# Review of Indoor Positioning: Radio Wave Technology
## 3 Radio Signals-Based Positioning
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Technologies** & **Parameters** & **Advantages** & **Disadvantages** \\ \hline \multirow{8}{*}{Wi-Fi} & \multirow{8}{*}{RSS/AOA} & Moderate power (216.71 mW & Affects time-varying RSS. \\  & & on average). & Difficult to finish the task of \\  & TDOA/TOA & No extra hardware. & building a smart city. \\  & RTT/CSI & Easy deployment. & Accuracy depends on the \\  & Cover large regions. & & amount of access points. \\ \hline \multirow{8}{*}{Bluetooth} & \multirow{8}{*}{TDOA} & \multirow{8}{*}{Easy deployment.} & Needs extra hardware. \\  & & Low power (0.367 mW on & Affect time-varying RSS. \\  & RSS/TOA & average). & Interviews with same \\  & TDOA & Easy deployment. & frequency band. \\  & AOA/TOF & Has a much higher data rate & Accuracy depends on its \\  & & than ZigBee. & access point. \\  & & than ZigBee. & Has a much shorter range \\  & & & than ZigBee. \\ \hline \multirow{8}{*}{RFID} & \multirow{8}{*}{RGS/TOA} & No contact and NLoS nature. & Needs extra hardware. \\  & RSS/TOA & Simultaneous and fast reading & Multipath effect and signal \\  & DOA/AOA & of multiple tag. & fluctuation. \\  & TDOA & Resilience to environmental & Large error with more target \\  & PDOA & changes. & tags to locate. \\  & PDOA & Reduce sensitivity regarding & Limited capabilities of the \\  & & user orientation. & passive tags. \\ \hline \multirow{8}{*}{ZigBee} & \multirow{8}{*}{RSS/TOA} & Lower power (17.68 mW on & Needs extra hardware. \\  & RSS/TOA & average). & Interference and strength of \\  & TDOA/AOA & No require much network & signals. \\  & TDOA/AOA & bandwidth. & Difficult to create a connection \\  & & Has higher latencies & with the smart phone. \\ \hline \multirow{8}{*}{UWB} & \multirow{8}{*}{UWB} & High accuracy. & Short range, high cost. \\  & AOA/TOA & Unaffected by interference. & Challenges in NLoS. \\  & TDOA & Fewer effects on humans. & Needs extra hardware. \\  & RSS/DOA & Suitable for body-centric and & Provides high accuracy. \\  & & wearable network. & Provides high accuracy. \\ \hline \multirow{8}{*}{NFC} & \multirow{8}{*}{RSS} & Low cost, high accuracy. & Accuracy depends on the \\  & RSS & Provides secure and private & number and proper placement \\  & & navigation. & of tags. \\ \hline \multirow{8}{*}{LoRa} & \multirow{8}{*}{TOA} & \multirow{8}{*}{Long range.  Extremely low energy.  Covers large area. & Signal attenuation and \\  & TDOA & & multipath. \\  & TDOA & & Long-range between server \\  & & Covers large area. & and device. \\  & & & Operate outdoor-to-indoor \\ \hline \multirow{8}{*}{SigFox} & \multirow{8}{*}{TGA} & Long range, covers large area. & Long-range between server \\  & & & Serves larger active nodes. & and device. \\  & & & Very low energy. & Operate outdoor-to-indoor \\ \hline Cellular & \multirow{8}{*}{TDOA/CSI} & Long-range. & \multirow{8}{*}{Requires synchronized based \\  & 1G/2G/3G & TDOA/RSS & High accuracy. & \\  & 4G/5G & RSRP/RSRQ & No extra cost. & stations. \\ \cline{1-1}  & & & \\ \cline{1-1}  & & RSS /TDOA & Improve the performance. & \\ \cline{1-1}  & & RSRQ/RSRP & Overcome the limitations. & Not enough information with \\ \cline{1-1} Hybrid & \multirow{8}{*}{PDOA/TOA} & Better than pure algorithm & single network \\ \cline{1-1}  & & AOA/DOA & Reduces system complexity. & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of radio-based technologies for indoor positioning.