“…Locationbased estimators employ auxiliary positioning systems such as global positioning system (GPS) that consume extra energy [61,62,63,64]. Neighborhood-based estimators, which are not scalable and suffer from inaccurate results, infer density from a census on packet traffic [5,65,66,67,68,69]. Power-based estimators combine the merits of location-and neighborhood-based estimators [70,58,71,72], although RSS is not a robust distance estimator.…”