J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.

SIGMA: Wireless System

with Geolocation

for Environmental

Monitoring

ARTICLE HISTORY

Received 15 June 2024

Accepted 22 September 2024

Jeaneth Acero

DETRI

Agrocalidad

Quito - Ecuador

jeaneth.acero@agrocalidad.gob.ec

ORCID: 0009-0009-9393-8105

Christian Reyes

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

christian.d.r.l@gmail.com

ORCID: 0009-0003-0869-5177

Christian Tipantuña

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

christian.tipantuna@epn.edu.ec

ORCID: 0000-0002-8655-325X

Danny S. Guamán

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

danny.guaman@epn.edu.ec

ORCID: 0000-0003-2794-3079

José Estrada-Jiménez

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

jose.estrada@epn.edu.ec

ORCID: 0009-0001-3931-9532

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

DOI:

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

10.5281/zenodo.14450305

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

SIGMA: Wireless System with Geolocation for

Environmental Monitoring

Jeaneth Acero

DETRI

Agrocalidad

Quito - Ecuador

jeaneth.acero@agrocalidad.gob.ec

ORCID: 0009-0009-9393-8105

Danny S. Guamán

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

danny.guaman@epn.edu.ec

ORCID: 0000-0003-2794-3079

Christian Reyes

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

christian.d.r.l@gmail.com

ORCID: 0009-0003-0869-5177

José Estrada-Jiménez

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

jose.estrada@epn.edu.ec

ORCID: 0009-0001-3931-9532

Christian Tipantuña

DETRI

Escuela Politécnica Nacional

Quito - Ecuador

christian.tipantuna@epn.edu.ec

ORCID: 0000-0002-8655-325X

Abstract—The increase in the number of automotive parks,

the emissions generated by industries, and the forest fires,

among others, deteriorate the air quality of the Metropolitan

District of Quito. Low-cost devices (sensors) distributed

throughout the city to collect and deliver information on

concentrations of gaseous pollutants in real time are essential for

preserving the health of the citizens. This kind of technology can

contribute to improving air quality by controlling the emissions

of harmful substances into the atmosphere. This paper shows a

prototype system for environmental monitoring using open

hardware and software technologies. The system comprises two

subsystems: a transmitter (mobile) and a receiver (fixed). The

transmitter unit has been installed in a public transport vehicle

(a taxi or any public transportation), which allows the

acquisition of environmental parameters such as carbon

monoxide, ozone, nitrogen, temperature, humidity, geographic

location, time, and date. The obtained measurements are sent in

real-time to a receiver subsystem, mainly consisting of a server,

where the received data is processed and published in a

pollution map. This data informs citizens by geographical areas,

about the different levels or concentration ranges of a particular

gas, and general air pollution in the city.

Index Terms—Air pollution gas sensors, Pollution Map,

Wireless Monitoring

I. INTRODUCTION

In the last ten years, the demographic and geographic

growth of the city of Quito has generated a significant increase

in public and private transportation, which in turn has led to a

rise in emissions of air pollutants generated by vehicle

combustion. This effect has deteriorated and is deteriorating

the quality of life of the city's inhabitants.

Environmental monitoring systems related to air pollution

are vital to preserving the ecosystem because they allow a

better perception of the polluting emissions sent to the

atmosphere and the air quality available at different points in

the city. Currently, the city of Quito has an Environmental and

Atmospheric Monitoring Network (REMMAQ), which is

made up of static monitoring stations in charge of obtaining,

processing, and presenting information on different

environmental pollutants; however, the number of stations is

minuscule compared to the size of the city (9 main stations)

[1].

Accordingly, this work implements a wireless prototype

for monitoring air pollutant gases, developed under free

hardware and software platforms. The developed system

allows real-time information on CO, O3, and NO2 gas

concentrations in the environment. In addition, the collected

data is processed and presented through a geographical map

of pollution using a web interface.

The main advantage of the prototype is its mobile feature,

which allows pollution information to be obtained anywhere,

only through an Internet connection through the 3G cellular

network. The prototype enables information to be received at

locations far from static monitoring stations, providing

additional data to the current network and providing

inhabitants with easily interpreted information.

II. R

ELATED WORK

Research related to the acquisition of pollutant gases in the

environment uses different technologies in the development

and implementation of the prototype. In [2], the MAQUMON

system uses sensors for the acquisition of pollution

information; the information is sent via Bluetooth technology

to a transmitter node (Gateway) installed in a moving vehicle.

