Patent ID: 6574226
Filing Date: 2003-06-03
Classification: H04L,H04Q

Abstract:
A data communication method for transmitting high-rate user data, having a length exceeding a predetermined length, using AAL type 2 protocol, the AAL type 2 protocol originally capable of transmitting user data units to an ATM network, each of the user data units having a length at least one of shorter than and equal to the predetermined length, and being transferred from a layer that is higher than the AAL type 2 protocol, the AAL type 2 protocol capable of extracting data from packets received from the ATM network and transferring the data to the higher layer, a sublayer being situated between the higher layer and the AAL type 2 protocol, the method comprising the steps of:attaching a restorative code to a user data unit using the sublayer, thereby preparing a data unit, the restorative code being used to restore the user data unit, the restorative code being limited to no more than three different fields and containing at least one of an error detection code and error correcting code for checking the user data unit; dividing the data unit into segments having a length equal to or less than the predetermined length; attaching successive codes to each of the segments, respectively, each of the successive codes indicating whether a successive segment follows a corresponding segment; transferring the segments with the successive codes to the AAL type 2 protocol in order to load the segments with the successive codes into packets; reassembling the data unit from the segments received from the AAL type 2 protocol in accordance with the successive codes attached to the segments; and restoring the user data unit in accordance with the restorative code in the data unit and transferring the user data unit to the higher layer.