You might want to read up a bit around the subject too, think of the advantages and disavantages of each system, their limitations and technical requirements. Have a light understanding of what is meant by cancellation, plot extraction and multilateration.
Do you know the capeabilities and vunerabilities of each system, do you know the requirements for aircraft to carry transponders?
I'd also have a look at a typical airport layout, and be aware of what technical systems and navigational aids there are and what they do.