recent development in cellular system

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Assignment of Mobile Communication

RECENT DEVELOPMENTS IN CELLULAR

SYSTEM

Introduction

Since the cradle of the cellular communication concept in 1990s, the cellularcommunication system has undergone rapid and explosive growth worldwide. The

worldwide cellular and personal communication subscriber base had surpassed 600

million in late 2001 and now it has reached more than 4 billion which is actually more

than 60 percent of worlds population and Nepal has more than 4 million (4,200,000subscribers in 2008, ranked 94th worldwide according to total number of mobile cellular

telephone subscribers, China is ranked 1st with 634,000,000 subscribers). Figure below

shows the worldwide mobile subscriber numbers and mobile penetration rates of 2008

This rapid growth worldwide in cellular communication, which is replacing fiber opticsor copper lines between fixed points several kilometers apart, has demonstrated

conclusively that wireless communication is a robust, viable voice and data transportation

mechanism and thus has led to further research and development of newer system andstandards. The evolution of communication technology is presented in the table below

Submitted by: Nirajan Raj Pokharel 063/Bex/216


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which will provide us the complete path of communication technology including cellular

system from its humble beginning to its current status. The following table is classified

on the basis of generation (G) including all the mobile technology available worldwidebut we shall be mostly focused on GSM and CDMA evolution since 2G and thus shall

see developments from generation to generation

Generation based Classification Communication Technology

0G (radio

telephones)

MTS MTA MTB MTC IMTS MTD AMTS OLT Autoradiopuhelin

1G

AMPS

familyAMPS TACS ETACS

Other NMT Hicap Mobitex DataTAC

2G

GSM/3GPPfamily GSM CSD

3GPP2 family CdmaOne (IS-95)

AMPS family D-AMPS (IS-54 and IS-136)

Other CDPD iDEN PDC PHS

2G transitional

(2.5G, 2.75G)

GSM/3GPPfamily

HSCSD GPRS EDGE/EGPRS

3GPP2 family CDMA2000 1xRTT (IS-2000)

Other WiDEN

3G (IMT-2000)

3GPP

family

UMTS (UTRAN) WCDMA-FDD WCDMA-TDD

UTRA-TDD LCR (TD-SCDMA)

3GPP2family

CDMA2000 1xEV-DO (IS-856)

3G transitional

(3.5G, 3.9G)

3GPP

familyHSDPA HSUPA HSPA+ LTE (E-UTRA)

3GPP2

familyEV-DO Rev. A EV-DO Rev. B

OtherMobile WiMAX (IEEE 802.16e-2005) Flash-

OFDM IEEE 802.20

4G

(IMT-

Advanced)

3GPP

familyLTE Advanced

WiMAXfamily

IEEE 802.16m

http://en.wikipedia.org/wiki/IS-54http://en.wikipedia.org/wiki/3GPP2http://en.wikipedia.org/wiki/IS-54http://en.wikipedia.org/wiki/3GPP2


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Second Generation (2G) Cellular Network

Second generation 2G cellular telecom networks were commercially launched on theGSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991. Three primary

benefits of 2G networks over their predecessors were that phone conversations were

digitally encrypted, 2G systems were significantly more efficient on the spectrumallowing for far greater mobile phone penetration levels; and 2G introduced data services

for mobile, starting with SMS text messages.

After 2G was launched, the previous mobile telephone systems were retrospectively

dubbed 1G. While radio signals on 1G networks are analog, and on 2G networks aredigital, both systems use digital signaling to connect the radio towers (which listen to the

handsets) to the rest of the telephone system.

GSM/3GPP family

GSM (Global System for Mobile Communications: originally fromGroupe Spcial Mobile) is the most popular standard formobile telephonysystems in the world. The GSM Association, its promoting industry trade

organization of mobile phone carriers and manufacturers, estimates that

80% of the global mobile market uses the standard. GSM is used by over4.3 billion people across more than 212 countries and territories. Its

ubiquity enables international roaming arrangements between mobile

phone operators, providing subscribers the use of their phones in many

parts of the world. GSM differs from its predecessor technologies in that both signaling and speech channels are digital, and thus GSM is

considered a second generation (2G) mobile phone system. This also

facilitates the wide-spread implementation of data communicationapplications into the system. The ubiquity of implementation of the GSM

standard has been an advantage to both consumers, who may benefit from

the ability to roam and switch carriers without replacing phones, and alsoto network operators, who can choose equipment from many GSM

