Satellite Communication for the 21 st Century

The communication scenario in the country is rapidly changing and its impact is seen in all aspects of the country's progress.  The Satellite   Communication has played a dominant role   by providing a platform to bring together remotest corners of the country.  Over the years, the Satellite Communication has provided impetus to the growth of  the distribution of the TV, VSATs  etc., to name a few.  With the liberalization of the economy and telecom policies, a host of applications are going to be benefited by the Satellite Communication.  The tremendous demand for the bandwidth and the complex connectivity requirements seen today in the information society is an indication of the role of the Satellite Communication in the 21st  century.   The key technologies to propel the Satellite Communication towards meeting the challenge is continuously evolving. With the rapid advancement of the field all over the world, the issues debated are technical, as well as legal and regulatory in nature.
In our country, premier organizations like ISRO along with many users both in the govt. and private sectors have more than two decades of experience in the various aspects of the Satellite Communication.  With a view to consolidate the experience gained so far and to get a pulse of the future trends in Satellite Communication, a Symposium on "Satellite Communication for the 21st Century"   was organized by Astronautical Society of India at ISRO  Satellite Centre, Bangalore on 25th May 2001.
The Symposium was inaugurated by Dr. K Kasturirangan, Chairman ISRO/Secretary DOS by lighting the lamp.  In his inaugural address he highlighted the role of the satellite communication in the development of the country and the trends that will be seen in future.  The addres was very illuminating and set the tone for the rest of the day.   Dr. P S Goel, Director, ISAC spoke on the technological advances in the field and ISRO's contribution  in terms of building communication satellites.  Dr. K N Shankara, Director SCPO, ISRO-HQ and Chairman, Technical Advisory Committee welcomed the gathering and introduced the topic of the Symposium to the audience.  The occasion also saw two more activities involving Astronautical Society of India, viz the release of the ASI newsletter by Dr. Kota Harinarayana, Distinguished Scientist, ADA and Vice President, ASI and the felicitation of some of the ASI members who have distinguished themselves by winning awards and by their achievements.  Dr. K Kasturirangan, Mr. Madhavan Nair, Mr. R V Perumal, Dr. P S Nair were felicitated  for the successful launch of GSLV and GSAT-1.  Dr. P S Goel was facilitated for the Padmasri award.  Dr. Kota Harinarayana was facilitated for the successful flight of LCA.  Dr. K N Shankara was felicitated  for Ram lal Wadhwa award (IETE), Dr. S Pal for the third millennium IEEE award and Mr. Rajkumar Samuel for the Aeronautical Society of India award.  Mr. K N Suryanarayana Rao, Chairman Organizing Committee proposed a vote of thanks. The inaugural session ended with the keynote address by the renowned Prof. Ashok Jhunjhunwala of IIT, on the topic "Making Telecom and IT work for us". His address dealt with the various aspects of  the Telecom needs of the, various lessons learnt in the past and prospects for the future, the bottlenecks and the solutions.  He stressed  the fact that  only cost effective solutions can be sustained in meeting the telecom needs of the country and technology can be a tool for achieving the cost effectiveness. He also presented glimpses of the work done by his group in the field which has been internationally acclaimed.

Making Telecom and IT work for us   -Prof. Ashok Jhunjhunwala

The development of a country is closely related to the development of infrastructure, more specifically the development of telecommunication infrastructure. Lack of telecommunication access can create strong divides among the population. In 1991,India and China both had about 5.5 million telephone connections. Today, India has 35 million compared to 200 million in China. There is an urgent need to add nearly 200 million telephones to the existing ones in the country.

If we look at the Indian scenario one can see that affordability holds the key for the expansion of the telecom infrastructure. This is evident if we study the expansion of the Cable TV in our country. Can we create similar situation in the telecom field?

