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GIS in midas' installations
Dr Narayanan Sampath
Midas Communications Technologies Pvt. Ltd.
No 1, Kalyani Nagar, Kottivakkam
Thiruvanmiyur, Chennai-600 041
Introduction
India is a very densely populated country with most of its people living in
villages. While the Indian metropolitan areas are developing fast,
particularly in the field of Information Technology, the rural population has
not moved much in the Independent India. While the metros of India can
communicate with the rest of the world in a matter of minutes, the rural
sections of the Indian Community tend to be using the old and antiquated
modes of communication.
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DECT
Interface Unit
PLATE 1
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India's advancement in the fields of Science and
Technology, in spite of so many other odds, is a matter of pride. With the
improvement in the Indian economy, the number of middle class and upper
middle class population has increased in good numbers. With the fifth pay
commission policy announcements, the quality of life and affordability of
this middle and upper middle class community has improved remarkably well.
This has resulted in converting some of the luxury items into almost a
necessity. An average middle class family, these days, can afford to own at
least a two-bedroom flat, a car and a phone. There were days when it was
almost impossible to establish connection for those who did not own a phone.
But nowadays, the streets are flooded with PCO centres where people who do
not have phone connection, can still communicate. However, these luxuries or
comforts are available only in the metropolitan India and again rural India
is still left way behind. Moreover, the wire line cost incurred by the
Department of Telecommunications (DoT) is in the order of Rs.30000 and
Rs.35000 per subscriber and this enormous cost is a factor that probably
slows down telephone connectivity to more people, apart from some other
factors.
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Compact
Base Station
PLATE 2
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The corDECT Wireless Local Loop technology developed by
Midas Technologies Private Limited (Midas) in association with the Indian
Institute of Technology, Madras (IITM), and Analog Devices Incorporated
(ADI), U.S.A. has helped overcome this cost and maintenance factor in
offering connectivity. The Discussion part of this paper will throw more
light as to how this has been achieved. Before that, a brief description of
the equipment used in the technology developed by Midas etc. will be
appropriate.
The aim of this paper is only an attempt to make everyone here aware that GIS
could provide some answers to faster and efficient installation of this
superior and indigenous technology.
Discussion
Instrumentation
Midas was founded in April 1994 by a few alumni of Indian Institute of
Technology, Madras, with the aim of developing a technology that could reduce
the cost and maintenance of telecommunication connectivity. With this in
mind, Midas developed the corDECT Wireless Local Loop (WLL) technology that
reduced the connectivity cost and maintenance. This system, as described by
Purohit, is expected to provide a superior alternative to the buried cable
method.
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Wallset
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Wallset
IP
PLATE 3
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The corDECT system (Plate 1) consists of a DECT Interface
Unit (DIU), a Compact Base Station (CBS), Wallset (WS), a Base Station
Distributor (BSD) and a Network Management System (NMS). The DIU performs
system control and does the interfacing to telecom network. The DIU acts as a
mini exchange. The Compact Base Station offers wireless access in the area on
twelve simultaneous channels and the Wallset is a wireless fixed terminal
connected to any standard telephone, modem or a fax machine. The Wallset Internet
Protocol (WS-IP) provides simultaneous voice and data facility to the
subscriber(s). The Base Station Distributor (BSD) connects four
remotely-located CBSs to the DIU, using E1 link, while the Network Management
System (NMS) manages multiple DIUs and their associated CBS and Wallsets.
Each DIU can provide connections to 1000 subscribers and would need about 20
Base stations and 1000 Wallsets along with their other accessories.
The DIU (Plate 2) is a DECT (Digital Enhanced Cordless Telecommunication) exchange
for wireless subscribers and provides an interface to Public Switched
Telephone Network (PSTN). The DIU handles functions such as call processing,
CBS powering and PCM/ADPCM (Pulse Code Modulation/Adaptive Differential PCM)
transcoding. System Operation and Maintenance (O&M) and remote fault
monitoring can be performed from the DIU or alternatively from a remote
location using the Network Management System (NMS).
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Base
Station Station Distributor
PLATE 5
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The
Compact Base Station (Plate 3) is a small wall mounted or pole mounted (over
a hill or otherwise) unit. Each unit serves one cell, providing upto 12
simultaneous speech channels. A CBS has two antennae for diversity. A
directional antenna, with significant gain, can be used when coverage
required is either confined to certain directions or coverage area is divided
into sectors covered by different base stations. Otherwise an
Omni-directional antenna can be used. A CBS can provide a distance of 10 kilometres
for communication. In some instances, a Relay Base Station (RBS) is used to
enhance the range of communication for the corDECT system by another 25
kilometres.
The Wallset (Plate 4) is a small wall-mounted unit, with an external antenna
and powered from A/C mains. An internal battery provides backup in case of
power failure. The external antenna provides gain and extends the range of a
CBS in areas where CBS density is low. The Wallset provides a standard RJ-11
telephone socket so that any telephone, fax machine, modem or even a payphone
can be connected to it. A multi-wallset is used to support four standard
phones, a payphone and modem or fax machine. A Wallset-Internet Protocol
(WS-IP) will provide Internet access at 35/70 kbps, with simultaneous voice
and data. This connects to a PC serial port, without the need for a modem. Th
WS-IP can be upto 10 kilometres away from the CBS.
