| 摘要 |
A method for creating variants of a DTV service, a method which is simpler than the method defined in GBS0600, and the method can handle all use-case scenarios for simulcast linking in a way almost equal to that defined in GBS0600. The method introduces switching between a mother service and a variant service, the mother service being a default service to which a receiver should tune, and the variant service being a service selected at a receiver side and linked to the mother service by a service link defining a switching relation between the mother service and the variant service. The method is defined by including switching information into the data-stream of the mother service, receiving the mother service data-stream, reading the switching information, and switching from the mother service to the variant service accordingly. The switching information can be carried in EPG data and thus utilize existing data structures. EPG data of the mother service, e.g. in the form of EIT data, can be used to carry switching data, expect for variant service events different from the mother service, where the EPG/EIT data are preferably cross-carried by the mother and variant service. Preferably, the receiver selects which one of a plurality of possible variant service to switch to, e.g. based on receiver capabilities and/or user access rights. Thus, EIT carriage efficiency for services with a large degree of sharing is high, and it offers advantages in tuning speed. Further, the method will lead to simpler and consistent receiver implementations. |
