26 Ficora may impose an obligation to lease out a radio mast antenna site and equipment facility referred to in subsection 1(4) and on the grounds referred to in subsection 1(4) on another than a telecommunications operator, if the operator leases out the antenna site and associated equipment facility to another telecommunications operator. The obligation referred to in subsection 1 does not apply, however, if relinquishing access rights endangers national security or data protection or if it is technically inappropriate from the viewpoint of the operator or is otherwise unreasonable. Section 58 Co-location and sharing Ficora may oblige the network operator to allow sharing and co-location of a property for other telecommunications operators if a network operator: 1) has placed a telecommunications cable or radio mast, related equipment, minor structures or poles referred to in section 233 in an area owned or controlled by another; 2) has placed a mobile network base station, related equipment or cable in a building owned or controlled by another party as referred to in section 233; or 3) has affixed necessary equipment to buildings and structures in a manner referred to in section 236; Ficora may impose an obligation referred to in subsection 1, if the construction and location cannot otherwise be organised satisfactorily and at a reasonable cost. A further requirement for imposing the obligation is that it shall not prevent or unreasonably restrict the network operator’s own use. In the event that the parties concerned do not agree on costs related to sharing or colocation, Ficora may issue further regulations on apportioning the costs. Section 59 Own use or reasonable future needs Notwithstanding any obligation imposed under section 56 or 57, the obligation shall not apply if the object of the access rights is used by the telecommunications operator itself or by an undertaking referred to in section 57(2), or if it is necessary for the reasonable own future needs of these undertakings. Chapter 9 Interconnection Section 60 Obligation to negotiate Interconnection means the physical and functional connecting of different communications networks to ensure that users can access communications networks and communications services of other telecommunications operators. A network operator has an obligation to negotiate in good faith on interconnection with another network operator.