equipment vendors. GSM also pioneered low-cost implementation of the

short message service (SMS), also called text messaging, which has since

been supported on other mobile phone standards as well. The standard

includes a worldwide emergency telephone number feature

3GPP2 family

http://en.wikipedia.org/wiki/Mobile_telephonyhttp://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/Roaminghttp://en.wikipedia.org/wiki/Roaminghttp://en.wikipedia.org/wiki/Mobile_phone_operatorhttp://en.wikipedia.org/wiki/Mobile_phone_operatorhttp://en.wikipedia.org/wiki/Mobile_phone_operatorhttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Short_message_servicehttp://en.wikipedia.org/wiki/Mobile_telephonyhttp://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/Roaminghttp://en.wikipedia.org/wiki/Mobile_phone_operatorhttp://en.wikipedia.org/wiki/Mobile_phone_operatorhttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Short_message_service


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CdmaOne (IS-95): Interim Standard 95 (IS-95) is the first CDMA-based

digital cellular standard by Qualcomm. The brand name for IS-95is cdmaOne. IS-95 is also known as TIA-EIA-95. It is a 2G Mobile

Telecommunications Standard that uses CDMA, a multiple access scheme

fordigital radio, to send voice, data and signaling data (such as a dialed

telephone number) between mobile telephones and cell sites. CDMA or"code division multiple access" is a digital radio system that transmits

streams ofbits (PN codes). CDMA permits several radios to share the

same frequencies. Unlike TDMA "time division multiple access", acompeting system used in 2G GSM, all radios can be active all the time,

because network capacity does not directly limit the number of active

radios. Since larger numbers of phones can be served by smaller numbersof cell-sites, CDMA-based standards have a significant economic

advantage over TDMA-based standards, or the oldest cellular standards

that used multiplexing. In North America, the technology competed

with Digital AMPS (IS-136, a TDMA technology). It is now being

supplanted by IS-2000(CDMA2000), a later CDMA-based standard.

AMPS family

D-AMPS (IS-54and IS-136): IS-54 and IS-136 are second-generation

(2G) mobile phone systems, known as Digital AMPS (D-AMPS). It was

once prevalent throughout the Americas, particularly in the United Statesand Canada. D-AMPS is considered end-of-life, and existing networks

have mostly been replaced by GSM/GPRS or CDMA2000 technologies.

This system is most often referred to as TDMA. That name is based on theacronym for time division multiple access, a common multiple access

technique which is used by multiple protocols, including GSM, as well as

in IS-54 and IS-136. However, D-AMPS have been competing againstGSM and systems based on code division multiple access (CDMA) for

adoption by the network carriers, although it is now being phased out in

favor of GSM/GPRS and CDMA2000 technology. D-AMPS uses existing

AMPS channels and allows for smooth transition between digital andanalog systems in the same area. Capacity was increased over the

preceding analog design by dividing each 30 kHz channel pair into three

time slots (hence time division) and digitally compressing the voice data,yielding three times the call capacity in a single cell. A digital system also

made calls more secure because analog scanners could not access digital

signals. Calls were encrypted, although the algorithm used (CMEA) was

later found to be weak.IS-136 added a number of features to the originalIS-54 specification, including text messaging, circuit switched data (CSD),

and an improved compression protocol. SMS and CSD were both

available as part of the GSM protocol, and IS-136 implemented them in anearly identical fashion. Former large IS-136 networks included AT&T in

the United States, and Rogers Wireless in Canada. AT&T and Rogers

Wireless have upgraded their existing IS-136 networks to GSM/GPRS.Rogers Wireless removed all 1900 MHz IS-136 in 2003, and has done the

http://en.wikipedia.org/wiki/CDMAhttp://en.wikipedia.org/wiki/Qualcommhttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/CDMAhttp://en.wikipedia.org/wiki/Multiple_accesshttp://en.wikipedia.org/wiki/Digital_radiohttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Cellular_phonehttp://en.wikipedia.org/wiki/CDMAhttp://en.wikipedia.org/wiki/Digital_radiohttp://en.wikipedia.org/wiki/Bithttp://en.wikipedia.org/wiki/PN_codehttp://en.wikipedia.org/wiki/Time_division_multiple_accesshttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/GSMhttp://en.wikipedia.org/wiki/Digital_AMPShttp://en.wikipedia.org/wiki/Time_division_multiple_accesshttp://en.wikipedia.org/wiki/IS-2000http://en.wikipedia.org/wiki/IS-54http://en.wikipedia.org/wiki/CDMAhttp://en.wikipedia.org/wiki/Qualcommhttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/CDMAhttp://en.wikipedia.org/wiki/Multiple_accesshttp://en.wikipedia.org/wiki/Digital_radiohttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Cellular_phonehttp://en.wikipedia.org/wiki/CDMAhttp://en.wikipedia.org/wiki/Digital_radiohttp://en.wikipedia.org/wiki/Bithttp://en.wikipedia.org/wiki/PN_codehttp://en.wikipedia.org/wiki/Time_division_multiple_accesshttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/GSMhttp://en.wikipedia.org/wiki/Digital_AMPShttp://en.wikipedia.org/wiki/Time_division_multiple_accesshttp://en.wikipedia.org/wiki/IS-2000http://en.wikipedia.org/wiki/IS-54


