PL  |  NL  |  FR  |  ES  |  PT  |  IT  |  DE  |  DK  |  NO  |  SE  |  FI  |  GR  |  JP  |  CN  |  KR  |  RU  |  AE

  Report this article

More information

Outdoor Wireless Security Camera a Better Bet versus the CCTV Camera

Mobile Broadband: The Technology That Enables Users to Get Online Anywhere

Enter the virtual world at your choice with Mobile Broadband

No Wires, Only by Bluetooth!

RFID Tags: What They are, how they are used and Why You Need a RFID Consultant

Sony Ericsson T700 Review

Canon Pixma MP980

3G for Internet Access on the Go

GEOCACHING

How To Download Games For PSP

Mobile Web applications and widgets

Finding music at Sprint.com

Mobile Telephony refers to communication using a mobile wireless technology. It is usually classified into four generations namely 1G, 2G, 3G and 4G. These generations help record the dramatic evolution mobile telephony have under gone since their first introduction nearly 30 years ago.

Advanced Mobile Phone System (AMPS) was the first commercial cellular network standard developed by Bell Labs. It was an analog mobile communication system which first appeared in the mid 70's but was introduced officially in 1983. This technology lies in the category of first generation (1G) cellular technology and is now obsolete. Since 2008 in USA, the carriers are not allowed to provide AMPS support. Some other countries including Australia have also discontinued the support for this technology. AMPS provided basic voice telephony over FDMA (Frequency Division Multiple Access) and used analog signals to carry voice. AMPS did not support text messaging or data support. Due to the analog nature of the system, AMPS signal were easily intercepted using frequency scanning tools and were hence susceptible to eavesdropping. Another major flaw with the AMPS was the lack of cell phone authentication, which led to toll fraud on the basis of phone cloning.

Global System for Mobile communications (GSM) is the most popular and widely used mobile telephony standard. GSM technology was initially introduced in the early 90's. The technology is very much popular in Europe and Asia. According to an estimate, around 80% of the mobile users around the globe are using this technology. GSM uses the TDMA (Time Division Multiple Access) technology and provides support for text and data in addition to voice. In later advancements higher data transfer capabilities were added by introducing General Packet Radio Service (GPRS) first and then Enhanced Data Rates for GSM Evolution (EDGE).

The 1^st generation (1G) of mobile telephony only supported voice transmission and there was no support for the transmission of text or data. Security in 1G was minimal due to the absence of encrypted communication. However 2G introduced the SMS text messaging service and later underwent further advancements with the introduction of GPRS based data services in its enhanced version, the 2.5G. The 2.5G network was capable of delivering data rates ranging from 56 Kbps to 114 Kbps. This led to the popularity of Multimedia Messaging Service (MMS), Wireless Application Protocol (WAP) and other data services. The use of digital codec greatly improved the capacity of the 2G cellular network and the use of encrypted calling signals has greatly minimized the possibility of eavesdropping.

The major difference between the first two generations of mobile telephony was that the signals used in 1G networks were analog while the signals in 2G were digital. 2G originated from Europe but is now used worldwide. The network has expanded in over 215 countries and most of the users (approximately 80%) around the globe are using it.

Mobile Telephone Switching Office (MTSO) is a system that manages all the operations of a cellular network. These operations include monitoring of mobile calls, signal strength of the cell phone, tracking location of mobile device, tracking billing information, arranging handoffs, cell towers communication management, and a lot more. It also connects the cellular phone call to the telephony network which means that it has the ability to control calls coming towards or going away from the telephony system. MTSO is considered to be the heart of the whole cellular system and it assigns frequencies to every call and reassigns the frequencies if a continuing call session is transferred from one channel of a core network to another. A cellular network can have one or more MTSOs.

3G Wireless Communication

The third generation in mobile telephony is a technology often referred to as broadband wireless. The first generation dealt with analog transmissions of voice-only data over circuit-switched networks. The second generation allows for digitally encoded voice and data to be transmitted between wireless devices, such as cell phones, and content providers. This generation provides a throughput of around 19.2 Kbps. Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), and Personal Communications Services (PCS) all fall under the umbrella of 2G mobile telephony. This technology can transmit data over circuit-switched networks and supports data encryption, fax transmissions, and short message services (SMSs).

