6 Normal procedures with successful outcome

22.0943GPPFollow Me service descriptionRelease 17Stage 1TS

6.1 Provision

Follow Me shall be provided after prior arrangement with the service provider. Follow Me will be provisioned for all Basic Services subscribed to and to which it is applicable.

NOTES:

– A Follow Me provision is required for the initiating subscriber and for the remote party in case the remote party corresponds to a subscriber.

– If Follow Me is provisioned for a mobile subscriber she may assume the role of an initiating subscriber and/or the role of a remote party.

– A Follow Me provisioning service provider may confine:

a.) the range of remote parties for which a FM provisioned subscriber may become initiating subscriber

b.) the range of potential initiating subscribers for a remote party.

c) the range of remote parties for which a FM provisioned subscriber may become FM service supervisor.

NOTE: (Health warning on security) The Follow Me feature is designed in such a way as to meet the security requirements of GSM-Railway operators. If the Follow Me feature is to be used by other operators – in particular if the remote party corresponds to a subscriber – operators are strongly advised to care for additional suitable security mechanisms to protect the remote party from potential harm by misuse of FM. These mechanisms are out of scope of this specification.
To support such mechanisms the possibility is foreseen to convey additional operator-specific information in the registration, interrogation and erasure procedures to the PLMN of the remote party. It should however be noted, that this is not a very secure mechanism. Operators should try to use existing security mechanisms where possible

6.2 Withdrawal

Follow Me will be withdrawn at the subscriber’s request or for administrative reasons.

6.3 Registration

Follow Me shall be registered with an appropriate control procedure by the initiating subscriber.

The initiating Subscriber registers the Follow Me feature with respect to a particular remote party.

The initiating subscriber shall provide the following information to the network:

the number of the remote party (e.g. the Basic MSISDN of a subscriber);

The initiating subscriber shall receive an indication if the FM registration request was accepted or rejected by the network.

As an operator’s option additional information (such as passwords) for registration may be required from the initiating subscriber. The registration procedure shall transport this information from the initiating subscriber to the network of the remote party. This information shall be coded as a USSD string with a length not exceeding 30 characters. The content of this information and the use of it are out of scope of this specification.

NOTE 1: The Follow Me feature may, at an instant, be registered to an initiating subscriber with respect to several remote parties. Conversely, a remote party can be registered only to one initiating subscriber at a time.

6.4 Erasure

A previous FM registration can be erased in either of the following ways:

a) The initiating subscriber can specifically erase her previous registration with an appropriate control procedure.

b) In case the remote party corresponds to a subscriber the remote party

can erase any previous registration with an appropriate control procedure.

c) The FM service supervisor can erase any previous registration to any remote party with an appropriate control procedure (forced erasure).

The subscriber who initiates the FM erase request shall be informed of the outcome of the request by the network.

For forced erasure by the FM service supervisor the initiating subscriber whose registration of Follow Me with respect to a remote party has been erased shall be informed of the successful forced erasure by the network.

As an operator’s option additional information (such as passwords) for erasure may be required from the subscriber. The registration procedure shall transport this information from the subscriber to the network of the remote party. This information shall be coded as a USSD string with a length not exceeding 30 characters. The content of this information and the use of it are out of scope of this specification.

6.5 Activation

Follow Me is activated by registration.

6.6 Deactivation

Follow Me is deactivated by erasure.

6.7 Invocation

Follow Me is automatically invoked by the network if it was previously registered. If Follow Me is registered all incoming calls to the remote party will be forwarded to the initiating subscriber by network invocation.

When Follow Me is active and operative and if the remote party is a subscriber, the ability of the remote party to originate calls is not affected.

6.8 Interrogation

An initiating subscriber (also the FM service supervisor) shall be able to interrogate the Follow Me data of any remote party, for which she is authorised to become initiating subscriber.

In case the remote party corresponds to a subscriber the remote party shall be able to interrogate her own Follow Me data stored in the network.

The network shall return the basic MSISDN of the initiating subscriber for which the remote party is registered to Follow Me.

As an operator’s option additional information (such as passwords) for interrogation may be required from the subscriber. The registration procedure shall transport this information from the subscriber to the network of the remote party. This information shall be coded as a USSD string with a length not exceeding 30 characters. The content of this information and the use of it are out of scope of this specification.