Active Buffer Management for Provision of VCR Functionalities

Definition

Active buffer management is used to adjust the contents of the buffer after execution of VCR functions in VoD systems.

The problem of providing VCR functions with the traditional buffering schemes is that the effects of VCR actions in the same direction are cumulative. When consecutive VCR actions in the same direction are performed, the play point will ultimately move to a boundary of the buffer. Thus, the active buffer management (ABM) scheme [1] was developed to use a buffer manager to adjust the contents of the buffer after the VCR functions such that the relative position of the play point can stay in the middle of the buffer. Figure 1shows the basic operational principle of ABM in a staggered VoD system with no VCR actions. Assuming the buffer can hold three segments. At some point, the buffer downloads segments z, z + 1, z + 2 and the play point is in segment z + 1. If there is no VCR action, after a period of time, the play point will be at the start of segment z +...