Satellite Internet is an alternative to dialup, ISDN, DSL, or cable Internet.

Satellite Internet is extremely interesting to customers who cannot get DSL or cable Internet.

Satellite Internet offers broadband speeds, but suffers from high latency due to long round-trip times made necessary by the distance to geostationary satellites.

The latency issues related to satellite Internet can be significantly reduced through the use of caches and protocol accelerators.

Types of Satellite Internet

The two main types of satellite Internet are those in which the return path is sent using dial-up and those in which the return path is sent via satellite uplink.

Dial Return Satellite Internet

Dial-return satellite Internet is a system where data is transmitted to a user via satellite, but all return traffic from the user is sent via a dialup modem.

Dial-return satellite Internet offers very good download speeds, but is limited to analog modem speeds on the upload side.

DVB-RCS Satellite Internet

DVB-RCS is the oldest standard for satellite Internet. DVB-RCS is part of the global DVB standards for satellite transmission.

DVB-RCS has never achieved significant market penetration and will most likely be phased out over the next decade.

The LinkStar system developed by ViaSat supports DVB-RCS.

IPoS Satellite Internet

IPoS (Internet Protocol over Satellite) is a newer satellite Internet protocol which was developed by Hughes Network Systems (HNS), the developers of Direcway.

HNS has attempted to increase adoption of their IPoS protocol by presenting to the ETSI as a standard. The ETSI has issued IPoS as ETSI TS 102 354.

IPoS has yet to achieve market acceptance outside of Hughes Network Systems.

Popular IPoS providers include HughesNet and companies like Satellite Internet.

S-DOCSIS Satellite Internet

S-DOCSIS is a modification of the DOCSIS cable-modem protocol for transmission over satellite.

To work well over satellite links, the DOCSIS protocol was modified to support additional modulation algorithms, such as QPSK. In addition, variable modulation protocols allow support for a wide range of satellite transmission attenuation conditions.

S-DOCSIS has been deployed in countries such as the United States, Canada, Saudi Arabia, France, Mexico, Colombia, and Malaysia.

S-DOCSIS is very likely to be the winner among satellite Internet standards due to the enormous advantages to economy-of-scale made available through sharing development costs with all of the existing cable DOCSIS systems.

The Surfbeam system developed by ViaSat is a S-DOCSIS system.