Vigyan Prasar: An Insight

Technology to the aid of science popularisation

The all too familiar television set acting as a window to the Internet and the world wide web? Something to look forward to! As a consequence of global networking via the Internet and the underlying concept of the WWW, finding ever-new ways of accessing information has become inevitable. But here is the catch. Surveys indicate that unlike TV receivers, computers are yet to gain entry into most households. Hence the Internet does not reach many. On the contrary, television occupies a place of pride in many a home and is even found at workplaces and schools. Developing a technology capable of porting information into the television could thus be a boon for many, especially children, whose thirst for information is generally insatiable.

A group of computer professionals at Innomedia , Bangalore, has been working on the technology of integrating the Cable TV network with a unique server -- the Cable TV based Home and Office Interactive Service (CHOIS) server--to provide information on demand.

Being aware of the utility of such a technology, Vigyan Prasar, along with TIFAC (the Technology Information, Forecasting and Assessment Council ) DST, Delhi have joined hands for a project aimed at spreading S&T awareness among school and college students through use of the CHOIS technology.

In the background is a telecomputer, the CHOIS Server and a CHOIS pad, employing which, users can request and view information that is available on the server by exploiting the existing infrastructure, i.e. the television receiver and the cable connection(s).

The telecomputer will have a repository of information. Such telecomputers are linked satellites for information exchange. On a larger scale, telecomputers can be placed in all major cities and linked. They also perform other tasks like maintaining user statistics, updating the servers connected to them, and in general, as Internet service provider(s).

A CHOIS server is installed at the cable head-end. This can be linked to the telecomputer via leased/dial up lines for data transfer on one side and, on the other, with a CHOIS pad through both analog and digital channels. The CHOIS pad is actually a set-top device which interfaces the TV receiver with the CHOIS server. This provides a two way link to the may cable service provider at the cable head-end. The user, with the help of a pointing device (which as well may be cell phone) can select channels and programmes for viewing by clicking on icons. In addition, it allows control of the attached TV, VCR or phone. Together, this technology can be used with advantage for porting content to specific groups. The interactivity achievable can be truly satisfying.

The technological advance in using the large bandwidth of the Cable TV Network to carry users' requests to the server on the reverse path (user to server) has made it possible to have interactive multiple access to the CHOIS Channel. Alternately, use of the telephone line for the reverse path is also a functional module, but then the number of users accessing concurrently gets limited by the number of client servers and the number of telephone lines.

CHOIServer is a pentium processor based high-speed super computer in scalable modules networked in master-slave architecture. A large dynamic memory, user-friendly software and a TV format presentation of information makes it readily acceptable to a community already used to viewing the fare provided by the Cable TV network.

CHOISpad is a set-top box attached with the television receiver (and linked to the computer for Internet access) which functions as a modem as well as control a signal sensor. The control signals received from the user's pointing device (i.e.) remote control are processed and forwarded to the CHOIServer to access the desired data. Received data are then screened and presented to the customer, whose identity as an authorised user is established. CHOISpad is also designed to have adequate memory to store hyper book information that has been demanded by the user so that the same once retrieved from the main server (CHOIServer) can be accessed by the user at will. The cable network at every location is not expected to be of a high standard and cable operators are least bothered if the last-mile customer has difficulty in accessing all channels. However, the reverse path needs to be so designed that control signals originating in the CHOIS pad reach the server without distortion. Therefore, CHOIS pads have been perfectly matched to the Server at the cable head-end to have a reliable reverse path irrespective of location, distance, environment and other systems functioning in the vicinity.

CHOIS remote is a pointing device specifically designed to control CHOISpad. It has a keypad similar to that of the TV/VCR remote and therefore it can also be used to control them. This device is carefully selected to eliminate the likely interference from fluorescent lights, and any EM light operating in the same room where CHOISpad is located.

With the technology in place, the emphasis then turns to content development and this is the forte of Vigyan Prasar.    Having initiated the project only recently, VP is engaged in putting together a package for its intended viewers and in developing a mechanism for its regular updation, upgradation and fresh periodic inputs.