Abstract: The present invention provide for scheduling protocol data units for transmission on a virtual channel. The scheduling is accomplished by first determining a relative theoretical departure time for a protocol data unit. Departure times are identified in each of a plurality of time domains based upon the relative theoretical departure time for the protocol data unit. An identified departure times is selected from a time domain and the protocol data unit is scheduled for transmission during the selected available departure time.

Abstract: Multiple symbol correction employing auxiliary pointers is enhanced by unique interaction of code structures either with ambiguous auxiliary pointers or data structures for precisely locating errors. For example, a code apparatus can correct two symbols in error only with two error location pointers; with three error location pointers, the code cannot correct the errors since error location is ambiguous. Once this has been determined, the features set forth in the present invention are employed to delimit the error burst such that the code apparatus may correct two symbols in error, even with ambiguous error location pointers. With no auxiliary pointers, methods and apparatus can create such auxiliary pointers in particular data structures and error patterns.