An efficient communication scheme for media on-demand services with hard QoS guarantees

The critical issue of multimedia communications is to provide quality of service (QoS) guarantees while system resources are efficiently used. The system utilization is usually low when hard QoS guarantees are required, due to 'burstiness' of multimedia traffic. We propose a scheme that provides hard QoS guarantees for media on-demand applications while fully utilizing system resources. The basic idea of the scheme is to convert variable bit-rate streams into constant bit-rate streams for transmission. The constant bit-rate is equal to the average bit-rate of the stream. This arrangement not only fully utilizes the system resources, but also simplifies the server and network design. The scheme requires extra buffering at the receiver (client). We show how to determine the buffering delay and end-to-end delay. Our experimental results show that using our scheme, the end-to-end delay is acceptable to most media on-demand applications, and in the case of heavily loaded multi-hop networks, may be lower than that experienced when no traffic smoothing is carried out. (C) 1998 Academic Press Limited.