Patent ID: 6460154
Filing Date: 2002-10-01
Classification: H03M,H04L

Abstract:
A method of communicating frames of digital data across a communications medium extending between a first modem and a second modem, each frame comprising a data field and an error field, the first modem having a first startable timer, comprising the steps of:the first modem receiving a first set of frames sent by the second modem; the first modem determining, for each frame in the first set, whether the data field in the frame is error-free, contains correctable errors or contains uncorrectable errors; if the data field is error-free, the first modem verifying whether the first timer is running and if so, discarding the data field, otherwise forwarding the data field to a first digital interface; if the data field contains correctable errors, the first modem correcting said errors and verifying whether the first timer is running and if so, discarding the data field, otherwise forwarding the corrected data field to the first digital interface; if the data field contains uncorrectable errors, the first modem verifying whether the first timer is running and if so, discarding the data field, otherwise encoding a first error message into the error field of a first frame, sending the first frame to the second modem and starting the first timer to time out after a predetermined expiry time; wherein said predetermined expiry time is equal to an amount of time required for a retransmitted version of a given frame to be received at the first modem following starting of the timer as a result of having determined that the given frame has uncorrectable errors.