The Base Station Distributor (Plate 5) is an optional unit and will be used
if a cluster of CBS is to be located at a distance of about 100 kilometres
from the DIU. The BSD is connected to the DIU on E1 lines and each E1 line
feeds to the 4 CBSs. The BSD is locally powered by -48V source and also feeds
power to the CBS.
The Network Management System (NMS) is software and is used to manage upto 30
DIUs and their subscribers. The NMS is interfaced to the PSTN on an E1 link
(2MB - PCM link) and could be located anywhere. The NMS performs operation
& maintenance (O & M) functions for all the DIUs and the subscribers connected
to them. It monitors the health of every card on each of the DIUs as well as
all the CBSs. The NMS carries out subscriber management for all subscribers.
When the DIUs are configured as an independent exchange, the NMS also
provides billing to all the subscribers.
Thus the corDECT Wireless Local Loop technology is a versatile and efficient
system of communication which can offer connectivity to the entire India at a
very low cost and maintenance. No digging for copper wire laying will be
necessary. The test installations of the system is shown in plate 6.
Installation
The computer connectivity is a welcome technological development that will
offer lot of hopes to those living in rural areas. But the vastness of the
Country and lack of proper transport facilities preclude the installation
process at the rate it should be done. The only guide available are the
topographic maps prepared by the Survey of India in the middle sixties or the
early seventies. The changes occurred between then and now are phenomenal
like the change in vegetation or disappearance or change of course of
waterways complicates the situation even further. Procurement of these maps
is not easy either. These maps are divided into two categories viz.
unrestricted and restricted. The unrestricted maps can be bought by anybody
off the counter while the restricted maps are available to only special
categories of people such as educational institutions etc. Even for these
restricted maps, special procedure has to be followed for purchasing these
maps and then an annual report submitted to the relevant authorities. Midas
being a Company, it is impossible to get these maps unless one beats the
system. Also, the Survey of India 's Office at Bangalore controls maps for
Tamil Nadu, Karnataka and Kerala while Hyderabad stocks maps for Andhra
Pradesh. Some of these maps are out of stock and there is no chance of
getting these maps for a long time.
Using the unrestricted maps, Midas chose Madurai District in Tamil Nadu for
offering the Computer connections for both voice and data. A visit by the
staff of Midas and n-Logue Communications to Madurai showed that the people
of this area were very much interested in the communication facility. A few
more visits were made to select two sites for two DIU installations. If these
efforts are projected on all India bases, just imagine the cost involved in
travel and other aspects of the project. The purpose of offering low cost
installation will be totally lost if all these costs are added up.
The Use of GIS
Geographic Information Systems are an important new entry point into fields
where location in geographic space makes a difference, what might be called
the mapping Sciences (Clarke, 1997). He also says that the evolution of the
GIS has now reached maturity, and the benefits to all are self-evident. This
benefit can now be applied in locating the siktes for the installations of
Midas' telecommunication system, although it might be first of it kind.
The Remote Sensing (RS) technique and the Geographical Positioning System
(GPS) would have produced images of all ground features of various places in
the world. The Geographical Information System (GIS) developed by the above
techniques offer a great relief in showing the latest positions of the
features including the towers, antennae, tall buildings etc. These features
help locating the exact positions for the installations from the boardroom of
Midas instead of making various visits to the sites. The author's personal
experience as an airborne and ground geophysicist with Australian Bureau of
Mineral Resources (now Australian Geological Survey Organisation) has shown
that the positions located by using GIS have been accurate when compared to
locations plotted by the aerial photographs. The pilot flying with the help
of air photos and the old Doppler navigation system often ended up in
guesswork as to either the featur would have changed or the waterways dried
up etc. The Conference might be aware that the GIS is being used in the
agricultural projects in India and abroad, but there is not enough
information about the use of GIS for the location of sites for communication
installations. Although some information is available from different sources,
it is possible that the job can be done more accurately to pinpoint the
locations using GIS. This being a new development in the scientific field, it
is difficult to estimate as to how much of GIS is being used and what are the
areas GIS has gone into. It is hoped that this conference containing very
distinguished GIS scientists will guide Midas in the right direction. As
mentioned in the introduction that the author is not here to talk about GIS
but learn from you as to how best GIS can be employed in selecting sites for
the installations of Midas' telecommunication technology developed to offer
connectivity to all section of the Indian Community.
Acknowledgements
The author acknowledges the help given by Dr. Koshy Varghese and Prof. Hema A
Murthy of IITM, in preparing this paper, Ms K Rampriya for providing the
plates and making them available on time and Mr. Shirish B. Purohit, Director
of Midas for his encouragement to present this paper. The help offered by the
others, directly or indirectly, is gratefully acknowledged.
References
- Clarke, Keith C; 1997 Getting Started with
Geographic Information Systems; Prentice-Hall Inc.,
- Purohit, Shirish B; 2001
Wireless in Local Loop; Voice & Data, January 2001;pp.132 & 133
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