Patent ID: 8437775

Claim:
A method in a first network node for enabling estimation of a position of a mobile terminal, wherein a cellular radio communication system comprises the first network node, a second radio network node, a plurality of radio network nodes and the mobile terminal, the second radio network node being managed by the first network node, the method comprising: receiving, via the second radio network node, a request for estimating the position of the mobile terminal; determining a first set of radio network nodes comprising the second radio network node and two additional radio network nodes, said two additional radio network nodes being selected among said plurality of radio network nodes; determining positioning signals for transmission from radio network nodes of the first set of radio network nodes to the mobile terminal, wherein each of the positioning signals is associated with a respective radio network node of the first set of radio network nodes; instructing each of the radio network nodes of the first set to transmit the positioning signal, associated therewith, to the mobile terminal; receiving, via the second radio network node, information for estimating the position of the mobile terminal from the mobile terminal; and estimating the position of the mobile terminal based on the received information, wherein the received information comprises information about timing estimates for each respective radio network node of the first set of network nodes and wherein each respective timing estimate is indicative of the distance between each respective radio network node and the mobile terminal; wherein determining positioning signals further comprises determining time-frequency positions for each of the positioning signals; and wherein the time-frequency position of each positioning signal is based on at least one of load at each respective radio network node of the first set and relative timing between network nodes of the first set of radio network nodes.