Video multiplexing with QoS constraints

Providing profitable video services is becoming one of the primary goals of many network services when delivering a large number of video streams in a single data link. Aggregated bandwidth utilization and QoS degradation are the issues that need to be considered. It is well known that Variable Bit Rate video traffic generated by Motion Picture Expert Group exhibits significant multiple-time-scale rate variability. This phenomenon causes difficulties for QoS provisioning, QoS control, and QoS management. Many research activities were concentrating on reducing the bursty nature of video traffic and increasing statistical multiplexing gain by using different buffering techniques at several transmission levels, which induces frame delays and delay variations. In this paper we propose a multiplexing technique that consists of two phases. First, we use the 'scene' property of the video traffic that exhibits a larger time scale for bit rate variation to segment the traffic. And second, we use MPEG temporal relationships to achieve multiplexing within each 'scene' segment in conjunction with the service classes requirements, so that better bandwidth utilization is achieved without sacrificing video quality. This approach is especially promising in the applications that have limited amount of resources, such as wireless network or in those that have a large amount of traffic types with different QoS requirements, such as video data servers or in situations where multicasting is not applicable. Finally, we suggest that even better statistical gain can be achieved by using the concept of differentiated services to multiplex on going traffic in a service-class fashion.