A method of communications, comprising: receiving , by a user equipment, UE , one or more positioning reference signals, PRSs , from each cell of a plurality of cells , a second positioning reference signal, PRS , of the one or more positioning reference signals, PRSs, from a cell of the plurality of cells includes a second time of departure of the second positioning reference signal, PRS, the second time of departure being relative to a first time of departure of a first reference positioning reference signal, PRS , received from the cell , the first reference positioning reference signal, PRS, being the first positioning reference signal, PRS, transmitted from the cell ; determining , by the user equipment, UE , arrival times of positioning reference signals, PRSs, from different cells of the plurality of cells; and transmitting , by the user equipment, UE , reference signal time difference, RSTD, values, a reference signal time difference, RSTD, value of the reference signal time difference, RSTD, values being determined by subtracting the second times of departure from the arrival times of PRSs from different cells of the plurality of cells , wherein the RSTD is calculated by: RSTD = T 1 − aX − T 2 − bY , wherein T 1 is an arrival time of a reference signal from a first cell among the plurality of cells; aX is the second time of departure of the reference signal from the first cell: T 2 is an arrival time of a reference signal from a second cell among the plurality of cells; and bY is the second time of departure of the reference signal from the second cell. receiving , by a user equipment, UE , one or more positioning reference signals, PRSs , from each cell of a plurality of cells , a second positioning reference signal, PRS , of the one or more positioning reference signals, PRSs, from a cell of the plurality of cells includes a second time of departure of the second positioning reference signal, PRS, the second time of departure being relative to a first time of departure of a first reference positioning reference signal, PRS , received from the cell , the first reference positioning reference signal, PRS, being the first positioning reference signal, PRS, transmitted from the cell ; determining , by the user equipment, UE , arrival times of positioning reference signals, PRSs, from different cells of the plurality of cells; and transmitting , by the user equipment, UE , reference signal time difference, RSTD, values, a reference signal time difference, RSTD, value of the reference signal time difference, RSTD, values being determined by subtracting the second times of departure from the arrival times of PRSs from different cells of the plurality of cells , wherein the RSTD is calculated by: RSTD = T 1 − aX − T 2 − bY , wherein T 1 is an arrival time of a reference signal from a first cell among the plurality of cells; aX is the second time of departure of the reference signal from the first cell: T 2 is an arrival time of a reference signal from a second cell among the plurality of cells; and bY is the second time of departure of the reference signal from the second cell. T 2 is an arrival time of a reference signal from a second cell among the plurality of cells; and bY is the second time of departure of the reference signal from the second cell. <EOS>