The Use Of SMS And GSM Computer Science Essay

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This paper is going to address the use of (Short Message Service) SMS to communicate data between equipment connected via mobile phones and (Global System for Mobile communication) GSM modems. I want to acknowledge that I am not the first author on the subject nor am I going to be the last. The first task I am going to do is to appreciate the work done so far. The author would like to acknowledge ----------------------'s article and contributions in this topic. The phenomenon of SMS data transfer in information technology has been experiencing fast change over the years, (See Fig 1 below). this is due to the capabilities brought by wireless networking as the GSMbrochure sated.

Therefore the objective of this paper is to interrogate articles, books, journals and various schools of thought on the use of technology devices to communicate data via text message for information systems. I am going to achieve this through dedicated and exploratory reading that will evaluate, review and summarise these publications. This document will track down the use of this technology, assumptions associated with it and methods of use appropriate for given devices. This will end with a logical conclusion based on my own judgement supported by warranted inference.

Fig 1.1 Showing SMS usage in European Markets in 1999-2000


1. Before a critical analysis of SMS data transfer between equipment I am going to look at the various terms and protocols used in information communication such as SMS, mobile phones, Bluetooth and GSM modems. The use of SMS service requires a connection to be established between a two devices which compiles to certain set standards. For any equipment to be considered suitable for SMS data transfer we need to make it comply with these agreed rules and regulations. These protocols include SMPP, UCP/EMI or CIMD2. (ETSI Sending/receiving SMS messages through a GSM modem uses the AT command set defined in the ETSI GSM 07.05 specification. In mobile phones there should be a connection to an SMS service provider or GSM modem that uses a SIM card linked to GSM network to send a text message. Mobile phone providers give a unique number (SMSC number) to each SIM card and this number is connected to when sending SMS data. So for any equipment to communicate with this mobile SMS device it has to connect to this number and SQL-RD forward the required information to the respective destination.

( ) SQL-RD supports the majority of the GSM modems available on the market and supports most business GSM phones, hence should be pivotal in linking some devices and sending SMS.

SMS applications are therefore designed to transfer data inform of texts and some numeric characters. Normally this is up to 160 characters. However, through various changes in the industry new devices are capable of communicating text messages they were not able in the past. For instance (Tseng et al., 2003) noted SMS applications such as portable cardiological records and emergency response systems emerging due to GSM popularity.

This explains a great evolution that needs to be exploited and improvised for the great use of SMS in many input and output devices. Majority of these devices can perform to a greater use and better service if this data communication capability could be added to their daily use. A close follow-up of this discussion is pointing out to the idea that many technical devices or applications can use SMS as a data transport mechanism to send information to a remote place via mobile phones linked to GSM modems.

A focus on this discussion points to a potential for new applications and new specific user demands persistently appearing calling for greater and broad data transfer over SMS. The mobile phone is a programmed wireless terminal with capabilities of receiving and originating short messages. This characteristic makes it welcome to communicate with any other wireless equipment even if it's not a mobile phone but has some wireless frequency for communication.

Since SMS messages can carry binary data it has proved to be a reliable transport medium of wireless downloads and uploads. This ability facilitates the transfer of data in form of ringtones, wallpapers, pictures and operator logos encoded in SMS messages. SMS technology is therefore perfect for sending alerts and notification within reasonable time in a wide range of remote devices. This can be clearly shown by the use of alerts in e-mails, stock market, news headlines and bank transactions alerts.

2. Now having looked at the nature and protocols that operate in SMS message I can give a review of how GSM modems and mobile phones can be pivotal in data communication. A GSM modem can be described as a wireless modem that works with GSM wireless network and sends or receive messages through radio waves. It requires (Subscriber Identity Module) SIM card from wireless carrier companies in order to work. The modem complies with AT commands (instructions to control modems). General Packet Radio Service (GPRS) is a type of technology referred to as packet switched and it's an extension of GSM, has higher speed in data transmission than GSM. In essence GSM modem is specifically designed for equipment integration and therefore should be integrated in any data communication system. ( GPRS can be used as the bearer of SMS. If SMS over GPRS is used, an SMS transmission speed of about 30 SMS messages per minute may be achieved. This is much faster than using the ordinary SMS over GSM, whose SMS transmission speed is about 6 to 10 SMS messages per minute. Adherents to this idea have even a better way of describing this as,

(Li-Chang Lo et al. 2008) stated that unstructured Supplementary Service Data (USSD) is a capability built into the GSM standard for support of transmitting information over the signalling channels of the GSM network. CHECK DIAGRAMS GSM is often referred to as second generation (2G) mobile phone system due to its digital technology as opposed to the analogous system.

There are several ways this can happen. A mobile phone can be connected to a computer via GSM/GPRS modem. AT commands are used to get SMS messages send from mobile phones or GSM/GPRS modem. An alternative way is to get access to respective SMS center (SMSC) of the wireless provider. All SMS messages received will be passed or forwarded to the linked computer or server using the set algorithms, rules or interfaces supported by the wireless carrier. A third access method involves the availability of SMS gateway and all the received messages will be forwarded to the computer or server using supported protocols by the same gateway. GSM modems are therefore what are used on the computer side of things and relatively easier or user friendly than one might expect. The diagram below illustrates how this communication can operate.

