Any good source explains the core switch and optical transmission?

CORE SWITCH: It consists of MSC<MGW<SGSN<GGSN ,ROUTERS & SWITCHES (All present in one room will be called CORE Equipment room).

1.Core Switch basically functions to Route(Switching) the CALLS of the network.

2.Each equipment has its own functionality to switch the Call & data in a Network.

3.SIGNALLING on IP media, On TDM media ,CC7 Signalling ,Protocols these are the basic term which are used in a Core switch network.

This is a brief information about the Core switch.