Method for estimating relative proximity of wireless network access nodes (A-G), and their availability to a mobile computing device (110, 210), without using geolocation data of said access nodes, wherein the mobile computing device comprises at least one wireless network interface (113, 213, 213') for communicating with wireless network access nodes, a processing unit (116, 216) and a memory element, the method comprising the following steps: a) at said mobile computing device, during consecutive time slots forming a timespan, discovering wireless network access nodes while the position of the mobile device is evolving; b) in each time slot, generating a discovery record (112, 212) for each discovered access node using the processing unit (116, 216), said discovery record comprising a unique identifier of said access node, together with timing information identifying the current discovery time slot, and storing said discovery record in said memory element; c) after said timespan, processing said discovery records (112, 212) using data processing means (140, 240), comprising: - for each discovered access node, generating metadata comprising an indication including at least an estimation of a displacement speed of said device at access node discovery, and a further indication of the access node's availability, wherein the indication comprises a discovery count, which is the number of discoveries of the access node within said timespan, and associating said metadata with the access node's unique identifier in a memory element; d) using the data processing means (140, 240), generating data indicating that any two discovered access nodes were in proximity of each other if they have been discovered in the same time slot, and storing said data in a memory element; wherein the mobile computing device (110, 210) further comprises sensing means for estimating the displacement speed of the device, and wherein the duration of said timeslots depends on the displacement speed of the device. a) at said mobile computing device, during consecutive time slots forming a timespan, discovering wireless network access nodes while the position of the mobile device is evolving; b) in each time slot, generating a discovery record (112, 212) for each discovered access node using the processing unit (116, 216), said discovery record comprising a unique identifier of said access node, together with timing information identifying the current discovery time slot, and storing said discovery record in said memory element; c) after said timespan, processing said discovery records (112, 212) using data processing means (140, 240), comprising: - for each discovered access node, generating metadata comprising an indication including at least an estimation of a displacement speed of said device at access node discovery, and a further indication of the access node's availability, wherein the indication comprises a discovery count, which is the number of discoveries of the access node within said timespan, and associating said metadata with the access node's unique identifier in a memory element; - for each discovered access node, generating metadata comprising an indication including at least an estimation of a displacement speed of said device at access node discovery, and a further indication of the access node's availability, wherein the indication comprises a discovery count, which is the number of discoveries of the access node within said timespan, and associating said metadata with the access node's unique identifier in a memory element; d) using the data processing means (140, 240), generating data indicating that any two discovered access nodes were in proximity of each other if they have been discovered in the same time slot, and storing said data in a memory element;