A communication system for positioning of a terminal device, the communication system comprising: at least three leaky coaxial cables (110, 120, 130) arranged in a space, each of the at least three leaky coaxial cables (110, 120, 130) having an inner conductor, an outer conductor and isolation layer between the inner conductor and the outer conductor, wherein the outer conductor of each of the at least three leaky coaxial cables (110, 120, 130) comprises at least one slot (115, 125, 135), the slots (115, 125, 135) arranged consecutive to each other along longitudinal axes of the leaky coaxial cables (110, 120, 130) to leak radio frequency signals and, further, the slots (115, 125, 135) of the different leaky coaxial cables (110, 120, 130) are positioned so that each slot (115, 125, 135) form a service area for serving the terminal device within the space so that the service areas are essentially distinct to each other, a server device for determining a position of a terminal device in response to a receipt of data from the terminal device through at least two coaxial cables (110, 120, 130), the server device is arranged to: determine an indicator value representing the at least two coaxial cables (110, 120, 130) through which the data from the terminal device is received from, compare the indicator value to a plurality of change patterns stored in a data structure in data storage accessible to the server device, the change patterns representing combinations of possible changes of the coaxial cables (110, 120, 130) serving the terminal device as it roams, and generate, in response to a match in a comparison, data representing the position of the terminal device. at least three leaky coaxial cables (110, 120, 130) arranged in a space, each of the at least three leaky coaxial cables (110, 120, 130) having an inner conductor, an outer conductor and isolation layer between the inner conductor and the outer conductor, wherein the outer conductor of each of the at least three leaky coaxial cables (110, 120, 130) comprises at least one slot (115, 125, 135), the slots (115, 125, 135) arranged consecutive to each other along longitudinal axes of the leaky coaxial cables (110, 120, 130) to leak radio frequency signals and, further, the slots (115, 125, 135) of the different leaky coaxial cables (110, 120, 130) are positioned so that each slot (115, 125, 135) form a service area for serving the terminal device within the space so that the service areas are essentially distinct to each other, a server device for determining a position of a terminal device in response to a receipt of data from the terminal device through at least two coaxial cables (110, 120, 130), the server device is arranged to: determine an indicator value representing the at least two coaxial cables (110, 120, 130) through which the data from the terminal device is received from, compare the indicator value to a plurality of change patterns stored in a data structure in data storage accessible to the server device, the change patterns representing combinations of possible changes of the coaxial cables (110, 120, 130) serving the terminal device as it roams, and generate, in response to a match in a comparison, data representing the position of the terminal device. determine an indicator value representing the at least two coaxial cables (110, 120, 130) through which the data from the terminal device is received from, compare the indicator value to a plurality of change patterns stored in a data structure in data storage accessible to the server device, the change patterns representing combinations of possible changes of the coaxial cables (110, 120, 130) serving the terminal device as it roams, and generate, in response to a match in a comparison, data representing the position of the terminal device.