1. A network device, adapted to a machine-type-communication (MTC) network comprising local-access devices, MTC gateways and at least one MTC server, the network device comprising: a first interface, connected to at least one MTC server, configured to receive capillary network information of MTC capillary networks and MTC gateway interconnection information of the MTC gateways from the at least one MTC server, wherein the MTC network comprises the MTC capillary networks, at least one mobile network operator domain, the MTC gateways and the at least one MTC server, wherein the mobile network operator domain comprises a core network and an access network, the mobile network operator domain comprises the network device, and part of the local-access devices connected to the MTC gateways such that the MTC capillary networks are connected to the mobile network operator domain through the MTC gateways, wherein the MTC capillary networks comprise the local-access devices which are MTC local-access devices, the local-access devices are located in the MTC capillary networks, the MTC gateways are interconnected with each other, the network device is located in the mobile network operator domain, and the network device is Access Network Discovery and Selection Function, wherein the capillary network information comprises busy hours of the MTC capillary networks and inter-capillary network connection, and the MTC gateway interconnection information comprise MTC gateway interconnection topology and MTC gateway interconnection network characteristics; a storage unit is connected to the first interface, configured to store the capillary network information and the MTC gateway interconnection information; at least one processor, connected to the storage unit to access the storage unit and programmed to executed: an aggregated topology generator to combine a access network topology of access network information provided by at least one mobile network operator and a MTC gateway interconnection topology of the MTC gateway interconnection information to build an aggregated topology map related to the MTC capillary networks, wherein the access network information of the access network comprises current load situation of at least one base station of the access network; and an inter-system routing policy (ISRP) controller, to process the aggregated topology map related to MTC capillary networks, and then generate enhanced policy rules, wherein the inter-system routing policy (ISRP) controller modifies pre-configured policy rules or create new policy rules to generate the enhanced policy rules, and the enhanced policy rules includes routing tables of data flow packets from the local-access devices to the MTC server; and a second interface, connected to the interconnected MTC gateways, configured to respectively transmit the enhanced policy rules to the interconnected MTC gateways.