FEATURES OF 4G WIRELESS SYSTEMS

Add a note hereThere are numerous features of 3G which needed to be modified for the future applications of the mobile communication networks and their service sectors. These collections of advanced versions, along with some others new advanced features, have been proposed for the forth coming 4G system. Of course, the complete picture is not clear yet, though it is believed that by the end of 2010 a better view of the complete 4G features will be known. Here we have captured the main features of the existing experimental 4G system and some of the essential future versions.

Add a note hereAs per the announcements of the 4G working groups, the infrastructure and the transreceiver terminals of 4G system will have almost similar structures like that of 2G and 3G except for some advanced features. The previous legacy systems will be in place to keep the existing users. The major change in the infrastructure for 4G will be "all packet-based system" and the technology on which it will be based is the IPv6. There are some other proposals for an open platform in which the new innovations and evolutions of the future can fit. One of the first technology really fulfilling the 4G requirements as set by the ITU-R will be LTE Advanced as currently standardized by 3GPP. LTE Advanced will be an evolution of the 3GPP Long Term Evolution. The higher data rates needed are for instance, achieved by the aggregation of multiple LTE carriers that are currently limited to 20MHz bandwidth and there are many such changes have been recommended. In the following sections we have listed some of the important features of the 4G systems.

Add a note here1 OFDM Based Physical Layer

Add a note hereThe main aim of 4G technology is to Provide high speed wireless broadband services. Airport lounges, caf├ęs, railway stations, conference arenas, and other such locations are required to have high speed internet services; in those places, 4G can play an important role. 4G is equipped with the proper arrangements at the physical layer to meet all the demands of those various scenarios. There are many difficulties, however, in providing high speed wireless internet services in these environments, such as multipath fading and the inter-symbol interferences generated by the system itself. As a result, OFDM technology is used to handle this problem.

Add a note here2 Inter-Symbol Interference Due to Time Delay

Add a note hereIn a multipath environment, the signals and their delayed versions arrive at different times. When the time delay between the different delayed signals is a large enough fraction of the transmitted signal's symbol period (actual time allotted for one symbol transmission), a transmitted symbol may arrive at the receiver during the next symbol period. This is well known as inter-symbol interference (or ISI). At higher data rates, the symbol period or duration is shorter; hence, it takes only a small time delay to introduce ISI. In case of broadband wireless, ISI is a big problem and reduces the quality of service significantly. In conventional situations, statistical equalization is the method for dealing with ISI, but at high data rates it is quite complex and requires considerable amount of processing power. OFDM appears as a better solution for controlling ISI in broadband systems like 4G

Add a note hereOFDM deals with this problem in a very intelligent way by introducing a guard interval before each OFDM symbol. This guard interval is the duration in which no information is transmitted. Digitally, it is nothing but a certain number of zeros transmitted between each couple of symbols. Whatever signal comes during that interval is discarded by the receiver, but when the guard interval is properly chosen then the OFDM signal can be kept undistorted.

Add a note here3 Effective Use of Bandwidth through OFDM

Add a note hereOFDM has the ability to optimize the consumption of resources. Extraneous bandwidths in the form of guard bands can, with proper implementation, be reduced to zero. Due to the orthogonal nature of the carriers used for different channels, it is possible to overlap the bands on each other and still recover them in the receiver without losing any quality. Because of this, OFDM is very effective in saving bandwidth. In low bandwidth systems where the demand for spectrum is very high, OFDM comes naturally as the first choice. The bandwidth saving has been shown in Figure 1


Add a note hereFigure 1: OFDM and bandwidth use

Add a note here Figure 1: OFDM and bandwidth use 

Besides the above advantages, OFDM based systems provide other facilities for digitalization and protocol supports. Processes like error correction and interleaving are easily supported by OFDM.

Add a note here4 Software Defined Radio for the 4G System

Add a note hereSoftware defined radio (SDR) is an emerging radio technology that can be used in various digital networks and can be controlled and programmed through software.

