Enrichment of speech calls by live video

Abstract

This contribution addresses the case when live packet-switched video is used to enrich circuit-switched speech calls in mobile telephony. Circuit-switched and packet-switched transmissions generally operate on completely different transmission paths resulting in different QoS in terms of delay and loss rates. In this case, video and audio data recorded at the same time are not multiplexed together and might arrive at completely different time instances at the receiver. This is a major challenge for the receiver and the service as lip synchronicity between the voice and the video can generally not be expected. Our presented method solves the synchronization problem purely by the use of signal processing, i.e. no inclusion of time stamps is needed. The method is simple to implement and it is able to handle signal disturbances over the link.