# Positioning Methods and the Use of Location and Activity Data in Forests
## 4 Location-Based Services, the Internet of Things, Wearable Technology, and Big Data
### Geofences  
Geofences, virtual boundaries, virtual fences, and proximity alerts are names for closely related concepts in which an action or alert is triggered when an object with a mobile device or other transponder crosses a geographic boundary associated with a pre-defined area or point of interest (POI) [178; 179]. Geofence boundaries may be defined as a radius around a POI or by an irregular polygon, typically based on GNSS coordinates [178]. Geofencing has been suggested for a variety of spatial-awareness applications, including location-based services for tourism (e.g., recommending nearby sights) and advertising (e.g., offering coupons to passers-by) [179], fleet monitoring and management (e.g., tracking shipments) [178], smart cooling (e.g., activating fans only when individuals are present) [180], and emergency response (e.g., keeping traffic lights green when an ambulance or police vehicle approaches an intersection) [181].  
In natural resources, geofences may help delineate hazardous areas. For example, [PERSON] et al. used geofences and biotelemetry devices to alert wind farm operators of the proximity of large birds to reduce collisions [182]. Geofences have also been evaluated for forestry applications to mark unsafe working areas around equipment hazards or snags (dead trees) on active logging operations [20; 21; 85]. [PERSON] et al. assessed errors associated with mobile geofences that move with a dynamic, point hazard, such as a hand faller [22]. In this case, the geofence represents a hazardous area for others, but can also define safe zones for the hand faller, triggering an alert when he or she approaches another geofence, such as around a second hand faller.  
Figure 11: In location-based service applications for mobile devices, proximity to Bluetooth beacon signals trigger the sharing of information provided in smartphone applications. Mobile applications may also then develop metrics based on how many users have passed a beacon location, or modify information provided based on a sequence of actions taken by users as they interact with multiple beacons. LBS can also base information on geographic coordinates (GNSS) or proximity to map-based features.  
Virtual fences are also used as animal containment systems and have been deployed widely in rangeland science to manage animal movement [183; 184; 185]. An alternative to traditional, static fencing, virtual boundaries can promote a variety of management goals, such as monitoring animal movement [186], separating individuals [185], limiting herbivory [184], protecting riparian habitats [185], reducing soil degradation [183], and relocating herds [183; 185]. Although virtual fencing is not infallible [187; 188] and may not be appropriate for non-social species [186], it has several advantages over traditional fencing, including the capacity to change spatially and temporally [184; 185; 186] and the ability to cover remote or difficult terrain [185]. Instead of triggering an alert, crossing a boundary administers a sensory stimulus, typically through a collar, aimed at altering the animal's behavior (i.e., further movement past the fence) [183; 184] (Figure 12). The stimulus may be a sound, vibration, light pulse, shock, or combination of cues that cause irritation or annoyance to train an animal to avoid an area [183; 185; 187].