WIS2 Overview
The WMO Information System 2.0 (WIS 2.0) has been designed to address the limitations of the current WIS and Global Telecommunication System (GTS). In particular, it supports the WMO’s Unified Data Policy and the Global Basic Observing Network (GBON) while meeting the growing demand for high-volume, high-velocity, and diverse data with strong reliability all all earth-system domains.
Unlike GTS, which relies on private dedicated links, WIS 2.0 leverages the public Internet and employs a publish-subscribe model using the MQTT protocol. This allows users to subscribe to specific topics and receive real-time data updates efficiently.
Each Data Publisher is required to operate a WIS2 node to publish data and metadata notifications and enable data downloads via HTTP(S).
WIS2 Global Services
Three types of Global Services are used to enable the dissemination of data in the WIS2 network:
- Global Broker: Provides MQTT(S) Broker that re-publishes data-notifications of all WIS2 Nodes. Users of WIS 2.0 will be able to access data in real-time by subscribing to a Global Broker and receiving notifications when new data is available for download from a Global Cache or from the data provider WIS2 Node.
- Global Discovery Catalogue: Provides a discovery catalogue, usable through an API or web interface, storing WIS 2.0 Discovery Metadata records. The Global Discovery Catalogue allows users to discover available datasets on WIS 2.0 and provide information on how and where to access the data.
- Global Cache: Provides HTTP(S) server where core data (as defined in WMO Resolution 1) can be downloaded from.
- Global Monitor: Provides monitoring dashboards based on metrics collected from other Global Services and alerting mechanism to ensure 24/7 operations
A Data Consumer in WIS 2.0 can discover the MQTTendpoints for subscribing to data using Global Discovery Catalogue. Data classified as "core" as per the WMO Unified Data Policy is available for download without access restrictions from the Global Cache. For "recommended data", a Data Consumer is accesses data directly from the data publisher. Note that recommended data may have access control requirements, which are described in WIS2 discovery metadata.
Each Global Service operator has a centre identifier. Please consult the following guidance on assigning a centre identifier.
What is a WIS2 node?
A WIS2 Node is a key component of WIS 2.0, deployed by National Centres (NC) and Data Collection or Production Centres (DCPC) to publish their data and metadata notifications efficiently.
A WIS2 Node is composed of twoc services endpoints that need to be exposed over the public Internet:
- MQTT broker: to publish WIS2 notifications for metadata and data
- HTTP server: to enable the download of data and metadata
WIS 2.0 Topic Hierarchy
Data Consumers subscribe to specific WIS2 topics to target the data-type they wish to receive.
The topic structure is is consistent with Annex 1 of the WMO Unified Data Policy:
Data announced via a message on origin/a/wis2/<centre-id>/data/core implies free and unrestricted access (as defined in Resolution 1). This data will be downloaded by the Global Cache and availability of this data will be announced on cache/a/wis2/<centre-id>/data/core
Access to data announced on origin/a/wis2/<centre-id>/data/recommended may require access control. Data published on this subtopic is not downloaded by WIS2 Global Caches.
Complete information on the Topic Hierarchy can be found at the Manual on WIS, Vol II, APPENDIX D: WIS2 TOPIC HIERARCHY
WIS 2.0 Notification Message
The Manual on WIS, Vol II, Appendix E: WIS2 Notification Message defines the attributes used in the message payload of a WIS2 Notification.
A WIS 2.0 Notification contains a "canonical" link indicating the HTTP(S) endpoint where the data can be downloaded from :
WIS2 Discovery Metadata
WIS 2.0 Discovery Metadata records are encoded according using the Manual on WIS, Vol II, APPENDIX F: WMO CORE METADATA PROFILE (VERSION 2).
Data Producers are required to publish a WIS 2.0 Notification on the topic origin/a/wis2/<centre-id>/metadata of their WIS2 Node, containing a canonical link to the WCMP2 record. The Global Discovery Catalogue is updated using the records published on a WIS2 Node's "metadata" subtopic.
Setting up a WIS 2.0 Node
In order to setup a WIS 2.0 Node for data sharing on WIS2.0, the Data Publisher needs to setup the following components to be accessible over the public internet:
- Provide an HTTP-endpoint for downloading the data advertised in the notifications and an MQTT-broker publishing WIS2 Notifications for data and metadata
- Create WIS2 Discovery metadata records for datasets using the WCMP2 standard
- Publish MQTT notification messages to notify the availability for each new metadata record and data granule
In order to accelerate the implementation of WIS2, WMO has supported the development of the "WIS2 in a box" (wis2box) software: a Free and Open Source (FOSS) Reference Implementation of a WIS2 Node. For more information see the wis2box documentation
WIS2 Node Registration
Registration of a WIS2 Node must be approved by the Permanent Representative with WMO (PR) for the country or territory in which the WIS Centre resides. The National Focal Point (NFP) on WIS matters can register a WIS2 Node on behalf of the PR for an official NC or DCPC listed in the Manual on WIS (WMO-No. 1060) Volume I: WIS 1.0.
- Request hosting a WIS2 Node via WIS National Focal Point (NFP)
- Assign a centre identifier: The centre identifier (centre-id) is an acronym as proposed by the Member and endorsed by the WMO Secretariat. (Guidance on assigning a centre-id of WIS2 Nodes can be found here).
- Complete the WIS2 Register: The WIS NFP shall complete the WIS2 Register operated by the WMO Secretariat.
- Provide Global Service details: The WMO Secretariat provides connection details for the Global Services (e.g. IP addresses) so that the WIS2 Node can be configured to provide the access.
- WIS2 Node assessment: It is conducted by the principal GISC verifies that the WIS2 Node is compliant with WIS2 requirements.
- Add new centre to WIS2: GISC notifies WMO Secretariat and confirms that this WIS2 Node can be added to WIS2
- Communicate details to the Global Services: WMO Secretariat provides the WIS2 Node connectivity details to the Global Brokers to subscribe to the WIS2 Node.
More guidance can be found at the Guide to WIS, Vol. II. 2.6.1.1 Registration and decommissioning of a WIS2 Node
Transition to WIS 2.0
Effective January 1, 2025, the WMO Information System 2.0 (WIS 2.0) officially enters its operational phase, marking a significant advancement in global data sharing.
The migration to WIS 2.0 is planned from 2025 to 2030, with a goal of achieving up to 90% transition. The Global Telecommunication System (GTS) is scheduled for decommissioning by 2033. For more information on the transition from GTS/WIS to WIS 2.0 please refer to Provisions for the Transition from WMO Information System (WIS) 1.0 and Global Telecommunication System to WIS 2.0 (WMO-No.1323).
(Last update: 7 Feb 2025)