3G standards were defined by the International Telecommunications Union (ITU) as IMT-2000. It is based upon the use of a wide array of communication technologies such as EDGE, HSPA, UMTS, W-CDMA, CDMA2000 and WiMAX. 3G networks are based on packet switching technology which allows it to deliver far greater bandwidth. 3G networks can provide a data rate of up to 384 Kbps while moving and up to 2 Mbps while stationary.Another significant advancement in 3G networks was the simultaneous use of both data and voice services. 3G network have complete support for global roaming. Some other features that are available in 3G phones include Internet, MMS, mobile TV, video conferencing, 3D gaming, internet and multi-player gaming. Currently the 3G network suffers from limited deployment. From a security perspective, 3G networks use the more advanced KASUMI cipher instead of the traditional A5/1cipher used in older networks.

4G is the future of cellular networks. This network will be based upon the Orthogonal Frequency Division Multiplexing (OFDM) technology and will have the ability to support data rates in excess of 1 Gbps. Telepresence and high definition video services would be available in 4G. Some other features include the promise of multimedia newspapers and TV programs.

Frequency Division Multiple Access (FDMA) is an analog transmission technology used for the allocation of frequency bands or channels in mobile communications, widely used in the first generation (1G) of the mobile telephony. FDMA is used as a channelization protocol by multiple-access protocols because it is a channel access method. In FDMA a frequency band allocated to a network is divided into multiple channels or bands and a unique channel is allocated to each user for voice or data transmission. If the frequency band is not utilized, it remains inactive. This allows users to receive and transmit signals at unique frequencies without the risk of interference between multiple users. 1G mobile technologies such as Advanced Mobile Phone System (AMPS), Total Access Communication System (TACS) and Nordic Mobile Telephone (NMT) uses FDMA technology.

Time Division Multiple Access (TDMA) is a digital transmission technology for mobile communications targeted for shared medium networks. TDMA splits the frequency channels into time slots which increase the volume of the data being transmitted. So the data transmission in TDMA is done through the allocation of time slots and each user gets a specific number of slots for a fixed amount of time. This technology is used in the second generation (2G) of the mobile telephony including Global System for Mobile Communications (GSM), iDEN, D-AMPS and Personal Digital Cellular (PDC), and it is most widely used around the world these days. Several users can share a single career frequency in TDMA. The satellite and radio systems extensively use this technology as well.

Code Division Multiple Access (CDMA) is another channel access method that is used in the third generation (3G) of the mobile telephony. CDMA is a spread-spectrum multiple access technology that uses a unique coding scheme for allowing multiple users to simultaneously communicate over same physical channel. So each group of users is provided with a unique shared code and there can be multiple users with different codes on same channel but only group of users having same code can communicate and understand each other. The major feature of this technology was that it allowed a number of signals to share the same frequency. The original standard of CDMA, also known as IS-95 or cdmaOne, is also still used in 2G of mobile telephony. CDMA is also recognized to provide higher data transfer rates as compared to other access methods.

So to explain all three further, let's take an example of a meeting room where two teams want to meet at a time. With FDMA, members of each team can speak in a different pitch or sound - distribution of frequency. While with TDMA, each team can get its turn to speak - division of time. And finally with CDMA, both teams can speak different languages at a time - division of code. There were security issues in FDMA and TDMA due to which there was a high probability of communication being intercepted. Also, there were bandwidth and time constraints in these two technologies. CDMA addressed all these issues as it maintains better security and any user can send any data at anytime.

CDMA2000 is an extension of the CDMA technology. The technology was first introduced in the 2.5G of the mobile telephony and later used in the 3G. CDMA2000 uses more efficient schemes with least amount of resources to provide high-speed data transfer and better voice capacity as compared to CDMA. Cellular services providers have started moving towards CDMA2000 as it reduces the delivery cost and enhances the user experience. CDMA2000 has the capability to provide data speed up to 153 Kbps in 1xRTT and 2.4 Mbps in 1xEV-DO for various advanced services such as video telephony, multicasting, push to talk and online multiplayer games. So, CDMA2000 provides high-speed broadband data connectivity, enhanced capacity for voice and data along with better privacy and security features.

Wideband Code Division Multiple Access (W-CDMA) is a mobile wireless technology used in 3G of the mobile telephony networks. It is actually the true 3G version of GSM and also known as Universal Mobile Telecommunications System (UMTS). It uses 5MHz-wide radio channels as compared to 1.25MHz radio channels used by CDMA2000. W-CDMA evolved from the need to have higher data speed currently offered by GPRS and EDGE. So, W-CDMA provides high-speed broadband mobile service capable of delivering data transfer rate up to 2 Mbps for voice, images, data and video communications. W-CDMA emerged through the 3G Partnership Project (3GPP) that concentrated on the interoperability among the 3G networks and part of the IMT-2000 family of 3G standards. Although CDMA2000 and W-CDMA where created by different projects, 3GPP2 and 3GPP, both share the same fundamental technology.