公开(公告)号：US06473399B1

公开(公告)日：2002-10-29

申请号：US09201389

申请日：1998-11-30

申请人： Mathias Johansson ,  Christian Roobol ,  Johan Larsson

发明人： Mathias Johansson ,  Christian Roobol ,  Johan Larsson

IPC分类号： G01R3108

CPC分类号： H04L1/0002 ,  H04L1/1809 ,  H04L1/1848

摘要： A data communications unit determines both efficiently and accurately when one or more data units should be received under a variety of conditions. In particular, the present invention compensates for transmission delays and for varying transmission rates over the communications channel. During a communication between first and second communications nodes, the first node receives a sequence of data units transmitted from the second node. The first communications node determines that one or more of the transmitted data units was either not received at all or was erroneously received (i.e., corrupted). The first node then sends a request to the second node to retransmit the one or more data units not received or erroneously received. A retransmit timer is started when the retransmission request is sent. The retransmit timer accounts for the delay time period required for the retransmit request to reach the second node, for the second node to retransmit the requested data units, and for the retransmitted data units to reach the first node. When the timer indicates that the delay time period has occurred/expired, a counter is started. Based on the counter's value, a determination is made whether all of the data units requested to be retransmitted have been properly received. If the determination indicates that the requested one or more data units has been retransmitted and properly received, no further action is taken. On the other hand, if the requested one or more data units to be retransmitted is not received or is erroneously received, the above-described procedure is repeated.

摘要翻译： 当在多种条件下应该接收到一个或多个数据单元时，数据通信单元有效地和准确地确定。 特别地，本发明补偿传输延迟和通过通信信道改变传输速率。 在第一和第二通信节点之间的通信期间，第一节点接收从第二节点发送的数据单元序列。 第一通信节点确定发送的数据单元中的一个或多个根本没有被接收或被错误地接收（即，被破坏）。 然后，第一节点向第二节点发送一个请求，以重发未被接收或错误接收的一个或多个数据单元。 当发送重传请求时，重新启动定时器。 重传定时器考虑到重新发送请求到达第二节点所需的延迟时间段，第二节点重新发送所请求的数据单元，以及重传的数据单元到达第一节点。 当定时器指示延迟时间段发生/到期时，计数器开始。 基于计数器的值，确定请求重传的所有数据单元是否已被正确接收。 如果确定指示所请求的一个或多个数据单元已被重传并被正确接收，则不采取进一步的动作。 另一方面，如果所请求的一个或多个要重传的数据单元未被接收或被错误地接收，则重复上述过程。