To simultaneously support guaranteed real-time services and best-effort service, a Priority-based Scheduling Architecture (PSA) designed for high-speed switches is proposed. PSA divides packet scheduling into high-priority phase and low-priority phase. In the high-priority phase, an improved sorted-priority algorithm is presented. It introduces a new constraint into the scheduling discipline to overcome bandwidth preemption. Meanwhile, the virtual time function with a control factor α is employed. Both computer simulation results and theoretic analysis show that the PSA mechanism has excellent performance in terms of the implementation complexity, fairness and delay properties.

This paper introduces the design procedure of the contrived network TV broadcasting transcoder/encoder system, especially develops a new variable bit-rate (VBR) coding bit allocation strategy with a constraint channel bandwidth and consistent picture quality for multiple parallel video sequences broadcasting, which accommodates the complicated video sources with different frame rates and GOP structures, and combines the buffer control and the optimized macroblock (MB) coding mode selection. The proposed strategy absorbs several reasonable metrics in a hierarchical structure, and provides flexibility and promotion for resource allocation in multi-access scenario. Experimental results demonstrate the effect of the proposed scheme.