for TCH assignment, you could start from SDCCH allocated for calls only and remove all TCH assignment failure…
for HO attempts, this is tricky ! you’re talking about incoming HO attempts ? Then you can check the number of incoming HO requests, or the number of HO requests “outgoing” from neighbor cells.
Of course, you must be careful with the names I give to the indicators, because I don’t work with Ericsson. So please be careful when you translate it into Ericsson language 🙂 The principle remains *approximatively* correct though.