Short messaging service has been a very simple, inexpensive communication protocol that is used in the mobile world. This paper explicates the concept of design and implementation of a versatile system that is used to “Monitor the home through mobile phones”.
The second part of our paper explains about the RFID system which in connection with GSM world can be used to monitor all the costly home appliances. The main advantage of our system is that it doesn’t require any internet connection. The other point is that it wont make any additional charges for the service.
This design paper explicates the power of SMS in the mobile communication and how RFID system can be connected to mobile phones which enhance the security of most of the house hold appliances. Now a days mobile communication is provided through many services like GSM, WLL, CDMA. This paper mainly concentrate about GSM based automation concepts.
PREAMBLE TO GSM
GSM stands for “ Groupe de travail speciale pour les services mobiles” which is generally known as Global System for Mobiles. The GSM standard is currently used in the 900MHz and 1800MHz bands. GSM is the name of a standardization group established in 1982 to create common European mobile telephone standard that would formulate specifications for pan-
European mobile cellular radio system operating at 900MHz.
SHORT MESSAGE SERVICE
The official definition given by International Engineering Constrium(IEC) for SMS:” short message service is a globally accepted wireless service that enables the transmission of alphanumeric messages between mobile subscribers and external system such as electronic mail, paging, and voicemail system.
DATA TRANSFER SCHEME
SMS is a service for sending massage of up to 160 characters to mobile phone that use GSM.
technology. The GSM system allows also SMS messages to be coded using
system defined code schemes., proprietary coding , or even binary data.
SMS messages are transported on SM protocols that are defined in GSM 03.40. Following is described a successful mobile originated (MO) SM signaling on the SM-TL between MS and mobile services switching centre(MSC). The SM-TL provides transfer service
to an upper layer , called the SM- application layer(SM-AL).
ROLE OF SOFTWARE:
The main job of the software is to translate machine level codes into PC compatible text messages.
The following are the jobs expected to be done by the software:
Receive signals from data cable.
Translate data to PC compatible text.
Identify Caller ID tag.
Perform Authentication checks before letting the control to remote user.
Compare the text with the pre-defined syntax. Classify the code to a command category. If the code is control oriented , send the specific bits to the specified pin of the parallel port. If the code is a data request , acquire data from the serial port and convert it to a GSM compatible format.
Transmit the next via the data cable. In case of emergency, transmit the pre-stored text to the specified set of numbers via the data cable. Perform the periodic checks to see the performance of the SIM. If the INBOX of the SIM is full , take steps to empty it.visually.
The system uses two ports viz:
DAU-9p Serial port- for connecting data cable.
The parallel port – for connecting the external requirements.
In this system the pin configuration followed is,
Eight pin for application control.
Two for temperature monitoring
Four for door status monitoring.
Two for emergency signaling.
Constituents of appliance control system:
An Opto- isolation circuit.
An amplification circuit.
An driver circuit.
Check for syntax.
If it is an appliance control command, go to step 4 else terminate.
Divide the command into two viz. appliance ID & state to be attained.
Accordingly , deliver bits to the corresponding port.
If the door is opened in an unusual manner , the pressure sensors senses and send the HIGH signal to the pin 15 of the parallel port. The software watches it and sends the SMS to the pre stored set of numbers.
The system incorporates a stand in software which provides GRAPHICAL USER INTERFACE.
The user can use the software to control&monitor the entire system. It acts as an interface between GSM world and PC Electrical appliances and PC
Sensors and PC
RFID SYSTEM FOR HOME MONITORING
A common method for identifying objects using RFID, is to store a special number that identifies a product, and perhaps other information, on a microchip that is attached to an antenna.
The antenna enables the identification information to a reader. The reader converts the radio waves into computer readable form. These computer readable for then passed through GSM modem and finally to the users cell phone. T from his/her mobile can read the movement and status of their home appliances from remote place.
HOW THE TAG WORKS?
A passive RFID tag has no battery, draws power from this magnetic field and uses it to power the microchip’s circuit. An active RFID tag has a battery, which is used to run the microchip’s circuit is to broadcast the signal to the reader.