公开(公告)号：US06292834B1

公开(公告)日：2001-09-18

申请号：US08818127

申请日：1997-03-14

Applicant: Hemanth Srinivas Ravi ,  Anders Edgar Klemets ,  Navin Chaddha ,  David de Val

Inventor： Hemanth Srinivas Ravi ,  Anders Edgar Klemets ,  Navin Chaddha ,  David de Val

IPC: G06F15167

CPC classification number: H04L65/1043 ,  H04L29/06027 ,  H04L65/4084 ,  H04L65/602 ,  H04L65/605 ,  H04L65/80 ,  H04N21/2187 ,  H04N21/222 ,  H04N21/23424 ,  H04N21/23439 ,  H04N21/2402 ,  H04N21/2662 ,  H04N21/8455

Abstract: 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.

Abstract translation: 一种用于通过包括诸如因特网的局域网（LAN）和广域网（WAN）的不同计算机网络从服务器向客户端计算机传输多媒体流的有效传输协议。 客户端计算机包括播放缓冲器，并且传输速率与服务器和客户端计算机之间的网络连接的可用带宽容量动态匹配。 如果播放缓冲器的播放时间是当前在播放缓冲器中的数据分组的数量的一个度量，则低于动态计算的减少_Bandwidth（DEC_BW）阈值，则通过向服务器发送DEC_BW消息来降低传输速率。 相反，如果在播放缓冲器中剩余的分组数量上升到高于动态计算的UpperBay_Bandwidth（INC_BW）阈值，并且在INC_BW等待期间内不降低到较低的INC_BW阈值，则传输速率增加。 传输速率可以从预定的一组离散带宽值中选择，或者从带宽值的连续范围内选择。 在一个变型中，除了响应网络连接容量的变化之外，客户端计算机还确定平均客户端计算能力。 因此，如果平均客户端计算容量小于网络容量，则两个容量中较小的一个是确定的，从而避免播出缓冲区溢出。