is a secure and reliable medium to connect geographically
dispersed locations. In a situation where other connectivity
options are not feasible, VSAT offers two distant advantages:
less deployment time and easy manageability. A look
at how Comsat Max has created a VSAT network that connects
remote and major locations nationwide and the advantages
your company will gain if you go the VSAT way. by Soutiman
Max's VSAT (Very Small Aperture Terminal) network provides
nationwide data and voice connectivity to enterprises.
Support for the VSATs is provided from 50 locations
spread across the country. It has an extended C-Band
hub in Turbhe (New Mumbai), and has built another hub
which runs on the Ku-Band, very recently in New Delhi.
The network topology is a mix of star and mesh.
Comsat Max started its operations in 1995. "At
that time, we felt that there was a need for reliable
and managed WAN solutions," said C S Raghava Rao,
Head - Technical operations, Comsat Max Limited. "The
predominant method of WAN connectivity was leased lines
which had several disadvantages. The lines were costly
and one had to apply for a leased line and wait weeks
for a connection. Leased lines have bandwidth slabs
and can't be shared on a network basis. Thus the capacity
is underutilized. In a large network sharing of bandwidth
helps in optimal use of resources, VSAT technology provides
speedy, cost effective and reliable solutions to the
A VSAT is a small fixed earth station which provides
a communication link required to setup a satellite-based
communication network. It represents a cost-effective
solution for those who want an independent communications
network to connect a large number of geographically
dispersed sites, especially sites where any other connectivity
options are not possible to implement.
networks offer value-added satellite-based services
capable of supporting the Internet, data, LAN, voice/fax
communications, and can provide powerful, dependable,
private and public network communications solutions.
A VSAT has certain clear advantages over leased lines
and other wireless communications media.
Comsat Max is one of the leading
VSAT service providers in India. The network
allows secure and reliable data, voice, and
The company felt that the predominant
method of WAN connectivity among Indian enterprises
was leased lines. This had disadvantages like
high cost, high time to deploy, and underutilization
A nationwide VSAT network was
built in phases and is now supported by 50
locations nationwide and two network management
hubs. Comsat Max uses SKY Blaster 360E to
offer broadband Internet access and multicasting
applications to its customers.
Comsat Max has built a VSAT
network that offers broadband and VPN services.
The company now has a growing list of over
value over cable
When it comes to cost its not quite fair to make general
comparisons between VSAT services and it's terrestrial
counterparts. Charges for terrestrial services are nearly
always distance-dependent, while VSAT connections cost
the same whether sites are one or 1000 Km apart. And
with most VSAT services the cost-per-connection comes
down considerably when a customer adds users. However,
Comsat Max and other VSAT service providers have considerably
reduced their fees lately.
A satellite network can be installed and made operational
within a week since miles of cable need not be installed.
And VSATs are available in remote locations since it
doesn't need the infrastructure of a telephone exchange
to be present.
a bank needs to expand it business by deploying 100
new ATMs (Automated Teller Machines) within six weeks,
can you imagine the time it will possibly take to wait
for leased lines? In such a case, VSAT connectivity
is the best option," opines Rao.
VSATs had a few disadvantages: VSAT bandwidth was not
very high and restricted to a few 100 Kbps. There was
also certain amount of latency (the time between initiating
a request for data and the beginning of the actual data
transfer) between nodes. But these limitations have
been overcome to a large extent due to advancement in
technology. Nowadays, VSAT providers offer up to 52.5
Mbps outroute (from hub to VSAT) and 307.2 Kbps inroute
(from VSAT to hub) data rates, and only 270 millisecond
The young VSAT provider
In 1995 Comsat Max started service using AT&T Clearlink
systems (satellite modems capable of handling TDM/TDMA
enabled its clients to use a dedicated data transmission
network and ensured reliability of transmission. The
system offered 64 Kbps inroute and 512 Kbps outroute
data rates. The hub at Turbhe used an extended C-band
antenna and TDM/TDMA technology to support VSATs on
a star topology. C-band is used extensively in Asia,
Africa, and Latin America and requires a larger antenna
than Ku-Band VSATs. The company had direct presence
in eight cities and franchises in 30 cities.
In early 1997, the DoT (Department of Telecommunications)
allowed the company to build a mesh network. This allowed
an easier passage for high-speed low-latency networks
because it reduced a hop, otherwise present in a star
In 1999 the company deployed Skystar Advantage LAN+
using FTDMA (Frequency & Time Division Multiple
Access) technology. This reduces probability of collisions
and can support interactive transactions, batch file
transfers, data broadcast, and voice communications.
Broad-cast of audio and video are available as add-on
A blast of broadband
Comsat Max now uses SkyBlaster 360E (a Ku-Band VSAT)
which uses a DVB (Digital Video Broadcast) standard
to offer broadband Internet access to its customers.
The product is a two-way satellite-based solution to
enable interactive Broadband IP and multicasting applications.
By using the DVB standard and IP capabilities, the SkyBlaster
360E supports most data and IP multicast applications.
The product works on Ku-Band-based networks which are
mostly used in Europe and North America. The company
uses the services of the INSAT-3B satellite.
The platform is able to network the central hub with
multiple locations spread across wide geographical areas.
"It's possible to provide outroute speeds upto
52.5 Mbps and inroute data rates upto 307.2 Kbps,"
claimed Rao. "The SkyBlaster allows us to provide
HTTP traffic acceleration and optimization, caching
capabilities, QoS (Quality of Service), multimedia streaming
applications like voice and video, and IP multicast
dash of VPN
"Although a VSAT network offers very high security,
we believe that our customer should be offered more
flexibility in the form of a dedicated network with
high bandwidth, low latency, and assured connectivity,"
said Rao. This prompted Comsat Max to set up an Internet
infrastructure to be used along with the VSAT architecture
to offer Internet and VPN services in 17 cities nationwide.
"What makes a difference is not the technology
but the people in our organization who drive the solutions.
A state-owned airline and a private-owned airline both
run Boeing 737 aircrafts. But why do you think passengers
prefer to fly private airlines? It's the difference
in levels of service and commitment to customers,"
on image for larger view
"Since we have a very large network and different
platforms/ devices like indoor and outdoor units and
routers, we had to choose a unified network management
platform that gave us an integrated view. We decided
to use Computer Associates' Unicenter TNG. It provides
an integrated interface that enables us to keep a tab
on the entire network from one screen. It also provides
audio and visual alerts. If a device goes down, the
system opens a trouble ticket (a kind of a maintenance
request). If the problem is not solved soon, the ticket
is escalated to a person of higher authority in the
form of an SMS or
e-mail message," explained Rao.
The cost of VSAT services has decreased dramatically
in the last few months. This is indeed a good sign for
large enterprises and smaller companies who are poised
is a myth that VSAT has seen its end. Around 30 percent
of all communications worldwide rely on VSAT, and its
deployment keeps increasing," said Rao.
Das Gupta can be reached at firstname.lastname@example.org