A target-delay-driven packet scheduling scheme for real-time interactive applications

Real-time interactive applications have become widespread exemplified by distance learning, online gaming, and voice/video conferencing. These applications have the most stringent packet delay requirement. If such packets arrive late to the recipients, exceeding the maximum tolerable delay, they will become obsolete and be dropped. In this paper, we propose to compute and use the difference, called the deadline, between the application dependent maximum delay requirement and the accumulated delay the packets experienced to guide the packet schedulers in selecting which packets to transmit next. The objective of this paper is to minimize the number of packets that exceed the maximum tolerable delay to their receivers. The resulting method is called the target-delay-driven scheduling in which the priority of a packet increases as its deadline decreases when traversing the network. Analysis and simulations show that the target-delay-driven scheduling has a significant delay performance improvement over the method without using the deadline in scheduling packets.