Mobile Phones (携帯電話)
12:34 AM Posted In AU , CDMA , DoCoMo , GSM , japan , network , technology , WCDMA
Very briefly, there are three mobile phone technologies supported by the major networks within Japan - PDC (Personal Digital Cellular), CDMA (Code Divisional Multiple Access) and WCDMA. DoCoMo, Vodafone and TU-KA support the established PDC, and DoCoMo and Vodafone have also introduced the newer WCDMA, while AU supports CDMA. All three of these technologies are incompatible with each other.
Outside of Japan, CDMA networks exist in about 40 other countries, but by far the most common technology in the world is GSM - which exists in over 200 countries (including major destinations in Europe, Africa and Asia Pacific). Within these countries, GSM uses four different frequencies - 850, 900, 1800 and 1900MHz.
The Japanese networks have looked to combine international CDMA, or GSM technology, with their domestic technology as a way to offer a service to their subscribers that allows them to use just one phone both in Japan, and internationally.