3. Cell Phone Technologies

      a. 1G 

      It refers to first generation wireless telephone technology. This is an analog standard for telecommunication, which was introduced in 1980s and was later replaced by 2G. 

      b. 2G

      It refers to second-generation wireless telephone technologies it was launched in Finland in the year 1991.2G technologies use digital radio signals.

      Different 2G technologies: Based on what type of multiplexing (process of combining multiple digital data streams it one signal) is used, 2G technologies can be divided into three categories:            

     a. TDMA (Time Division Multiple Access)

     b. CDMA (Code Division Multiple Access)

     c. FDMA (Frequency Division Multiple Access)

Advantages to 2G over 1G:

1. These technologies enable various mobile phone networks to provide the services such as text messages, picture messages, multimedia messages (MMS)

2. All the text messages are digitally encrypted. Digital encryption allows for the transfer of data in such a way that only intended receiver can receive and read it.

3. Signals are digitally coded which improves the voice and reduced noise in line

4. 2G technologies can pack more calls per amount of bandwidth than 1G.

5.  2G cell phone units are generally smaller than 1 G units as they emit less radio power.

      c.  2.5G General packet radio service (GPRS)

      The major impetus for 2.5G is the "always-on" capability. Being packet based, 2.5G technologies allow for the use of infrastructure and facilities only when a transaction is required, rather than maintaining facilities in a session-like manner. This provides tremendous infrastructure efficiency and service delivery improvements.

      Using GPRS as a bearer for WAP, for instance, will allow for the use of WAP on a per-transaction rather than a per-minute-of-use basis. More importantly perhaps is the ability for GPRS to allow for autonomous service realization through the always-on capability. For example, a GPRS customer could receive content or services without actually manually invoking a service or transaction. This has significant implications for mobile commerce and location based services.

GPRS is a service commonly associated with 2.5G technologies. It has data transmission rates of 28 kbps or higher. GPRS came after the development of the Global System for Mobile (GSM) service, which is classified as 2G technologies. GPRS could provide data rates from 56 kbps up to 115 kbps.

d. 2.75G Enhanced Data rates for GSM Evolution (EDGE)

EDGE is standardized by 3GPP as part of the GSM family and it is an upgrade that provides a potential three-fold increase in capacity of GSM/GPRS networks. The specification achieves higher data-rates (up to 236.8 kbit/s) by switching to more sophisticated methods of coding (8PSK), within existing GSM timeslots.

e. 3G Universal Mobile Telecommunications Standard (UMTS)

It refers to third generation of standard mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunication-2000 (IMT-2000)  specifications by the International Telecommunication Union.

3G technologies are intended for the true multimedia cell phone typically called smart phones. It allows simultaneous use of speech and data services and higher data rates it comes with enhancements over previous wireless technologies, like high-speed transmission, advanced multimedia access and global roaming. 3G helps to simultaneously transfer both voice data (a telephone call) and non-voice data (such as downloading information, exchanging e-mail, and instant messaging).

The standard supported mobile/portable voice, images, data, and video communications at up to 2 Mbps (local area access) or 384 Kbps (wide area broadcast). 

Some features provided by 3G technologies are

1. Several times higher data speed. 3G networks have potential speed up to 3Mbps

2. Enhanced audio and video streaming

3. Video-conferencing support

4. Web and WAP browsing at higher speeds.

5. IPTV (TV through the Internet) support.

f. 3.5G High-Speed Downlink Packet Access (HSDPA)

The 3.5G solution promises a data download speed of up to 14Mbps (megabits per second) and an upload speed of up to 1.8Mbps. Compared to that, the mere 384Kbps (kilobits per second) download, and uploads up to 64Kbps that a 3G network now offer. 3.5G rely on the new High-Speed Downlink Packet Access protocol, which are responsible fast transfer speeds over those of 3G.

g. 4G are short for Fourth (4th) Generation Technology

 4G Technology is basically the extension in the 3G technologies with more bandwidth and services offers in the 3G. 4G technologies are the future technologies that are mostly in  their maturity period. The expectation for the 4G technologies  is basically the high quality audio/video streaming over end-to-end Internet Protocol.