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1. SMS Based Wireless Home Appliance Control System
(HACS) for Automating Appliances and Security
Abstract
This pape r mainly foc use s on the controlling of home a ppliances remote ly and providing sec urity
whe n the user is away from the pla ce. The system is SMS ba sed and use s wireless technology to
revolutionize the standa rds of living. This system provides ide al solution to the problems fa ced by
home owners in daily life . The system is wireless therefore more ada ptable and cost-e ffective.
The HACS system provides se curity a gainst intrus ion a s we ll as automates various home a ppli-
anc es using SMS. The syste m uses GSM technology thus providing ubiquitous ac cess to the sys-
tem for security and automated a pplia nce c ontrol.
Ke ywords: Short Messa ge Se rvice (SMS), Globa l System for Mobile communication (GSM),
Ra dio Frequenc y (RF), AT Comma nds, ubiquitous a cce ss and Automation.
Introduction
The aim of the paper is to investigate a cost effec tive solution that will provide c ontrolling of
home appliance s remotely and will a lso ena ble home security aga inst intrusion in the a bse nce of
home owner.
The motivation is to fac ilitate the users to automate their homes having ubiquitous ac cess. The
system provide s availa bility due to development of a low cost syste m. The home a pplia nces con-
trol syste m with a n affordable cost wa s thought to be built that should be mobile providing re-
mote access to the appliances and a llowing home se curity.
Home security has been a ma jor issue where crime is inc re asing and eve rybody wants to take
prope r measures to preve nt intrusion. In a ddition there wa s a nee d to automate home so that user
can take adva ntage of the technologic al advanc ement in such a way that a person getting off the
office does not ge t melte d with the hot climate . Therefore this pa per proposes a system that al-
lows user to be control home applia nces ubiquitous ly and also provide sec urity on detec tion of
intr usion via SMS using GSM technol-
ogy.
The ne xt section will e xpla in the rela ted
work; section 3 e xpla ins the proposed
system, methodology and a lgor ithm.
Section 4 discusses the framework,
working, cha ra cteristics, stre ngths and
constraints of the system. Section 5 ex-
pla ins the results a nd section 6 is con-
clusions and the future work.

2. Related Work
Delgado, Picking, and Grout (2006) c onsider the problems with the implementation of home
automation systems. Furthermore the possible solutions a re devised through var ious network
technologies. Se veral issues affecting home automation systems such as la ck of robustne ss, com-
patibility issue a nd acceptability among the old and disa bled people are discussed.
Ciubotaru-Petrescu, Chiciude an, C ioarga , and Stanescu (2006) present a design a nd implementa-
tion of SMS ba sed control for monitor ing syste ms. The paper has three modules involving sens-
ing unit for monitor ing the complex a pplica tions. A processing unit tha t is microcontrolle r a nd a
communic ation module that uses GPRS modem or cell phone via serial port RS-232. The SMS is
used for sta tus re porting suc h as powe r fa ilure.
In their paper, Conte and Sc aradozzi (2003) view home automation systems as multiple agent
systems (MAS). In the pape r home a utoma tion system ha s be en propose d that includes home a p-
plia nces and devices that a re controlled a nd ma inta ine d for home mana geme nt. The ma jor task is
to improve pe rforma nce.
In their paper, Alkar and Buhur (2005) propose a n Internet Based Wireless Home Automation
System for Multifunctiona l De vice s. This paper proposes a low cost and flexible web-base d solu-
tion but this system has some limitations such as the range and power failure.
Murthy (2008) e xplores primary health-c are manage ment for the rural population. A solution
proposes the use of the mobile web-technologies providing the PHC se rvices to the rura l popula-
tion. The system involve s the use of SMS and cell phone technology for informa tion ma nage -
ment, transactiona l exchange and personal communica tion.
Ja warka r, Ahme d, Ladhake, and Tha kare (2008) propose remote monitor ing through mobile
phone involving the use of spoken c omma nds. The spoken commands are genera ted a nd sent in
the form of te xt SMS to the c ontrol system and then the microcontroller on the basis of SMS
take s a dec ision of a pa rticula r ta sk.
Potamitis, Georgila , Fakota kis, and Kokkina kis, G. (2003) suggest the use of speech to interact
remote ly with the home applianc es to perform a particular action on beha lf of the use r. The ap-
proac h is inc lined for people with disa bility to perform re al- life ope ra tions at home by directing
applianc es through spee ch. Voice separation strate gy is se lecte d to take appropriate decision by
speech recognition.
Preliminaries
Home Appliance Control System (HACS)
Home applianc e control system is base d on GSM network technology for transmission of SMS
from se nder to receiver. SMS sending a nd receiving is used for ubiquitous ac cess of appliance s
and allowing brea ch control at home.
The syste m proposes two sub-systems. Applianc e control subsystem enables the user to c ontrol
home appliance s remotely wherea s the security alert subsyste m provides the remote se curity
monitoring. The syste m is capa ble e nough to instruct user via SMS from a specific cell number to
cha nge the condition of the home applianc e according to the user’s needs a nd requirements. The
se cond aspect is tha t of se curity a lert which is achieve d in a way tha t on the detection of intrusion
the system allows automatic gene ra tion of SMS thus ale rting the user against security risk.
