近幾年來，應用層前向錯誤更正技術(Application Layer-Forward Error Correction；AL-FEC)，尤其是其中的無碼率(rateless)AL-FEC，受到很深的矚目。無碼率AL-FEC可以保護比較大的資料區塊，而且只需要比最佳的理想碼(idea code)多一些冗餘就可以將資料還原。同時，它的編解碼相當地有效率，即使只用軟體實作(沒有使用硬體加速)，在個人電腦上的編解碼速度就可以到達Gbps等級的吞吐量(throughput)。然而，我們發現當考慮在台灣高鐵上透過WiMAX網路來接收串流服務時，現今的無碼率AL-FEC可能並不是最佳的解決方案。因此，我們提出了一種基於中國餘式定理(Chinese Remainder Theorem, CRT)的AL-FEC。這個新方法可以支援比傳統理想碼更大的編碼區塊而且比傳統無碼率碼需要更少的傳輸冗餘，使得該新方法更適用於保護在頻寬有限且傳輸錯誤率高的網路上的資料傳輸。

In recent years, Application-Layer Forward Error Correction (AL-FEC), especially rateless AL-FEC, receives a lot of attention due to its superior performance in both transmission and computation efficiency. Rateless AL-FEC (e.g., Raptor code or LT code) can protect large data block with the overhead omewhat close to ideal codes. In the meantime, its data processing rates of both encoding and decoding are quite efficient even in software implementations (probably reaching Gbps throughput on a modern PC). However, we found that conventional rateless AL-FEC may not be the bestcandidate when considering streaming over WiMAX networks for high speed rail reception in Taiwan. Therefore, we proposed a new AL-FEC scheme based on Chinese Remainder Theorem (CRT). The scheme supports greater symbol size than conventional ideal codes and requires less overhead than rateless codes, making the proposed AL-FEC scheme more feasible to harsh bandwidth-limited networks.