> Can't, say, Ericsson take the radios in their cell towers or picocells, redo their tape-outs for phone scale, and end up with a workable mobile radio? Genera

> Can't, say, Ericsson take the radios in their cell towers or picocells, redo their tape-outs for phone scale, and end up with a workable mobile radio? Generally speaking, no. Sometimes in the base stations, you'll find FPGA and such, which are super expensive. The even bigger issue is that you're implementing the other side of the over-the-air protocol, and a whole bunch more stuff too (signaling in the carrier's network). Whereas the modem in a phone is designed to talk to just a single system. Also, the protocols are designed to be asymmetric. The cell station is fixed, but has relatively unlimited size and power constraints compared to the phone. They also have to talk to multiple phones simultaneously, and manage their access to the network.