Architecture of the SISNeT platform

SISNeT is today relying on the ESTB broadcast SIS. This is excellent for allowing ESTB GEO SIS broadcast monitoring through the Internet but does not allow a real back up of the ESTB GEO SIS in case of GEO outages.

In addition, SISNeT adds the GEO transmission delay to the SISNeT broadcasting, and conditions the SISNeT availability to the status of the EGNOS receiver (located at the SISNeT Base station). For these reasons, ESA has launched a complementary SISNeT development, aimed at directly connecting the SISNeT Base Station and Data Server to the ESTB Central Processing Facility.

In addition to this improvement, the SISNeT technology tends to continuously integrate new functionalities, in response to the needs of SISNeT developers. For instance, GPS low-end receivers (normally PCMCIA) do not typically provide either the GPS ephemeris information or the GPS ionospheric model parameters. The SISNeT platform has been upgraded, allowing users to get that information which is necessary to build SISNeT-powered EGNOS receivers.
ESA firmly believes that this EGNOS / Internet synergy will open a considerable number of powerful applications for Satellite Navigation.