Bell Lab researcher - 1 hour of presentation followed by 8~11 individual interviews. Each interview has about 1 hour long discussion with technical staffs. During the presentation, it is required to present projects during the PhD. It is very intensive and many questions are given to the presenter.
As for 1-on-1 interview, you are required to have at least one hour discussion with the researchers or the VPs. Each one will ask you about the projects you have done or a couple of questions that they want to know. Overall, the questions are dependent on whom you will meet.