Implementation And Application Of SMS Gateway

SMS(Short Message Service) is the communication standard(GSM 03.40 and GSM 03.38) which constituted by ETSI(European Telecommunications Standards Institute), it is the GSM system provides to users' one kind of data service. It is the main telecommunication service which the GSM digital cellular mobile correspondence network provided as the voice transmission and the facsimile. Along with Mobile widespread used, qua a base service of GSM network, SMS more and more get people's approval and recognition, the multifarious application of the service based on SMS also vigorous development.The SMS has following merits in technically:24 hours on-line: If users 24 hours opening Mobile, they can receive and send short message all time. Moreover the SMSC can store the short message provisionally. Therefore even if users cannot receive the short message and when they opening Mobile they still could receive the short message which the SMSC saved for them.Can transmission many kinds of data: The SMS has three kinds of mode: Block mode, PDU mode and text mode. Most commonly used mode is the PDU, through the PDU encoded SMS content to be allowed to be the text, the sound or the picture. Along with the SMS protocol development, the SMS will be able to support more kinds of data.Safeguard the security in the transmission: If the users use the STK card, it can encrypt the information before the short message send. After arrives the destination to decipher by receive the information, has realized to the information security safeguard.These merits of SMS are many wireless networks not has. Because the SMS technology has the merits covers broadly, on-line all time, automatic transmission, the expense is inexpensive, the stable higher, and so on. Therefore it quite suit to frequent long-distance range transmission, small current capacity data application domain. For example the building equipment safe monitoring, the vehicles monitoring dispatch, field data gathering and hold controls, monitoring the water state, the environment long-distance monitor, the CPS localization and so on. Through SMS technology can realize many kinds of information service based on the GSM network. Because the GSM network can realized the networking in the national scope and roams, compares the traditional system superiority which has in the wireless network cover. Adds on data transfer function which GSM itself have, all enable these applications to obtain the rapid popularization.GSM Modem uses the GSM mobile communication system control command collection of the Modem, namely AT command. The GSM Modem AT command collection was command foundation increased the collection pronunciation, the data, the SMS, the facsimile, the SIM card and the merchant in field standard, the Hayes which some related SMS and the SIM card processing instruction formed from the definition instruction to a body command ultra collection, It follows ETSI the GSM07.07 standard, altogether has more than 150 strips.The AT command collection original is the standard language use for between the computer and the Modem carries on the communication, mainly uses for to control the Modem digit dialing, reply and so on. But the Mobile is uses the AT command collection to complete the SMS send, receive and control wireless GSM signal and so on. from the principle of work looked the handset also is GSM Modem, it including keyboard, liquid crystal screen, low-layer communication module ME and software. ME is in the Mobile the lowest layer communication module, it is responsible for the wireless transmission, TA (Terminal Adaptor) causes entire ME exterior connection standardization.The PDU(Protocol Data Unit) mode is one kind uses the AT command to transmit the hexadecimal system encoded binary system user data the connection protocol. The PDU mode can support the different encode form. This transfer method is similar in the computer network the package exchange, each SMS complete user data send a block data adds on the destination address and the control information time transmits. Some AT command structure does not need to understand the news block the content, only transmits the block data in the mobile termination and between the terminal device upper formation resident program, extremely suits the mode based on this kind of AT command application procedure. The PDU string not only contains news itself, but also includes other information, like short message service center number, destination number, reply number, encoding method and service time and so on. The send and receive PDU string, the structure is not same. The common Mobil and the GSM SMS module all support the PDU mode. When SMS gateway and GSM SMS module connection, we use based on AT command collection PDU mode carry on the control to the SMS module, completes the SMS receiving and send. The communication technique progress unceasingly changes along with the users require, we may develop the new way of SMS application to adapt the change. At present Mobile and computer mutually send and receive the short message already apply to the enterprise work, negotiable securities and traffic and so on field. The way of Mobile and computer interaction by SMS not only can plenitude use computer resources, but also broke the limit of the LAN, goes down to the information terminal to individual, enhanced the intelligence transmission in real time.This article to the GSM SMS definition, background, merit has carried on a comprehensive introduction, and thorough research SMS network system structure, data interface, GSM Modem and AT Command and so on the related technology has carried on the detailed introduction, designed SMS Gateway based on the rule processing above technology thorough research foundation. And realize the prototype system on Linux environment used C programming language. This SMS gateway use standard communication protocol and communication interface. The system completely realized control and manage the GSM Modem receive and send by software. This system fused the computer high speed processing capability and the Mobile SMS agile characteristic, it can according to which the users has beforehand defined rules of the system provides operation type processing the received short message.When receives the short message, the system will act according to there analyze form to decompose each field, will inspect whether for definition key word. If will appoint the character string is the key word, then the system will contrast in the regular table. If matches the rule which the user defines in advance, then SMS gateway according to the corresponding rule processing the SMS. Realized information retrieval, monitoring and warning, automatic control and so on. Its application in network security aspect, when the client comes under the network attack, The client automatically warning to the SMS gateway ,the SMS gateway can act according to the rule which defines in advance to appoint number send warning short message. After the related personnel receives warning short message, immediately to SMS gateway send command short message, the gateway will execute the command or the procedure according to the command short message processing the network attack, enhanced to the warning real time and processing timeliness.