DATA INTEGRATION IN BIOLOGICAL MODELS
P. Mariño, F. P. Fontán, M. A. Domínguez and S. Otero
Electronic Technology Department, University of Vigo, Spain
Keywords:
Database applications, wireless networks, information systems.
Abstract:
Biological research in agriculture needs a lot of specialized electronic sensors in order to fulfill different goals,
like as: climate monitoring, soil and fruit assessment, crop tracking, and so on. That research must be sup-
ported by consistent biological models able to simulate diverse environmental conditions, in order to predict
the right human actions before risky biological damage could be irreversible. In this paper is described an
experimental distributed network based on climatic an biological wireless sensors, for providing real measure-
ments in order to validate different biological models used for viticulture applications.
1 INTRODUCTION
The experimental wireless network is deployed in a
peninsula surrounded by two large sea arms called
“rias” in Spanish language.
Currently differences in productivity and quality
of grapes are broadly related with relative heights
and sea proximity from each of four zones but nev-
ertheless more rigorous biological and climatic re-
search (Gail, 2007) must be done, in order to pro-
vide accurate biological models for ecological sim-
ulations applied to viticulture. For that reason multi-
disciplinary work must be done among electronic en-
gineers, biologists and ecologists.
Each zone has an electronic zonal station (EZS),
in order to bring differences (microclimates), in mea-
surements like: temperature, relative humidity, leave
humidity, soil temperature, solar radiation, rain gauge
(tipping bucket), and other biological sensors. A data
logger and a radio modem is included in each EZS
in order to sense, process and transmit the data, en-
abling the development of an automatic wireless sen-
sor network (WSN), which nodes (the EZSs) are ac-
cessible from a wide area. These wireless communi-
cation capabilities allow that data could be remotely
monitored. The implementation of a warehousing ap-
proach, allows the data to be stored in a centralized
database that is responsible for query processing. The
stored data will be used for biological and ecological
models.
Firstly the paper describes the different elements
employed in the experimental network. These include
(a) the wireless nodes (b) the base station (c) the re-
peaters and (d) the data management. Finally some
measurements from EZSs are depicted.
2 DATA ACQUISITION SYSTEM
The electronic zonal stations (EZSs) are connected
with the base station (BS) by the UHF band (not li-
censed) between 869.4MHz to 869.65MHz, and the
BS is also connected through Internet to the Data Base
(DB), the biological and ecological models (BEMs),
and to the Web access (Fig. 1). Each zonal station
comprises an UHF radio modem that transmits the
sensors information to the BS through a data call. A
powering solar panel (PSP) is located near each EZS
for feeding its circuits. In order to reduce costs, the
BS makes a call to all the EZSs every 24 hours by
means of a polling procedure (Mariño et al., 2006).
During these calls the EZSs send all the informa-
tion that has been stored on that period. Therefore
the BS periodically executes the reading data process
and later database storage of the received information,
through an Ethernet local area network.
2.1 Data from Sensors
An electronic zonal station (EZS) is the basic acqui-
sition equipment of the distributed system, that car-
ries out the data registration (measurements and pro-
cessing), and the communication with the base station
(BS). In this way, each EZS comprises an automatic
measurement unit with data transfer capability. The
389
Mariño P., P. Fontán F., A. Domínguez M. and Otero S. (2008).
DATA INTEGRATION IN BIOLOGICAL MODELS.
In Proceedings of the Tenth International Conference on Enterprise Information Systems - DISI, pages 389-392
DOI: 10.5220/0001667603890392
Copyright
c
SciTePress
Figure 1: Network architecture and database interfaces.
data acquisition process is made inside the EZS by
the sensors and the data logger. Each EZS comprises
the following sensors: temperature, relative humidity,
leave humidity, soil temperature, solar radiation, rain
gauge (tipping bucket), and other biological and eco-
logical features depending on running models (Poza
et al., 2006).
All that sensors are integrated in the data logger.
The data logger is the EZS nucleus, it captures the
data from each sensor, automates the measurements,
synchronises the data and manages the communica-
tions. The data transmission is carried out by means
of the data logger and the UHF radio modem con-
nected to it. Next, the data captured by the EZS is sent
to the database (DB), through the base station (BS),
where they are saved. The communication process
setting, through the UHF radio modem connected to
the data logger, allows the control and programming
of several tasks as well as the acquisition of stored
data.
The data captured by the data logger are organised
in registers. The registers comprise the sensor out-
puts as well as the time and date. These registers are
then sent to the storage system where they are saved
for a future access. The data logger is programmed
for capturing and storing the sensors information each
minute. Due to the limited capacity of the storage sys-
tem integrated in the data logger, the data can only be
stored during a day (24 hours). Figure 2 illustrates
the data logger, the storage system, the UHF radio
modem and connections with the sensors and elec-
trical supply. Al these elements are placed inside a
box which protects them from the weather conditions.
This box and all the sensors are fixed to a metallic
base located at the site.
Figure 2: EZS data acquisition and communications sys-
tem.
3 GLOBAL DATA MANAGEMENT
The information obtained from the EZSs are collected
by the BS and stored in the DB for later process, anal-
ysis and query. The BS requests and compiles the
data from the different EZSs to store them in the DB.
