The Global Telecommunications System (GTS) was established by the World Meteorological Organization and is used by National Meteorological Services (NMS) throughout the world to receive, send and relay meteorological data and products.
The Regional Meteorological Data Communication Network (RMDCN) provides a computer network infrastructure for the meteorological community in WMO Region RA-VI (Washington) and RA-II (Beijing).
WMO's Global Telecommunication System (GTS) is the communications and data management component, that allows the World Weather Watch (WWW) to operate through the collection and distribution of information critical to its processes. The system is implemented and operated by National Meteorological Services, of WMO Members, and international organisations, such as ECMWF and EUMETSAT. This secured communication network enables real-time exchange of information, critical for forecasting and warnings of hydrometeorological hazards, in accordance with approved procedures.
The WMO Information System (WIS) is the coordinated global infrastructure responsible for the telecommunications and data management functions. WIS provides an integrated approach, suitable for all WMO programmes, to meet the requirements for routine collection and automated dissemination of observed data and products, as well as data discovery and access and retrieval services for all weather, climate, water and related data, produced by member countries and organisations.
WMO website has more information on the GTS.
Regional Meteorological Data Communication Network (RMDCN)
The RMDCN network is based on the Multiprotocol Label Switching (MPLS) backbone infrastructure of Orange Business Services (OBS), a merger of Orange, Equant and France Telecom. This technology allows OBS to implement an IP Virtual Private Network (IPVPN) for the RMDCN community. The main characteristics of the new network include any-to-any connectivity between RMDCN members; load balancing for mission critical sites, and multiple resilience options — depending on user requirements. (Source: WMO and ECMWF)
ECMWF website has more information.