Add a note hereAccording to the SDR Forum, SDR technology is "radio that provides software control of a variety of modulation techniques, wide-band or narrow-band operation, communication security functions (such as hopping), and waveform requirements of current and evolving standards over a broad frequency range." SDR has the ability to support wireless applications in various networks like Bluetooth, WLAN, GPS, radar, WCDMA and GPRS.

Add a note hereCurrently, all of the major operations such as modulation, demodulation, coding, decoding, interference management, channel allocation and capacity management are done through the control software. One of the biggest advantages of the SDR is that it can ensure a secure communication network through implementation of encryption systems like the AES (Advanced Encryption Standard). This means that SDR is very reliable and useful for military and other high-level, secret communications. Due to these features, SRD is the most suitable method of data handling at the higher levels in 4G. With the link protocol standards now moving into 3G and 4G, networks differ dramatically in many ways. This is a big problem for both consumers and service vendors; while it can be handled through upgrading the handset, upgrading is usually not a good choice due to the high cost. Additionally, the wireless network operators face many interfacing problems during the migration of a network from one generation to another. Finally, the use of incompatible systems in different countries can hinder global communication. Through the use of SDR, all these scenarios can be handled smoothly.

Add a note hereThe SDR system uses a generic hardware platform which has its own programmable units, microprocessors, digital signal processors, field programmable gate array and analog RF modules. The software modules of the SDR that implement link layer protocols and modulation/demodulation operations are called radio applications, and these applications provide link layer services to higher layer communication protocols such as WAP and TCP/IP. SDR has the ability to significantly reduce the life-cycle costs and can also support advanced capabilities in different portable networks. The SDR technology is also reconfigurable; it allows several software modules to co-exist, and also permits dynamic configuration on the handset as well as in the back-end equipment. As a result of this flexibility, the problem of discrepancies due to legacy handsets is solved, and the extra cost for a new handset is not required. SDR can also handle the implementation of multi-mode, multi-band and multi-standard terminals. All of these demonstrate that SDR is clearly the most desirable technology for 4G.

Add a note here5 MIMO Antenna Systems for 4G

Add a note here4G like its predecessor 3G would use the advanced versions of the MIMO Antennas. The antennas used for the 3G system were smart enough to take care of many advanced operations at the signal level. This system must continue for 4G as well, and may even be made more sophisticated for 4G, as the number of signal-level decisions would be far greater in the case of 4G compared to 3G

Add a note here6 IPv6 Based Packet Transmission

Add a note hereThe all-packet infrastructure is quite popular in the wireless communication, and now it is also true for the 4G systems as well. The biggest difference between 3G and 4G is the all-IP network (AIPN) structure of 4G, which means that all communication will be controlled by TCP/IP protocols. As a result, the whole communication will be packet switched and the circuit switching part will be taken out of this advanced version. Not only can this make the system compatible with all digital devices, but internet access will be quite flexible and high data rates can be achieved. According to the 3GPP LTE team, this target will be achieved by the end of 2008. Similarly, the 3GPP2 LTE teams are also busy trying to keep pace with their competitors.

Add a note here7 Presence of TDD and FDD

Add a note hereTDD (Time Division Duplex) and FDD (Frequency Division Duplex) are different modes of CDMA. In FDD transmission mode, both the transmitter and the receiver transmit simultaneously. This simultaneous transmission is possible because they are both on different frequencies. In TDD mode of operation either transmitter or receiver can transmit at one time. This is because they use the same frequency for the transmission.

Add a note hereAt present all the major 3G Networks are using FDD mode of operation, but in the 4G system both the FDD and TDD will co-exist.

Add a note hereIn the FDD mode of operation, the uplink and downlink use separate frequency bands. These carriers have a bandwidth of 5 MHz and are divided into 10-ms radio frames; each frame further id divided into 15 time slots. The frequency allocation consists of one frequency band at 1920-1980 MHz and one at 2110-2170 MHz. These frequency bands are used in FDD mode both by the UE (user equipment) and the Network. The lower frequency band is used for the Uplink (UL) transmission and the upper frequency band is used for the Downlink (DL) transmission. The frequency separation is specified with 190 MHz for the fixed frequency duplex mode and with 134.8MHz to 245.8MHz for the variable frequency duplex mode.