SMS messages SMS message PC,laptop mobile phones, PDA with GSM modem/GSM software

cc SMS

Customer message Remote server with

Applications, GSM Control software

ccu SQL,EXCELL,etc SMS message

cellular antenna (

Fig 1.2 illustrates SMS data transfer via mobile phone and GSM modem

Regardless of the architecture and application the software used must allow scripts talk to modem and phone to/from the Bluetooth devices. Then the server software should be able to talk to the equipment too. In this scenario Bluetooth devices are sending SMS to server via mobile phone and GSM modem there are lots options for free software to choose or one can attempt write his own to suit specific requirements.

However, the only disadvantage is that not all of them can properly support SMS data transfer when acting as a modem. The other drawback is that GSM/GPRS cannot hold huge amount of SMS data traffic. TDMA help to solve this problem at times. GSM utilizes 900 and 1800 MHz frequencies and time division multiple access (TDMA) technology to send and receive mobile data (Tseng et al, 2005). Hence one is always expected to know his GSM band before purchasing a modem or mobile phone. In some cases this process might include a bit of SMS software or application development which needs some expertise.

Interestingly through load balancing of SMS traffic this problem can be overcome. In this process each mobile phone/ modem has a number and SIM card. Instructions in form of AT commands are given to each phone or GSM/GPRS modem about how to handle SMS message. The use of API (Application programming interface) and SDK (Software development kit) libraries can be a solution for interaction with mobile phone and GSM/GPRS modem through AT commands. These libraries can provide encapsulation and switching between wireless modem systems SMS to SMSC based messages by altering or modifying configuration files or source code.

3. The evolution of wireless communication has led to some short wavelength radio transmission standards. These short wavelength devices have managed to join the bigger wireless network and exchange data over short distances including SMS messages. This technology is seen on many input and output devices such as PDAs, mobile phones, cameras, remote controls, sensors, video games and many more consumer goods. Notably Bluetooth, Wi-Fi ( normally for domiciled equipment and its applications) and infra red have made such a wide usage so much that every new short wave length gadget is almost preconfigured to use one of them. In this section I am going to focus on how Bluetooth technology has been useful in using SMS to communicate data between equipment connected via mobile phones and GSM modems.

One of the great successes achieved by the use of Bluetooth is the ability to connect a number of devices in one moment without synchronization difficulties. Over the years since its introduction Bluetooth is increasing its capabilities raising the potential to be used in transmitting SMS messages on a large scale and very remote areas.

( Bluetooth uses a radio technology called frequency-hopping spread spectrum, which chops up the data being sent and transmits chunks of it on up to 79 bands (1 MHz each) in the range 2402-2480 MHz This range is in the globally unlicensed Industrial, Scientific and Medical (ISM) 2.4 GHz short-range radio frequency band.

In order to fully accomplish this task it has a protocol called L2CAP (Logical Link Control & Adaptation Protocol) which can carry up to 64kb payloads and maximum transmission unit (MTU) of 672 bytes preconfigured. Around 48bytes is normally set as minimum data size. However, the L2CAP can be reconfigured to suit a given condition hence forth making the channel convenient for sending SMS data across different technology.

This is a significant discovery since it promotes data transmission within unlicensed ranges where other devices can get connected. In its implementation it involves the master -slave protocols that is heavily characterised by packet exchanging. The master device (the one sending data) will determine the rate at which data is transferred. This rate is normally set to transmit at 312.5 µs intervals, which are commonly referred to as the master's clock. If the master broadcast SMS it can be simultaneously received by all connected devices. This is enhanced by a protocol commonly referred to as Service Discovery Protocol (SDP). Bluetooth Special Interest Group (SIG) sets the standards and specifications which comply with other market players in networking, computing and telecommunications. It is this association with other consumer electrical producers that made Bluetooth to be easily networked with the rest of wireless consumables. Proponents of this discovery include

( The Bluetooth Core Specification provides for the connection of two or more 'piconets' to form a 'scatternet', in which certain devices serve as bridges, simultaneously playing the master role in one piconet and the slave role in another. The diagram below shows the network layout.

Becker 2007 pg 5. Piconet of two (a) or more (b) devices, scatternet (c)

Therefore the transmission of SMS from Bluetooth devices is made quite efficient since each devices can do both sending and receiving of data at a given time. Consequentially mobile phones and GSM modems can also form part of this data transmission network (scatter net). This can also be illustrated by how a computer's input and output devices (keyboard, mouse, and printer) are using this technology.

(Harold, 2007) made an enormous discovery about Bluetooth technology. He states that, "Bluetooth is primarily designed for low power consumption with short ranges of 100m, 10m and 1m", however, one has to note in practice these ranges tend to slightly vary. He further maintains that since the devices use radio communication protocol they do not necessarily need to be in line of sight of each other always. The diagram below shows some of the ranges that can be covered by Bluetooth technology.


