Mostly, candidates will be called for the Initial round after a rough sorting of resumes internally.

Preferences will be given to candidates with a telecom background.

The Initial round will be telephonic, and they'll primarily concentrate on determining what sort of work you are currently involved with and your proficiency in it. Then, if they are satisfied, they'll ask some technical questions just to ensure you can be ramped up in their project quickly.

Once shortlisted in the first round, you'll be called for a F2F round where you'll be grilled on your skill set and telecom domain expertise. The interviewers mostly don't mind the relevance of experience in the domain as long as the domain is telecom. Sometimes, if the interviewers don't have the required expertise in a particular area, another expert will be called. It's professional in that aspect.

Then, the third round is a managerial round, where the manager of the product for which you've been interviewed will have a discussion with you. This can be technical, depending on the manager. But mostly, it's a discussion to get a feel for your expectations/attitude, sort of stuff.

If everything goes fine, HR will get in touch with you and discuss compensation and will send an offer letter.

DISCLAIMER: This is a personal experience and should not be considered a general format. Interview experiences are purely subjective.