I worked in embedded domain for 3 years ( C/C++) and it was more of application programming with little exposure of Linux system calls. I used to write code for a product which is used in power sector. Later due to various reasons i had to switch my job to IT and now i am working in IT form past 2 years and now i really want to switch back to embedded profile with my previous experience. i have given couple of interviews and they are focusing on real time experience in communication protocols and interfacing and i haven't got any real experience on those and i do know those protocols theoretically. Can anyone suggest me how to switch back by learning all that is needed for fitting myself now into embedded domain ?