Applications where the transmitter immediately forgets the information as soon as it is sent (such as most television cameras) cannot use ARQ; they must use FEC because when an error occurs, the original data is no longer available.
发送方在发送后立即忘记信息的应用（例如大多数摄像头）不能使用ARQ；它们必须使用FEC，因为当发现错误时，原始数据已不再可用。