HERE is committed to maintain the best possible production service for all customers. Given that the production environment is live and common to all API users, it should be used only for general production use and for functional/integration testing.
The production environment is not designed to support sudden, unannounced high loads, including performance tests. If you need to do performance testing, contact HERE to discuss options.
The production version of HERE GNSS Service can be found at wss://gnss.hereapi.com:443/websocket/v1.