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same with their 800 MHz spectrum as the equipment failed. Rogers

deactivated their IS-136 network (along with AMPS) on May 31, 2007.

AT&T soon followed in February 2008, shutting down both TDMA andAMPS.Alltel, who primarily uses CDMA2000 technology but acquired a

TDMA network from Western Wireless, shut down their TDMA and

AMPS networks in September 2008. US Cellular, who now also primarilyuses CDMA2000 technology, shut down their TDMA network in February

2009.IS-54 is the first mobile communication system which had provision

for security, and the first to employ TDMA technology.

Other

CDPD: Cellular Digital Packet Data (CDPD) was a wide-area mobile

data service which used unused bandwidth normally used by AMPS

mobile phones between 800 and 900 MHz to transfer data. Speeds up to19.2 kbit/s were possible. The service was discontinued in conjunction

with the retirement of the parent AMPS service; it has been functionally

replaced by faster services such as 1xRTT, EV-DO, andUMTS/HSPA.Developed in the early 1990s, CDPD was large on the

horizon as a future technology. However, it had difficulty competing

against existing slower but less expensive Mobitex and DataTac systems,and never quite gained widespread acceptance before newer, faster

standards such as GPRS became dominant. CDPD had very limited

consumer offerings. AT&T Wireless first offered the technology in the

United States under the PocketNet brand. It was one of the first consumer

offerings of wireless web service. A company named Omnisky providedservice for Palm V devices. Cingular Wireless later offered CDPD under

the Wireless Internet brand (not to be confused with Wireless InternetExpress, their brand for GPRS/EDGE data). PocketNet was generally

considered a failure with competition from 2G services such as Sprint's

Wireless Web. After the four phones AT&T Wireless had offered to the public (two from Panasonic, one from Mitsubishi and the Ericsson

R289LX), AT&T Wireless eventually refused to activate the devices.

Despite its limited success as a consumer offering, CDPD was adopted ina number of enterprise and government networks. It was particularly

popular as a first-generation wireless data solution for telemetry devices

(machine to machine communications) and for public safety mobile dataterminals. In 2004, major carriers in the United States announced plans toshut down CDPD service. In July 2005, the AT&T Wireless and Cingular

Wireless CDPD networks were shut down. Equipment for this service now

has little to no residual value.

iDEN: Integrated Digital Enhanced Network (iDEN) is a mobile

telecommunications technology, developed by Motorola, which provides

its users the benefits of a trunked radio and a cellular telephone. iDEN

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places more users in a given spectral space, compared to analog cellular

and two-way radio systems, by using speech compression and time

division multiple access (TDMA). iDEN is designed and licensed tooperate on individual frequencies that may not be contiguous. iDEN

operates on 25 kHz channels, but only occupies 20 kHz in order to provide

interference protection via guard bands. By comparison, TDMA Cellular(Digital AMPS) is licensed in blocks of 30 kHz channels, but each

emission occupies 40 kHz, and is capable of serving the same number of

subscribers per channel as iDEN. iDEN uses frequency-division duplexingto separately transmit and receive signals, with transmit and receive bands

separated by 39 MHz, 45 MHz, or 48 MHz depending on the frequency

band being used .iDEN supports either three or six interconnect users

(phone users) per channel, and six dispatch users (push-to-talk users) perchannel, using time division multiple access. The transmit and receive

time slots assigned to each user are deliberately offset in time so that a

single user never needs to transmit and receive at the same time. This

eliminates the need for a duplexer at the mobile, since time-divisionduplexing of RF section usage can be performed.

PDC: Personal Digital Cellular (PDC) is a 2G mobiletelecommunications standard developed and used exclusively in Japan.

