Satellite Internet is a term used to describe the method of accessing the global Internet network via the satellite spacecraft. Usually, most of the customers choose satellite due to unavailability of the local terrestrial DSL or ISDN infrastructure. There are two main types of Satellite Internet service: two-way and one-way, which is usually complemented by a one-way multicast service, also known as offline data delivery in order to download large data volumes like movies and music files efficiently.
Two-way VSAT Service
Two-way Satellite Internet access service is a completely autonomous set up which does not require any IP connectivity from the subscriber - it can provide Satellite Internet access anywhere in the satellite coverage map. This means that almost in any point of our planet there is a chance to get a high-quality, affordable broadband Internet access. The two-way Satellite Internet access subscriber is required Earth Station equipment which is generally referred as VSAT - Very Small Aperture Terminal - equipment . The VSAT Earth Station, in it's turn, establishes two-way radio circuit with the satellite spacecraft and is used both for downloading and uploading data from and to Internet.
One-way DVB(Digital Video Broadcasting) Service
This is the most affordable Satellite Internet access service available on the market. With one-way scenario, the subscriber uses it's narrowband terrestrial or wireless Internet connection (dial-up, ISDN or leased line, GPRS, EDGE, CDMA, etc) as an outbound transmit circuit. The Satellite ISP acts as the downlink provider, enabling the subscriber to download data via satellite. This concept is very popular as many users require broadband links for data download purposes only and usually do not require a broadband uplink channel. Additionally, the benefits are that one-way Satellite Internet equipment costs are pretty low as this scenario works on a standard satellite TV antennas and universal LNB available almost in every satellite shop locally. Usually, Satellite ISP use DVB (Digital Video Broadcasting) standard as the transport for IP packets and the customer is required to install a DVB router or internal PCI.
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