erl / drop : amount of erlangs between two drops.
It has no physical meaning, consider it as a tool. This is very very hard to visualize what it means…
High erl/drop : lot of traffic in the cell and little amount of call drops —> Good cell
Low erlang / drop: that’s where it gets complicated… it can mean two things:
1./ very little amount of traffic and just a few call drops –> acceptable cell
2./ high amount of traffic and VERY high amount of drops –> Very bad cell.
in my opinion, this is a useless indicator because you still need to check out other indicators to understand what it means, and how serious the problem is. For example, you need to check the number of call drops and the amount of erlangs.
But some operators love it, but I think they are just being snobish 🙂 They are so proud having “invented” a new indicator… :))