Desaraju Venugopal

Presently efforts are under way for achieving high throughput satellite (HTS) systems in Ku and Ka bands through Geo Stationary Orbit (GSO satellites and Non GS0 (NGSO) satellite constellations in Low Earth Orbit (LEO) and Medium Earth Orbit (MEO) for IP Core and Broadband Access applications. These efforts aim to achieve throughput of about 1 TBPS...

The widespread demand for expansion of satellite DTH services continues as technological developments combined with cost effective delivery of large number of TV programs and content of relevance to its consumers. At the same time, the increasing pervasiveness of Internet is creating new possibilities and opportunities in all walks of life includin...

Over the last decade Internet has emerged as not only a tool for personal and corporate communications but also as an important source of information, innumerable number of web based applications, social networking and entertainment. The developing world has also realized the potential of Internet to transform the lives of people in all cross secti...

The last decade saw the emergence of Ka band satellite communication systems in different parts of the world. Ka-band satellites offer several advantages like large bandwidth availability, higher bit rates, ease of generation of multiple beam satellites, small size user terminals, etc. With increasing mobility of the people, availability of communi...

It is nearly half a century since the establishment of first commercial satellite communication system. Over these years satellite communication systems have grown in leaps and bounds which included threats of extinction from optical fibre and digital compression technologies. However, it is to the intrinsic features of satellites communication sys...

As a result of social, political, economic and technological transformations during the last two decades the communication requirements of the individual, business, social and governmental sectors have undergone a sea change. From the plain voice telephony, fax and low bit rate data mainly from home or office, the requirements have grown for broadb...

The Indian domestic telecom sector has seen phenomenal growth over the past few years. The number of mobile phone subscribers in India has already crossed 500 million by December 2009 and increasing at about 15 million subscribers per month. This phenomenal growth also has lead to poor quality of service with frequent call drop outs, and so on, due...

The model has been designed to calculate mobile bandwidth saving using FMC Techniques. The model is based on the average time the subscribers spend at home/office, the number of fixed lines in a mobile cellular coverage area, the average traffic generated by each subscriber, etc. The number of mobile phone subscribers in India has already crossed 7...

With the introduction of IP based transmission schemes, true convergence at services level is getting achieved with different types of services like audio, video and data being merged into multimedia services and provided on the same signal. IP protocol enables the transportability of packetized signals across all types of media. It is now well rec...

The last two decades decade saw the emergences of hybrid satellite/terrestrial systems in different parts of the world for providing digital audio services and subsequently for digital multimedia services in different parts of world. These systems are built around use of satellite system for wide area coverage and supplemented by terrestrial transm...

Availability of speedy communication links to individuals and organizations is essential to keep pace with the business and social requirements of this modern age. While the PCs have been continuously growing in processing speed and memory capabilities, the availability of broadband communication links still has not been satisfactory in many parts...

An improved quality of life through education and developmental communication is an important necessity of societal up-liftment in the new millennium, especially in the developing nations. The population explosion and the associated pressure on the scarce resources to meet the basic necessities have made it more or less impossible for most of the n...

With the availability of Mobile Satellite Service (MSS) payload on the INSAT-2C satellite, launched-in December, 1995, introduction of one-way low bit rate Personal Messaging Service (PMS) from small hand-held terminals becomes feasible. The one way messaging service concept is the reverse of paging service. However, unlike terrestrial based paging...

This paper describes the domestic mobile satellite communication system (MSCS) that is scheduled to be introduced in India in 1995/1996 as a part of the INSAT system. The INSAT MSCS will operate in the 2.6/2.5 GHz band. After briefly describing the need for a domestic MSCS, the reasons for selecting the S-band and the overall features of the system...

Domestic satellite communication systems are being widely used for trunk telephony and television broadcasting and a major segment of satellite capacity will continue to be used for those purposes. However, advances in satellite systems technology have now opened the way for a wide variety of applications using small and inexpensive ground terminal...

The extent of a rural satellite telecommunications network in an overall domestic network is defined. The desirable features of low cost terminals system and the general choice of the terminal size and equipment are discussed. The impact of satellite gain on the earth station and satellite EIRP is analyzed. Different types of networks like the mesh...

An approximate theoretical expression for the mutual coupling between two waveguide radiators directed radially inward and located on a perfectly conducting concave sectoral surface has been developed using reaction concept. The radius of curvature of the surface is assumed to be large so that the apertures can be considered on locally plane surfac...

A pattern recognition approach for deciding whether a given segment of speech should be classified as voiced speech, unvoiced speech or silence based on a set of five measurements of the signal is given by Atal and Rabiner [1]. In this paper, we demonstrate that it is possible to achieve this classification with much less computational effort. Thes...

Attention is drawn to some recent results of pattern recognition theory in the context of designing an automatic speaker verification system of prescribed performance. Associated problems of data base preparation, the number of customers for which the system is to be designed, and the number of features to be used are discussed.

In this paper, we describe studies made on designing speaker recognition schemes using an interactive signal processing facility. The facility consists of a HP 2100S minicomputer based Fourier Analyzer System. This facility accepts speech input and provides a display of results at various stages of recognition procedure. Such a system permits the u...

A mathematical formulation of an automatic speaker verification scheme as a two class pattern recognition problem is presented. Expressions for the expected values and the variance of the design-set and the test set error rates are derived. The bound on the performance of an automatic speaker identification system as a cascade of independent verifi...