The invention claimed is:1. A method for a mobile switching node to page a terminal device in a group of terminal devices associated with a common subscriber number, the method comprising:receiving, from a mobile management node, an indication that the terminal device supports a circuit switching call function;storing the indication;receiving a request to implement the circuit switching call function in regard to a subscriber number associated with the group of terminal devices;selecting, responsive to the request, the terminal device from the group of terminal devices associated with the common subscriber number based on the indication; andsending, to the mobility management node responsive to the request, a circuit switching paging request for the terminal device.2. The method of claim 1, wherein the indication is received from the mobility management node.3. The method of claim 2, wherein the indication is received from the mobility management node using a location update request.4. The method of claim 1, wherein the indication shows that the terminal device supports only short message service, or both short message service and circuit switched fallback voice call service.5. A method for a mobility management node to page a terminal device in a group of terminal devices associated with a common subscriber number, the comprising:receive, by the mobility management node, device capability information for the terminal device;determining, by the mobility management node based on the received device capability information, that the terminal device supports a circuit switching call function;sending, to a mobile switching node responsive to the determining, an indication that the terminal device supports a circuit switching call function to enable selection of the terminal device by the mobile switching node from the group of terminal devices for a paging request associated with the circuit switching call function;receiving, from the mobility switching node following the sending, a circuit switching paging request for the terminal device; andpaging the terminal device.6. The method of claim 5, wherein the determining that the terminal device supports the circuit switching call function is based on an information element in a combined attach request or in a tracking area update request from the terminal device.7. The method of claim 5, wherein the indication is sent to the mobile switching node using a location update request.8. A mobile switching node device to page a terminal device in a group of terminal devices associated with a common subscriber, the mobile switching node comprising:processing circuitry;memory containing instructions executable by the processing circuitry whereby the mobile switching node device is operative to:receive, from a mobile management node, an indication that the terminal device supports a circuit switching call function;store the indication;receive a request to implement the circuit switching call function in regard to a subscriber number associated with the group of terminal devices;select, responsive to the request, the terminal device from the group of terminal devices associated with the common subscriber number based on the indication; andsend, to the mobility management node responsive to the request, a circuit switching paging request for the terminal device.9. The mobile switching node device of claim 8, wherein the instructions are such that the mobile switching node device is operative to receive the indication from the mobility management node.10. The mobile switching node device of claim 8, wherein the indication shows that the terminal device supports only short message service, or both short message service and circuit switched fallback voice call service.11. A mobility management node device to page a terminal device in a group of terminal devices associated with a common subscriber, the mobility management node comprising:processing circuitry;memory containing instructions executable by the processing circuitry whereby the mobility management node device is operative to:receive, by the mobility management node, device capability information for the terminal device;determine, by the mobility management node based on the received device capability information, that the terminal device supports a circuit switching call function;send, to a mobile switching node responsive to the determining, an indication that the terminal device supports a circuit switching call function to enable selection of the terminal device by the mobile switching node from the group of terminal devices for a paging request associated with the circuit switching call function;receive, from the mobility switching node following the sending, a circuit switching paging request for the terminal device; andpage the terminal device.12. The mobility management node device of claim 11, wherein the instructions are such that the mobility management node device is operative to determine whether the terminal device supports the circuit switching call function based on an information element in a combined attach request or in a tracking area update request from the terminal device.13. The mobility management node device of claim 11, wherein the instructions are such that the mobility management node device is operative to receive the indication in a location update request.14. The mobility management node device of claim 11, wherein the indication shows that the terminal device supports only short message service, or both short message service and circuit switched fallback voice call service.