Circuit Board of the STB

D-View is a Digital Set Top Box in compliance with MPEG 2/DVB standards that enables the viewers to access wide range of services like Digital Transmission, Web-browsing using any of the front end Network interface modules of Satellite, Terrestrial or Cable. The broadcasters, through the multi system operators (MSO) transmit the TV signals and are increasingly demanding their viewers to pay for the services and hence transmit scrambled signals.

To address these requirements C-DAC, Noida has designed a multi-purpose Set Top Box enabling decoding and decrypting of signals from all the three modes of transmission. The decryption of the pay channels can be achieved either by embedded CAS (like Conax & NDS) or Common interface module. In both CAS systems local authorization would be provided through smart card.

Digital Set Top Box has been categorized as:

• D-View 1- for Digital Terrestrial Transmission (DTT)
  
  
• D-View2 -for Direct to Home through Satellite (DTH)
  
  
• D-View 3- for Direct to Home through Cable

D-View 0 version is free to air, and would cost the viewers about Rs. 3000/-. The cost of other three versions of D-View range from Rs. 3000/- to Rs. 6000/-.

D-View is incorporated with attractive On Screen displays (OSD) along with features of Timer, calendar, games etc. Multilingual OSD can also be provided on customer /manufacturer’s request.

Premier versions of D-view would consist of Personal Video Recording (PVR) having dual tuner & built in hard disk.

DIGITAL SET TOP BOX

Set-top boxes (STB) act as a gateway between user's television and telephone, satellite, terrestrial or cable feed (incoming signal). The STB receives encoded and/or compressed digital signals from the signal source (satellite, TV station, cable network, etc.) and decodes (and/or decompresses those signals, converting them into analog signals displayable on television. Set-top boxes are usually embedded computers that process digital information. These typically have on-screen user interfaces that can be seen on the TV screen and interacted with, through the use of a Hand-held remote controller. STBs also have facilities for upgrading software such as browsers and Electronic Program Guides (EPGs) hard-drives and smart card slots for purchases and eCommerce applications.

Common Interface describes hardware and software architecture for Conditional Access Systems whereby the generic "host" set-top box is not dedicated to one particular encryption system. Consumers can use detachable hardware, which allows them to receive encrypted services they pay subscription fee(s) for. The interface between host set-top box and the CI hardware is standardized (PCMCIA-Interface) so that the same set-top box can be used to handle a variety of encryption systems.

With a set-top box and a standard (analog) TV set, viewers with this service can see a number of channels, more than with a standard TV subscription. Also the image can be better.

A conditional access (CA) system comprises a combination of scrambling and encryption to prevent unauthorized reception. Encryption is the process of protecting the secret keys that are transmitted with a scrambled signal to enable the descrambler to work. The scrambler key, called the control word must, of course, be sent to the receiver in encrypted form as an entitlement control message (ECM). The CA subsystem in the receiver will decrypt the control word only when authorized to do so, that authority is sent to the receiver in the form of an entitlement management message (EMM). This layered approach is fundamental to all proprietary CA systems in use today. This technique is Primarily used in a Digital Set Top Box.