In order to improve the quality of multimedia applications two different solution can be considered. The first possibility is to adapt the multimedia data transmission to the current channel characteristics. The second solution is based on techniques that can change the network characteristics, so making the video streaming conditions more favorable. In this work both solutions are analyzed and new techniques are proposed. If the network characteristics can not be changed, the streaming application must adapt itself the actual link conditions to improve the video quality. In this book I introduce different adaptive retransmission decision algorithms, based on network load, delay and packet importance. Today's mobile devices are equipped with multiple interfaces to make the connection possible to different type of networks. In order to efficiently utilize the interface capabilities, multi?path multimedia streaming can be used. I have proposed a multi?path streaming method that chooses a set of paths maximizing the overall quality at the client. The introduced new algorithm, method and solutions can be utilized in the networks improving user satisfaction.