4G 486547 225534100 2008-07-14T04:57:04Z Two stripe 493877 Removed subjective content and nonsensical statement about wired and wireless converging. ~~~~ {{Expand|date=January 2007}} {{concept product}} {{this|the mobile phone standard}} {{Table Mobile phone standards}} '''4G''' (also known as '''Beyond 3G'''), an abbreviation for '''Fourth-Generation''', is a term used to describe the next complete evolution in ''wireless communications''. A 4G system will be able to provide a comprehensive IP solution where voice, data and streamed multimedia can be given to users on an "Anytime, Anywhere" basis, and at higher data rates than previous generations. As the second generation was a total replacement of the first generation networks and handsets; and the third generation was a total replacement of second generation networks and handsets; so too the fourth generation cannot be an incremental evolution of current 3G technologies, but rather the total replacement of the current 3G networks and handsets. The international telecommunications regulatory and standardization bodies are working for commercial deployment of 4G networks roughly in the 2012-2015 time scale. At that point it is predicted that even with current evolutions of third generation 3G networks, these will tend to be congested. There is no formal definition for what 4G is; however, there are certain objectives that are projected for 4G. These objectives include: that 4G will be a fully [[Internet protocol suite|IP-based]] integrated system. 4G will be capable of providing between 100 Mbit/s and 1 Gbit/s speeds both indoors and outdoors, with premium [[quality of service|quality]] and high [[security]]. <ref name="4Groadmap">{{cite book|first = Kim|last = Young Kyun|coauthors = Prasad, Ramjee|title = 4G Roadmap and Emerging Communication Technologies|publisher = Artech House 2006|pages = pp 12-13|isbn=1-58053-931-9}}</ref> Many companies have taken self-serving definitions and distortions about 4G to suggest they have 4G already in existence today, such as several early trials and launches of WiMax, which is part of the formal ITU standard for 3G. Other companies have made prototype systems calling those 4G. While it is possible that some currently demonstrated technologies may become part of 4G, until the 4G standard or standards have been defined, it is impossible for any company currently to provide with any certainty wireless solutions that could be called 4G cellular networks that would conform to the eventual international standards for 4G. These confusing statements around "existing" 4G have served to confuse investors and analysts about the wireless industry. ==Objective and approach== === Objectives === 4G is being developed to accommodate the quality of service (QoS) and rate requirements set by forthcoming applications like wireless broadband access, [[Multimedia Messaging Service]] (MMS), [[Videoconferencing|video chat]], [[mobile TV]], [[High-definition television|HDTV]] content, [[Digital Video Broadcasting]] (DVB), minimal service like voice and data, and other streaming services for "anytime-anywhere". The 4G working group has defined the following as objectives of the 4G wireless communication standard: *A [[spectral efficiency|spectrally efficient]] system (in bits/s/Hz and bits/s/Hz/site),<ref name="spectral_efficient">{{cite web | title= 4G - Beyond 2.5G and 3G Wireless Networks | url=http://www.mobileinfo.com/3G/4GVision&Technologies.htm | accessdate = 2007-03-26 |publisher=[[MobileInfo.com]]}}</ref> *High network capacity: more simultaneous users per cell,<ref name="4gfeatures">{{cite web | title= 4G Features | author=Jawad Ibrahim| date= December 2002|publisher=[[Bechtel]] Telecommunications Technical Journal | url=http://www.bechteltelecoms.com/docs/bttj_v1/Article2.pdf | accessdate = 2007-03-26 }}</ref> *A nominal data rate of 100 Mbit/s while the client physically moves at high speeds relative to the station, and 1 Gbit/s while client and station are in relatively fixed positions as defined by the [[ITU-R]],<ref name="4Groadmap" /> *A data rate of at