gsm introduction

Editor's Notes

• #2: {"11":"By 1993 there were 36 GSM networks in 22 countries [6]. Although standardized in Europe, GSM is not only a European standard. Over 200 GSM networks (including DCS1800 and PCS1900) are operational in 110 countries around the world. In the beginning of 1994, there were 1.3 million subscribers worldwide [18], which had grown to more than 55 million by October 1997. With North America making a delayed entry into the GSM field with a derivative of GSM called PCS1900, GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications. \nThe developers of GSM chose an unproven (at the time) digital system, as opposed to the then-standard analog cellular systems like AMPS in the United States and TACS in the United Kingdom. They had faith that advancements in compression algorithms and digital signal processors would allow the fulfillment of the original criteria and the continual improvement of the system in terms of quality and cost. The over 8000 pages of GSM recommendations try to allow flexibility and competitive innovation among suppliers, but provide enough standardization to guarantee proper interworking between the components of the system. This is done by providing functional and interface descriptions for each of the functional entities defined in the system \n","24":"270.833 kb/s per carrier\nGMSK with a time bandwidth product BT =0.3\nSlow frequency hoping 217/hops/second.\nSynchronization compensation for up to 233micro seconds absolute delay\nBlock and convolutional channel coding copuled with interleaving to combat channel perturbations- overall channel rate of 22.8 kb/s\nFull rate channel 13 kb/s voice coder rate using regular pulse excitation/linear predictive coding RPE/LPC, half rate channel 6.5 kb/s using\nVector coder rate using vector sum excited linear predictivie coding VSELP\nOverall full rate channel bit rate of 22.8 kb/s.\nEach cell can have from 1 to 16 pairs of carriers.\n","10":"By 1993 there were 36 GSM networks in 22 countries [6]. Although standardized in Europe, GSM is not only a European standard. Over 200 GSM networks (including DCS1800 and PCS1900) are operational in 110 countries around the world. In the beginning of 1994, there were 1.3 million subscribers worldwide [18], which had grown to more than 55 million by October 1997. With North America making a delayed entry into the GSM field with a derivative of GSM called PCS1900, GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications. \nThe developers of GSM chose an unproven (at the time) digital system, as opposed to the then-standard analog cellular systems like AMPS in the United States and TACS in the United Kingdom. They had faith that advancements in compression algorithms and digital signal processors would allow the fulfillment of the original criteria and the continual improvement of the system in terms of quality and cost. The over 8000 pages of GSM recommendations try to allow flexibility and competitive innovation among suppliers, but provide enough standardization to guarantee proper interworking between the components of the system. This is done by providing functional and interface descriptions for each of the functional entities defined in the system \n"}