IEEE Consumer Electronics Magazine - September/October 2022 - 91

Table 1. Performance comparison between LoRa and
Zigbee systems.
Parameter
Response time
Energy consumption
Network resilience
Overhead
Figure 4. System to perform measurements.
and activities reports during the period that the
person remained in the common area. The integrated
data acquisition module collects data from
the sensors and provides a snapshot of the person's
basic vital signs. Concerning the sensor network,
the system encompasses devices deployed
throughout the residential area to monitor traffic
areas. The system is programmed with specific
noise thresholds learned both day and night (to
establish exact patterns). In addition, each day of
the week has its average thresholds because not
all days are equally busy at the exact times. The
sensors are located on the streets near houses
because the condominiums have a more secluded
specific area for parking. When the sensor thresholds
of any street change noticeably, this can represent
the close approach of a vehicle, which will
generate an alarmfor crossing people.
The sensors devoted to this task measure
variations in the environmental sound. To set
the reference, the first data collection was carried
out measuring the regular environmental
sound in the area without any other external
source emitting sounds. Once set, if the following
samples exhibit an increase in the sound
level, it can be assumed that it is due to vehicles
passing through.
SYSTEM IMPLEMENTATION AND
VALIDATION
To validate the proposed system, we carried
out precision tests for different people for
15 days (24/7). This information provided valuable
insights to optimize resources, distances, number
of people, movements, waiting times, information
search times, and usermonitoring.
September/October 2022
Comparison Between Two Wireless
Technologies for the System
We analyze the network's performance in the
residential and common areas using Zigbee and
LoRa technologies to compare the response capacity
and energy consumption and the processing of
each network. These performance metrics indicate
the efficiency of the network for this application
and in the conditions described for the care and
prevention of accidents in a noninvasive way for
older adults in residential areas. Table 1 presents
that LoRa's response time is 3% faster than Zigbee,
making it more resilient, i.e., more responsive to
changes and reconfigurations in the network.
Zigbee has 26% less energy consumption
compared to LoRa. The overhead is measured
concerning the amount of communication
protocol control packets, which might cause
some increase in the network's collisions. Still, it
increases the efficiency of information delivery.
Generally, in IoT applications, Zigbee is used
for monitoring confined spaces. LoRa is more
used for long-range applications, so it is faster in
response to end-to-end packets and recovery of
the network configuration (resilience). LoRa is
better suited for real-time two-way communication.
This is a fundamental aspect, and it means
discarding communications by ZigBee in the
case of projects where the devices to be communicated
are very far from the data concentrator.
However, Zigbee proposes fewer control packets,
which optimizes the network's energy by
having fewer collisions and fewer packet retransmissions.
In summary, the essential criteria for
choosing the ideal system (technology) in this
type of application are the residential area and
the density of sensors to cover the areas.
Table 2 presents the similarity of precision
presented by the proposed system (the arch and
91
Zigbee
0.00212 s
0.003456 J
2.456 s
10%
LoRa
0.00204 s
0.01283 J
2.332 s
14%
IEEE Consumer Electronics Magazine - September/October 2022

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