A positioning system configured for an indoor space, the system comprising: two or more signalling nodes that, upon receiving a request to transmit a location data signal, emit at least one of invisible light, sound and radio frequency signals through different channels carrying location data of each signalling node, where each signal type is emitted from each of the signalling nodes with the same initial intensity in all directions; a terminal comprising: a sensor (140, 160, 180) that detects at least two of the invisible light, sound and radio frequency signals emitted by the two or more signalling nodes; and a position calculation unit that calculates the terminal's position based on the signal strengths of the at least two signals received from the two or more signalling nodes, wherein the position calculation unit, in the event two signals that have different level of received signal strength were detected, calculates the position of the terminal through the following equation x + xB R 2 − 1 2 + y + yB R 2 − 1 2 = Dx R R 2 − 1 where: A and B refer to node A and node B emitting the two signals; xB is the x-axis coordinate of node B on the assumption that node A is the origin; yB is the y-coordinate of the node B; R is the ratio of received signal strength of the node A and the node B; and D is the distance between node A and node B, and wherein the position calculation unit, in the event two signals having the same level of signal strength where detected, calculates the position of the terminal as belonging to a circle with the position of node A and node B as points lying on the opposite ends of the circle and the diameter of said circle being the distance between points A and B.. two or more signalling nodes that, upon receiving a request to transmit a location data signal, emit at least one of invisible light, sound and radio frequency signals through different channels carrying location data of each signalling node, where each signal type is emitted from each of the signalling nodes with the same initial intensity in all directions; a terminal comprising: a sensor (140, 160, 180) that detects at least two of the invisible light, sound and radio frequency signals emitted by the two or more signalling nodes; and a position calculation unit that calculates the terminal's position based on the signal strengths of the at least two signals received from the two or more signalling nodes, wherein the position calculation unit, in the event two signals that have different level of received signal strength were detected, calculates the position of the terminal through the following equation x + xB R 2 − 1 2 + y + yB R 2 − 1 2 = Dx R R 2 − 1 where: A and B refer to node A and node B emitting the two signals; xB is the x-axis coordinate of node B on the assumption that node A is the origin; yB is the y-coordinate of the node B; R is the ratio of received signal strength of the node A and the node B; and D is the distance between node A and node B, and wherein the position calculation unit, in the event two signals having the same level of signal strength where detected, calculates the position of the terminal as belonging to a circle with the position of node A and node B as points lying on the opposite ends of the circle and the diameter of said circle being the distance between points A and B.. a sensor (140, 160, 180) that detects at least two of the invisible light, sound and radio frequency signals emitted by the two or more signalling nodes; and a position calculation unit that calculates the terminal's position based on the signal strengths of the at least two signals received from the two or more signalling nodes, A and B refer to node A and node B emitting the two signals; xB is the x-axis coordinate of node B on the assumption that node A is the origin; yB is the y-coordinate of the node B; R is the ratio of received signal strength of the node A and the node B; and D is the distance between node A and node B, and wherein the position calculation unit, in the event two signals having the same level of signal strength where detected, calculates the position of the terminal as belonging to a circle with the position of node A and node B as points lying on the opposite ends of the circle and the diameter of said circle being the distance between points A and B..