least 100 Mbit/s between any two points in the world,<ref name="4Groadmap" /> *Smooth [[handoff]] across heterogeneous networks,<ref name="mobilitymanagement">{{cite web | title= Mobility Management Challenges and Issues in 4G Heterogeneous Networks | auhors= Sadia Hussain, Zara Hamid and Naveed S. Khattak| publisher=[[Association for Computing Machinery|ACM]] Proceedings of the first international conference on Integrated internet ad hoc and sensor networks | date= May 30 - 31, 2006| url=http://delivery.acm.org/10.1145/1150000/1142698/a14-hussain.pdf?key1=1142698&key2=8898704611&coll=GUIDE&dl=&CFID=15151515&CFTOKEN=6184618 | accessdate = 2007-03-26 }}</ref> *Seamless connectivity and global [[roaming]] across multiple networks,<ref name="beyond3garticle">{{cite web | author= Werner Mohr | date = 2002 | publisher = [[Siemens]] mobile | title= Mobile Communications Beyond 3G in the Global Context | url=http://www.cu.ipv6tf.org/pdf/werner_mohr.pdf | accessdate = 2007-03-26}}</ref> *High quality of service for next generation multimedia support (real time audio, high speed data, HDTV video content, mobile TV, etc)<ref name="beyond3garticle" /> *Interoperability with existing wireless standards,<ref name="pathto4g">{{cite web | title= The Path To 4G Will Take Many Turns | url=http://www.wsdmag.com/Articles/ArticleID/10001/10001.html | abstract = Emerging standards, intensive research, and powerful enabling technologies make for an interesting race to 4G mobile broadband. | author = Noah Schmitz| date= March 2005 | accessdate = 2007-03-26 | publisher = [[Wireless Systems Design]]}}</ref> and *An all IP, packet switched network.<ref name="beyond3garticle" /> In summary, the 4G system should dynamically share and utilise network resources to meet the minimal requirements of all the 4G enabled users. === Approaches === As described in 4G consortia including [https://www.ist-winner.org/ WINNER], ''WINNER - Towards Ubiquitous Wireless Access'', and [http://www.wireless-world-research.org/ WWRF], a key technology based approach is summarized as follows, where Wireless-World-Initiative-New-Radio (WINNER) is a consortium to enhance mobile communication systems.<ref name="WINNER">{{cite web |url= http://www.comnets.rwth-aachen.de/typo3conf/ext/cn_download/pi1/passdownload.php?downloaddata=860%7C1 |title= WINNER - Towards Ubiquitous Wireless Access |year= 2007 |publisher= [[WINNER]]}}</ref><ref name="WINNER II">{{cite web |url= https://www.ist-winner.org/deliverables.html |title= WINNER II - Public Deliverable |year= 2006-07 | publisher= [[WINNER]] II}}</ref> ==== Consideration points ==== * Coverage, radio environment, spectrum, services, business models and deployment types, users ==== Principal technologies ==== *Baseband techniques<ref name="WWRF WG5">{{cite web |url= http://www.wireless-world-research.org/fileadmin/sites/default/files/about_the_forum/WG/WG5/Briefings/WG5-br2-High_Throughput_WLAN_WPAN-V2004.pdf |title= High Throughput WLAN/WPAN |year= 2004 | publisher= [[WWRF]] | author=G. Fettweis, E. Zimmermann, H. Bonneville, W. Schott, K. Gosse, M. de Courville}}</ref> **[[OFDM]]: To exploit the frequency selective channel property **[[MIMO]]: To attain ultra high spectral efficiency **[[turbo code|Turbo principle]]: To minimize the required SNR at the reception side *Adaptive radio interface *[[Modulation]], spatial processing including multi-antenna and multi-user MIMO *Relaying, including fixed relay networks (FRNs), and [[Cooperative wireless communications|the cooperative relaying concept]], known as multi-mode protocol It introduces a single new ubiquitous radio access system concept, which will be flexible to a variety of beyond-3G wireless systems. ==Wireless System Evolution== '''First generation:''' Almost all of the systems from this generation were analog systems where voice was considered to be the main traffic. These systems could often be listened to by third parties. Some of the standards are [[NMT]], [[AMPS]], [[Hicap]], [[CDPD]], [[Mobitex]], [[DataTac]], [[TACS]] and [[ETACS]]. '''Second generation:''' All the standards belonging