Method and program for enhanced PLMN selection in a public land mobile network

1. A method for enhanced Public Land Mobile Network (PLMN) selection in a cellular mobile network, wherein a User Equipment comprises information related to a PLMN selection mode indicating a manner of selecting between PLMNs for the User Equipment, the method comprising:

transmitting the information related to the PLMN selection mode to a Registered Public Land Mobile Network (RPLMN) of the User Equipment; and

performing an attachment of the User Equipment to an other PLMN based on the information related to the PLMN selection mode under conditions where the RPLMN and the other PLMN are both available to the User Equipment for attachment, wherein the information related to the PLMN selection mode indicates the manner of selecting between PLMNs for the User Equipment is a manual PLMN selection mode, and wherein the information related to the PLMN selection mode further comprises a Mobile Country Code (MCC) and a Mobile Network Code (MNC) corresponding to the other PLMN;

wherein the information related to the PLMN selection mode is transmitted to a radio access network of the RPLMN by:

using a Subscriber Profile Identity (SPID) concept and a single code point being defined or multiple code points being defined for the information related to the PLMN selection mode for indicating, the manual PLMN selection mode: or

using an RRC CONNECTION REQUEST COMPLETE message by indicating only in case that the manual PLMN selection mode is verified.

2. The method according to claim 1 , wherein the information related to the PLMN selection mode depends on a subscriber preference with regard to selection of which public land mobile network should serve the User Equipment, and wherein the information related to the PLMN selection mode is stored in the User Equipment.

3. The method according to claim 1 , wherein the information related to the PLMN selection mode is transmitted to the other PLMN.

4. The method according to claim 1 , wherein the information related to the PLMN selection mode is transmitted from the User Equipment to a core network of the RPLMN or to a radio access network of the RPLMN.

5. The method according to claim 1 , wherein the information related to the PLMN selection mode is transmitted to a core network of the RPLMN and the information related to the PLMN selection mode is transmitted from the core network to a radio access network of the RPLMN on transition from an idle mode of the User Equipment to a connected mode of the User Equipment.

6. A Registered Public Land Mobile Network (RPLMN) for enhanced Public. Land Mobile Network (PLMN) selection, the RPLMN being the RPLMN to a User Equipment, wherein the User Equipment comprises an information related to a PLMN selection mode indicating a manner of selecting between PLMNs for the User Equipment, the RPLMN being configured to:

receive the information related to the PLMN selection mode of the User Equipment from the User Equipment; and

facilitate attachment of the User Equipment to an other PLMN based on the information related to the PLMN selection mode under conditions where the RPLMN and the other PLMN are both available to the User Equipment for attachment, wherein the information related to the PLMN selection mode indicates the manner of selecting between PLMNs for the User Equipment is a manual PLMN selection mode, and wherein the information related to the PLMN selection mode further comprises a Mobile Country Code (MCC) and a Mobile Network Code (MNC) corresponding to the other PLMN;

wherein the information related to the PLMN selection mode is transmitted to a radio access network of the RPLMN by:

using a Subscriber Profile Identity (SPID) concept and a single code point being defined or multiple code points being defined for the information related to the PLMN selection mode for indicating the manual PLMN selection mode; or

using an RRC CONNECTION REQUEST COMPLETE message by indicating only in case that the manual PLMN selection mode is verified.

7. A non-transitory computer-readable medium of a User Equipment, the User Equipment comprising information related to a Public Land Mobile Network (PLMN) selection mode indicating a manner of selecting between PLMNs for the User Equipment, having processor-executable instructions for enhanced PLMN selection in a cellular mobile network stored thereon, the instructions, when executed by a processor, causing the following steps to be performed:

transmitting the information related to the PLMN selection mode to a Registered Public Land Mobile Network (RPLMN) of the User Equipment; and

performing an attachment of the User Equipment to an other PLMN based on the information related to the PLMN selection mode under conditions where the RPLMN and the other PLMN are both available to the User Equipment for attachment, wherein the information related to the PLMN selection mode indicates the manner of selecting between PLMNs for the User Equipment is a manual PLMN selection mode, and wherein the information related to the PLMN selection mode further comprises a Mobile Country Code (MCC) and a Mobile Network Code (MNC) corresponding to the other PLMN;

wherein the information related to the PLMN selection mode is transmitted to a radio access network of the RPLMN by:

using Subscriber Profile Identity (SPID) concept and a single code point being defined or multiple code points being defined for the information relate to the PLMN selection mode for indicating the manual PLMN selection mode: or

using an RRC CONNECTION REQUEST COMPLETE message by indicating only in case that the manual PLMN selection mode is verified.