A method for determining (S301), in a network including a plurality of radio cells, at least one power saving group comprising at least two radio cells of said plurality of radio cells, the method comprising retrieving (S31) neighboring data including a plurality of entries corresponding to a plurality of combinations of respective two radio cells of said plurality of radio cells, wherein each of said plurality of entries represents overlapping amount information in relation to said respective two radio cells, comparing, for each pair of two radio cells, each of two overlapping amount information elements corresponding to the respective pair of two radio cells with a neighborhood determination threshold, ThN, determining, if at least one of said two overlapping amount information elements is larger than said neighborhood determination threshold, ThN, said respective two radio cells as neighbor radio cells, identifying (S32) radio cells of said plurality of radio cells as power saving group reference cells based on said neighboring data, identifying (S33) radio cells of said plurality of radio cells as power saving group helping cells respectively for at least one identified power saving group reference cell based on said neighboring data, and assigning (S34) each of said identified power saving group helping cells to one of said identified power saving group reference cells based on said neighboring data, wherein each of said at least one power saving group comprises one of said identified power saving group reference cells and at least one identified power saving group helping cell assigned to said one of said identified power saving group reference cells, and wherein said overlapping amount information is indicative of a portion of a geographical coverage of one cell of said respective two radio cells which is overlapped with a geographical coverage of the other cell of said respective two radio cells. retrieving (S31) neighboring data including a plurality of entries corresponding to a plurality of combinations of respective two radio cells of said plurality of radio cells, wherein each of said plurality of entries represents overlapping amount information in relation to said respective two radio cells, comparing, for each pair of two radio cells, each of two overlapping amount information elements corresponding to the respective pair of two radio cells with a neighborhood determination threshold, ThN, determining, if at least one of said two overlapping amount information elements is larger than said neighborhood determination threshold, ThN, said respective two radio cells as neighbor radio cells, identifying (S32) radio cells of said plurality of radio cells as power saving group reference cells based on said neighboring data, identifying (S33) radio cells of said plurality of radio cells as power saving group helping cells respectively for at least one identified power saving group reference cell based on said neighboring data, and assigning (S34) each of said identified power saving group helping cells to one of said identified power saving group reference cells based on said neighboring data, wherein each of said at least one power saving group comprises one of said identified power saving group reference cells and at least one identified power saving group helping cell assigned to said one of said identified power saving group reference cells, and wherein said overlapping amount information is indicative of a portion of a geographical coverage of one cell of said respective two radio cells which is overlapped with a geographical coverage of the other cell of said respective two radio cells. <EOS>