Call-handling for an off-premises, telecommunications terminal with an installed subscriber identity module
View Patent ↗An apparatus and method are disclosed that enable an organization's enterprise-wide network to accommodate roaming wireless terminals that are affiliated with the local enterprise networks within the enterprise-wide network. In particular, the illustrative-embodiment system is capable of handling a wireless terminal such as a cellular telephone that is able to use different subscriber identity module cards, or “SIM” cards, in different geographic regions or service-provider networks. A mobility client that is part of the wireless terminal registers when it detects that a new SIM card has been installed at the wireless terminal, whereby the client provides the subscriber-specific information that the wireless terminal reads from the SIM card. The mobility client identifies itself to the server by a user identifier, such as the station extension with which the terminal is affiliated back at the home local enterprise network. Upon successful registration, the client receives an access number that is suitable for its current location.
1. A method for notifying an enterprise-wide network that one or more parameter values have changed at a wireless terminal operating within the enterprise-wide network, the method comprising:
receiving, at a client portion of the wireless terminal, subscriber-specific information from a removable subscriber information module, the receiving being based on the subscriber information module having been installed at the wireless terminal, and the subscriber-specific information comprising values of a mobile carrier code, a mobile network code, and a mobile subscriber identification number;
detecting that at least one of the values of the mobile carrier code, mobile network code, and mobile subscriber identification number has changed with respect to any previous value stored thereof at the client portion;
transmitting, from the wireless terminal to a coordinating data-processing system within the enterprise-wide network, a registration message that comprises a user identifier and the subscriber-specific information, the user identifier i) being known to the client portion and ii) being unique within the address space of the enterprise-wide network; and
receiving an access number from the coordinating data-processing system in response to the transmission of the registration message, the access number being based on the subscriber-specific information.
2. The method of claim 1 further comprising:
detecting that a called number is being dialed at the wireless terminal; and
originating a call from the wireless terminal to the access number, based on the detection.
3. The method of claim 2 further comprising:
transmitting in-band, from the wireless terminal, one or more digits of the called number after the originated call to the access number has been completed.
4. The method of claim 1 wherein the user identifier comprises a station extension that has been previously made available to the wireless terminal, and wherein the station extension is based on an enterprise-wide numbering plan for the enterprise-wide network.
5. The method of claim 1 wherein the subscriber-specific information comprises an international mobile subscriber identifier.
6. The method of claim 1 wherein the user identifier is unknown to the subscriber information module.
7. A wireless terminal comprising:
a card reader for receiving subscriber-specific information from a subscriber information module when the module is inserted at the wireless terminal, the subscriber-specific information comprising values of a mobile carrier code, a mobile network code, and a mobile subscriber identification number;
a processor that is electrically connected to the card reader, the processor being able to detect that at least one of the values of the mobile carrier code, mobile network code, and mobile subscriber identification number has changed with respect to any previous value stored thereof at the wireless terminal;
a memory for storing a user identifier that has been made available from a source other than the subscriber information module;
a transmitter for transmitting, from the wireless terminal to a coordinating data-processing system within an enterprise-specific network, a registration message that comprises the user identifier and the subscriber-specific information, the user identifier being unique within the address space of the enterprise-wide network; and
a receiver for receiving an access number from the coordinating data-processing system in response to the wireless terminal having transmitted the registration message, the access number being based on the subscriber-specific information.
8. The wireless terminal of claim 7 further comprising a user interface for accepting dialed digits that correspond to a called number that is being dialed;
wherein the wireless terminal originates a call to the access number when the dialed digits are accepted.
9. The wireless terminal of claim 8 wherein the transmitter transmits in-band one or more digits of the called number after originating the call to the access number.
10. The wireless terminal of claim 7 wherein the user identifier comprises a station extension that has been previously made available to the wireless terminal, and wherein the station extension is based on an enterprise-wide numbering plan for the enterprise-wide network.
11. The wireless terminal of claim 7 wherein the subscriber-specific information comprises an international mobile subscriber identifier.