Excerpts:

On Convergence

There has been considerable hype since the early 90s on convergence, especially after the International Telecommunication Union (ITU) held a megashow in Geneva in 1995. Eversince the ITU released its specifications I-150 in 1991, relating to the asynchronous transfer mode (ATM) standards, both public telephone and data network operators have been awaiting the development ofa common platform to transport delay sensitive voice/video and data traffic on the same network.

How will it come about?

Total convergence based on which a multimedia global information infrastructure (GII) is proposed to be built is in a conceptual stage. GII involves high bandwidth e.g. tens of megabits per second access to provide interactive multichannel, multimedia communication based on fibre to the home (FTTH).European countries are actively involved in R&D under the aegis of R&D in advanced communication technologies in Europe (RACE). Many countries have an existing analogue cable TV network based on co-axial cable with analogue repeaters and broadcast TV based on direct broadcast satellite. The current technology and architecture of these networks make them essentially unidirectional and designed for broadcast of analogue TV signals. The next step in the evolution of these networks is the digitisation of the broadcast TV channel using moving picture super group standard (MPEG) encoding. Anumber of technical issues relating to digital compression for transmission of moving picture will have to be settled before the existing infrastructure is provided for bi-directional transmission of voice and video as well as high speed data. Therefore, true convergence of telecommunication, information technology and broadcasting must await resolution of large number of intricate problems relating to network interworking, compatibility of terminals and standards.

On when "true" convergence will be a reality

Even after standards and technologies are available, market and regulatory issues, true convergence is likely to be realised only in the next decade because of absence of mass market for multimedia products, which are quite costly at present. While the convergence of fixed line networks for voice and data (PSTN & internet) may be possible in the next five to 10 years, the convergence of services based on wireless access and wireline access, must wait for the development of mature thirdgeneration public land mobile telecommunication systems.

Present second generation digital cellular standards such as CDMA digital AMPS etc. are quite deficient with regard to many bearer & teleservices.

Third generation system like universal mobile telecommunication systems (UMTS), which has been renamed as international mobile telecommunication (IMT-2000), will combine the different domains of mobile telephone, cordless telephones, mobile data and satellite services with the concept of intelligence added to it. It will be multifunctional, multiservice, multi-applications digital mobile system that will provide personal communications at tens of megabit speeds. It is designed to support universal roaming and hopefully offer broadband multimedia services. Quite obviously a lot of work needs to be done by global standardisation organisations like ITU to arrive at mutually agreed standards based on which affordable products in mass scale could be offered in the market by the year 2005/2010.

Thirdgeneration cellular systems will provide convergence of diverse wireless technologies for digital cellular services. It is expected that only by the year 2010 various wireless network services will be able to converge on a single platform and large scale affordable products available to the network operators for deployment.

To be continued