Method and device for controlling receiver buffer fullness level in multimedia streaming

An adaptive control system for use in a multimedia streaming system, the streaming system comprising at least a streaming client adapted for receiving a sequence of packets from a streaming server through a communication link, said control system comprising:

• in the client:
• a module configured to convey to the server through the communication link a message including information indicative of scheduled playout time of a selected one of the packets in the sequence to be played out, the selected one of the packets having a scheduled playout time, wherein the client comprises a receiver buffer for storing at least part of the sequence of packets;
• and
• in the server:
• a further module configured to compute a fullness level in the receiver buffer at least partly based on the information in the message so as to allow the server to adjust transmission characteristic in the server at least partly based on the fullness level wherein the fullness level is computed based on a sequence number of the selected packet, a time difference between the scheduled playout time of the selected packet and a current time, and the sequence number of a last packet in the sequence to be played out.

An apparatus comprising:

• a receiver buffer configured to store at least a portion of a sequence of packets to be played out received from a server through a communication link;
• and
• a module configured
• to select one of the packets from stored portion of the sequence of packets in the receiver buffer at a time instant, the selected one of the packets in the sequence having a scheduled playout time;
• and
• to convey to the server through the communication link a message including information indicative of scheduled playout time of the selected one of the packets, wherein the server is configured to compute a fullness level in the receiver buffer at least partly based on the information in the message, and wherein the fullness level is computed based on a sequence number of the selected packet, a time difference between the scheduled playout time of the selected packet and a current time, and the sequence number of a last packet in the sequence to be played out.