# 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
### Location-Based Services  
Location-based services (LBS) refer to services that account for the real-time, geographic positions of a person or mobile object, as determined by RF, Bluetooth or BLE, GNSS, assisted GNSS (perpetual locating of a device), or broadband satellite networks [169]. They may include reactive services activated by a user, such as mapping a location or displaying nearby points of interest, or proactive services automatically initiated when a user enters a specified area [170]. LBS require a real-time exchange of data between a user and a service provider over a wireless network, typically through a mobile device like a smartphone [169; 171; 170]. Data may be used for location-tracking of others, such as finding a friend or location-aware services based on apps making use of the device's position to trigger some action or notification. A simple example of LBS is the updating of date and time on a mobile device associated with the user crossing into a time zone [172; 173]. With the availability of consumer-grade beacon transmitters such as Apple's iBeacon(tm) and Google Eddystone(tm) beacons, any object can transmit location-based information to a mobile device using BLE [174]. This approach, though developed for retail marketing in urban areas, can also be integrated into forest recreation, education and outreach, and logistics applications using outdoor beacons with currently available software development platforms (Figure 11).  
LBS have applications in navigation (e.g., Google Maps), fleet and asset management, personal safety, mobile marketing, mobile gaming, points of interest (e.g., finding nearby stores or restaurants), and enhanced emergency services (e.g., enabling the tracing of 911 calls from mobile phones by polling the devices' GNSS coordinates) [175; 170; 173; 169]. [PERSON] et al. proposed using Twitter messages as a form of LBS to gather spatial and temporal information about fire movement in real-time [176].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Method** & **Range** & **Static Position Accuracy 1** & **Technology** & **Reference** \\ \hline \multicolumn{5}{c}{_Single User_} \\ \hline GNSS & Global & 1–2 m (5–10 m canopy) & \begin{tabular}{c} Recreational \& mapping \\ grade \\ \end{tabular} & [29] \\ RTK-GNSS & Global & 5 cm (1 m canopy) & Survey grade & [29] \\ PPP-GNSS & Global & \(<\) 5 cm (\(>\) 0.5 m canopy) & Survey grade & [67; 70] \\ GNSS-INS & Global & GNSS/INS: 0.5–1 m & Tightly-coupled systems 2 & [103; 104; 105; 106] \\ \hline \multicolumn{5}{c}{_Multi-node_3} \\ \hline GNSS-RF & Line-of-sight & 2–4 m (\(<\) 10 m canopy) & \
\begin{tabular}{c} Recreational grade – U.S. \\ GPS only \\ Commercial grade \\ \end{tabular} & [21] \\ UWB & 100 m (15 m NLOS) & 3 cm–0.5 m (1 m NLOS) & Commercial grade & [77; 95; 96] \\  & up to 50 m &
\begin{tabular}{c} BLE \\ Bluetooth 4.x \\ Bluetooth 5.0 \\ \end{tabular} & [117; 118] \\ Bluetooth & Up to 1 km & \(<\) 20 cm–5 m & Active UHF RFID (RSS) & [77; 126; 127; 128; 129] \\ QR code & Global & Same as GNSS & GNSS & [29] \\ \hline \hline \end{tabular}  
* Root mean square error (RMSE) for all values except Bluetooth and RFID, which are reported as mean error; 2 Raw GNSS measurements are used to aid INS; 3 Refers to whether positions are readily transferred to other devices (single user solutions can easily become ‘multi-node’ if integrated with GNSS-RF, Bluetooth, etc.).  
\end{table}
Table 1: PNT technology spatial range and accuracy.  
A recurring consideration for LBS research and applications is the issue of privacy [169; 170; 172; 173; 175; 177] due to the potential for surmising a variety of personal information from a user's location. For instance, user queries may reveal sensitive information on health, lifestyle preferences, or political and religious affiliations [175]. Privacy may be protected through data encryption [169; 175] or location anonymity techniques, which send a user's location along with false \"dummy\" locations, so service providers do not know the user's true position [177].