In android, which layer of code handles multiple RILs, e.g. 3G vs 4G

Question

I'm trying to figure out the preferred way of handling more than one "vendor RIL" on an android device. Suppose I have two distinct radios, one 3G and one 4G, each with its own vendor RIL (assume Gingerbread release). Some questions:

Would this require two separate instances of the RIL daemon (rild.c), and if so what bit of code (above the RIL daemon, I assume) arbitrates the connections?

Does android have built-in support for multiple RILs at all?

I'm digging through the source trying to figure this out, so any pointers would be appreciated.

Answer 1

Answering my own question...There is no built-in support for multiple RILs. You have to roll your own :(