Add a note hereThe TDD mode differs from the FDD mode in that both the uplink and the downlink use the same frequency carrier. There are 15 time slots in a radio frame that can be dynamically allocated between uplink and downlink directions. Thus the channel capacity of these links can be different which is very advantageous especially when people are downloading stuff on their mobiles. The chip rate of the normal TDD mode is also 3.84 Mbps, but there exists also a "narrowband" version of TDD known as TD-SCDMA. The carrier bandwidth of TD-SCDMA is 1.6 MHz and the chip rate 1.28 Mbps. TD-SCDMA has been proposed by China and potentially has a large market-share in China if implemented.

Add a note here8 Self-Organizing Characteristics of 4G

Add a note hereThe resource and duty management operations of 4G would be quite different from the present scenario. Extensive automation in the system and self-organizing characteristics can create an intelligent management. This is a quite strange feature unique to 4G that could lead the system to a complete new level.

Add a note here9 Two-Tier Coverage

Add a note hereIn case of 4G, the geographical coverage would consist of at least two tiers. The normal coverage would be through normal macro cells, but in order to handle the traffic and resources properly during the peak-hours, microcells would be kept in place. Depending on the traffic distribution, the transmission and control duties are switched to the appropriate cells. In some hot spots the coverage layering would be composed of multiple layers to improve the quality of service and resource management.

Add a note here10 4G Uplink and down Link Frequencies (Proposed)

Add a note hereThough the spectrum of 4G is still under planning, we have a rough idea about the uplink and downlink frequencies from the early developers. OFDM is used to divide the whole spectrum or bandwidth into thousands of small narrow bands. each having different frequencies. By doing this, the system becomes resistant to multipath fading and thus capable of providing better quality of service.

Add a note hereThe 4G system also uses OFDMA for the downlink and single carrier FDMA (or SC-FDMA) for the uplink. It optimizes the data rate by using four MIMO antennas per station, which we have seen can provide tremendously high data rates. The channel coding schemes are chosen to be suitable for the OFDM signals. Turbo codes are preferred in this application.

10.1 Downlink

Add a note hereThe OFDM system for the downlink uses maximum 2048 subcarriers. The subcarrier spacing in OFDM downlink is 15 kHz. The mobile device must have the ability to receive all the 2048 subcarriers but the base station needs only 72 subcarriers for transmission. The transmission is divided into sub frames of 1.0 ms duration and each time slot is of 0.5 ms duration. The net length of a radio frame is 10ms. For downlink the popular modulation formats are QPSK, 16 QAM, 64 QAM and 256 QAM. The spectrum for the downlink has not been finalized; but it is expected to be wider than the mobile WiMAX and in the similar range of WiMAX.

10.2 Uplink

Add a note hereFor uplink, the proposed multiplexing method is SC-FDMA, and proposed modulation methods are QPSK, 16 QAM and sometimes 64 QAM. SC-FDMA is used to suppress the high PAPR, as in the case of OFDMA. For high data rates the constellation size may go up to 256 QAM. Of course it is still under review and the current road map is considering 64 QAM as the proper choice. Uplink spectrum of 4G would be in the same range as the WiMAX but it would have more bandwidth for faster data rate.

