Introduction of GSM
On the expansion of telephones and then mobiles in the world, the need for establishing some universal standard was felt by the communication companies and their user too. Then worked started on it till the formation of standards and then it is continuing to improve the implementation. The standardization group was established in 1982to perform some special task related to communication sector. This mobile communication group was given responsibilities to form standard for telephone and mobile in European. The group worked on the formulation of specifications for a pan-European mobile cellular radio system operating at 900MHZ. The world GSM came at a later stage when mobile communication gets some progress and a new generation came, called the 2nd generation then the Global System for Mobile (GSM) come in into existence. The 2nd generation cellular standard were developed to furnish voice services and also the data delivery through use of digital modulation. The Group Special Mobile which was developed and founded 1982. The CEPT (Conference of European Post and Telecommunication) formulate standards and specification and also formed some sub groups to work efficiently. The aim was to replace the incompatible analog system in the communication sector at that time. The GSM standardization responsibility was taken by special mobile group under ETSI (European telecommunication Standards Institute). It developed the full set of specifications named phase-I, these were available in 1990 Under ETSI. The GSM is named as “Global System for Mobile communication”. Today many mobile network providers all over the world use GSM (more than 135 Countries in Asia, Africa, Europe, Australia, America) More than 1300 million subscribers in world. The important components and terms associated with the GSM technologies to furnish it work all together is described in following points.
GSM SERVICES
- Tele-services
- Offered services
- Mobile telephony
- Emergency calling
- Bearer or Data Services
Unified Messaging Services (UMS)
- Group 3 fax
- Voice mailbox
- Electronic mail
Supplementary services
- Call Waiting: It is service network offers to notify the caller that the number is either busy or not available and if you want then wait otherwise disconnect it.
- Call Hold: This allows the caller to put on hold to take another call.
- Call Barring: The paid service for all calls including the outgoing calls for billing.
- Call Forwarding: The service which facilitates the Calls to be sent to other numbers as defined by the user.
- Multi Party Call Conferencing: This service provide facility to link multiple caller to-gather to communicate all at the same time.
- CLIP – Caller Line Identification Presentation
- CLIR – Caller Line Identification Restriction
- CUG – Closed User Group
GSM SPECIFICATIONS
OPERATION OF GSM
CHARACTERISTICS OF GSM STANDARD
- The GSM is a digital system works on the frequency band of 900, 1800 MHz.
- The GSM provided the TDMA over radio carriers of frequency 200 KHz or the carrier spacing with them.
- TDMA channels per carrier could be of two type 16 half rate or 8 full rate.
- User/terminal authentication for fraud control.
- Encryption of speech and data transmission over the radio path.
- Full international roaming capability.
- Low speed data services (upto 9.6 Kb/s).
- Compatibility with ISDN.
- Support of Short Message Service (SMS).
ADVANTAGES OF GSM OVER ANALOG SYSTEM
- Capacity increases
- Reduced RF transmission power and longer battery life.
- International roaming capability.
- Better security against fraud (through terminal validation and user authentication).
- For ensuring security and privacy through the encryption capability for information.
