| 摘要 |
<p>Information providers act as sources of information consisting of a plurality of variable length messages and issue control packets, enabling/disabling packets and data packets. Each data receiver has a unique address as a permanent attribute. The enabling/disabling packets selectively enable or disable a specific data receiver or a specific group of data receivers. Therefore to avoid that the loss of the enabling/disabling packet leads to the loss of the corresponding whole set of packets, each data receiver stores packets for later use in the re-establishment of the entire set of transmission packets. However, only data packets provided by any FRIEND information provider (i.e. information provider from which the data receiver is authorized to receive information on a selective basis) are managed by the data receiver. Then when, during a re-transmission, an enabling/disabling packet related to the information stored into the data receiver is received, such information is immediately made available to the user of the data receiver, without waiting for its complete re-transmission.</p> |