to this generation are commercial centric and they are digital in form. Around 60% of the current market is dominated by European standards. The second generation standards are [[GSM]], [[iDEN]], [[D-AMPS]], [[IS-95]], [[Personal Digital Cellular|PDC]], [[CSD]], [[PHS]], [[GPRS]], [[HSCSD]], and [[WiDEN]]. '''Third generation:''' To meet the growing demands in network capacity, rates required for high speed data transfer and multimedia applications, 3G standards started evolving. The systems in this standard are essentially a linear enhancement of 2G systems. They are based on two parallel backbone infrastructures, one consisting of circuit switched nodes, and one of packet oriented nodes. The [[International Telecommunication Union|ITU]] defines a specific set of air interface technologies as third generation, as part of the [[IMT-2000]] initiative. Currently, transition is happening from 2G to 3G systems. As a part of this transition, numerous technologies are being standardized. *'''2.75G''': **[[Enhanced Data Rates for GSM Evolution|EDGE]]/EGPRS *'''3G''': **[[UMTS]] ([[W-CDMA]]) **[[CDMA 2000]] & [[1xEV-DO]]/IS-856 **[[FOMA]] **[[TD-SCDMA]] **[[Generic Access Network|GAN]]/UMA **[[WiMax]] *'''3.5G''': **[[UMTS]] ([[HSDPA]]) **[[UMTS]] ([[HSUPA]]) *'''4G''': **[[3GPP Long Term Evolution|3GPP LTE]] '''Fourth generation:''' According to the 4G working groups, the infrastructure and the terminals of 4G will have almost all the standards from 2G to 4G implemented. Although legacy systems are in place to adopt existing users, the infrastructure for 4G will be only packet-based (all-IP). Some proposals suggest having an open platform where the new innovations and evolutions can fit. The technologies which are being considered as pre-4G are the following: [[WiMax]], [[WiBro]], [[iBurst]], [[3GPP Long Term Evolution]] and 3GPP2 [[Ultra Mobile Broadband]]. ==Components== ===Access schemes=== As the wireless standards evolved, the access techniques used also exhibited increase in efficiency, capacity and scalability. The first generation wireless standards used plain [[TDMA]] and [[FDMA]]. In the wireless channels, [[TDMA]] proved to be less efficient in handling the high data rate channels as it requires large guard periods to alleviate the multipath impact. Similarly, [[FDMA]] consumed more bandwidth for guard to avoid inter carrier interference. So in second generation systems, one set of standard used the combination of FDMA and TDMA and the other set introduced a new access scheme called [[CDMA]]. Usage of CDMA increased the system capacity and also placed a soft limit on it rather than the hard limit. Data rate is also increased as this access scheme is efficient enough to handle the multipath channel. This enabled the third generation systems to used CDMA as the access scheme IS-2000, UMTS, HSXPA, 1xEV-DO, TD-CDMA and TD-SCDMA. The only issue with CDMA is that it suffers from poor spectrum flexibility and scalability. Recently, new access schemes like [[OFDMA|Orthogonal FDMA]] (OFDMA), [[SC-FDMA|Single Carrier FDMA]] (SC-FDMA), [[Interleaved FDMA]] and [[MC-CDMA|Multi-carrier code division multiple access]] (MC-CDMA) are gaining more importance for the next generation systems. [[WiMax]] is using OFDMA in the downlink and in the uplink. For the [[3GPP Long Term Evolution|next generation UMTS]], OFDMA is being considered for the downlink. By contrast, IFDMA is being considered for the uplink since OFDMA contributes more to the [[Crest factor|PAPR]] related issues and results in nonlinear operation of amplifiers. IFDMA provides less power fluctuation and thus avoids amplifier issues. Similarly, MC-CDMA is in the proposal for the [[802.20|IEEE 802.20]] standard. These access schemes offer the same efficiencies as older technologies like CDMA. Apart from this, scalability and higher data rates can be achieved. The other important advantage of the above mentioned access techniques is that they require less complexity for equalization at the receiver. This is an added advantage especially in the [[MIMO]] environments since the [[spatial