Method and apparatus for transmitting data packets

摘要

The invention relates to a method and apparatus for transmitting data packets over a channel wherein the data packets have compressed headers. After compressing a header using a context, a number of consecutive update packets are transmitted, each containing data indicating said context. According to the invention, the channel quality is determined and the number of update packets is set accordingly. The channel quality may be determined by measuring the block error rate or the signal-to-noise ratio. Alternatively, the channel quality may be estimated by evaluating whether a NACK message has been received. The total number of update and non-update packets transmitted during a context update phase may be set according to the Round Trip Time. The number of non-update packets may further be determined based on codec properties. The invention may advantageously be used over unreliable, e.g. wireless, channels.