The initial phone interview involved some basic C questions and a coding assignment that had to be completed and e-mailed back within a day of the phone interview.

The actual interview was from 10:00 AM to 5:30 PM, with approximately nine interviews in total. Questions ranged from C coding to 3GPP wireless questions and wireless communication theory.

It's best not to "BS" anything. Be honest and upfront with the interviewer about what you know and what you don't know, because if you claim to know something you don't, it can go very badly. For what you do know, perform a "core dump" of all your knowledge and also demonstrate that you can think on your feet and not get stuck on a question.

Explain the different wireless modulation schemes, their comparable probability of error ratios, and how they relate to overall data throughput, along with the reasons why.