When the transmitter node finds an available WiFi network, it

transmits all the acquired information to a remote server to

present the results in a web interface later. Its operation is

based on data acquisition and accumulation (storage), using

geolocation marks to reference the samples so that it does not

send information in real-time.

On the other hand, in [3], a system based on a wireless

sensor network (WSN) that acquires CO pollution data

through the MiCS-552 sensor and the Octopus II platform is

developed. The data collected by the WSN is transmitted to a

central node (Gateway), which sends them to the remote

database via text message (SMS) through the GSM cellular

network. Access to the information is done through an Internet

connection, although, the system does not have a user-friendly

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

DOI:

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

10.5281/zenodo.14450305

J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.

web interface that allows the interpretation of the information

in a visual and didactic way.

According to the literature review, most researchers use

technologies for the local transmission of information [4].

However, none focuses on transmitting data in real-time to a

remote server through the cellular network via an Internet

connection. Previous works also lack web interfaces for the

presentation and straightforward interpretation of the

information.

In the current research work, real-time monitoring of the

pollution levels of CO, O

, and NO

gases in Quito is carried

out. The information is transmitted to a remote server through

the cellular telephone network and 3G technology for Internet

connection. The acquired data are presented through a user-

friendly web interface, under the considerations established in

the Quito Air Quality Index (IQCA) [1], in a geographic map

of pollution and pollution vs. time graphs.

Figure 1. General scheme of the prototype system

III. PROTOTYPE SYSTEM ARCHITECTURE

The prototype system consists of a transmitter and a

receiver subsystem, which interact with each other,

monitoring and displaying the levels of CO, O

, and NO

pollution in the air. The general scheme of the prototype and

the sequence of information processing between the

subsystems are presented in Fig. 1 and Fig. 2, respectively.

The information processing in the transmitting subsystem is

shown in Fig. 3. In contrast, the sequence of sending data to

the receiving subsystem is presented in Fig. 4. The different

hardware and software components that compose the

prototype are shown in Table I.

Figure 2. Sequence of information processing between the transmitting

subsystem and the receiving subsystem.

A. Transmitting subsystem

The transmitter subsystem is responsible for performing

the following functions:

Figure 3. Sequence of information processing in the transmitting subsystem

Figure 4. Sequence of sending data from transmitting subsystem to receiving

subsystem

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

DOI:

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

10.5281/zenodo.14450305

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

Table I.

PROTOTYPE SYSTEM ELEMENTS [7][8][9][10][11][12][13]

Hardware

Raspberry Pi 2

CPU: quad-core Cortex A7 at 900 MHz.

GPU: video core IV, dual core.

RAM: 1GB DDR2

Ports: 4 x USB 2.0, 1X 40 GPIO pin, 1 x HDMI

1.4, 1 x Ethernet, 1 x Combo audio/mic.

Arduino UNO

Microcontroller: ATmega328P

Digital I/O Pins: 14 (6 outputs PWM)

Analog input pins: 6

CO Sensor

Model: MQ-7

Technology: semiconductor

Type of response: analog

O3 Sensor

Model: MQ-131

Technology: semiconductor

Type of response: analog

NO2 Sensor

Model: NO2-AE

Technology: electrochemical

Type of response: analog

Temperature Sensor and

Humidity

Model: DHT-22

Type of response: digital

Detection range: -40 a 125

℃

Accuracy: 0,2 ℃

GPS Module

Model: Adafruit Ultimate GPS

Tracking sensitivity: -165 dBm

Acquisition sensitivity: speed: 0,1 m/s

Modem cellular

Model: Huawei E173s-6

Type: USB stick

Communication technologies: 3G

Display LCD

Model: LCD JHD162A

Type: 16x2

Software

O.S. Rasp.Pi

Raspbian Jessie release 8.0

Server

CentOS, Apache, MySQL, PHP

• Acquire gas concentration levels of CO, O

and NO

temperature and relative humidity.

• Acquire data on the GPS connection status, latitude,

longitude, time, and date of the air sample.

• Process the acquired data, conditioning it for LCD

preview and transmission to the receiver.

• Present the information through an LCD.

• Structure the data set and send the information to the

receiver.

Initially, the subsystem receives all analog signals from

the CO, O

, and NO

gas sensors and digital signals sent by

the temperature and relative humidity sensor and the GPS

module. The Arduino UNO Single Board Microcontroller

receives all this information through its input ports. The

Arduino UNO board processes the received data to send it in

a suitable format to the receiving subsystem and displays it on

an LCD. Before sending information to the receiver, a set of

data (Data) is formed by the Single Board Microcomputer

Raspberry Pi, which is made up of the following fields:

• Devide Id: Identifier of the transmitter subsystem.

