초록 ▼

An efficient transmission protocol for transmitting multimedia streams from a server to a client computer over a diverse computer network including local area networks (LANs) and wide area networks (WANs) such as the internet. The client computer includes a playout buffer, and the transmission rate

An efficient transmission protocol for transmitting multimedia streams from a server to a client computer over a diverse computer network including local area networks (LANs) and wide area networks (WANs) such as the internet. The client computer includes a playout buffer, and the transmission rate is dynamically matched to the available bandwidth capacity of the network connection between the server and the client computer. If a playtime of the playout buffer, which is one measure of the number of data packets currently in the playout buffer, drops below a dynamically computed Decrease_Bandwidth (DEC_BW) threshold, then the transmission rate is decreased by sending a DEC_BW message to the server. Conversely, if the number of packets remaining in the playout buffer rises above a dynamically computed Upper Increase_Bandwidth (INC_BW) threshold and does not drop below a Lower INC_BW threshold for at least an INC_BW wait period, then the transmission rate is incremented. The transmission rate can be selected from among a predetermined set of discrete bandwidth values or from within a continuous range of bandwidth values. In one variation, in addition to responding to changes in network connection capacity, the client computer also determines an average client computational capacity. Accordingly, if the average client computational capacity is less than the network capacity, the lower of the two capacities is the determining one, thereby avoiding a playout buffer overrun.

대표청구항 ▼

[ What is claimed is:] [1.]1. In a client computer, a method of dynamically adjusting a data transmission rate of a data stream from a server to the client computer, the client computer coupled to the server via a computer network, the computer network providing a network connection with a variable

[ What is claimed is:] [1.]1. In a client computer, a method of dynamically adjusting a data transmission rate of a data stream from a server to the client computer, the client computer coupled to the server via a computer network, the computer network providing a network connection with a variable bandwidth for transmitting the data stream, the data stream including a plurality of data packets, said client computer including a playout buffer for buffering the incoming data packets, the method comprising:initializing the data transmission rate for said data stream;dynamically computing a decrement bandwidth (DEC_BW) threshold for the playout buffer; anddecrementing the transmission rate upon determining that a difference between a first time of a first data packet and a last time of a last data packet in said playout buffer drops below said dynamically computed DEC_BW threshold.