Q:

Digital Broadcasting - settop box

I'm very new to settop box project.Is there any materials  available to study the basics of its internals and the working of it.I dont know how to start understand about it.I was looking for the  architecture of middleware,DCCM and other components.I need to know how these components interact with each other.I need to know how by pressing a particular event in the EPG menu we could able to get the event corresponding to the service.I need to know the interaction between the tables.How to set the reminder in EPG and how the interactive TV works.

A:

This is only a very partial answer to your question. Rather i would say, this is the first preliminary work you must accomplish before getting deeper into interactivity. 
The tutorial here on PSIP: Program specific information show how the ATSC (or DVB is similar) is organized in the form of periodic tables including some tables that indicate EPG. By reading and processing such tables you will be able to accomplish the desired work. 
Essentially, EPG table contains the information about the program and its respective time. And the actual timing information is contained in the TDT and TOT table. These tables tells the STB's the current time (on wall clock). Once, the respective time occurs, as per the TDT/TOT, the notification action can fire. 
Below here are two more important references to Transport stream structures.

PSIP tutorial
The ATSC transport layer, including program and system information protocol (PSIP)

Please read the above pre-requsite and then refine your question. 

