A method for controlling a digital television, DTV, located inside an independent room among a plurality of rooms in a hotel wherein the DTV includes an access point, AP, card, the method comprising: receiving display type information from a compact wireless device located within the independent room, wherein the display type information is type information of data capable of being processed by the compact wireless device; transmitting the received display type information to a hotel management server; receiving general additional information and additional information dependent on the display type information from the hotel management server; controlling the general additional information to be displayed on the DTV, and transmitting the additional information dependent on the display type information to the compact wireless device, wherein the AP card includes: i) a service set identifier, SSID, configured in a form of a predetermined unique value that is a combination of a unique number and a name of a user staying in the hotel room number, and ii) a Wired Equivalent Privacy, WEP, key configured in the form of a predetermined unique value that is a combination of the name of the user staying in the hotel room number and a card number; receiving emergency alert information and independent room identification, ID, information from the hotel management server; comparing independent room ID information pre-stored in the DTV with the received independent room ID information; parsing the emergency alert information, if the pre-stored independent room ID information is identical to the received independent room ID information; and switching an operation mode of the DTV from a power-off mode to a wake mode on the basis of the parsed emergency alert information, and displaying the emergency alert message. receiving display type information from a compact wireless device located within the independent room, wherein the display type information is type information of data capable of being processed by the compact wireless device; transmitting the received display type information to a hotel management server; receiving general additional information and additional information dependent on the display type information from the hotel management server; controlling the general additional information to be displayed on the DTV, and transmitting the additional information dependent on the display type information to the compact wireless device, wherein the AP card includes: i) a service set identifier, SSID, configured in a form of a predetermined unique value that is a combination of a unique number and a name of a user staying in the hotel room number, and ii) a Wired Equivalent Privacy, WEP, key configured in the form of a predetermined unique value that is a combination of the name of the user staying in the hotel room number and a card number; i) a service set identifier, SSID, configured in a form of a predetermined unique value that is a combination of a unique number and a name of a user staying in the hotel room number, and ii) a Wired Equivalent Privacy, WEP, key configured in the form of a predetermined unique value that is a combination of the name of the user staying in the hotel room number and a card number; receiving emergency alert information and independent room identification, ID, information from the hotel management server; comparing independent room ID information pre-stored in the DTV with the received independent room ID information; parsing the emergency alert information, if the pre-stored independent room ID information is identical to the received independent room ID information; and switching an operation mode of the DTV from a power-off mode to a wake mode on the basis of the parsed emergency alert information, and displaying the emergency alert message.