 It is in this context that Prof. Jhunjhunwala's group at IIT Chennai has endeavored to evolve affordable telecommunication technologies for the country.  Essentially, the cost per line has to be brought down to about Rs.10,000/- in order to provide 200 million telephone & internet connections to the vast population in the country.  This calls for cost reduction by a factor of 3 to 5. Is it possible?

The group at IIT Chennai found that the only way to reduce cost is to develop appropriate access network technologies with inherent low cost. This will enable smaller operators who invest a modest amount of capital to provide service in a local area.  This local area can be a small town rural or urban.

Prof. Jhunjhunwala's group has developed corDECT wireless in loop(WLL) technology towards providing the necessary affordable technology.   With five years of effort, they have developed a number of access products and they have brought down the network cost to about Rs.18,000 per line.  The technology provides 35/70 KBPS internet and simultaneous telephone service in a range up to 25 kms.  In addition, there is the Direct Internet Access System - a DSL product which provides simultaneous telephone and internet connection at 144 KBPS and 2 MBPS.  A particular combination of 25% DSL, 50% WLL and 25% shared wireless provides cost as low as Rs.12,000 per line, a figure very near to the target.

He drove home the fact that this technology is already a reality and is being deployed in 25 cities including Delhi, Mumbai, Jaipur etc. by agencies like BSNL, MTNL and BSOs.  The most important feature of this is the international acceptance of the system.  The system is already operational in many developing countries like Argentina, Brazil, Madagoskar, Kenya, Nigeria, Angola, Tunisia, Yenen, Nepal & Egypt.  In Egypt corDECT system is being advantageously used in conjunction with a link through communication satellite.

The group at IIT-Chennai had to overcome a lot of initial resistance. They encountered problems like the nonavailability of the spectrum to the unequal playing field with respect to the imported products as far as the taxes are concerned. But the team refused to be defeated and through sustained efforts they were able to meet the challenge.  They have provided an outstanding example of how a small dedicated team can make so much difference to provide unique solutions to the unique problems of our country.  Ultimately, the planners who implement the solutions have to selectively chose the basket of technologies both indigenous and imported to provide a overall cost effective and practical solution.  When we do this, we will automatically be technology leaders instead of becoming foot leaders at best, as Prof. Jhunjhunwala put it, if we follow the west. A very good message indeed for our ASI freternity. 




The technical sessions followed the inaugural sessions contained invited lectures from top professionals and academicians in the field from India and abroad on various topics of Satellite Communication. The following were the lectures delivered in the symposium: 
"Impact of converging Technologies" : overview of the Communication Industry - Mr. Anand Talwai, CEO, e4e labs, Bangalore 

Mr. Talwai started from the example of communication services like the data, voice, picture over the medium like the Wireline (copper and optical) and Wireless (Line of sight & satellites). The business aspect in the example is dictated by the user perspective, Technology perspective, Service Provider Perspective and the Supply and Demand.  The Technological Perspective relate to the digitization of all the signals, Electronic Switching and routing, emergence of standard protocols and the dramatic increase in the bandwidth availability.  The user perspective points to the fact that all over the world, the data traffic has overtaken Voice and is growing, and Mobile has over taken Fixed in many parts.

The new network scenario demands that the networks be designed for adaptability and change.  Configurability, Modularity and Personalization are the new mantra.  The convergence of services aided by the increased deregulation will have the impact on the pricing of the services and the customer benefits.  This in turn attracts more customers and this cycle  throws up challenge to the Technology and the Service Providers.   It is finally upto the technologists to apply technology to satisfy customer needs at affordable prices.
"Emerging Mobile Satellite Communication Systems" - Mr. D K Nimal, Globalstar India

Mr. D K Nimal  gave a talk on the global star programme which is primarily meant for Mobile Satellite Communication to hand held terminals.  The services include voice, data, fax and position location.  The system consists of 48 LEO constellation.  The satellites are put it 1414 km orbit in 8 planes, 6 satellites in one plane.  One feature about the Globalstar system is the high signal quality and availability and also compatability with multiple cellular standards.  He also illustrated new applications where the services are provided to commercial airlines.


