Patent ID: 9232445
Filing Date: 2016-01-05
CPC Classification: H04W

Claim Text:
1. A method to manage a Circuit Switch Inter Radio Access Technology (CS IRAT) handover of a user equipment (UE) from a 2G/3G network to a Long Term Evolution (LTE) network wherein at least two different routing paths corresponding to at least two different handover technologies are possible for transferring handover messages from a Base Station Controller/Radio Network Controller (BSC/RNC) node of said 2G/3G network to a target eNodeB of said LTE network, said method comprising: transmitting, by the UE, CS IRAT handover from 2G/3G to LTE capabilities to the BSC/RNC node; selecting, by the BSC/RNC node, a routing paths among said different routing paths based on the UE capabilities for CS IRAT handover from 2G/3G to LTE and transmitting to a Mobile Switching Center/Visitor Location Register (MSC/VLR) node of said 2G/3G network a message comprising information indicative of the selected path corresponding to the selected CS handover technology; and transferring, by the MSC/VLR node, said handover message to said target eNodeB through a Mobility Management Entity (MME) node or through an Interworking Function (IWF) node depending on said information of the selected path corresponding to the selected CS handover technology; wherein said information indicative of the selected path is a target cell identifier and when the RNC/BSC node detects the need to handover the UE to the LTE network for a CS call, the RNC/BSC node sends to the MSC/VLR a handover message including a target LTE cell ID (eNodeB CGI), in case SRVCC handover, or a virtual 2G/3G cell ID, in case of CSoPS handover, said IDs are pre-configured in the mapping and routing tables of BSC/RNC node, MSC/VLR node and the IWF node to allow the association of the LTE cell ID with the virtual 2G/3G cell ID.