Also the BS is provided with an UHF radio modem
to make the polling query of each EZS in the wire-
less network. Therefore the BS is a PC connected to
a wireless network and Internet that executes the de-
veloped program to perform its operations flowchart.
Since all the measured data must have the same
time reference for its later process, the BS obtains
the system reference clock from a real time network
server by the NTP synchronization protocol (Network
Time Protocol).
The data from the EZSs are centralized in a rela-
tional database. This DB presents one interface with
the BS through which all the system information is
introduced, and three interfaces to access this infor-
mation: general data access, access to interesting data
to analyse viticulture features, and query of data for
providing models. The interface between BS-DB and
ICEIS 2008 - International Conference on Enterprise Information Systems
390
queries-DB are executed directly by means of ODBC
(Open Database Connectivity).
The general data access will directly take place
through an Internet accessible Web page. Whereas
for queries related to the analysis of viticulture fea-
tures and models, the access is made through specific
views for each type of study (Mariño et al., 2006).
Figure 3 shows an example of the EZS data manage-
ment. This picture illustrates the structure of commu-
nications among equipments, interfaces and layers.
4 THE STATE-OF-THE-ART AND
THE IMPLEMENTED
NETWORK
Past decade has been very fruitful in the development
and application of several standards for mobile, no-
madic and fixed wireless networks related with sen-
sors (Demirkol et al., 2006). Some specific problems
about this kind of networks have been well studied,
like: energy efficiency due to collisions, overemitting-
receiving, control of packets and idle listening; scal-
ability and changes adaptation in network size, node
density and topology; communication paradigms like
node-centric, data-centric and position-centric; and
many others.
Nevertheless this great researching effort over
wireless networks for sensors, there is no any ac-
cepted MAC for them, because this kind of sensor
networks has a very big dependence of the applica-
tion. Recent surveys about the most advanced wire-
less networks like MANETs (Conti and Giordano,
2007) show poor real results in front of expected
ones, because the great complexity involved in simu-
lated MAC protocols, on big programming tools, was
not after validated with implementation, integration
and experimentation over real equipment (chips, mi-
crocircuits, modems, antennas, and others). In this
way, a particular field of application, called “wire-
less sensor networks” (WSN) is proposed for envi-
ronmental monitoring, industry and precision agricul-
ture, among other sectors of activity. The WSNs are
featured by a stronger interdisciplinary collaboration
for creative projects, and a change in the communica-
tion paradigm from node-centric to data-centric one,
because the main point is the transfer of data from the
application field, and not the communication between
all the network nodes.
4.1 The Wireless Sensor Network
(WSN)
Several comparatives among general wireless stan-
dards like ZigBee, Ultra Wide Band (UWB) and WiFi
have been made in order to evaluate some examples of
application included industrial wireless sensors. Also,
more specific WSN applications could be found about
environmental research like: hydrology (Moore et al.,
2000), fire monitoring (Ruiz et al., 2005), and others.
Given the hilly nature of the vineyard zones (Sec-
tion 1), the coverage challenges for linking the EZSs
with the BS (Section 3) were founded in power, data
speed and acceptable error ratio. For example, in
the Meis zone the coverage area was over 5km, with
difference in heights about 200m, very prone to in-
terpose obstacles in the line-of-sight (LOS) among
EZS-BS. In order to achieve a wireless network with
very low cost and reduced power consumption, be-
cause static nodes are transmitting infrequently (low
duty cycle) only two-way small data packets, the Eu-
ropean ISM band (868-870MHz) was selected, where
one channel with a data rate of 20kbps is available.
In this ISM band the used radio modems for linking
EZS-BS, have the following features: 10-500mW of
transmitting power, 25kHz of channel spacing, half-
duplex communication, 10% duty cycle and 36 sec-
onds of maximum emission time (must be controlled
by the data logger, Section 2.1). To avoid an obstacle
in the LOS between the BS and the EZS, a repeater
station (RS) is inserted with other ISM radio modem
and a directive antenna, linking the EZS (2,1km) with
the BS (5,17km).
5 FUTURE DEVELOPMENTS
Experimental work over the implemented WSN is be-
ing made in the following lines:
Addition of new climatic and biological sensors to
the EZSs.
Deployment of new EZS over the four different
vineyard zones for providing more spatial resolu-
tion to biological and ecological models.
Design of a wireless broadband (20Mbps) net-
work in order to provide crop tracking by real time
images, and infrared cameras (zonal isotherm
maps), by WiMax (IEEE 802.16) equipment over
the 5GHz ISM band (Fig. 1).
Integrate those images in the global data manage-
ment system (Section 3), for giving to the biologi-
cal and ecological researchers new knowledge for
future enhancement of models.
DATA INTEGRATION IN BIOLOGICAL MODELS
391
Figure 3: Communication example between elements, interfaces and layers.
6 CONCLUSIONS
The authors have developed an experimental dis-
tributed network based on the WSN paradigm for
wireless sensors. This WSN is based on the European
ISM band for providing a low cost and low power
consumption network, bringing real measurements to
validate different biological and ecological models
used for viticulture applications. Also a global data
management system is designed to integrate consis-
tently the measured data in the models. New develop-
ments in the experimental wireless network are being
tested to add real time images and infrared cameras
information, by means of broadband network stan-
dards.
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