Internet Routing in Space, also known as IRIS, is a project being conducted by the U.S. Department of Defense to place an IP (Internet protocol) router on a geostationary satellite. The project is intended for military communications but may eventually be used by the private sector as well. If widely implemented, this technology has the potential to dramatically increase flexibility and traffic handling capability compared with existing satellite Internet systems.
With current satellite Internet technology, transmission of packets between earth-based end users requires that the data be sent from the source end user to the satellite, where it is received and retransmitted by a repeater. The signal then goes down to a centralized router on the surface, then back up to the satellite where it is processed by a second repeater and then sent down to the destination end user. That means every packet must be received and retransmitted at least three times and must make two complete round trips to the satellite. In the IRIS system, the satellite will receive packets directly from the source and transmit them directly to the destination, eliminating all intermediate surface nodes and requiring only one round trip to the satellite. This will reduce the latency, simplify the system, improve reliability and lower the overall maintenance cost.
The IRIS project is scheduled to be completed and the satellite launched in 2009. Cisco Systems is designing the software for the on-board router. The hardware is being built by Intelsat, the largest provider of fixed satellite services worldwide. Overall coordination will be done by the U.S. Defense Information Systems Agency.
NASA reported in November 2008 that the Agency had completed a successful test of a deep space communications network for their similar project, Interplanetary Internet.
> NASA reports on their first successful test of deep space communications network.
> BBC News describes the basics of the IRIS project.
> Govtech.net has more information about Internet Routing in Space.