- ISDN and wider range of services
GSM APPLICATIONS
Development of GSM based controller:
OPERATING PROCEDURE
APPLICATIONS GSM Based Controller of appliances system
Software of System (Code Listings , Program for Microcontroller used in this project)
#include<reg51.h> // header file included for 8051 family microcontroller definitions #define led P0 // LEDs are connected at Port zero, the representation of dummy load void update_status(unsigned char[]); // The string for devices status storage void main() // main function starts here { unsigned char j,i,h,phone_no[10],dstat[2]={"26"},m=0; /* initialization and declaration of variables to be used in the program */ lcd_init(); // LCD initialization Sub routines serial_init(); // Serial port for RS232 communication initiation sub routine sms_init(); // GSM modem initialization for SMS clear_messages(); // Subroutine to clear all previous Messages from memory longdelay(); // Subroutine for a delay for wait function disp(0x80,"GSM MODEM READY"); longdelay(); clrscr(); // call of sub-routine to clear the display of LCD delay(100); disp(0x80,"GETTING DEVICE"); disp(0xc0," STATUS"); longdelay(); longdelay(); longdelay(); i=read(0xa0,0x01); P2=i; // writing data on Port 2 longdelay(); clrscr(); disp(0x80,"OK "); disp(0X80,"PRESS #"); disp(0xc0,"TO CHANGE NO"); i=get_key(0x00); if(i=='$') { clrscr(); goto Code_Label_01; } goto Code_Label_02; Code_Label_03: clrscr(); disp(0X80,"* = CONTINUE"); disp(0xc0,"# = CHANGE NO"); i=get_key(0x01); Code_Label_02: clrscr(); if(i!=0x23&&i!=0x2a) { disp(0x80,"WRONG ENTRY"); longdelay(); longdelay(); longdelay(); clrscr(); goto Code_Label_03; } if(i=='#') { disp(0x80,"ENTER NO"); lcd_com(0xc0); h=0; phone_no[h]=0; i=0; while(i<=9) { lcd_dis(0xb0); i++; } lcd_com(0xc0); while(h!=10) { i=get_key(0x01); phone_no[h]=i; lcd_dis(phone_no[h]); delay(500); h++; } } clrscr(); Code_Label_04:disp(0x80,"NO ="); if(i=='*') { i=0x10; delay(200); while(i<=0x19) { j=read(0xa0,i); lcd_dis(j); delay(100); i++; } } disp(0x85,phone_no); disp(0x8f," "); disp(0xc0," # = CONFIRM"); i=get_key(0x01); if (i!='#') { clrscr(); goto Code_Label_04; } clrscr(); disp(0x80,"CONFIRMED"); disp(0xc0,"NO = "); sequential_write(0xa0,0x10,phone_no); i=0x10; delay(200); lcd_com(0xc5); while(i<=0x19) { j=read(0xa0,i); lcd_dis(j); delay(100); i++; } longdelay(); longdelay(); Code_Label_05:disp(0x80," # * "); disp(0xc0,"CANCEL CONTINUE"); i=get_key(0x01); clrscr(); if(i!='*'&&i!='#') goto Code_Label_05; if(i=='#') goto Code_Label_03; Code_Label_01: longdelay(); disp(0x80,"GSM MODEM IDLE"); lcd_com(0xc0); m=0x31; while(m<=0x39) { lcd_com(0xc0); i=get_no(m); longdelay(); if(i=='*') break; m++; } if((m>=0x30)&&(m<=0x39)) goto Code_Label_06; else goto Code_Label_07; Code_Label_06:disp(0x80,"NEW SMS RECEIVED"); delay(100); longdelay(); longdelay(); clrscr(); disp(0x80,"CHECKING NUMBER"); j=sender_no(m); if(j==1) { //del_messg(m); if(m!=0x39) goto Code_Label_01; else goto Code_Label_07; } clrscr(); disp(0x80,"CHECKING MESSAGE"); j=disp_messg(m); longdelay(); longdelay(); clrscr(); Code_Label_07:if(m==0x39) { clrscr(); disp(0x80,"INBOX MEMORY FULL"); clear_messages(); clrscr(); disp(0x80,"MEMORY CLEARED"); } i=P2; dstat[0]=i; update_status(dstat); clrscr(); //del_messg(m); goto Code_Label_01; while(1); } void update_status(unsigned char arr[]) { unsigned char i=0; start_i2c(); delay(2500); write(0xa0); delay(2500); write(0x01); delay(2500); while(arr[i]!=0) { write(arr[i]); delay(2500); i++; } delay(2500); stop_i2c(); }
global system for mobile communication pdf What is the use of global system for mobile communication? GSM is the most widely accepted standard in telecommunications global system for mobile communication ppt GSM in Wireless Communication GSM is an open and digital cellular technology used for mobile communication. gsm architecture Introduction to Global System for Mobile Communication gsm network list What is the global system for mobile communication architecture? types of gsm Global system for mobile communication (GSM) is a globally accepted standard for digital cellular communication gsm architecture in mobile communication What is global system for mobile communications standard? Global System for Mobile Communication (GSM) gsm architecture ppt The global system for mobile communication organizes the geographical area into hexagonal cells, the size of which is controlled gsm architecture pdf free download What is the example of global system for mobile communication? Introduction to GSM - Global System for Mobile Communication
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