|
|
210 |
HLR box HLR [label="Deallocate old pseudonymous IMSI"];
|
|
210 | 211 |
MSC <= HLR [label="Cancel Location Request"]; |
211 | 212 |
MSC => HLR [label="Cancel Location Result"]; |
212 | 213 |
---; |
213 | 214 |
|
214 | 215 |
MSC <= HLR [label="Insert Subscriber Data Request"]; |
215 | 216 |
MSC => HLR [label="Insert Subscriber Data Result"]; |
216 |
HLR box HLR [label="Start Next_Pseudo_IMSI_Timer"];
|
|
217 |
HLR box HLR [label="Start Next_Pseudo_IMSI_Timer"];
|
|
217 | 218 |
MSC <= HLR [label="Update Location Result"]; |
218 |
MSC box MSC [label="Finish Location Updating with ME"],
|
|
219 |
MSC box MSC [label="Finish Location Updating with ME"],
|
|
219 | 220 |
|
220 |
HLR box HLR [label="Wait for Next_Pseudo_IMSI_Timer expiry"];
|
|
221 |
HLR box HLR [label="Wait for Next_Pseudo_IMSI_Timer expiry"];
|
|
221 | 222 |
|||; |
222 | 223 |
...; |
223 | 224 |
|||; |
224 |
HLR box HLR [label="Next_Pseudo_IMSI_Timer expired"];
|
|
225 |
HLR box HLR [label="Next_Pseudo_IMSI_Timer expired"];
|
|
225 | 226 |
|
226 |
HLR box HLR [label="\nAllocate new pseudonymous IMSI\nif subscriber only has one allocated\n"];
|
|
227 |
HLR box HLR [label="\nAllocate new pseudonymous IMSI\nif subscriber has only one allocated\n"];
|
|
227 | 228 |
SMSC <= HLR [label="Next Pseudonymous IMSI SMS"]; |
228 | 229 |
SMSC box SMSC [label="Deliver SMS to ME"]; |
229 | 230 |
} |
230 | 231 |
---- |
231 | 232 |
|
232 | 233 |
==== Update Location Request |
234 |
|
|
233 | 235 |
When Update Location Request arrives, the HLR does not look up the subscriber |
234 | 236 |
by the IMSI, but by the pseudonymous IMSI instead. Unless the subscriber has |
235 | 237 |
two pseudonymous IMSI allocated and used the old pseudonymous IMSI in the |
... | ... | |
258 | 260 |
|
259 | 261 |
==== Insert Subscriber Data Result |
260 | 262 |
|
261 |
ISD works like before, then set Next_Pseudo_IMSI_Timer |
|
263 |
When Insert Subscriber Data Result arrives, a subscriber specific |
|
264 |
Next_Pseudo_IMSI_Timer starts. |
|
262 | 265 |
|
263 | 266 |
==== Next_Pseudo_IMSI_Timer Expires |
264 | 267 |
|
265 |
* if subscriber has only one pseudo IMSI: |
|
266 |
* abort if not enough IMSIs available |
|
267 |
* generate new pseudo IMSI as described earlier |
|
268 |
* set imsi_pseudo_i like last one + 1 |
|
269 |
* send SMS to subscriber's SIM with newer pseudo IMSI |
|
268 |
If the subscriber has only one pseudonymous IMSI allocated, and the amount of |
|
269 |
available IMSIs in the HLR is high enough, a second pseudonymous IMSI and |
|
270 |
related imsi_pseudo_i gets allocated for the subscriber (as described in |
|
271 |
<<hlr-imsi-pseudo-storage>>). |
|
272 |
|
|
273 |
If the subscriber still has only one pseudonymous IMSI, because not enough |
|
274 |
IMSIs were available in the HLR, the process is aborted here and no SMS with |
|
275 |
a next pseudonymous IMSI is sent to the subscriber. The subscriber will get a |
|
276 |
new pseudonymous IMSI during the next Location Updating Procedure, if the HLR |
|
277 |
has enough IMSIs available at that point. |
|
278 |
|
|
279 |
An SMS is sent to the SMS - Service Centre (SMS-SC) with the newer pseudonymous |
|
280 |
IMSI (higher imsi_pseudo_i, see <<hlr-imsi-pseudo-i>>) and related |
|
281 |
imsi_pseudo_i value. |
|
270 | 282 |
|
271 | 283 |
[[sms-format]] |
272 | 284 |
==== SMS Format |
Also available in: Unified diff
spec: next pseudo_imsi_timer expires