Please go through this link: http://www.radio-electronics.com/info/telecommunications_networks/ims-ip-multimedia-subsystem/tutorial-basics.php
Try "The 3G IP Multimedia Subsystem (IMS): Merging the Internet and the Cellular Worlds", u can buy from amazon at (its a very good book) http://www.amazon.com/The-3G-Multimedia-Subsystem-IMS/dp/**********
May be the one which allows to use trial packages, also is there any application server with diameter package so to connect with HSS.
Does LTE network send any specific message to UE so that UE come to know network supports IMS call ? Or Does the LTE network broadcast information such as "it does not support IMS call" ?