- This topic is empty.
15th November 2003 at 11:24 #36883Nishad.MGuest
why sim cards are not used in CDMA phones,and like to know the PN sequence comes in simplified manner,can any one one give me a valuable reply19th November 2003 at 07:45 #36884PankajGuest
Why?? there is no technical reason of not having the SIM from the very begining and now because of the absence of the proper standards indutry didn’t spend in teh SIM. In fact now the CDMA is also moving towards the SIM cards and in that world these are called R-UIM (Removable User identity Module). There are two standards that define this IS-808 and IS-820. China Unicomm has deployed their own propritary solution (very close to IS808) and now the industry trend is to use that solution.
To answer your “why”, USA had been using Analog technology for mobile communication. Since CDMA was invented in US and the primary mkt for CDMA was US, evry one worked with an evolution plan from Analog to CDMA. The Analog phones do not have the SIM and when CDMA started, the phone naturally were supporting Analog and CDMA and hence no one felt the need SIM card. Europe is all GSM and hence they never looked into these things. It is only in Asia that they look into both technologies, deploy both technologies and hence tend to comapre and then try to pickup some good parts from the other technology.20th November 2003 at 05:00 #36885prabhakar vermaGuest
Pankaj that was the right answer…
I truely agree with you..21st November 2003 at 13:42 #36886Nishad MGuest
hi Mr. Pankaj,
I really appriciate your attitude to answer my query. Please give me your email address.
Nishad22nd November 2003 at 09:20 #36887Nishad.MGuest
Is it possible to use GSM and CDMA in a single instrument,if its possible please tell me how is it…expecting ur reply
regards24th November 2003 at 10:29 #36888PankajGuest
Slight correction. China Unicom is close to IS-820 (not IS-808 as i stated earlier).26th November 2003 at 04:31 #36889PankajGuest
As per my knowledge, some handset manufactureres are coming up with these type of handsets. However this is still in priliminary stage and i do not know of any commercial offerings.