Section: 6.4.9.1 Security procedures applied
Content: The security mode procedure shall be applied as part of emergency call establishment, or PS connection establishment for an emergency session, as defined in TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  [35]. Thus, integrity protection (and optionally ciphering) shall be applied as for a non-emergency call or non-emergency related PS connection. If authentication of the (U)SIM fails for any reason, the emergency call or PS connection establishment for emergency session shall proceed as in 6.4.9.2 d) below. Once the call, or PS connection, is in progress with integrity protection (and optionally ciphering) applied, failure of integrity checking or ciphering is an unusual circumstance and must be treated in the same manner as other equipment failures, that is, the call, or emergency related PS connection, will terminate.