# Cyber-Physical Systems for Water Supply Network Management: Basics, Challenges, and Roadmap
## 3 CPS Architecture and Applications
### NFC  
Near field communication (NCF) is a standardized ISO/IEC 18092 wireless communication technology used for short distances, providing bidirectional communication between endpoints [55]. It operates in the 13.56 MHz frequency with a low data rate of around 106 to 424 kbps. NCF communication technology uses an amplitude shift keying (ASK) modulation scheme, which offers high bandwidth efficiency. The communication distance is extremely low (<0.1 m), but the data rate is higher those of ZigBee and Z-wave. The notion behind 6 LoWPAN was that low-power devices with small processing capacities should be able to engage in internet tasks. Hence, it enables wireless transmission of data via an Internet protocol possible for smaller devices with relatively low processing characteristics. The 6 LoWPAN consumes less power and provides up to 100 m of communication range. DASH7  
DASH7 is a wireless communication technology conceived by DASH Alliance to provide a very low power consumption over a long range. It is viewed as an expansion of the active RFID based on  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Technology** & **Network Standard** & **Frequency** & **Modulation Scheme** & **Data Rate** & **Network Topology** & **Coverage** & **Power Usage** \\ \hline \multirow{3}{*}{LoRaWAN} & \multirow{3}{*}{LoRa Alliance} & 868 MHz (Europe) & \multirow{3}{*}{CS} & \multirow{3}{*}{Up to 100 kbps} & \multirow{3}{*}{Star} & 5 km (urban): & \multirow{3}{*}{Low} \\  & & 433 MHz (asia) & & & & & 20 km (urban) \\ \hline \multirow{3}{*}{6 LowPAN} & \multirow{3}{*}{RFC6282} & \multirow{3}{*}{868 MHz; 915 MHz; 24 GHz} & BPSK; & \multirow{3}{*}{250 kbps} & \multirow{3}{*}{Mesh} & \multirow{3}{*}{Up to 100 m} & \multirow{3}{*}{Low} \\  & & & O-QPSK & & & & \\ \hline \multirow{3}{*}{SigFox} & \multirow{3}{*}{SigFox} & 868 MHz (Europe) & \multirow{3}{*}{BPSK} & \textless{10 kbps} & \multirow{3}{*}{Star} & 10 km (urban): & \multirow{3}{*}{Low} \\  & & 915 MHz (North America) & & & & & 50 km (urban) \\  & & 433 MHz (asia) & & & & & \\ \hline DASH7 & DASH Alliance & 433; 868; 915 MHz & 2-GFSK & Up to 167 kbps & \multirow{3}{*}{Star} & 10 km (urban): & \multirow{3}{*}{Low} \\  & & & & & & & \\ \hline Weightless & Weightless SIG & Sub-GHz band & DGPSK & Up to 100 kbps & \multirow{3}{*}{MAM} & 10 km (urban): & \multirow{3}{*}{Low} \\ \hline NB-IoT & 3 GPP & Licorsed LTE frequency bands & QPSK & 20-200 kbps & \multirow{3}{*}{Star} & 1 km (urban): & \multirow{3}{*}{Low} \\  & & & & & & 10 km (urban) \\ \hline \multirow{3}{*}{Inston} & Smart Labs & 915 MHz & FSK & Up to 13 kbps & Dual mesh & 40 m & Low \\ \cline{2-6}  & \multirow{3}{*}{–} & \multirow{3}{*}{Between 30 GHz and} & & \multirow{3}{*}{–} & \multirow{3}{*}{–} & \multirow{3}{*}{–} & \multirow{3}{*}{–} \\  & & & & & & & \\ \cline{1-1} \cline{5-5} \cline  
the ISO/IEC 18000 standard [54; 56], with working frequencies of 433, 868, and 915 MHz unlicensed ISM band. By utilizing a two-level Gaussian frequency shift keying (2-GFSK) modulation scheme in the sub-GHz bands [54], DASH7 provides data rates of 167 kbps with communication range around 2 km [57]. LoRa is a promising technology offering low-cost, low-power, and long-range communications. It has a communication range of 1 km in urban settlements and 10 km in rural regions [58]. LoRaWAN is based on LoRa and are both standardized by LoRa Alliance. LoRaWAN can be viewed as an upgrade to LoRa with improved data rate and communication distance. LoRa has a low data rate of 0.3-50 kbps, while in LoRaWAN, an improved data rate of up to 100 kbps can be achieved. Both wireless communication technologies use a chirp spread spectrum (CSS) modulation, which employs wideband linear frequency modulated chirp pulses to encode information [58; 59]. They use an ISM band with a different operating frequency, which differs from one region to the other. For example, in Europe, LoRa and LoRaWAN operate in 868 MHz in Asia and North America, frequencies of around 433 and 915 MHz are reported [58].