What are the events 1a, 1b, 1c, etc.?

 e1a – a Primary CPICH enters the reporting range, i.e. add a cell to active set.

 e1b – a primary CPICH leaves the reporting range, i.e. removed a cell from active set.

 e1c – a non-active primary CPICH becomes better than an active primary CPICH, i.e. replace a cell.

 e1d: change of best cell.

 e1e: a Primary CPICH becomes better than an absolute threshold.

 e1f: a Primary CPICH becomes worse than an absolute threshold.