open network provision conditions - the conditions, harmonized according to the provisions of this Directive, which concern the open and efficient access to public telecommunications networks and, where applicable, public telecommunications services and the efficient use of those networks and services. Without prejudice to their application on a case-by-case basis, the open network provision conditions may include harmonized conditions with regard to: - technical interfaces, including the definition and implementation of network termination points, where required, - usage conditions, including access to frequencies where required, - tariff principles.