hi rf fan,
the fact is:
if you put twice more calls on a cell, it means the BSC has to double its “signalling” processing. Meaning it has to monitor twice more calls than before.
so yes, half rate is putting more load on the system, from a signalling point of view (i’m not talking about Air/Abis signalling ! i’m talking about BSC processing load & also BTS load). But perhaps the BTS/BSC can support this load without any problem. Or perhaps it can’t. I’ve heard stories about some systems that couldn’t (in the past… –> i don’t know what is the situation right now)