## 4 Discussion
### Real Experimentation  
Figure 17 shows two real scenarios with the implementation of two types of wireless technologies for wireless sensor networks: Zigbee and LoRa. We have implemented a sensor network of 12 sensors, divided into six sensors for Zigbee wireless technology and six sensors for LoRa wireless technology. We have deployed them in an engineering area of the Universidad Panamericana, Guadalajara campus, Mexico. For Zigbee, we have the Scenario 1 configuration of CC2650 sensor nodes and a CC2530 coordinator node from Texas Instruments in an area of 500 \(\times\) 500 m. For LoRa, we have a configuration of the interconnectivity of networks of sensing devices with LoRa communication (sub-1 GHz) to emulate a smart city. Each network will have its own sniffer to acquire and analyze the packets sent between the nodes and connectivity between devices through a Gateway with the possibility of sending the data to the cloud. The LoRa gateway has the following characteristics:  
* Full Linux operating system--Kernel v4.x running on Atmel A5 Core @ 536 MHz
* Multiple interfaces such as LoRaWAN, 802.11a/b/g/n, Bluetooth v4.0, and Ethernet
* 8-Channel LoRaWAN support with up to +27 dBM max transmit power
* Comprehensive Certifications for FCC/IC (RG191) and CE (RG186)
* Industrial temperature range (\(-30^{\circ}\)C to 70 \({}^{\circ}\)C)
* Advanced deployment tools including intuitive web-based configuration, integrated LoRa packet forwarder, and default settings for multiple LoRaWAN Network Server vendors
* Enterprise-grade security built on Laird's years of experience in wireless
* Industry-leading support works directly with Laird engineers to help deploy your design
* LoRa Network Server pre-sets--The Things Network, Loriot, Stream, and Senet The specifications of LoRa sensors:
* It is an evaluation card that supports the protocols: LoRa, Sigfox, Sub 1 Ghz. * Arm Cortex-M0 + microcontroller. * Supports ARM Mbed, Atollic as Development Tool. * Can be powered from USB or AAA batteries. * VL6180X Proximity, Gesture and Ambient Light Sensing Module. * Slider that controls 2 functions: Range measurement, beyond 400 mm. Ambient light detection, up to 100 kLux1. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Number of Nodes** & **Availability Routes (\%)** & **Retransmissions** & **Resilience (Sec)** \\ \hline
100 & 62\% & 1.3 & 3.863 \\
150 & 60\% & 1.6 & 4.124 \\
200 & 55\% & 1.8 & 4.958 \\
250 & 44\% & 2.1 & 6.672 \\
300 & 33\% & 2.5 & 8.846 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Performance metrics with relevant impact on energy for PEGASIS under jamming conditions. * 4-digit display showing distance of a target from proximity sensor or lux value from ambient light detection. * Motion detection module using a PIR sensor. * The Nanopower operational amplifier allows the implementation of very low power systems. * A single quad op-amp spans the entire analog PIR motion detection front comprising amplification and filter stages, and window comparators, enabling a simple, small solution for cost-optimized systems. * GUI provides real-time TLV8544 visual current draw. * Onboard high and low threshold indicators and on GUI provide instant visual feedback. The main advantages of Zigbee are that it avoids network saturation, something significant when there are many devices connected to the same network, it is simpler and less expensive than Bluetooth or WiFi and offers low energy consumption. The main drawbacks are the need to use a bridge device and the shorter transmission distances. LoRa is a relatively new technology with a network architecture typically presented in a star topology. The gateways are a transparent bridge that relay messages between end-devices (nodes) and a central network server. One of the challenges facing current wireless technologies is that communication nodes are unable to differentiate interference signals from legitimate transmissions or changes in communication activity due to node movement, at the expense of local and network resources.