Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Mobile phones connect to a terrestrial cellular network of base stations (cell sites), whereas satellite phones connect to orbiting satellites. Both networks are interconnected to the public switched telephone network (PSTN) to allow any phone in the world to be dialled. The table below summarizes the history of Mobile Telephony:
| Radio Phones
| 1- Massively used in world war II for communication between ships.2- Used as part of a closed network such as a police radio or taxi dispatch system.
| Mobile Radio Telephones(In some literature also referred to as 0G of Mobile telephony)Some standards were -1- MTA (Mobile Telephone system A), was developed by Ericsson and commercially released in Sweden. Later improved as MTB/C&D.2- AMTS used in Japan and 3- ARP used in Finland
| They were available as a commercial service that was integrated with public switched telephone network and had their own telephone numbers. These mobile telephones were usually mounted in cars or trucks, though briefcase models were also made. The network was made automatic with time and didn’t require manual operators.
| 1G Standards used were:1- NMT - Nordic Mobile Telephone (NMT) Nordic Countries.2- AMPS (Advanced Mobile Phone System) used in the United States and Australia.3- TACS (Total Access Communications System) in the United Kingdom, C-450 in West Germany, Portugal and South Africa.
| 1- Was characterized by development of cellular technology which marked the beginning of widespread mobile telephony commercially.2- Users could easily switch from one network to another without breaking the calls.3- Voice transmission from cell phones to base station was done using analog signals. Portable cellular phone was developed by Martin Cooper of Motorola.
| 2GStandards:1- TDMA based - GSM, PDC in Japan and D-AMPS in USA.2- CDMA based - IS95/CDMAOne popularly called CDMA.2.5G Standards:1- GPRS (General Packet radio Service)2- EDGE (Enhanced Data rates for GSM Evolution)
| 1- Widespread use of mobile telephones. Phone conversations were digitally encrypted and provided more security.2- Lower power for hand sets and more efficient use of spectrum was possible.3- 2G introduced data services for mobile, starting with SMS text messages.4- GPRS could provide internet through data communication at 65-130 kbps.5- EDGE enabled speed of more than 200 kbps
| 3GWireless Data communication at speed more than 200kbpsStandard:1- UMTS: - Universal Mobile Telecommunications System (W-CDMA for air interface, GSM based core network and USIM cards for authentication).2- CDMA2000
| 1- Enabled high speed internet access, efficient voice communication, video telephony, mms etc.
| 3.5G/4GWireless Data communication at speed more than 20 Mbps to 1 gbps.1- Use of microwaves instead of radio waves.2- WiMax – IEEE 802.163- OFDM/HSDPA
| 1- High speed and seamless multimedia communication.
2G Mobile Networks
2G (or 2-G) is short for second-generation wireless telephone technology. Second generation 2G cellular telecom networks were commercially launched on the GSM standard in Finland in 1991. Three primary benefits of 2G networks over their predecessors were that phone conversations were digitally encrypted (provided more security), 2G systems were significantly more efficient on the spectrum allowing for far greater mobile phone penetration levels; and 2G introduced data services for mobile, starting with SMS text messages. 2G technologies can be divided into TDMA (Time Division Multiple Access) -based and CDMA (Code Division Multiple Access) based standards depending on the type of multiplexing used. The main 2G standards are: 1. GSM (TDMA-based), originally from Europe but used in almost all...
References: 2. CDMA – An Access Method that Makes a Difference Version 1.0, August 9, 2006, AdvancedVoIP.com
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