Transmission of Video Streams with Constant Bandwidth Allocation

Encoded video streams present numerous problems in bandwidth allocation, multiplexing and admission control as a result of their Variable Bit Rate (VBR) characteristics. In particular, as video signals show a large range of variability, peak rate allocation results in very low bandwidth utilization. However, other allocation schemes tend to cause cell loss, delay and delay jitter, which make it difficult to guarantee quality of service (QoS). It is therefore necessary to develop a scheme that has no cell loss while guaranteeing QoS and achieving high bandwidth utilization at the same time. In this article, we propose a new scheme to accomplish this, which employs a 2-phase smoothing technique before transmitting VBR signal to produce an on-off signal with fixed bandwidth. Hence, it is possible to allocate a constant bandwidth for each stream, which results in high bandwidth utilization and a guaranteed deterministic QoS.