A method for a user equipment for operating in a first cellular network supporting unlicensed spectrum access, the user equipment camping on a first base station (sBS) of the first cellular network, the user equipment maintaining a first set of configuration parameters of the first cellular network provided by the first base station, wherein a configuration parameter of the first set, alone or in combination with the other parameters of the first set of configuration parameters, characterizes the first cellular network, the method comprising for the user equipment the steps of, before reading of first system information block of any one of the set of neighbor base stations: - measuring strength of signals transmitted by the first base station (sBS), - measuring strength of signals transmitted by at least one of a set of neighbor base stations operating in unlicensed spectrum, - determining a second set of configuration parameters corresponding to a second base station out of the set of neighbor base stations, wherein the determining is based on received signals transmitted by the second base station; - considering said second base station for cell re-selection under the following conditions: - the measured signal strength for said second base station is higher than said measured signal strength of first base station (sBS), and - said determined second set of configuration parameters corresponds to said maintained first set of configuration parameters, meaning, with high probability, that the second base station belongs to the first cellular network as the first base station, - carrying out a cell re-selection to the second base station when said conditions apply, wherein the first and second set of configuration parameter comprise data relating to system frame numbering, the user equipment receives from the first base station (sBS) an indication that the base stations of the first cellular network are operating system frame number synchronized and wherein said determined second set of configuration parameters corresponds to said maintained first set of configuration parameters when the UE detects that a system frame number of the first base station is synchronised with a same system frame number of the second base station. the user equipment camping on a first base station (sBS) of the first cellular network, the user equipment maintaining a first set of configuration parameters of the first cellular network provided by the first base station, wherein a configuration parameter of the first set, alone or in combination with the other parameters of the first set of configuration parameters, characterizes the first cellular network, the method comprising for the user equipment the steps of, before reading of first system information block of any one of the set of neighbor base stations: - measuring strength of signals transmitted by the first base station (sBS), - measuring strength of signals transmitted by at least one of a set of neighbor base stations operating in unlicensed spectrum, - determining a second set of configuration parameters corresponding to a second base station out of the set of neighbor base stations, wherein the determining is based on received signals transmitted by the second base station; - considering said second base station for cell re-selection under the following conditions: - the measured signal strength for said second base station is higher than said measured signal strength of first base station (sBS), and - said determined second set of configuration parameters corresponds to said maintained first set of configuration parameters, meaning, with high probability, that the second base station belongs to the first cellular network as the first base station, - carrying out a cell re-selection to the second base station when said conditions apply, - measuring strength of signals transmitted by the first base station (sBS), - measuring strength of signals transmitted by at least one of a set of neighbor base stations operating in unlicensed spectrum, - determining a second set of configuration parameters corresponding to a second base station out of the set of neighbor base stations, wherein the determining is based on received signals transmitted by the second base station; - considering said second base station for cell re-selection under the following conditions: - the measured signal strength for said second base station is higher than said measured signal strength of first base station (sBS), and - said determined second set of configuration parameters corresponds to said maintained first set of configuration parameters, meaning, with high probability, that the second base station belongs to the first cellular network as the first base station, - carrying out a cell re-selection to the second base station when said conditions apply, wherein the first and second set of configuration parameter comprise data relating to system frame numbering, the user equipment receives from the first base station (sBS) an indication that the base stations of the first cellular network are operating system frame number synchronized and wherein said determined second set of configuration parameters corresponds to said maintained first set of configuration parameters when the UE detects that a system frame number of the first base station is synchronised with a same system frame number of the second base station.