| 摘要 |
PURPOSE:To prevent production of an AIS alarm due to one loss of a TDMA burst(Tb) by using a unit of a pointer for an allocated unit to a TDMA burst, allocating sequentially the Tb for each allocation unit and allocating an AU/TU pointer inputted continuously to a different Tb. CONSTITUTION:A TDMA burst(Tb) is formed by a multi-frame(MF) of a 4SDH frame period to allocate a TU pointer and #n/m indicates the input sequence in an MF unit/MF. The signal TU1 is allocated in the Tb in the order of #11-4, then #2 1-4 and then #6 1-4 and again Tb#1. In this case, when the Tb$2 is lost but the $1 is normal, pointers in the #2 are all rewritten into 1 and regarded to be in error, but #3 is coincident with #1 again and restores to the normal state. This state continues up to #6 and an error takes place again at #7, restores normally at #8 and no AIS alarm is raised through the repetition above. So long as a line is not completely interrupted, sensitive line interruption processing is suppressed. |
