A method for determining an indoor location of a target device in connection with a plurality of beacons having a known position in a space, the method comprising the steps of: - transmitting with a transmitter device a plurality of signals having different respective transmit signal powers, said transmitter device being said target device, and - receiving at least two of said plurality of transmitted signals with respective receiver devices, said respective receiver devices being beacons of said plurality of beacons, and determining for said at least two received signals an indication of the received signal power, characterized in that the method further comprises: - determining for each of said at least two received signals, based on a path loss model, an estimated distance between said transmitter device and said respective receiver device, yielding a set of error functions between said estimated distance and the actual distance to be determined, - assigning weights w j that take into account said different transmit signal powers, whereby a higher weight is given to a lower transmit signal power, - estimating the indoor location of said target device, based on multilateration, by weighing said set of error functions with said weights, whereby information on the transmit signal power is encapsulated in a data field comprised in said transmit signals and information on the identity of the transmitter device is comprised in said transmit signals, as follows: - defining the error function f i,j between estimated and measured distance per measurement as f i, j = x - x i 2 + y - y i 2 - d i, j for i = 1.. M (#beacons) for j = 1.. N (#power levels) where (x,y) is the position of the target device one is looking for, ( x i, y i) the known position of the beacon used in that measurement and d i,j a distance estimation based on the indication of the received signal power, - applying the least squares methodology to minimize the error function F F = ∑ i = 1 M ∑ j = 1 N w j ⋅ f i, j 2 - transmitting with a transmitter device a plurality of signals having different respective transmit signal powers, said transmitter device being said target device, and - receiving at least two of said plurality of transmitted signals with respective receiver devices, said respective receiver devices being beacons of said plurality of beacons, and determining for said at least two received signals an indication of the received signal power, - determining for each of said at least two received signals, based on a path loss model, an estimated distance between said transmitter device and said respective receiver device, yielding a set of error functions between said estimated distance and the actual distance to be determined, - assigning weights w j that take into account said different transmit signal powers, whereby a higher weight is given to a lower transmit signal power, - estimating the indoor location of said target device, based on multilateration, by weighing said set of error functions with said weights, whereby information on the transmit signal power is encapsulated in a data field comprised in said transmit signals and information on the identity of the transmitter device is comprised in said transmit signals, as follows: - defining the error function f i,j between estimated and measured distance per measurement as f i, j = x - x i 2 + y - y i 2 - d i, j for i = 1.. M (#beacons) for j = 1.. N (#power levels) where (x,y) is the position of the target device one is looking for, ( x i, y i) the known position of the beacon used in that measurement and d i,j a distance estimation based on the indication of the received signal power, - applying the least squares methodology to minimize the error function F F = ∑ i = 1 M ∑ j = 1 N w j ⋅ f i, j 2 - defining the error function f i,j between estimated and measured distance per measurement as f i, j = x - x i 2 + y - y i 2 - d i, j for i = 1.. M (#beacons) for j = 1.. N (#power levels) where (x,y) is the position of the target device one is looking for, ( x i, y i) the known position of the beacon used in that measurement and d i,j a distance estimation based on the indication of the received signal power, - applying the least squares methodology to minimize the error function F F = ∑ i = 1 M ∑ j = 1 N w j ⋅ f i, j 2