3GPP LTE/3GPP2 LTE AND THE ROAD AHEAD


Recent revisions of both UMTS (3GPP LTE) and IMT-2000 (3GPP2 LTE) have recommended new dimensions to their technologies for the future growth. The seventh revision (M. 145707) was approved by the ITU Radio communication Assembly in October 2007. The seventh revision was by far the most radical in the history of IMT-2000; for the first time, an entirely new radio interface was added. This sixth radio interface, entitled "IMT-2000 OFDMA TDD WMAN", introduced OFDMA technology into IMT-2000. At the same time, Revision 7 included 3GPP2's OFDMA-based UMB technology as well as an initial framework description of 3GPP's OFDMA-based "Long-Term Evolution" technology, in two different forms. As a result, Revision 7 of M. 1457 suddenly contains six radio interfaces, of which four include OFDMA. These four radio interfaces share a number of other technological features as well, including support of packet-based (IP) networks. This radical change of technologies, broadly supported across a variety of independent standards organizations, marks the global recognition of the initiation of 4G mobile communications. IMT-2000 has expanded beyond its 3G origins.


IMT-2000 OFDMA TDD WMAN and its Foundation: IEEE Standard 802.16

IMT-2000 OFDMA TDD WMAN is the version of IEEE Standard 802.16 that is specified in the WiMAX Forum Mobile System Profile. A summary description of the radio interface is provided in document IEEE L802.16–06/03 1r2, with which IEEE initially proposed the addition of a subset of 802.16 (designated as "IP-OFDMA") to ITU-R.
IEEE Standard 802.16, the Wireless MAN Standard for Wireless Metropolitan Area Networks, has been under development and evolution since 1999. The standard has always, as a fundamental design principle, supported differentiated QoS to allow a mix of simultaneous multimedia services on a single network. It originally supported only "fixed" (stationary) terminals, but it was enhanced for full mobility with the introduction of the IEEE 802.16e amendment, which was approved in 2005. The WiMAX Forum ("WiMAX Forum") has developed the WiMAX Forum Mobile System Profile to specify a particular version of the standard that could be tested for certification purposes. Certified products were announced in April 2008. IEEE Standard 802.16 is developed, maintained, and enhanced by the IEEE 802.16 Working Group on Broadband Wireless Access. The Working Group currently has 433 members and meets six times a year, with attendance recently running over 400. IEEE 802.16's expertise in the pioneering OFDMA technology is deep. The Working Group introduced OFDMA into its fixed-access standard with the amendment 802.16a in 2003. This was based on standardization work that began with contributions on OFDMA introduced into the Working Group in the year 2000.

The 802.16 Working Group is currently developing a revision of the base standard and all the subsequent amendments. Completion of this revision draft, unofficially and temporarily known as 802.16Rev2,is expected in late 2008. While the revision project is being completed, the Working Group is continuing its progress on the developments of three further amendments:

Recently, project 802.16h is developing improved coexistence mechanisms for license-exempt operations and for the further flexibilities in the system. Similarly, project 802.16j is developing a multi-hop relay specification and will specify a relay station that can communicate with mobile terminals. This will offer a valuable new tool to system operators for extending range and capacity.

Project 802.16m is developing an advanced air interface, as described in more detail below.

The Amendment in 802.16 and IMT-Advanced

After the IEEE 802.16e amendment was completed (mainly for the WiMAX), members of the IEEE 802.16 community began to consider how an enhanced version of IEEE 802.16 could satisfy the emerging requirements of IMT-Advanced. In late 2006, following a significant effort, the Working Group was authorized to develop the IEEE 802.16m Project, which has the stated scope of amending the IEEE 802.16 Wireless MAN-OFDMA specification to provide an advanced air interface to meet the cellular layer requirements of IMT-Advanced next generation mobile networks while providing "continuing support for legacy Wireless MAN-OFDMA equipment." This was an extraordinary initiative for better mobility.

While the ITU's view of the IMT-Advanced process timeline has varied over time, the Task Group's view of the 802.16m project schedule has remained mostly independent. The basic intent of the project, and the planned 2009 completion date for the 802.16m amendment, have remained constant.

