Monday, December 28, 2009
New Technology - 3G Spectrum
21st Century Technology - 3G Spectrum
The 21st Century Technology 3G is useful in transfer of more information, faster data access and multimedia services through mobile phones. 3G is the third generation of tele standards and technology for mobile networking, superseding 2.5G. It is based on the International Telecommunication Union (ITU) family of standards under the IMT-2000. It's a technology apprehensively expected by mobile users in all over the world.
3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver speeds up to 14.4 Mbit/s on the downlink and 5.8 Mbit/s on the uplink.
Unlike Wi-Fi or WLAN networks, 3G networks are wide-area cellular telephone networks that evolved to incorporate high-speed Internet access and video telephony. Wi-FI networks are short range, high-bandwidth networks primarily developed for data.
Meaning of Spectrum
Radio spectrum refers to a range of radio frequencies. The bandwidth of a radio signal is the difference between the upper and lower frequencies of the signal. For example, in the case of a voice signal having a minimum frequency of 200 hertz (Hz) and a maximum frequency of 3,000 Hz, the bandwidth is 2,800 Hz (3 KHz). The amount of bandwidth needed for 3G services could be as much as 15-20 Mhz, whereas for 2G services a bandwidth of 30-200 KHz is used. Hence, for 3G huge bandwidth is required.
Now you can understand why 3G spectrum has become such a precious and scarce resource in the Technology age - everybody from Media broadcasters to the Mobile companies wants spectrum, and it is in short supply.
Benefits of 3G Technology
3G services will enable video broadcast and data-intensive services such as stock transactions, e-learning and telemedicine through wireless communications in a fast speed. That's why all telecom operators are waiting to launch 3G in India to cash in on revenues by providing high-end services to customers, which are voice data and video enabled.
Problems with 3G
Although 3G was successfully introduced to users across the world, some issues are debated by 3G providers and users:
Expensive input fees for the 3G service licenses.
Numerous differences in the licensing terms.
Large amount of debt currently sustained by many telecommunication companies, which makes it a challenge to build the necessary infrastructure for 3G
Lack of member state support for financially troubled operators.
Expense of 3G phones.
Lack of buy-in by 2G mobile users for the new 3G wireless services.
Lack of coverage, because it is still a new service.
High prices of 3G mobile services in some countries, including Internet access.
Current lack of user need for 3G voice and data services in a hand-held device
History of 3G
The first pre-commercial 3G network was launched by NTT DoCoMo in Japan branded FOMA, in May 2001 on a pre-release of W-CDMA technology. The first commercial launch of 3G was also by NTT DoCoMo in Japan on October 1, 2001. The first commercial United States 3G network was by Monet Mobile Networks, on CDMA2000 1x EV-DO technology, but this network provider later shut down operations. In June 2009, more than 190 3G networks were operating in 40 countries and 154 HSDPA networks were operating in 71 countries, according to the Global Mobile Suppliers Association (GSA).
Technical Complexities of 3G
The technical complexities of a 3G phone or handset depends on its need to roam onto legacy 2G networks. In the first country, Japan, there was no need to include roaming capabilities to older networks such as GSM, so 3G phones were small and lightweight. In most other countries, the manufacturers and network operators wanted multi-mode 3G phones which would operate on 3G and 2G networks (e.g., W-CDMA and GSM), which added to the complexity, size, weight, and cost of the handset. As a result, early European W-CDMA phones were significantly larger and heavier than comparable Japanese W-CDMA phones. The general trend to smaller and smaller phones seems to have paused, perhaps even turned, with the capability of large-screen phones to provide more video, gaming and internet use on the 3G networks, and further fuelled by the appeal of the Apple iPhone.
The Speed of 3G
The ITU has not provided a clear definition of the speeds users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the speeds it specifies are not being met. It is often suggested by industry sources that 3G can be expected to provide 384 kbit/s at or below pedestrian speeds, but only 128 kbit/s in a moving car. While EDGE is part of the 3G standard, some phones report EDGE and 3G network availability as separate things.
Network standardization of 3G
The International Telecommunication Union (ITU) defined the demands for 3G mobile networks with the IMT-2000 standard. An organization called 3rd Generation Partnership Project (3GPP) has continued that work by defining a mobile system that fulfills the IMT-2000 standard. This system is called Universal Mobile Telecommunications System (UMTS).
evolution of 3G Technology
2G networks were built mainly for voice data and slow transmission. Due to rapid changes in user expectation, they do not meet today's wireless needs. Evolution from 2G to 3G can be sub-divided into following phases:
* 2G to 2.5G
* 2.5G to 2.75G
* 2.75G to 3G
The first major step in the evolution to 3G occurred with the introduction of General Packet Radio Service (GPRS). So the cellular services combined with GPRS became 2.5G. GPRS could provide data rates from 56 kbit/s up to 114 kbit/s. It can be used for services such as Wireless Application Protocol (WAP) access, Short Message Service (SMS), Multimedia Messaging Service (MMS), and for Internet communication services such as email and World Wide Web access.
From 2.5G to 2.75G
GPRS networks evolved to EDGE networks with the introduction of 8PSK encoding. Enhanced Data rates for GSM Evolution (EDGE), Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC) is a backward-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. 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 by switching to more sophisticated methods of coding (8PSK), within existing GSM timeslots. EDGE can be used for any packet switched application, such as an Internet, video and other multimedia.
From 2.75G to 3G
From EDGE networks the introduction of UMTS networks and technology is called pure 3G. EDGE is standardized by 3G 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 by switching to more sophisticated methods of coding (8PSK), within existing GSM timeslots.
3g Security
3G networks offer a greater degree of security than 2G predecessors. By allowing the UE to authenticate the network it is attaching to, the user can be sure the network is the intended one and not an impersonator. 3G networks use the KASUMI block crypto instead of the older A5/1 stream cipher. However, a number of serious weaknesses in the KASUMI cipher have been identified. In addition to the 3G network infrastructure security, end to end security is offered when application frameworks such as IMS are accessed, although this is not strictly a 3G property.
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