"Market forces and Future Drivers in Satellite Communications" - Mr. Andre Jones, viasat, USA.

Mr. Andre Jones came down from USA specially to deliver an important talk on the above mentiontion topic.  He was very excited to be at ISAC on the occasion and he was particularly happy that he could just reach the venue in time after a long tiresome continuous international  flight.

In his talk he specially focussed on the Broadband System and the advances that are expected in the new future.  Historically, the cost structure has undergone a shift from being Equipment intensive to Bandwidth intensive.  The role of the technology is to enable viable economics for Broadband by satellite.  He brought out a particularly interesting aspect of Broadband VSAT links in which adaptive self intereference cancellation is used to carry two different satellite signals in one carrier.  The forward channel and the return channel share the same frequency to double the capacity. He talked about the use of Code Reuse Multiple Access (CRMA) which overcomes overhead, delays and complexity of reservation schemes. The new result is reduction of subscriber terminal cost and availability of full burst rate throughput.  He gave a typical example of a new generation Ku-band satellite system architecture with 35 spot beams which provides upto 0.5MBPS connectivity to   small 60cm terminals.  One more example is a real time,interactive office in the sky, where a broadband connectivity is provided to commercial airlines.  He concluded his talk by stating that new generation of Ku and C Band competitive broadband VSAT system will enter the mainstream of Telecommunications offering a lot of benefits to the users.


"Advanced Satellite Communication Technologies" - Dr. S Pal, Deputy Director, ISAC.


Dr. Pal gave a very informative talk on the above subject.  Starting from the definition of word communication, he covered a wide spectrum of items in the area of Satellite Communication technology.   The audience came to know recent trends in Satellite Communications, the demands of the users and the new satellites being planned to meet the demand.   He drove home the point that in the decade to come the information exchange will take place through what are called as information highways and Satellite Communication will play a very important role. He also touched upon technological developments that are taking place in the onboard segment and how they are going to influence the user and the ground equipment.  He introduced the audience to new areas like the navigation, a field which has many applications.
"Using Satellite Access for Broadband and High Speed VSAT applications" - Mr. S Bharathy, AVP, HCL Comnet Systems Services Ltd.

Mr. S Bharathy was of the view that the use of VSAT for broadband applications suffered because of the regulatory restrictions which limited the VSATs to applications requiring less than 64 KBPS.  He however pointed out that the new guidelines permit VSATs to transmit upto 512 KBPS.  With the change in the scenario a typical Ku Band  VSAT terminal with 1.2 to 2.4 M diameter antenna has the potential to go upto 40 MBPS in reception mode and 512 KBPS in transmission mode.  The growth drivers are essentially the Traffic, Connectivity and Applications.  The High speed broadband VSAT services will open up a host of applications from Banking to Tele-health services.  The enabling technology is ready for use
"Satcom  Applications" : Country scenario - Mr. A R Dasgupta, Deputy Director, SAC

Mr. A R Dasgupta gave a very interesting talk on the above subject.  He outlined the unique requirements of our county and how Satellite Communication has been harnessed to meet the challenges.  He particularly dealt upon the various services provided by INSAT network for the Fixed and Mobile services, DCPs, Television and Radio broadcasting.  The audience came to know of the very high level of of contribution of the Satellite Communication in a developing country like ours.  In his view it is going  to play still higher role in the years to come.

 The audience of well over 250 delegates and others represented a very good cross section of professionals from private, government and academic institutions.

On the whole the Seminar presentations were of a very high standard, coming as it is from very top of the professionals in the field.  It was natural that the attendance was thick right upto the end and the audience lapped everything up.

 The Session Chairmen namely Mr. Madhavan Nair, Dr. A K S Gopalan and Dr. K N Shankara lent a lot of dignity and decorum to the event.  Besides controlling the time, they gave their own captivating observations.  They were competently assisted by Mr. V Mahadevan.