Patent attributes
A cross reality system enables any of multiple devices to efficiently and accurately access previously stored maps and render virtual content specified in relation to those maps. Both stored maps and tracking maps used by portable devices may have wireless fingerprints associated with them. The portable devices may maintain wireless fingerprints based on wireless scans performed repetitively, based on one or more trigger conditions, as the devices move around the physical world. The wireless information obtained from these scans may be used to create or update wireless fingerprints associated with locations in a tracking map on the devices. One or more of these wireless fingerprints may be used when a previously stored map is to be selected based on its coverage of an area in which the portable device is operating. Maintaining wireless fingerprints in this way provides a reliable and low latency mechanism for performing map-related operations.