The 802.16m task Group has generated a set of system requirements that reflects the evolving IMT-Advanced requirements but also adds unique demands. Primary among these additions is a requirement for support for legacy Wireless MAN-OFDMA systems. The 802.16m Task Group has also developed an extensive "Evaluation Methodology Document". The Task Group is currently developing a System Description Document (SDD) before generating the draft standard. The primary purpose of the SDD is to allow alternative technical approaches to be assessed and agreed before detailed specifications are added to the draft standard. More information on the 802.16m and IMT-Advanced is available elsewhere.

Flexibility of IEEE 802.16 Technology for the Evolution of 4G

As mentioned previously, one of the key requirements of the IEEE 802.16m project is strong legacy support of Wireless MAN-OFDMA mobile stations and base stations. Fortunately, the flexibility of Wireless MAN-OFDMA allows for the possibility to satisfy these requirements. This flexibility is a distinct benefit of OFDMA technology and is a key reason that industry has turned to OFDMA for 4G. User demands for higher-rate services can be met partially by greater spectral efficiency, which is a benefit of OFDMA and of MIMO antenna technology that can be easily supported by OFDMA. Another way to increase throughput is to apply greater spectral bandwidths. 

OFDMA, because it subdivides the channel into many narrow sub-channels, is extremely scalable to broad as well as narrow channels, with little effect on the spectral efficiency. The technology is readily adaptable to multiple frequencies and to both paired and unpaired bands, using FDD and TDD duplexing, respectively. The technology lends itself to adaptability at the ASIC, allowing the possibility of very adaptable devices. Some ASIC designers are taking advantage of these features to provide chipsets that can operate with a broad range of channel bandwidths, sub-carrier counts, frequency ranges, and duplex methods.

The flexibility of IEEE 802.16 also provides new opportunities to operators regarding the services they wish to provide. Novel differentiating features can be introduced using the same basic network technology. For example, NextWave Wireless has introduced the MXtvTM mobile multicast and broadcast technology that runs using a portion of the time and frequency resources available on a normal two-way WiMAX network. This is another illustration of why it is difficult to define 4G from a service perspective. 4G technology, such as IEEE 802.16, will support a wide range of innovative services and applications.


4G Prospects of IMT 2000

Given the vast success of 2G systems, the 3G market has developed relatively slowly. Even though the original 3G standards were developed in the 1990s, global 3G operators typically report that, as of 2007, fewer than 10% of the customers are using 3G equipment. These operators have invested heavily in 3G technologies that are only recently beginning to fulfill their potential. In many cases, they see 4G not as an immediate prospect but as a long-term evolution that will require another round of investment, not only in the radio access equipment but also in the core network.

On the other hand, a number of other companies are ready to move forward with 4G on an earlier time scale. In general, those that are unburdened by legacy requirements in all or part of their spectra are more likely to see 4G as the best investment for mobile broadband networks. A number of these companies worldwide are implementing IEEE 802.16 Mobile WiMAX networks in 2008 and 2009.

The 4G mobile communication systems are based on several fundamental technology differentiators, including OFDMA and packet transport. 4G mobile communications was pioneered by IEEE Standard 802.16. The international community has recognized the transition to the new 4G technologies by approving Recommendation ITU-R M.1457-7 in October 2007.


LTE: Moving towards Mobile Broadband

The LTE (Long Term Evolution) project has tried to bring out novel and efficient mobile system for the public use since its inception. At first it focused on a broadband service built on the GSM framework. Though it did not succeed, the UMTS technology and the system that came out of it was 3G, which is quite good in comparison to its predecessors.

The intention and future steps of LTE are quite clear now; the main aim is to achieve personal broadband services in all its standards. The LTE has already achieved 3G technologies and it has been used abundantly in most parts of the world where mobile communication is already advanced, it. The next project they are now looking forward to achieve is 4G, the advanced personal mobile communication technology that can enable the high data rate broadband communication in the personal service provider's network. It is expected that sometime between 2012 and 2014 this new technology will be able to provide the services in the more technologically advanced countries. The aforementioned frequency allocation as well as the other features like the TDD and FDD will be implemented, which will result in optimized services at a rate 100MBPS or more.

