03.333G security3GPPLawful InterceptionStage 2TS

Figure A1 shows the interception of a basic mobile originated circuit switched speech or data call where the originating mobile (A) is the target for interception. B is not necessarily also a mobile subscriber and resides on a different exchange.

Figure A1: Interception of mobile originated circuit switched calls

In figure A1 the result (answer) of the set-up of the stublines is not shown. This assumes no special action is taken in case of failure.