Maximum Permitted Power

Maximum Permitted Power





Class 1



~100 meters

Class 2



~10 meters

Class 3



~1 meters

Showing Bluetooth ranges Courtesy of Wikipedia

Harold's work on Bluetooth is an encouraging finding it proves that essentially a Bluetooth antenna can work almost like a mobile phone base station. Therefore one can safely conclude that any equipment with this technology can be reliably used in SMS data transmission between equipment connected via mobile phones and GSM modems (as shown in Fig1.2). A Bluetooth barcode scanner, camera, PDAs, watch and so on can make remote business or individual peoples' life a bit easier in sending and receiving data in SMS format. The maximum potential for every equipment can be fully tested and extended when it's connected to a higher class transceiver due to higher transmission power and signal of the upper class. For instance class 3 equipment can perform with less attenuation when connected to class 1 device. SIG didn't give the maximum ranges but rather minimum hence the strength or range of each device can be application oriented. This gives the manufacturers the ability to fine tune their technology devices to suit each individual circumstance or need. Yet SMS data transmission is safely channelled from many connected devices to cell phones, GSM modems, server and extra.

Security concerns have been raised on the use of Bluetooth connection. This has always been a cause for concern in wireless communication. Several test and experiments have proved that Bluetooth technology can also provide robust security parameters in various ways. (------) name, class, technical profile and services offered is not enough to guarantee security. Even the 48-bit unique address is far from it. However, through pairing of devices by the users the problem can be minimised. During implementation of pairing process a certain secret key (link key) is generated and the link becomes encrypted via authentication making data transfer secure. Various versions of Bluetooth have different levels of security offered. As one might expect the latest version have more and better ways of protecting data than their predecessors. (Vainio 2005), states that the E22 algorithm together with PIN codes entered on both devices have a great effect in securing the air interface in data transfer.

In as much as (Becker 2007) is concerned the weakest link in the wireless connection is the user who apparently picks short and easy PINs, ignorant of security matters and leaves Bluetooth connection permanently switched on. This can be an ideal environment for crime and data theft hence user interaction must be properly informed and trained for maximum safety.

SMSSec: An end-to-end protocol for secure SMS

Johnny Li-Chang Lo, a, , Judith Bishopa, and J.H.P. Eloffa, [Author vitae] aComputer Science Department, University of Pretoria, Lynnwood Street, Pretoria, Gauteng 0002, South Africa

23 May 2008.

GSMbrochure Reliable Data Communication

via GSM Networks

Tseng et al., 2003 C.L. Tseng, I.C. Chou and R.G. Lee, Integrating GPS-positioning and GSM-SMS services into a tele-emergent system for elder, J. Natl. Taipei Univ. Technol. 36 (2003) (2), pp. 25-30 (in Chinese).

Computers and Electronics in Agriculture

Volume 53, Issue 1, August 2006, Pages 45-59 Feasibility study on application of GSM-SMS technology to field data acquisition Chwan-Lu Tsenga, Joe-Air Jiangb, , , Ren-Guey Leec, Fu-Ming Lub, Cheng-Shiou Ouyangb, Yih-Shaing Chenb and Chih-Hsiang Chang aDepartment of Electrical Engineering, National Taipei University of Technology, Taiwan

bDepartment of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taiwan

Newton, Harold. (2007). Newton's telecom dictionary. New York: Flatiron Publishing.

Juha T. Vainio (2000-05-25). "Bluetooth Security". Helsinki University of Technology. Department of Computer Science and Engineering

Helsinki University of Technology

Andreas Becker (2007-08-16) (PDF). Bluetooth Security & Hacks. Ruhr-Universität Bochum. Retrieved 2007-10-10.

Asoke K. Talukder et al Telematics and Informatics

Volume 27, Issue 3, August 2010, Pages 350-359 Copyright © 2009 Published by Elsevier Ltd.

-- In developing nations, Internet infrastructure in scarce; however, majority of people in developing countries also need access to information that matter for their daily life and livelihood. As cost of computers are higher than mobile phones and infrastructure for running computers by stable electricity is not widely available at many places of under developed and developing (hence, referred as developing) countries. One of the major options for under-privileged people in developing countries to access information is through mobile phone. A mobile device with GPRS for access to Internet services is still expensive for a common man to afford in developing countries. Therefore, to offer mobile web for the developing countries, we need to look at SMS (Short Message Service) as transport bearer, which is cheaper and can support most of the actionable services (many important services which needs a few bytes to exchange the information). SMS as transport bearer has one constraints - it does not interoperate (i.e., a user belong to one service provider is not able to access services by SMS-data of another service provider). In this paper, we propose a routing algorithm that makes SMS-data interoperable. We also propose architecture for mobile web over SMS as transport bearer for seamless application access in roaming, number portability, and vehicular condition. Substantial researches have been done on performance of TCP/IP for wireless web that mainly focused on three applications viz., file transfer, Electronic mail, and World Wide Web. This paper presents performance of actionable information through online transaction over TCP/IP and SMS under similar conditions; it shows SMS is not at a disadvantage compared to TCP/IP.

SMS has seen unprecedented growth in the last few years. In Europe SMS has already crossed three billion messages per month mark. The current figures and future projections in the European market below, clearly demonstrate the popularity of SMS in Europe. The ttp://