While the intentions and the expectations of 4G projects are partially clear now, the projects that will follow 4G are highly speculative. The 5G, or successor of 4G, would be a very different kind of system from the intelligence and operational point of views. It is difficult to predict what the features and requirements of a 5G system would be; however, in course of time the scenarios will gradually become clear. 5G would not only be a fast broadband system, but it would also incorporate many advanced technologies that are beyond our current imagination.
In brief, we can say the Long-Term (Radio) Evolution or LTE is also part of 3G technology. It is a 3GPP research item for the Release 8, also known as 3.9G or "Super 3G" by some researchers. It is planned to be commercialized in 2009, with an aim at peak data rates of 20 Mbps (for Down Link) and around 10 Mbps (for UL).

UMTS AND 3G


UMTS is well known as the technology of 3G; many people say it is the 3GSM. Basically, the UMTS technology is one of the advanced mobile communication technologies for wideband or broadband operations on the GSM infrastructure and its evolved versions. In its modern 3G version UMTS uses WCDMA as the air interface multiple access method.

UMTS system was mainly using the GSM framework for two reasons: first, to retain the existing customers in the same network, and second, to provide new dimensions which are able to give broadband services in personal communication systems.

At present all the major 3G Networks are using the FDD (frequency division duplex) mode of operation. As far as time division duplex is concerned, there are no commercial TDD networks at the moment, although some of the network service providers like T-Mobile have announced that they would install TDD Network in Europe and North America. The reason why TDD has not been used yet is the difficulty in its implementation; when both of them (TDD and FDD) stay together, the situation becomes even more complex.

4G became necessary when it was found that the 3G was lagging behind the competing technologies like the WiMAX. The 4G project and its road map was not very much related to the WiMAX development, but it was later found to be a basic need for the 3GPP members to come out with a better technology. Though there is not much difference between them, it is quite obvious that the 3GPP members do not want to lag behind.

The migration of the 2G to 3G was so smooth in the European countries that many people did not even realize that a transition had taken place. Just using the 3G handsets they were able to get the advanced services from their same service provider. Of course, UMTS subscribers differentiated from GSM subscribers based on a SIM card. For UMTS and GSM subscriber the SIM is different; UMTS subscribers use USIM while GSM subscribers use SIM. However, if the service provider wants, it can provide the 3G services on the same existing GSM SIM. Similarly, in case of the 4G it is expected that the UMTS's advanced version may make it quite flexible for the change from 3G to 4G

WHY 3GPP2?


3GPP2 stands for Third Generation Partnership Project 2. This project was started in the year 1998 when the then-new standard IMT2000 or the CDMA2000 was under development. The standards for this technology and its future were found to be really vast, resulting in the need for collaboration among the different standard making bodies around the world. The name 3GPP2 was derived from the 3GPP, and the supervising organization for the 3GPP2 was the ITU or the International Telecommunications Union.

The main motto of 3 GPP2 was to form a collaborative third generation (3G) telecommunications specifications for global mobile communication. Because the Europeans were involved in 3GPP, they were not that interested in 3GPP2, so the 3GPP2 project is comprised of North American and Asian leaders of CDMA 2000. They are developing global specifications for ANSI/TIA/EIA-41 Cellular Radio telecommunication Intersystem Operations network evolution to 3G and beyond. The aim is also to develop and set the complete global specifications for the radio transmission technologies (RTTs) supported by ANSI/TIA/EIA-41.

3GPP2 was born out of the International Telecommunication Union's (ITU) International Mobile Telecommunications IMT-2000 initiative, covering high speed, broadband, and Internet Protocol (IP)-based mobile systems featuring network-to-network interconnection, feature/service transparency, global roaming and seamless services independent of location and mobility. The main idea behind this project is to bring high-quality mobile multimedia telecommunications to a worldwide mass market by achieving the goals of increasing the speed and ease of wireless communications. This is in response to the problems faced by the increased demand to pass data via telecommunications, and providing "anytime, anywhere" services.

