1. A method for a broadcast receiving device to receive a broadcast, comprising: receiving a broadcast stream including audio or video; receiving triggered declarative object (TDO) metadata for a TDO, wherein the TDO metadata includes first information representing an acquisition path of the TDO being one of broadcast and internet, and second information representing an appearance frequency of a time slot that contains the TDO; downloading the TDO over the internet when the first information represents that the TDO is available for downloading over the internet; and managing a storage based on the second information, wherein the TDO metadata includes network characteristic information for a downloading scheduled TDO, wherein the downloading the TDO comprises, determining internet network connecting state and internet network speed when the network characteristic information indicates that the downloading scheduled TDO necessarily needs to use an internet network, determining current network state information including the internet network connecting state information and internet network speed information satisfies the network characteristic information, and notifying a viewer of the network characteristic information for the downloading scheduled TDO, when the current network state information does not satisfy the network characteristic information.