Discrete-time analysis of packet data discarding in high speed multimedia networks

Packet discarding policies have been shown to significantly enhance the goodput of the system in high speed networks. In this paper, we develop a discrete time queueing model that combines two major discarding policies - the Partial Message Discard (PMD) and the Early Message Discard (EMD) policy. The PMD policy discards any subsequent packets that belong to a message that has lost a packet due to buffer overflow. The EMD policy protects against PMD by allowing the packets of a new message into the system only when the queue length is below a particular threshold. Packets can also be corrupted by the wireless medium which causes them to be discarded from the system. We represent packet data stream generation in high speed data networks by using the discrete Platoon Arrival Process (PAP), for capturing the correlation of intervals between packet arrivals. Using this model, we are able to obtain the probabilities of a successful message transmission and the Goodput of the system. The details of our model will be given for the case of a single source arrival. We briefly describe and present our results for the case of two arrival sources. The model has applications in streaming multimedia.