tailieunhanh - GSM, cdmaOne and 3G systems P4

Trái ngược với hệ thống GSM, được thiết kế và phát triển bởi một số tổ chức khác nhau làm việc cùng nhau, các công nghệ cdmaOne được thiết kế bởi một công ty duy nhất, Qualcomm Incorporated. Mạng lưới thương mại đầu tiên đã được đưa ra cdmaOne của Hutchison tại Hồng Kông vào ngày 28 tháng 9 1995 và kể từ thời gian mà các mạng thương mại dựa trên công nghệ cdmaOne đã được đưa ra tại nhiều nước trên thế giới bao gồm cả Hàn Quốc và Hoa Kỳ. công nghệ CDMA của Qualcomm được 'lại. | GSM cdmaOne and 3G Systems. Raymond Steele Chin-Chun Lee and Peter Gould Copyright 2001 John Wiley Sons Ltd Print ISBN 0-471-49185-3 Electronic ISBN 0-470-84167-2 Chapter 4 The cdmaOne System Introduction In contrast to the GSM system which was designed and developed by a number of different organisations working together the cdmaOne technology was designed by a single company Qualcomm Incorporated. The first commercial cdmaOne network was launched by Hutchison in Hong Kong on 28 September 1995 and since that time commercial networks based on the cdmaOne technology have been launched in many countries around the world including Korea and the United States. Qualcomm s CDMA technology was re-branded as cdmaOne in 1997. Prior to this the technology was commonly referred to as IS-95 which is the name of the standard which describes the cdmaOne technology in the United States . Interim Standard number 95 1 . The cdmaOne technology was originally designed to provide a high capacity overlay for the first generation analogue Advanced Mobile Phone System AMPS operating in the 800 MHz cellular band in the United States. This gave an AMPS operator the option of increasing its network capacity in specific areas by replacing a number of 30 kHz AMPS carriers with one or more MHz cdmaOne carrier. Dual mode cdmaOne AMPS mobile stations MSs are able to use the cdmaOne system where available and they will revert to the AMPS system in areas where there is no CDMA coverage. With the introduction of personal communications systems PCS in the United States the cdmaOne technology was modified to operate in the 1900 MHz PCS frequency band in a single mode configuration citecdma-pcs. This version of the cdmaOne technology was commonly referred to as CDMA-PCS prior to the re-branding. In addition to the versions of cdmaOne described above other variations exist which have been modified to operate in particular frequency bands in different countries throughout the world. At this