Method for switching a base station from an inactive operational mode to an active operational mode in a hierarchically structured mobile

A method for switching a base station (32, 34) from an inactive operational mode to a more active operational mode in a hierarchically structured mobile communication network (2, 3) with at least one small cell base station (31, 32, 33, 34) and at least one macro cell base station (21, 22, 23) in a radio access network (2), the method comprising the steps of:

• a) determining a current operational mode of the at least one small cell base station (31, 32, 33, 34);
• b) switching the at least one small cell base station (31, 32, 33, 34), from an inactive operational mode to the more active operational mode depending on the determined current operational mode, by a switching signal, said switching signal being included in a paging signal for establishing data traffic between the at least one macro cell base station (21, 22, 23) and a mobile station (50, 51) assigned to the at least one small cell base station (31, 32, 33, 34), the paging signal being sent to any of i) the at least one macro cell base station (21, 22, 23), ii) a subsidiary to a small cell base station (31, 32, 33, 34) in active operational mode, and iii) the subsidiary to the small cell base station (31, 32, 33, 34) in an inactive operational mode;
• c) checking whether at least one predefined criteria in addition to a parameter indicating the current operational mode of the at least one small cell base station (31, 32, 33, 34) is fulfilled;
• and
• d) depending on the checking result of step c), transmitting a switching signal from a higher level network entity (6, 21, 22, 23) to the at least one small cell base station (31, 32, 33, 34),
• wherein the at least one predefined criteria includes network performance information parameters, said network performance information parameters including any of energy consumption parameters, quality of services related parameters, and timing related parameters.