• Latitude: The transmitter's latitude (geographical

location) at the moment of the air sample acquisition,

expressed in decimal format.

• Longitude: The transmitter's longitude (geographic

location) at the time of air sample acquisition,

expressed in decimal format.

• Time (Hour): Time at which the air sample was

acquired, expressed in the format hh:mm:ss.

• Date: The date the air sample was acquired,

expressed in the format year-month-day.

• CO: Concentration of CO in the air sample,

expressed in mg/m3.

• O

: Concentration of O

in the air sample, expressed

in mg/m3.

• NO

: Concentration of NO

in the air sample,

expressed in mg/m3.

• Temperature: Ambient temperature at the time of

acquisition of the air sample, expressed in degrees

Celsius.

• Relative humidity: Relative humidity at the time of

air sample acquisition, expressed in percent.

The structured data sends the information to the receiving

subsystem via the 3G interface connected to the Internet.

B. Calibration of Gas Sensors

To obtain the gas contamination data for CO, O

and NO

a multipoint calibration was performed, which consists of

subjecting the sensor to different concentration levels of a

specific gas (e.g., CO for the MQ-7 sensor) to obtain a straight

line voltage response as a function of the gas concentration

percentage. The multipoint calibration of these sensors was

performed in [5], whose calibration equations are shown

below:

 = 0.568 − 212.94

( 1 )

 =

0.6479 − 520.63

1000

( 2 )

 = 0.06105 − 50

( 3 )

Where Eq. 1, Eq. 2, and Eq. 3 correspond to the MQ-7,

MQ-131, and NO2-AE sensors, respectively.

The variable  corresponds to the gas concentration in

ppm, and the variable x corresponds to the response voltage

provided by the sensor, which is represented in bits. The

voltage  results from the A/D conversion to 12 bits of the

analog voltage provided by the sensor, so its values are

between 0 and 4095 bits [5].

The concentrations of CO, O

, and NO

gases acquired in

the environment through the sensors are expressed in ppm, so

Eq. 4 is applied to convert from ppm to mg/m3 and then to

ug/m3, considering the atmospheric pressure of the place and

the temperature at which the sample is obtained [6].

 =

 ×  × 

62.38 ×

(

273 + 

)

( 4 )

Where:

• A is the gas concentration in mg/m3.

• P is the atmospheric pressure in mmHg.

• M is the molecular weight of the gas.

• B is the concentration of the gas in ppm.

• 62,38 is the universal ideal gas constant.

• T is the temperature in ℃.

C. Sampling Path

A sampling area has been established for better

visualization of the contamination data. It consists of a transfer

route for the prototype, allowing evidence and limiting a

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

DOI:

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

10.5281/zenodo.14450305

J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.

geographical area in Quito. Additionally, contamination

circles have been generated, which present graphically

(different colors) the contamination values sent by the

transmitter subsystem (for example, see Fig. 6).

D. Receiving subsystem

The receiving subsystem performs the following

functions:

• Receive and process the information sent by the

transmitter.

• Store the processed data.

• Display pollution levels on a geographical map.

• Present the pollution levels in a numerical report.

• Display pollution levels in a time graph.

• Manage specific database tables.

The server that hosts the receiving subsystem consists of a

virtual machine installed in the server of the Informatics

Laboratory of the Faculty of Electrical and Electronic

Engineering of the Escuela Politécnica Nacional. The

implementation of the receiving subsystem is based on LAMP

software (Linux, Apache, MySQL, and PHP). The main task

of the receiving subsystem is to receive and collect all the data

sent by the transmitting subsystem. Additionally, it

determines the belonging of an air sample to a specific area

(pollution circle) within the established sampling route. The

processing of the set of information is programmed in a script,

Figure 5. Database schematic

which performs all the activities mentioned above through

software processing. After receiving and processing the

information, it is stored in an orderly manner in a database,

allowing access to it and guaranteeing its availability and

integrity. The database used is of the relational type, formed

by different tables depending on the type of information to be

stored. The designed database is shown in Fig. 5

Finally, all the acquired information is presented to the

user through a web application connected to the Internet, the

web interface, and the means of interaction between the user

and the receiving subsystem.

The elements contained in the web application are:

• Home (home web interface): Presents a brief

introduction to the project.

• Situation of Quito: Provides information on

national and local regulations regarding air pollution.

• Gas map: Presents a geographic map of air

pollution.