multiplexing]] transmission of MIMO systems inherently requires high complexity equalization at the receiver. In addition to improvements in these multiplexing systems, improved [[modulation]] techniques are being used. Whereas earlier standards largely used [[Phase-shift keying]], more efficient systems such as 64[[QAM]] are being proposed for use with the [[3GPP Long Term Evolution]] standards. ===IPv6=== {{main|Network layer|Internet protocol|IPv6}} Unlike 3G, which is based on two parallel infrastructures consisting of [[circuit switched]] and [[packet switched]] network nodes respectively, 4G will be based on packet switching ''only''. This will require low-latency data transmission. By the time that 4G is deployed, the process of [[IPv4 address exhaustion]] is expected to be in its final stages. Therefore, in the context of 4G, [[IPv6]] support is essential in order to support a large number of wireless-enabled devices. By increasing the number of [[IP address]]es, IPv6 removes the need for Network Address Translation ([[Network address translation|NAT]]), a method of sharing a limited number of addresses among a larger group of devices. In the context of 4G, IPv6 also enables a number of applications with better multicast, security, and route optimization capabilities. With the available address space and number of addressing bits in IPv6, many innovative coding schemes can be developed for 4G devices and applications that could aid deployment of 4G networks and services. ===Advanced Antenna Systems=== {{main|MIMO|MU-MIMO}} The performance of radio communications obviously depends on the advances of an antenna system, refer to [[smart antenna|smart]] or [[intelligent antenna]]. Recently, [[Multiple antenna research|multiple antenna technologies]] are emerging to achieve the goal of 4G systems such as high rate, high reliability, and long range communications. In the early 90s, to cater the growing data rate needs of data communication, many transmission schemes were proposed. One technology, [[spatial multiplexing]], gained importance for its bandwidth conservation and power efficiency. Spatial multiplexing involves deploying multiple antennas at the transmitter and at the receiver. Independent streams can then be transmitted simultaneously from all the antennas. This increases the data rate into multiple folds with the number equal to minimum of the number of transmit and receive antennas. This is called [[Multiple-input multiple-output communications|MIMO]] (as a branch of [[intelligent antenna]]). Apart from this, the reliability in transmitting high speed data in the fading channel can be improved by using more antennas at the transmitter or at the receiver. This is called ''transmit'' or ''receive diversity''. Both transmit/receive diversity and transmit spatial multiplexing are categorized into the space-time coding techniques, which does not necessarily require the channel knowledge at the transmit. The other category is closed-loop multiple antenna technologies which use the channel knowledge at the transmitter. ===Software-Defined Radio (SDR)=== [[Software-defined radio|SDR]] is one form of open wireless architecture (OWA). Since 4G is a collection of wireless standards, the final form of a 4G device will constitute various standards. This can be efficiently realized using SDR technology, which is categorized to the area of the radio convergence. <!-- commenting this out until someone fixes it. I don't understand it, and what I do understand doesn't appear to be appropriate to this section ==> added efficiently ===Adaptive modulation and coding (AMC)=== For a fixed combination of modulation and coding, lets say an x units of throughput is achieved at layer2 in fading scenario 1 and y units of throughput in fading scenario 2. The system resources (CPU and Memory) and the power used for transmitting in both the scenarios are same. Let us analyze two cases here ===Case 1:=== The condition x>y occurs when many bits received through scenario 2 is erroneous. So, the resources and power spent for second transmission is wasted. ===Case 