HACS syste m consists of the following compone nts (shown in Figure 1):-
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3. PC: This unit contains the software compone nts such as the HACS System through which the
applianc es a re controlled a nd home security is monitored.
GSM Mode m It is a hardwa re compone nt that a llows the c apa bility to send and re ceive SMS to
:
and from the system. The communication with the syste m take s place via RS232 seria l port. Ce ll
phone c an be attac hed at the plac e of GSM hardware but it limits the ha rdware functionality such
as sending or receiving of SMS.
Mobile Device: Ce llular phone containing SIM c ard has a specific number through which com-
munication takes pla ce. The device communicates with the GSM Modem via radio frequency.
Mobile user transmits SMS using GSM tec hnology.
Methodology
The me thodology followed in the HACS is give n as:-
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4. SMS Based Wireless Home Appliance Control Sy stem
• GSM hardware tests are run in or der to che ck the ha rdware support. The system will
call GSM modem and it will ge t activated.
• After ac tivation the Modem will chec k for hardwa re support. If the ha rdware is missing
or some other hardwa re proble m there will be error, resulting in c ommunication fa ilure
and the applica tion will be terminated.
• If ha rdware responds the n the serial port will be opene d for communication a nd GSM
hardware will allow tra nsmiss ion of SMS.
• The system will the n c onnec t and a fte r connec tion establishme nt the syste m will be
able to de tect intrus ion and will a le rt user about the bre ach and similarly the s yste m
will update status of appliances by rec eiving SMS from the pre-de fined c ell number.
• SMS will be sile ntly ignore d if cell numbe r is una uthor ize d.
Pseudo code
The pseudo code for HACS is give n as:-
begin
Run Tests
If Tes t = 0
Terminate program
If Tes t = 1
Communication = OK, port will open
Click Connect
Cont rols {Cj | j=1, 2, 3, 4} = enable
If intrusion = 1
Send s ecurity alert
If incoming SMS = 1
Simulate applianc es
end
Characteristics of HACS
The propose d system chara cteristics involve remote controlling of applianc es, intrusion dete ction,
system security a nd auto-conf igura tion such tha t system automatica lly adjusts the syste m settings
on running ha rdware support c hec k. The system ha s useful fe atures such a s displaying of battery
leve l, charging status and signa l stre ngth of the mobile thus making system re liable.
Strengths of HACS
HACS syste m has ma ny advanta ges such as remote controlling of home a ppliances, ava ilability
and ease of users. The user c an ge t ale rts anywhe re through the GSM te chnology thus ma king the
system loca tion independent. The system c ontains low cost components easily available which
cuts down the overall system c ost.
Moreove r system a lerts user a bout bre ach via SMS providing home se curity a lso it allows secure
access due to pre -configure d number. The ease of deployme nt is due to wire less mode of c om-
munication. GSM technology provides the benefit that the system is ac cessible in re mote a reas as
well. The syste m relia bility increa se s due to the useful features suc h as batte ry leve l che cking,
cha rging status and signa l stre ngth indicating the system about threa ts. The system integration is
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5. simple and is also sc alable and exte nsible. The auto-configuration c apability allows the system
auto enabling/disabling of certain features.
Constraints of HACS
The syste m functionality is ba sed on GSM te chnology so the technologic al constraints must be
kept in mind. The system is vulnerable to power failure but this disruption ca n be avoided by at-
taching the volta ge source thus a llowing users to a vail the grea t adva ntage of this system.
Conclusion and Future Work
In the paper low cost, secure , ubiquitous ly accessible, a uto-configura ble, remote ly c ontrolled so-
lution for a utoma tion of homes has been introduc ed. The a pproac h discusse d in the paper is novel
and has achieve d the ta rget to c ontrol home appliances re motely using the SMS-ba sed system
sa tisfying user needs a nd requirements.
GSM tec hnology capable solution ha s proved to be controlled remotely, provide home security
.
and is c ost-effec tive a s c ompa re d to the previously existing syste ms. Henc e we ca n conclude that
the required goals and objec tives of HACS have been achie ved.
The ba sic leve l of home appliance control and remote monitoring ha s be en impleme nted. The
system is e xtensible and more levels can be further developed using a utoma tic motion/glass
breaking detectors so the solution can be integrated with these and other detection systems. In
case of re mote monitor ing other applianc es c an a lso be monitored such that if the leve l of tem-
perature rises above certain leve l then it should generate SMS or sensors c an a lso be applied that
can dete ct gas, smoke or fire in c ase of eme rgenc y the system will automatic ally ge nerate SMS.
In future the system will be small box combining the PC and GSM modem. This hardware ca n be
importe d from Taiwa n and Singapore. The ha rdware will be self c ontained a nd ca nnot be prone to
ele ctric failure . This a pplia nce will have its own e ncapsulated UPS and c harging system.
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