Evaluation of the protocols within the CODE mesh VSAT network

The Co-Operative Data Exchange (CODE) network is a very small aperture terminal (VSAT) system which provides interconnection of local area networks (LANs) at remote sites via satellite. CODE provides both star and mesh capability, dynamically assigning channels on request to the participating sites. The routing function required to ensure the data arrives at the correct end destination is also provided. The CODE hub can provide a data rate of up to 2 Mbps as an outbound signal and the remote sites can respond to the hub (star) or communicate between remote sites (mesh) at 64 kbps. CODE provides the end-user with a standard ethernet interface which provides access to a TCP/IP (transmission control protocol internet protocol) transport service that can support applications such as data dissemination, database interrogation and update, Telnet and e-mail. The CODE technology was initially developed and the CODE network first operated at Ka band frequencies on the European Space Agency´s Olympus satellite. The CODE network has now been transferred to the Ku band space segment and also to the alternative Ka band capacity. One example of a Ku band network is the Spanish CODE network which consists of a hub and eight remote sites located at Telecommunication Schools throughout Spain (including the Canary Isles) and uses the HISPASAT space segment to deliver lecture courses from Madrid. The outbound signal is a multimedia signal combining digital voice, video and data with an audio return link. The system has been operational since the end of February 1994