A method of providing communication over a mobile communication network comprising two or more fixed nodes (2a, 2b) each operating a fixed radio cell (3a, 3b) for serving one or more user equipments via a first radio interface (5a, 5b), wherein each of the fixed radio cells (3a, 3b) is identified by a physical cell ID (6a, 6b), selected out of a set of N physical cell IDs, and one or more mobile relay nodes served by the two or more fixed nodes (2a, 2b) via a second radio interface (8a, 8b), the one or more mobile relay nodes each operating a mobile radio cell for serving one or more user equipments via a third radio interface, wherein each of the mobile radio cells is identified by a physical cell ID selected out of the set of N physical cell IDs, the method comprising the steps of: dynamically assigning a physical cell ID of the set of N physical cell IDs to the one or more mobile radio cells, measuring a signal strength of a serving fixed radio cell and a signal strength of surrounding fixed radio cells by a mobile relay node, if the signal strength of a surrounding fixed radio cell exceeds the signal strength of the serving fixed radio cell, sending a handover request to the serving fixed node by the mobile relay node and executing a handover acceptance procedure between the serving fixed node and a target fixed node, if the handover is accepted, then assigning a new physical cell ID of the set of N physical cell IDs to a mobile radio cell operated by the mobile relay node, transmitting the new physical cell ID from the serving fixed node or the target fixed node to the mobile relay node and switching from an old physical cell ID to the new physical cell ID by using the new physical cell ID by the mobile relay node to identify the mobile radio cell operated by said mobile relay node. dynamically assigning a physical cell ID of the set of N physical cell IDs to the one or more mobile radio cells, measuring a signal strength of a serving fixed radio cell and a signal strength of surrounding fixed radio cells by a mobile relay node, if the signal strength of a surrounding fixed radio cell exceeds the signal strength of the serving fixed radio cell, sending a handover request to the serving fixed node by the mobile relay node and executing a handover acceptance procedure between the serving fixed node and a target fixed node, if the handover is accepted, then assigning a new physical cell ID of the set of N physical cell IDs to a mobile radio cell operated by the mobile relay node, transmitting the new physical cell ID from the serving fixed node or the target fixed node to the mobile relay node and switching from an old physical cell ID to the new physical cell ID by using the new physical cell ID by the mobile relay node to identify the mobile radio cell operated by said mobile relay node. assigning a new physical cell ID of the set of N physical cell IDs to a mobile radio cell operated by the mobile relay node, transmitting the new physical cell ID from the serving fixed node or the target fixed node to the mobile relay node and switching from an old physical cell ID to the new physical cell ID by using the new physical cell ID by the mobile relay node to identify the mobile radio cell operated by said mobile relay node.