2:=== Lets take a case z>x>y where z is the maximum throughput tat can be achieved in the fading scenario 1, for some other coding and modulation. Since this combination of coding and modulation is not used, the system and channel is not fully utilized. This is an under used condition. Especially, in multiuser environment both cases will become inefficient. To avoid such under-run and erroneous conditions, the fading channel condition is known priorly and accordingly the modulation and coding schemes are decided. For example, in HSDPA, the channel condition for the last transmission is known through the feedback channel and next transmission's modulation and coding is decided. Similar technique is also used in WiMax. So in 4G, based on network resource, fading condition, system resource and mobility conditions new AMC techniques are being proposed.--> == Developments == The Japanese company [[NTT DoCoMo]] has been testing a 4G communication system prototype with 4x4 MIMO called [[VSF-OFCDM]] at 100 [[Mbit]]/s while moving, and 1 [[Gbit]]/s while stationary. NTT DoCoMo recently reached 5 Gbit/s with 12x12 MIMO while moving at 10 km/h,<ref>{{cite web|url = http://www.nttdocomo.com/pr/2007/001319.html|date=2007-02-09|publisher=[[NTT DoCoMo]] Press|title=DoCoMo Achieves 5 Gbit/s Data Speed}}</ref> and is planning on releasing the first commercial network in 2010. [[Digiweb]], an Irish fixed and wireless broadband company, has announced that they have received a mobile communications license from the Irish Telecoms regulator, [[ComReg]]. This service will be issued the mobile code ''088'' in Ireland and will be used for the provision of 4G Mobile communications.<ref>Press Release: [http://media.digiweb.ie/pr/2007/05/04/digiweb-mobile-takes-088/ Digiweb Mobile Takes 088]</ref><ref>RTÉ News article: [http://www.rte.ie/news/2007/0405/digiweb.html Ireland gets new mobile phone provider]</ref> [[Pervasive network]]s are an amorphous and presently entirely hypothetical concept where the user can be simultaneously connected to several wireless access technologies and can seamlessly move between them (See [[Handoff|handover]], [[IEEE 802.21]]). These access technologies can be [[Wi-Fi]], [[Universal Mobile Telecommunications System|UMTS]], [[Enhanced Data Rates for GSM Evolution|EDGE]], or any other future access technology. Included in this concept is also smart-radio (also known as [[cognitive radio]] technology) to efficiently manage spectrum use and transmission power as well as the use of [[Mesh networking|mesh routing]] protocols to create a pervasive network. [[Sprint Nextel|Sprint]] plans to launch 4G services in trial markets by the end of 2007 with plans to deploy a network that reaches as many as 100 million people in 2008.... and has announced WiMax service called Xohm. Tested in Chicago, this speed was clocked at 100 Mbit/s. [[Verizon Wireless]] announced on [[September 20]], [[2007]] that it plans a joint effort with the [[Vodafone Group]] to transition its networks to the 4G standard LTE. The time of this transition has yet to be announced. The [[Germany|German]] WiMAX operator Deutsche Breitband Dienste (DBD) has launched WiMAX services (DSLonair) in [[Magdeburg]] and [[Dessau]]. The subscribers are offered a tariff plan costing 9.95 [[euro]]s per month offering 2 Mbit/s download / 300 kbit/s upload connection speeds and 1.5 GB monthly traffic. The subscribers are also charged a 16.99 euro one-time fee and 69.90 euro for the equipment and installation.<ref>{{cite web|url=http://www.dslonair.de/index.php?id=154|language=de|title=Privatkunden Tarife|publisher=[[Deutsche Breitband Dienste]]| accessdate = 2007-08-30}}</ref> DBD received additional national licenses for WiMAX in December 2006 and have already launched the services in Berlin, Leipzig and Dresden. American WiMAX services provider [[Clearwire]] made its debut on [[Nasdaq]] in [[New York]] on March 8, 2007. The [[IPO]] was [[underwriting|underwritten]] by [[Merrill Lynch]], [[Morgan Stanley]] and [[JP Morgan]]. Clearwire sold 24 million shares at a price of $25 per share. This adds $600 million in cash to Clearwire, and gives the company a market valuation of just over $3.9 billion.