5.2.2 A is a mobile subscriber who may benefit from OR

22.0793GPPService definitionStage 1Support of Optimal Routeing (SOR)TS

5.2.2.1 Description of the call routing

If A sets up a call to B, then the originating PLMN shall interrogate the HPLMN of the mobile subscriber B in order to know how to route the call.

If B is registered in the same country as A, then the call shall be routed directly to B as described below.

If B has activated a Call Forward to a destination located in the Home Country of B or in the country where A is registered and this leads to the invocation of Early Call Forwarding, then the call shall be routed directly from A to the forwarded-to-party.

In any other cases, the call shall be routed to the mobile subscriber B via HPLMN(B).

If the call cannot be completed, the originating PLMN shall receive an indication of the reason of the failure of the call completion.

Thereafter, if the mobile subscriber B has activated a Conditional Call Forward to a destination located in her Home Country or to a destination in the country where A is registered and this leads to the invocation of Late Call Forwarding, then the originating PLMN shall route the call directly to the forwarded-to-party.

The remaining leg of the call from the intermediate point to the ultimate destination may be optimally routed.

5.2.2.2 Call scenarios handled in OR Phase 1

In the following scenarios, the IPLMN is VPLMN-A.

1) The call from the A subscriber to the B subscriber is completed (Basic OR)

a) B is located in the same country as A

Scenario 3: BASIC OR, B in the same country as A

NOTE: Call records shown in the figure are only for information

b) B is located in her Home Country (Network usage optimization)

Scenario 4: BASIC OR, B in her home country

NOTE: Call records shown in the figure are only for information

2) The call set up by the subscriber A is being forwarded to a C party

2.1) Early Call Forward

NOTE: for the two following scenarios, the location of B is not relevant.

a) the C party is in the same country as the A subscriber, but different from HPLMN B country.

Scenario 5: Early CF, C in the same country as A

NOTE: Call records shown in the figure are only for information.

b) the C party is in the same country as HPLMN-B

Scenario 6: Early CF, C in the same country as HPLMN-B

NOTE: Call records shown in the figure are only for information

2.2) Late Call Forward

a) B and C are in the same country as A

Scenario 7: BASIC OR + OR for Late Call Forwarding, B in the same country as A, C in the same country as A

NOTE: Call records shown in the figure are only for information

b) B is in the same country as A and C is in the same country as HPLMN-B

Scenario 8: BASIC OR + OR for Late Call Forwarding, B in the same country as A, C in the same country as HPLMN-B

NOTE: Call records shown in the figure are only for information

c) B is in her home country and C is in the same country as A

Scenario 9: BASIC OR + OR for Late Call Forwarding, B in the same country as HPLMN-B, C in the same country as A

NOTE: Call records shown in the figure are only for information

d) B and C are in the country of HPLMN-B

Scenario 10: BASIC OR + OR for Late Conditional Call Forwarding, B in the same country as HPLMN-B, C in the same country as HPLMN-B

NOTE: Call records shown in the figure are only for information.