A mobile communication system comprising: a first network node; a second network node; and a dedicated network node comprised in a dedicated network, wherein the first network node includes a subscriber information acquisition unit configured to acquire subscriber information on user equipment from a subscriber server based on an attachment request from the user equipment forwarded by the second network node, the subscriber information including availability for the user equipment to use the dedicated network, and a selection instruction transmission unit configured to send the second network node a selection instruction to select the dedicated network based on the subscriber information acquired by the subscriber information acquisition unit, and the second network node includes a selection instruction reception unit configured to receive the selection instruction from the first network node, and a network selection control unit configured to determine the dedicated network node comprised in the dedicated network based on the selection instruction received by the selection instruction reception unit, and to transmit the attachment request from the user equipment to the determined dedicated network node, characterized in that the dedicated network node includes: a handover processing unit configured, when the dedicated network node receives a handover request for the user equipment from the second network node and if the user equipment is permitted to use the dedicated network, to determine a different dedicated network node comprised in the dedicated network and linked with a handover target of the user equipment, and to forward the handover request to the determined different dedicated network node, and a change information acquisition unit configured to acquire from the subscriber server change information indicating a change in availability for the user equipment to use the dedicated network. a first network node; a second network node; and a dedicated network node comprised in a dedicated network, wherein the first network node includes a subscriber information acquisition unit configured to acquire subscriber information on user equipment from a subscriber server based on an attachment request from the user equipment forwarded by the second network node, the subscriber information including availability for the user equipment to use the dedicated network, and a selection instruction transmission unit configured to send the second network node a selection instruction to select the dedicated network based on the subscriber information acquired by the subscriber information acquisition unit, and the second network node includes a selection instruction reception unit configured to receive the selection instruction from the first network node, and a network selection control unit configured to determine the dedicated network node comprised in the dedicated network based on the selection instruction received by the selection instruction reception unit, and to transmit the attachment request from the user a selection instruction reception unit configured to receive the selection instruction from the first network node, and a network selection control unit configured to determine the dedicated network node comprised in the dedicated network based on the selection instruction received by the selection instruction reception unit, and to transmit the attachment request from the user equipment to the determined dedicated network node, characterized in that the dedicated network node includes: a handover processing unit configured, when the dedicated network node receives a handover request for the user equipment from the second network node and if the user equipment is permitted to use the dedicated network, to determine a different dedicated network node comprised in the dedicated network and linked with a handover target of the user equipment, and to forward the handover request to the determined different dedicated network node, and a change information acquisition unit configured to acquire from the subscriber server change information indicating a change in availability for the user equipment to use the dedicated network. a handover processing unit configured, when the dedicated network node receives a handover request for the user equipment from the second network node and if the user equipment is permitted to use the dedicated network, to determine a different dedicated network node comprised in the dedicated network and linked with a handover target of the user equipment, and to forward the handover request to the determined different dedicated network node, and a change information acquisition unit configured to acquire from the subscriber server change information indicating a change in availability for the user equipment to use the dedicated network.