GSM system

GSM system has become a mainstream worldwide (hereinafter 2G) second-generation mobile phone. South Korea and Japan and in North Korea, GSM has not been adopted. For its own method for PDC called (Personal Digital Cellular) was the mainstream in Japan, while the services and terminal of its own popular, it was in seclusion state international roaming services and the entry of foreign handset makers does not proceed. In South Korea, became the group adopts overall scheme cdmaOne Qualcomm American (Qualcomm) company called (IS-95), such as LG Electronics and Samsung Electronics leap internationally. North America Unlike the EU, and without forcing the selection of technology to mobile operators, government was left to the choice of their respective owners   https://marklester.co.uk. It is at present as a result, cdmaOne GSM and is are you almost antagonistic.

(Hereinafter referred to as 3G), 2G is adopted method of its own, different frequencies in each country and region, based on the lessons learned that could not use the same method in all the world, the third-generation mobile phone third-generation mobile phone in decision standard, the IMT-2000, an index to be available worldwide mobile phone erected. However, in the process of standards development, CDMA2000 and W-CDMA is a form of parallel adoption, GSM camp to W-CDMA, cdmaOne camp (part of North and South America and Asia) that it was decided to migrate to CDMA2000. The Chinese government is trying to introduce the TD-SCDMA from your own point of view of self-technology development. The patent relates to a generation of 3G technology, the license price of the "Qualcomm" is as too high, between the phone and vendors Qualcomm (sales company), of several companies chipset vendors, it is currently pending.

NTT DoCoMo, Softbank Mobile has adopted the W-CDMA, overseas manufacturers entrants and international roaming have been promoted in Japan. 2G has adopted the CDMA2000 system for cdmaOne system is KDDI (au). However, cdmaOne and CDMA2000 of Japan, for the avoidance of interference with UHF television broadcast wave, the frequency of the upstream and downstream is reversed with other countries. International roaming is not possible in the Global Passport CDMA terminal except for this.