INTRODUCTION TO CDMA & WIRELESS SERVICES
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01-01-2011, 01:39 PM
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Basic landline services
Dolphin mobile services
Garuda mobile sevices
Jadoo mobile services
Difference b/w CDMA & GSM
CDMA stands code division multiple access
Both data & voice are separated from signal s using codes and then transmitted using wide frequency range.
in CDMA more space is left in channel for data transfer.
14%of worldwide market goes to CDMA
In CDMA all user share same 1250 kHz wide carrier.
In CDMA has digital transfer rate of 9.6kbps,same as GSM
Voice data part of the connection is transmitted at a rate of 8kbps.
Theoretically CDMA allowing a maximum of 131 connections,as compared to 48 GSM connection in a similar bandwidth.
GSM stands global system mobile.
Roaming readiness and fraud prevention are two major advantage from this technology.
In GSM,TDMA(time division multiple acess) technique is used.
GSM system create 8 time division channels in 200khz wide carrier.
Only one subscriber at a time is assigned to each time slot or channel.
Description of various CDMA N\W
MSC(Mobile Switching Centre)
VLR(visitor location register)
Bsc (base switching centre)
Hlr (home location register)
Scp (service control point)
Gmsc (gateway msc)
Aaa (authentication,authorization and accounting)
Security technique in mobile communication
Over the air programming
Mobile equipment identifier(MEID)
International mobile equipment identity(IMEI)
Electronic serial number.
Over The Air Programming
Over the air programming(OTA) methods of distributing new s/w updates to cell phone to access services such as MMS.
OTA messaging provides remote control of mobile phone for service and subscription activation, personalization for mobile operator and third parties.
This technique is mainly used in CDMA .
Mobile Equipment Identifier
A MEID is globally unique number identifying a physical piece of CDMA mobile station equipment.
The number format is generally hexadecimal digit.
The MEID was created to replace ESN.