| 摘要 |
<p>The disclosed system provides reliable communication over the UDP transport layer in a handheld device. By providing reliable communication over the UDP transport layer instead of using the TCP transport layer, memory requirements are reduced, and applications running on the handheld device have reliable data transfers performed on their behalf. Additionally, the use of standardized components, such as the UDP transport layer and a standard network layer like the IP layer, enables the handheld device to efficiently communicate with many other devices in a standardized manner. The disclosed system provides the reliable communication by utilizing a UDP+ layer on top of the UDP transport layer. The UDP+ layer acts as an interface between the application layer and the UDP layer both to provide reliable communication to the application layer and to hide the complexities involved with performing this functionality from the application layer. To provide reliable communication, the UDP+ layer acknowledges all messages received, and the UDP+ layer utilizes a retry timer such that when receipt of a message has not been acknowledged and the retry timer expires, the UDP+ layer resends the message. The value of the retry timer as well as other values used during retransmission of the message are configurable by the user to optimize performance. Also, the UDP+ layer utilizes a number of messages that are used to open a connection, transfer data, and close a connection.</p> |
