12-04-2012, 04:06 PM
VSNL
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Brief history of VSNL
The first Submarine Telegraph Cable from U.K. landed in Bombay in 1870, heralding the era of external telecommunications in India.
The Eastern Telegraph Co. (ETC) of 1872 and the Indian RadioTelegraph Co. (IRT) of 1927 merged to form the Indian Radio and Cable Communications Co. (IRCC) in 1932.
The H.F. Radio telegraph made its appearance on the scene in 1927, followed by Radio telephony in 1933
Consequent to India's Independence in 1947, there were phenomenal developments in her communication system and technology. The Government of India took over the IRCC, giving birth to the Overseas Communications Service (OCS), a Government Department.
The satellite era dawned in 1970. India also had, by 1982, wideband submarine telephone cable system and Troposcatter system in the external telecommunications network
On April 1, 1986, the Videsh Sanchar Nigam Limited (VSNL) - a wholly Government owned corporation - was born as successor to OCS.
INTERNET LEASED LINES
The success of any organization depends on its ability to precisely capture and efficiently transfer information in order to seize vast opportunities available around the globe.
TATA Indicom Internet Leased Line Service helps you become a part of the global network and be a global citizen.
State of-the-art technology. State of-the- services
Our inherent strength is state-of-the-art infrastructure that provides high-speed, redundant, load-balanced backbone Internet connectivity. This connectivity comes with a high uptime, as most of the cities where we offer our services has an alternative path for carrying the Internet traffic, in case any of the main links fail.
Our sophisticated network management tools carry out proactive monitoring of leased circuits and our performance management tools track bandwidth performance online, ensuring optimal performance. All built on an easy scalable architecture that allows us to augment bandwidth as and when the requirement arises.
SCPC (Single Channel Per Carrier) TV Service
VSNL provides SCPC TV services for Analog and Digital channels. The SCPC TV uplinking facilities could be used for both point-to-point contribution feed as well as for broadcasting purposes. Customers can decide the bit rate effective from 3 Mbps to 8 Mbps for low definition TV to upto 40 Mbps for high definition TV as per requirement. Normally the bandwidth of analog channels are either 20 MHz or 30 MHz.
DSNG (Digital Satellite News Gathering) Service
DSNG service is one of the most versatile video services on offer. We provide end-to-end digital SNG transmission service from news source to studio location any where in the world. The comprehensive package includes advanced state-of-the-art Flyaway terminals and associated space segment. Our Flyaway terminal can be used for live coverage of important events, news gathering from remote places and right from the heart of action. DSNG services are indispensable tools for frontline reporting. Our SNG terminals stationed at New Delhi and Chennai form the core of this service. The DSNG Flyaway terminals are equipped with both circular as well as linear C band feed system and can thus be used to access any satellite network as per customer's convenience.
VIDEO CODEC 2300
It has selectable data rates of p*64 bits where p=1 to allow users to integrate video, voice and data traffic.
It uses the CCITT recommendations h.261 for picture coding. In addition to real time moving picture transmission the codec an also handle document transmission once transmitted the last document is saved and can then be recalled.
VIDEO CASSETTE RECORDER
It is possible to connect a videocassette recorder into the system to both play and record meetings.
ADVANTAGES:
The most obvious benefit is the cost. For example: -bringing three executives of a company from different locations in the world for a meeting at a common location could be cause more and may be in lakhs but by using VC we can organize that meeting with less cost so it a really be a big advantage in the communication field that cause less cost in organizing meetings.
• It can lead to more timely decisions.
• It can help in making more involved decisions.
• Quick decision making with less chances of wrong decision.
• Through video conferencing
Application Layer:
The application layer is the OSI layer closest to the end user, which means that both the OSI application layer and the user interact directly with the software application.
This layer interacts with software applications that implement a communicating component. Application layer functions typically include identifying communication partners, determining resource availability, and synchronizing communication.
When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit.
When determining resource availability, the application layer must decide whether sufficient network resources for the requested communication exist. In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer.
Some examples of application layer implementations include Telnet, File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP).