Internet Protocol (IP)
The Internet Protocol (IP) is really an entire family of data communication protocols, popularized for email and Web browsing. History
IP is an outgrowth of US government and university research over the past 30 years and now dominates the field of computer communications.
Application of IP services and networks to the satellite field came rather late, partly because these standards grew out of the telephone and fiber optic networks. Applications beyond computers
The resources available under IP appear to be limitless. Current applications include:
- Voice over IP (VoIP)
- Video conferencing (H.323)
Current generations of modems and VSAT equipment support IP almost to its full capability, even though satellite links introduce about one quarter second of additional delay.
IP is structured in a five-layer architecture model; this is in contrast to the now defunct Open Systems Interconnection (OSI) model that is composed of seven layers.
The integrated layers of the Internet Protocol suite. This shows the IP layer (at Layer 3), which employs the familiar IP addresses (example of an IP Address: 192.168.1.107)
To allow efficient use of satellite capacity, a typical IP link will employ a different protocol within the satellite network. Outside of the earth station and VSAT, normal user devices employ the IP standard without modification.
Illustration of how a standard protocol (P1) is employed by normal computers, while the satellite link employs special protocols (Psi and Pso for inbound and outbound, respectively) that are optimized for the delay and error characteristics of satellite radio communications.