• Site administration: Allows access to the

administration of specific database tables, gas

concentration reports, and pollution vs. time graphs.

Figure 6. Results of CO test on monitoring path

Figure 7. Test results of O

on monitoring path

IV. TEST AND RESULTS

A. Outdoor Scenario

Monitoring tests of CO, O

, and NO

gases in outdoor

environments. The results obtained from monitoring CO, O

and NO2 gases using the MQ-7, MQ-131, and NO2-AE

sensors are presented in Fig. 6, Fig. 7, and Fig. 8, respectively.

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

DOI:

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

10.5281/zenodo.14450305

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

The results show that the SIGMA prototype presents

greater concentrations of contamination in the environment by

CO, O

, and NO

gases within the monitoring route in the

desirable range of the IQCA. Additionally, the acquired data

was easier to interprete due to the implemented web interface.

Figure 8. Test results of NO

on monitoring route

Figure 9. Resultados prueba de CO en indoor

Figure 10. Resultados prueba de O

en indoor

B. Indoor Scenario

The monitoring tests of CO, O

, and NO

gases in indoor

environments were carried out in the kitchen area of the

cafeteria of the Escuela Politécnica Nacional. This area was

selected because it is a work environment where continuous

combustion processes occur during the day (use of LPG for

cooking food). The results obtained from monitoring CO, O

and NO2 gases using the MQ-7, MQ-131, and NO2-AE

sensors in indoor environments are presented in Fig. 9, Fig.

10, and Fig. 11, respectively.

Analyzing the results, the SIGMA prototype found gas

concentrations of CO and O

within the desirable level of

IQCA. The graphical interface shows that the variations in the

established area were sporadic, presenting peaks of

contamination within a short period. Readers can access [6]

for a detailed view of the implementation of the whole system

and the specification of subsystems.

Figure 11. Resultados prueba de NO

en indoor

V. C

ONCLUSIONES

This article focuses on developing a low-cost prototype

that is easy to implement with devices based on free and

scalable hardware and software. However, it has also taken a

step towards the Internet of Things in Smart Cities as it is a

real-time data acquisition system with an interactive map that

allows users to visualize updated information in a didactic way

through color indicators according to the established in the

IQCA.

The prototype system allows wireless monitoring of air

pollutant gases (CO, O3, and NO2), thus contributing real-

time information on the areas with the highest air pollution

index. The web interface and the pollution circles established

on the map allow for a more straightforward interpretation of

the pollution data acquired within the sampling route. The

design of the database is scalable and provides the possibility

of obtaining information from several transmitters

simultaneously, as well as future data. In addition, the

contamination vs. time graph provides information on the

variations of gas concentrations in indoor environments,

allowing a better perception of the changes in short periods.

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

DOI:

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

10.5281/zenodo.14450305

J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.

According to the tests performed, the transmitter

subsystem is suitable for monitoring CO, O3, and NO2 gases

in outdoor and indoor environments with reduced temperature

variations and contamination levels above the minimum

detection range of the sensors used.

Future work is intended to use electrochemical sensors to

acquire samples of pollutant gases, thus improving the

accuracy of the data. Also, using 4G-LTE technology for its

higher speed decreases the sampling time. A network of

wireless sensors installed in several vehicles throughout the

Metropolitan District of Quito could be implemented,

allowing the monitoring of environmental parameters so that

with the analysis of these, the regulatory entity can make

decisions that contribute to achieving sustainable

development in terms of improving the quality of the

environment for citizens.

EFERENCES

[1] Secretaría de Ambiente Quito, Documento Índice Quiteño de Calidad

del Aire, [En línea]. Disponible en: http://www.quitoambiente.gob.ec/

ambiente/images/Secretaria_Ambiente/red_monitoreo/informacion/iqc

a. pdf. [Último acceso: Febrero 2016].

[2] Secretaría de Ambiente Quito, Red de Monitoreo Atmosférico, 2016.

[En línea]. Disponible en:

http://www.quitoambiente.gob.ec/ambiente/index.php/politicas-y-

planeacion-ambiental/red-de-monitoreo. [Último acceso: Febrero

2016].

[3] P. Volgyesi, A. Nádas, X. Koutsoukos y A. Lédeczi, Air Quality

Monitoring with SensorMap, International Conference on Information

Processing in Sensor Networks, 2008.

[4] J.-H. Liu, Y.-F. Chen, T.-S. Lin y D.-W. Lai, Developed Urban Air

Quality Monitoring System, Fifth International Conference on Sensing

Technology, 2011.