As we have mentioned above, the concept of a "Partnership Project" was given by the European Telecommunications Standards Institute (ETSI) early in 1997 with the proposal to create a Third Generation Partnership Project (3GPP) using the Global System for Mobile (GSM) technology and its future versions. Although discussions took place between ETSI and the ANSI-41 community with a view to consolidating collaboration efforts for all ITU members, in the end it was deemed appropriate that a parallel Partnership Project be established  3GPP2 which, like its sister project 3GPP, embodies the benefits of a collaborative effort (timely delivery of output, speedy working methods etc.). At the same time there was a need of recognition as a specifications-developing body, providing easier access of the outputs into the ITU after transposition of the specifications in a Standards Development Organization (SDO) into a standard.


Members of 3GPP2

The primary members of the 3GPP2 project are the Standard Development Organizations of both the east and west. In the west the leading players are the European and American standard development organizations, and in the east the front runners of mobile communication include countries like Japan, Korea and China. These countries’ standard development organizations are participating in this project, whose five main members are:
  • TIA - Telecommunications Industry Association (North America)
  • TTA - Telecommunications Technology Association (Korea)
  • TTC - Telecommunications Technology Committee (Japan)
  • ARIB - Association of Radio Industries and Businesses (Japan)
  • CCSA - China Communications Standards Association (China)
The project is a not only a collaboration of standard making organizations, but also an opportunity for experts of the technology creating organizations, like the IPv6 Forum, to share their advice. Besides the above SDO organizations, the technology building partners are also active players of this project. They are:
  • The CDMA Development Group (CDG)
  • IPv6 Forum
  • Mobilelgnite
  • Femto Forum
The 3GPP2 recommended 3G systems are:
  1. IMT-2000 CDMA Multi-carrier, also known as CDMA2000 (3X) developed by 3GPP2. (IMT-2000 CDMA2000 includes 1X components, like CDMA2000 1X EV-DO.)
  2. IMT-2000 CDMA TDD, also known as UTRA TDD and TD-SCDMA. TD-SCDMA is developed in China and supported by TD-SCDMA Forum.
  3. IMT-2000 TDMA Single Carrier, also known as UWC-136 (Edge) supported by UWCC.
  4. IMT-2000 DECT supported by DECT Forum.

WHAT IS 3GPP?


The development of the GSM technology unified the Europe with a bond and realized a true European Union. Following the success of GSM, there was a need for a broadband system based on the GSM framework. This led to European countries looking forward to an advanced personal broadband service, which they called the 3G. So overall, the 3G standard is nothing more than personal broadband services on the GSM core network. Of course, the technology behind the 3G system is an advanced version known as the UMTS or the Universal Mobile Telecommunication System. Its main competitor is the IMT 2000, supervised by ITU.

Members of 3GPP

There are six organizational members of the 3GPP project. These members are the regional standard development organizations of different countries or continents. They are:
  • European Telecommunications Standards Institute (ETSI, Europe)
  • Association of Radio Industries and Businesses (ARIB, Japan)
  • Telecommunication Technology Committee (TTC, Japan)
  • China Communications Standards Association (CCSA, China)
  • Alliance for Telecommunications Industry Solutions (ATIS, North America)
  • Telecommunications Technology Association (TTA, South Korea)
The project was planned in 1997 and work started in December 1998. This 3GPP project started their work for the future of GSM. First the GPRS came in 2000, then the EDGE or the 2.7G (also the EGPRS) came in the year 2003. Later in the same year 3G came to the market commercially. Of course, the experimental versions of these technologies had come much before their public use. NTT DoCoMo first tried the experimental version of 3G in October 2001. Then in the US, the IMT 2000 based CDMA2000 lx EV-DO came into existence in 2003.

So overall, we can say that 3GPP is a European project in collaboration with the other leading members of the world, which seeks to create post-GSM networks on the GSM framework with the goal of meeting future mobile needs. The main contribution in the post-3G era which is coming to the public is 4G.

