Technical phone interview coming up for software engineering

I'm not sure whether it's okay to state the company name or not, but I'll say that it's an aerospace company. They sent an e-mail saying these topics will be tested.

The interview will be technical in nature and include the following topics;

Coding in C++ or Java 
Class design
Data structures (don’t worry about graphs)
Concurrency

I'm a graduating undergrad with little to no industry experience. I have coding in C++ and data structures down. What exactly does "class design" entail? Also, my curriculum never even touched upon implementing concurrency. Only theoretically. Does anyone have experience with interviews of this nature? How should I prepare? Any advice would be great, thank you!