Within the current EUMETCast configuration, the multicast system is based upon a client/server system with the server side implemented at EUMETSAT headquarters and the client side installed on the individual EUMETCast reception stations.
The multicast stream is transported to the user via Satellite networks (EUMETCast Satellite service) or terrestrial networks (EUMETCast Terrestrial demonstration service).
Each receiving station decodes the signal and recreates the data/products according to a defined directory and file name structure.
A single reception station can receive any combination of the services provided on EUMETCast. Data for which access is restricted, in accordance with EUMETSAT Data Policy, is made secure by the USB decryption scheme.
Important Note: New EUMETCast Africa Service
Files are encoded into a multicast stream at the EUMETCast Platform. The multicast stream is then transported to the user via two main networks: EUMETCast Satellite and EUMETCast Terrestrial.
On EUMETCast Satellite the multicast is transferred via a dedicated communications line from EUMETSAT to the uplink facility. There the multicast is encoded into a DVB signal and transmitted to a geostationary communications satellite for broadcast to user receiving stations. Each receiving station decodes the signal and recreates the original multicast stream.
On EUMETCast Terrestrial the multicast is transferred via a multicast-enabled dedicated network to the user. Users must be eligible to connect to the national research networks and the research network must be included in the EUMETCast Terrestrial network.
The EUMETCast Client stations decode the multicast back into files according to the subscription of the user.
EUMETCast Terrestrial is currently a demonstration service and is being evaluated for its potential to work as a back-up to the EUMETCast Satellite service.
Data File Encryption/Decryption
The EUMETCast system allows files to be independently targeted towards a single user, or group of users, thus enabling the secure control of access to the data at individual file and individual user level. The encryption of the data is performed by the EUMETCast uplink and decryption by the EUMETCast Client Software, installed on the reception station. The data encryption keys are typically valid for just one transmission and encrypted with the user key (password) of the target user.
Those data controlled in accordance with EUMETSAT Data Policy are only accessible by users who have been given the necessary decryption keys for the EUMETSAT service/s they have been licensed to receive. To access these services, in addition to the decryption keys, users will need to operate a station equipped with a EUMETCast Key Unit (EKU).
The EKU decryption device is connected, via USB, to the reception station. The decryption device is used by the EUMETCast Client Software to decrypt the data key of the next transmission. EUMETSAT manages the distribution of the decryption devices to registered users.
Service Management and Service Directories
The service configuration management is done by EUMETSAT, who controls the service configuration on the multicast platform. Management of the satellite transponder bandwidth capacity available to EUMETCast is achieved with channels and by the use of a priority scheme. The multicast platform management software adapts the uplink stream according to the relative priorities of the data waiting to be transmitted on a particular channel.
The EUMETCast interface is based on a concept called Service Directories into which the data to be multicast are transferred from the EUMETSAT Ground Segment. These service directories are part of the multicast system platform. A distribution list is associated with each service directory, this identifies all the EUMETCast users entitled to receive the data transferred to the directory.
The service directory structure is also used to allocate bandwidth characteristics to a particular set of products or directories.
The satellites used by the uplink providers to relay the EUMETCast multicast form part of the Eutelsat satellite fleet.
EUTELSAT™ 10A, located at 10° E, carries a powerful payload of Ku-band capacity, supplying coverage across Europe, North Africa and the Middle East. Under the current arrangements provided by the uplink provider, EUMETCast is available via one of the wide beam Ku-band transponders.
EUTELSAT™ 8 WEST, located at 8° West, carries a Ku/C-band payload of 50 transponders (40 Ku-band, 10 C-band) with European African and western Asia coverage. Under the current arrangements provided by the Africa turnaround provider, EUMETCast is available via one of the C-band transponders.
For more information on these two satellites visit the Eutelsat website.
To view the current transponders in use for EUMETCast reception go to the Reception Station Set-up page.
EUMETCast Terrestrial is a demonstration dissemination service. It functions like the satellite service, but using a terrestrial network instead of a satellite network. The network used is the National Research and Education Network (NREN) and the GÉANT infrastructure. Only organisations eligible for access to a NREN can access the service, if the NREN supports multicasting.
EUMETCast Terrestrial is being evaluated for its potential to work as a back-up to the EUMETCast Satellite service.
Reference reception stations are used to monitor the status of the system. There are reference reception stations at each data provider, the uplink service provider and on every turnaround service provider. Each data provider is responsible for the end-to-end monitoring of its own data. EUMETSAT monitors the end-to-end service relative to the data provided by EUMETSAT.