Subject : Satellite Communication and Networks

Topic : Satellite Links

Open system interconnection (OSI) is a generalized network architecture protocol reference model utilized in networking including satellites.

It is the complete reference model developed by international.It consists of seven layer architecture.

The upper layers that is 7,6,5 namely application,presentation and session layer deal with application issues and usually implemented software.Application layer is the closest with end user.

The lower layers that is 4,3,2,1 namely transport,network,data link and physical layers handles data transport issues.

The physical and data link layer are implemented in hardware and software.The physical layer is closest to physical network medium that is actual cable network and is responsible for transport of information.