DIFFERENCES BETWEEN 3G AND 4G

Add a note hereThough the 4G is the evolved version of 3G there are many fundamental differences between the two systems, the greatest of these being speed enhancement of 3G network services.
Add a note hereThe main differences between the 3G and 4G have been listed below.

Add a note here1 The Speed or Data Rate
Add a note hereThe maximum speed or the data rate of 3G system is 2MBPS. With that speed we can definitely get a better service than the 2G system or its advanced versions like the GPRS (where the maximum possible speed is 204 KBPS). Although 3G substantially enhanced the data rate, the data contents of the present wireless broadband services make it impossible to carry on far with the 3G system. 4G was the solution to overcome that bottleneck of the 3G technologies. In 4G the aim is to get a data rate of 100MBPS or even more in the indoor environment. In theory, 4G will be at least 50 times faster then the 3G system; this is the main difference between the 3G and 4G technologies. In other words, the bandwidth of 4G system would be much higher than the 3G system.

Add a note here2 Packet Switched Infrastructure
Add a note hereIn 4G, the whole network will be packet switched. The IP based infrastructure will be used for the 4G system exclusively. IPv6 is the version on which the whole protocol system will govern the different kinds of switching for the data transfer. 4G switching aspects will therefore be more sophisticated and complex than the 3G system.

Add a note here3 Quality of Service or QoS
Add a note hereThe quality of services in 4G networks is going to be much better than the 3G and its contemporary technologies. The improvement in main service factors will be due to the high broadband of the 4G systems, the improved quality of service of the IPv6 systems compared to previous IP versions, and better reception and transmission services from the smart antenna based MIMO system.

Add a note here4 Network Security
Add a note hereNetwork security is another important aspect, one for which people are ready to pay. Network security in 4G is different from that of the 3G or 2G versions, in part because the security provided through the 4G networks is made up of two tiers. That means not only the MSC authentication is required but along with that there are some adder securities. We have seen the added security arrangement of the 4G systems in the OSI model. The Information Privacy Layer is there to take care of the security related aspects of the information that is exchanged in the 4G networks.

Add a note here5 Management of Resources
Add a note hereThe resource management in 4G is much better than 3G. Optimization is present in the 3G system, but most of the optimizations are not that adaptive and dynamic. In contrast to that, 4G would have very smart adaptations in the resource management sector. Adaptive algorithms are used to provide optimization everywhere, from the modulation and coding, to the individual scalable channel bandwidth allocation.

Add a note here6 Differences between the WiMAX and the 4G
Add a note hereSome people mistakenly believe that 4G and WiMAX are the same technology and only the application domains of the two are different. Here we would like to clarify that 4G and WiMAX are different types of technologies and the standards for the technologies are also different in many respects. Of course, there are some similarities between the two. The truth is that the WiMAX business group and the people who are working with the WiMAX technology want to popularize WiMAX as the 4G wireless technology, leading people to think that WiMAX and 4G are the same thing. In reality it is not accepted by the research community and the technology development group of either technology.
Add a note hereLike 4G, WiMAX can deliver high data rate (up to 70 Mbps over a 50Km radius). However, as mentioned in the earlier sections, with 4G wireless technology people would like to achieve up to 1Gbps (indoors). Additionally, WiMAX technology (802.16d) does not support mobility very well. To overcome this mobility problem 802.16e, or Mobile WiMAX, is being standardized in the same way as 4G. Ultimately though, when it comes to performance and speed 4G remains the winner.
Add a note hereThe important thing to remember here is that all the research for 4G technology is based around the orthogonal technology OFDM. WiMAX is also based on OFDM, and this fact gives more credibility to those in the WiMAX lobby who would like to term WiMAX as a 4G technology. It is worth mentioning that 4G is going to be an ultramodern, high performance mobile system. Most of the advanced features of 4G are due to OFDM, MIMO and other advanced technologies. It is seen as a hybrid system which is based on both 3G and other advanced systems, including WiMAX.

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