Mobile phone service providers divide each city into small cells and install a mobile phone tower in each cells so it is also called cellular phones. In cellular service there are two main technologiesGSM and CDMA. GSM stands for Global System for Mobile Communications and CDMA stands for Code Division Multiple Access.
GSM service is available in more than 200 countries and is used by around 2 billion people worldwide. Normally GSM networks operate in 900 MHz or 1800 MHz. Another important feature of GSM is Subscriber Identity Module or SIM Card. It is a small smartcard which contains subscriber information and phonebook. For higher speed data transmission either GPRS or EDGE can
be used in GSM phones.
CDMA is a form of multiplexing which divide signals by random pseudo codes instead of conventional multiplexing methods like dividing by time or frequency. CDMA is widely used in cellular networks and global positioning systems (GPS).
Cellular Subscribers : As on Apr 2007 India has 167 million mobile phone subscribers. Out of this 125 million are GSM users and 41 million CDMA users.
Cellular Service Providers : BSNL, Bharti Airtel, Hutch, Idea, Aircel, Spice and MTL are the main GSM providers in India. Reliance Communications and Tata Indicom are the
main CDMA providers in India.
Bharti Airtel : Airtel is providing cellular services in Delhi, Mumbai, Kolkata, Chennai, Andhra Pradesh, Gujarat, Haryana, Himachal Pradesh, Jammu and Kashmir, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Goa, Orissa, Punjab, Rajasthan, Tamil Nadu, UP and West Bengal. Airtel is the No.1 cellular service provider in India using GSM technology. Airtel has 23% market share in India with a total subscriber base of 38 million.
Bharat Sanchar Nigam Limited (BSNL) : BSNL is a state owned telecom company which has GSM presence in almost every cities and towns. BSNL has 27 million subscribers with a market share of 16%.
Tata Indicom : Tata Indicom is a main CDMA provider in India with 16 million subscribers all over India. Tata Indicom has presence in almost every states and cities in India.