<ref name="WiMaxDay.net">{{cite web| url = http://www.wimaxday.net/site/2007/03/08/wimax-restores-market-confidence-as-clearwire-ipo-nets-600-million/ | publisher = [[WiMAX Spectrum Owners Alliance]] (WiSOA)| author = WiMAX Day | title = WiMAX rallies market as Clearwire IPO nets $600 million| date = 2007-03-08}}</ref> == Applications == The [[killer application]] of 4G is not clear, though the improved bandwidths and data throughput offered by 4G networks should provide opportunities for previously impossible products and services to be released. Perhaps the "killer application" is simply to have mobile always on Internet, no [[Walled garden (media)|walled garden]] and reasonable flat rate per month charge. Existing 2.5G/3G/3.5G phone operator based services are often expensive, and limited in application. Already at rates of 15-30 Mbit/s, 4G should be able to provide users with streaming [[high-definition television]]. At rates of 100 Mbit/s, the content of a [[DVD-5]], for example a movie, can be downloaded within about 5 minutes for offline access. == Pre-4G wireless standards == :''See also section [[3G#3G evolution/pre-4G|3G evolution/pre-4G]] of the [[3G]] article.'' According to a Visant Strategies study there will be multiple competitors in this space:<ref>{{cite web|publisher=[[Wireless Week]] | date = 2006-02-01 | url = http://www.wirelessweek.com/article/CA6303575.html | title=WiMAX Has Company| accessdate = 2007-03-26}}</ref> *[[WiMAX]] - 7.5 million units by 2010 (May include fixed and mobile) *[[Flash-OFDM]] - 13 million subscribers in 2010 (only Mobile) *[[3GPP Long Term Evolution]] of [[UMTS]] in [[3GPP]] - valued at US$2 billion in 2010 (~30% of the world [[population]]) *[[Ultra Mobile Broadband|UMB]] in [[3GPP2]] *[[IEEE 802.20]] Fixed WiMax and Mobile WiMax are different systems, as of July 2007, all the deployed WiMax is "Fixed Wireless" and is thus not yet 4G (IMT-advanced) although it can be seen as one of the 4G standards being considered. ==See also== <div style="-moz-column-count:3; -webkit-column-count:3; column-count:3;"> *[[IEEE 802.21]] *[[List of Deployed WiMAX networks]] *[[Mesh networking]] *[[3G]], [[3.75G]] - [[UMTS]], [[HSDPA]], [[HSUPA]], [[3GPP Long Term Evolution|LTE]] *[[Handoff|Handover]] *[[iBurst]] </div> ==References== === Citations === {{reflist|2}} === Additional resources === * {{cite conference |url= http://csdl2.computer.org/comp/proceedings/wetice/2001/1269/00/12690060.pdf |title= Research Directions for Fourth Generation Wireless |author= Brian Woerner |booktitle= Proceedings of the 10th International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (WET ICE ’01) |location= Massachusetts Institute of Technology, Cambridge, MA, USA |date=June 20-22, 2001 }} (118kb) * {{cite journal |url= http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1252799&isnumber=28028 |title= Challenges in the migration to 4G mobile systems |author= Suk Yu Hui |coauthors= Kai Hau Yeung |publisher= City Univ. of Hong Kong, China |journal= Communications Magazine, [[IEEE]] |date= December 2003 |volume= 41 |pages= 54 |doi= 10.1109/MCOM.2003.1252799}} * {{cite web |url= http://www.alcatel.com/publications/abstract.jhtml?repositoryItem=tcm%3A172-262211635 |title= 4G Mobile | date= 2005-06-13 | publisher = [[Alcatel-Lucent]]}} * {{cite web |url= http://www.newscientist.com/article.ns?id=dn7943 |title = 4G prototype testing |date= 2005-09-02 |publisher= [[New Scientist]] |author= Will Knight}} * {{cite web |url= http://www.caribbeannetnews.com/cgi-script/csArticles/articles/000021/002142.htm |title= Caribbean telecoms to invest in 4G wireless networks |date= 2006-06-27 |publisher= [[Caribbean Net News]]}} [[Category:Mobile phone standards]] [[bn:ফোর জি (4G)]] [[de:Next Generation Mobile Networks]] [[es:Telefonía móvil 4G]] [[fr:4G]] [[id:4G]] [[it:4G (telefonia)]] [[ka:4G]] [[ja:第四世代携帯電話]] [[pl:4G]] [[pt:4G]] [[ru:4G]] [[su:4G]] [[fi:4G]] [[sv:4G]] [[vi:4G]] [[tr:4. Nesil GSM Hizmeti]] [[zh:4G]]