handover decision: congestion: figure out the tradeoff: re-assign within same cell vs. handover to another cell
If a TCH kind on a cell is congested (below min-free-tch-X threshold), we can either re-assign to another TCH kind on the same cell, or handover to another cell and keep the same TCH kind.
- is the neighbor cell's rxlev acceptable?
- will it cause congestion on the neighbor?
- how about inter-BSC handover?
This is a complex tradeoff decision which deserves some head cracking on.
Look at and test current implementation (handover_decision_2.c) and see if it can be improved / configured in a useful way.
The first way to go is to avoid inter-BSC handover as long as possible; only if the rxlev/ta drop past tolerable levels and a neighbor-BSS is better than a local cell.
I'm not sure anymore whether this issue is worth considering past the approach described in #3686,
we should probably always consider inter-BSC handover as the very last option before calls get dropped.