Virtual channel table for a broadcast protocol and method of broadcasting and receiving broadcast signals using the same

DETAILED DESCRIPTION Accordingly, the present invention is directed to a virtual channel table that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a virtual channel table for a broadcast protocol, and a method of broadcasting by using the same table, which are capable of identifying and permitting discrimination between active and inactive channels from the channels received by a broadcast receiver.
Another object of the invention is to provide a virtual channel table for a broadcast protocol, and a method of broadcasting by using the same table, which are capable of rapidly displaying only the channels being broadcast at a current time.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.
The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
According to an aspect of the present invention, there is provided a virtual channel table for a broadcast protocol which comprises identification information capable of identifying and permitting discrimination between active and inactive channels in the bit stream syntax thereof.
The identification information may be loaded on or included in at least one reserved field in the virtual channel table.
Preferably, the identification information assigns at least one or more bits of a reserved field as a flag, thereby indicating that a corresponding channel is an inactive channel.
For example, the value of the program number field "program_number" in the virtual channel table is set to "0," thereby indicating that the corresponding channel is the inactive channel.
The identification information sets the value of the number elements field "number_elements" of the service position descriptor field "service_location_descriptor" in the virtual channel table to "0," thereby indicating that the corresponding channel is an inactive channel