ABSTRACT
The text A/B flag is an important part of proper radiotext transmission. When the receiver detects a change in the A/B flag state, the radiotext receiver buffer will be cleared, preventing the possibility of a mixture of old and new text messages being displayed on the receiver. Depending upon the exact implementation of the radiotext feature on the receiver, it may still be possible that an incomplete message is displayed, but by properly using the A/B flag, mixed text messages can be prevented. The exact character location can be determined for each group transmission. Some general guidelines for radiotext transmission are: those are keep the data in line with the audio program content; this provides the maximum usefulness to the listener, remember that the user must access the feature; if it is changed too rapidly, then many messages will be overlooked and reception conditions vary widely; repeat the text data for no less than 30 seconds to ensure proper reception.