[5] J. Suntaxi, Diseño y construcción de un prototipo portátil de monitoreo

ambiental, mediante un sistema autónomo de adquisición de datos

portátil con comunicación USB hacia un PC, Quito, 2015.

[6] J. Acero y C. Reyes, Sistema prototipo para el monitoreo inalámbrico de

gases contaminantes del aire desarrollado bajo plataformas de hardware

y software libre, Quito: Escuela Politécnica Nacional, 2016.

[7] Arduino, ≪Arduino,≫ 2015. [En línea]. Disponible:

https://www.arduino.cc/en/pmwiki.php?n=Main/ArduinoBoardUno.

[8] RaspberryPi Foundation, ≪RaspberryPi,≫ 2015. [En línea].

Disponible: https://www.raspberrypi.org/. [Ultimo acceso: 17 Agosto

2015].

[9] Adafruit Industries GPS, ≪Adafruit, ≫ 17 Enero 2015. [En línea].

Disponible: https://learn.adafruit.com/adafruit-ultimate-gps. [Último

acceso: 17 Enero 2015].

[10] HANWEI ELECTRONICS CO. LTD, ≪Parallax Inc,≫ 12

Septiembre 2015. [En línea]. Disponible:

https://www.parallax.com/sites/default/files/downloads/605-00007-

MQ-7-Datasheet.pdf. [Último acceso: 12 Septiembre 2015].

[11] Henan Hanwei Electronics Co., Ltd., ≪http://www.cooking-

hacks.com,≫ 10 diciembre 2015. [En línea]. Disponible:

http://www.cookinghacks.com/skin/frontend/default/cooking/pdf

/MQ-131.pdf. [Último acceso: 12 febrero 2016].

[12] Alphasense, ≪http://www.alphasense.com/,≫ 10 diciembre 2015.

[En línea]. Disponible:

http://www.alphasense.com/WEB1213/wpcontent/uploads/2013/07/N

O2AE.pdf. [Último acceso: 12 febrero 2016].

[13] Aosong Electronics Co.,Ltd, ≪www.sparkfun.com,≫ 12 diciembre

2015. [En línea]. Disponible:

https://www.sparkfun.com/datasheets/Sensors/Temperature/DHT22.p

df. [Ultimo acceso: 15 febrero 2016].

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

AUTHORS

Jeaneth Acero received her bachelor's degree in Telecommunications

Engineering from Escuela Politécnica Nacional, Ecuador, in 2016

and her MSc. degree in information technology with a major in

cybersecurity in networks and communications from Universidad

Internacional SEK, Ecuador, in 2020.

Christian Reyes received her bachelor's degree in Telecommunications

Engineering from Escuela Politécnica Nacional, Ecuador 2016. He

received the CCNA certiﬁcation in 2014 and is currently an ICT advisor

at Communications Gold Partner.

Jeaneth Acero

Christian Reyes

J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

AUTHORS

Christian Tipantuña received his bachelor's degree in

Telecommunications Engineering from Escuela Politécnica Nacional,

Ecuador, in 2011, his MSc degree in Wireless Systems and Related

Technologies from Politecnico di Torino, Turin, Italy, in 2013, and the

Ph.D. degree in Network Engineering at Universitat Politècnica de

Catalunya, Barcelona, Spain in 2022. His current research interests

include UAV-enabled communications and optical networks.

Danny S. Guamán is currently an Associate Professor with the Escuela

Politécnica Nacional, Ecuador. His main research interests include

the analysis of data disclosure, assessment of privacy compliance in

information systems, and computer science education.

Christian Tipantuña

Danny S. Guamán

J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.

ISSN:1390-9266 e-ISSN:1390-9134 LAJC 2025

LATIN-AMERICAN JOURNAL OF COMPUTING (LAJC), Vol XII, Issue 1, January 2025

AUTHORS

José Estrada-Jiménez received his bachelor’s degree from Escuela

Politécnica Nacional (EPN), Quito, Ecuador, in 2007 and his M.S.

and Ph.D. degrees from Universitat Politécnica de Catalunya (UPC),

Barcelona, Spain, in 2013 and 2020, respectively. His current research

interests include data privacy and information security.

José Estrada-Jiménez

J. Acero, C. Reyes, C. Tipantuña, D. Guamán, and J. Estada-Jiménez,

“SIGMA: Wireless System with Geolocation for Environmental Monitoring”,

Latin-American Journal of Computing (LAJC), vol. 12, no. 1, 2025.