TRANSMISSION SYSTEM

摘要

The transmission system according to the invention can be used for reliably multicasting a group of data packets from a primary station (2) via a network (4), such as the Internet, to a plurality of secondary stations (6). The primary station (2) collects feedback information, which is related to a state of reception (Li) of the group of data packets, from the secondary stations (6). In order to prevent an implosion of feedback information messages from congesting the network (4) the primary station (2) repeatedly transmits feedback requests, which comprise a reply probability value (p) and the worst state of reception (Lthresh) reported to the primary station (2) thus far, to the secondary stations (6).The secondary stations (6) transmit the feedback information to the primary station (2) in dependence on the reply probability value (p) and only when the state of reception (Li) is worse than the worst state of reception reported thus far (Lthresh). The reply probability value (p) and the worst state of reception reported thus far (Lthresh) are adapted by the primary station (2) in dependence on the feedback information received so that a maximum number of feedback information messages are collected from the secondary stations (6) without congesting the network (4). If the state of reception (Li) comprises the number of data packets erroneously received (Li) by the secondary stations (6), the primary station (2) can transmit correction information based on this number of erroneously received data packets (Li) and the group of data packets transmitted to the secondary stations (6) so that the secondary stations (6) can effectively correct the erroneously received data packets with the correction information.