After a peak of nearly 80 million subscribers to PDC, it had 46 million

subscribers in December 2005, and is slowly being phased out in favor of3G technologies like W-CDMA and CDMA2000. At the end of October

2008, the count had dwindled down to 10.4 million subscribers. Like D-

AMPS and GSM, PDC uses TDMA. The standard was defined by theRCR (later became ARIB) in April 1991, and NTT DoCoMo launched itsDigital mova service in March 1993. PDC uses 25 kHz carrier, pi/4-

DQPSK modulation with 3-timeslot 11.2 kbit/s (full-rate) or 6-timeslot 5.6

kbit/s (half-rate) voice codecs.PDC is implemented in the 800 MHz(downlink 810-888 MHz, uplink 893-958 MHz), and 1.5 GHz (downlink

1477-1501 MHz, uplink 1429-1453 MHz) bands. The air interface is

defined in RCR STD-27 and the core network MAP by JJ-70.10. NEC andEricsson are the major network equipment manufacturers. The services

include voice (full and half-rate), supplementary services (call waiting,

voice mail, three-way calling, call forwarding, and so on), data service (up

to 9.6 kbit/s CSD), and packet-switched wireless data (up to 28.8 kbit/sPDC-P). Voice codecs are PDC-EFR and PDC-HR.Compared to GSM,

PDC's weak broadcast strength allows small, portable phones with light

batteries at the expense of substandard voice quality and problemsmaintaining the connection, particularly in enclosed spaces like elevators.



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PHS: PHS is essentially a cordless telephone like DECT, with the

capability to handover from one cell to another. PHS cells are small, withtransmission power of base station a maximum of 500 mW and range

typically measures in tens or at most hundreds of meters (some can range

up to about 2 kilometers in line-of-sight), contrary to the multi-kilometer

ranges of CDMA and GSM. This makes PHS suitable for dense urbanareas, but impractical for rural areas, and the small cell size also makes it

difficult if not impossible to make calls from rapidly moving vehicles.

PHS uses TDMA/TDD for its radio channel access method, and 32 kbit/sADPCM for its voice codec. Modern PHS phone can also support many

value-added services such as high speed wireless data / Internet

connection (64 kbit/s and higher), WWW access, e-mailing, textmessaging and even color image transfer. PHS technology is also a

popular option for providing a wireless local loop, where it is used for

bridging the "last mile" gap between the POTS network and the

subscriber's home. Actually, it was developed under the concept of

providing a wireless front-end of an ISDN network. Thus a base station ofPHS is compatible with ISDN and is often connected directly to ISDN

telephone exchange equipment e.g. a digital switch.

Second Generation (2G) transitional (2.5G, 2.75G)

GSM/3GPP family

HSCSD: High-speed circuit-switched data (HSCSD) is an enhancement

to circuit switched data (CSD), the original data transmission mechanismof the GSM mobile phone system, four times faster than GSM, with datarates up to 38.4 kbit/s. Channel allocation is done in circuit-switched

mode, as with CSD. Higher speeds are achieved as a result of superior

coding methods, and the ability to use multiple time slots to increase datathroughput. One innovation in HSCSD is to allow different error

correction methods to be used for data transfer. The original error

correction used in GSM was designed to work at the limits of coverageand in the worst case that GSM will handle. This means that a large part of

the GSM transmission capacity is taken up with error correction codes.

HSCSD provides different levels of possible error correction which can be

used according to the quality of the radio link. This means that in the bestconditions 14.4 kbit/s can be put through a single time slot that under CSD

would only carry 9.6 kbit/s, for a 50% improvement in throughput. The

other innovation in HSCSD is the ability to use multiple time slots at thesame time. Using the maximum of four time slots, this can provide an

increase in maximum transfer rate of up to 57.6 kbit/s (i.e., 4 14.4 kbit/s)

and, even in bad radio conditions where a higher level of error correctionneeds to be used, can still provide a four times speed increase over CSD

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(38.4 kbit/s versus 9.6 kbit/s). By combining up to eight GSM time slots

the capacity can be increased to 115 kbit/s. HSCSD requires the time slots

being used to be fully reserved to a single user. It is possible that either atthe beginning of the call, or at some point during a call, it will not be

possible for the user's full request to be satisfied since the network is often

configured to allow normal voice calls to take precedence over additionaltime slots for HSCSD users. The user is typically charged for HSCSD at a

rate higher than a normal phone call (e.g., by the number of time slots

allocated) for the total period of time that the user has a connection active.This makes HSCSD relatively expensive in many GSM networks and is

one of the reasons that packet-switched general packet radio service

(GPRS), which typically has lower pricing (based on amount of data

transferred rather than the duration of the connection), has become morecommon than HSCSD. Apart from the fact that the full allocated

bandwidth of the connection is available to the HSCSD user, HSCSD also

has an advantage in GSM systems in terms of lower average radio

interface latency than GPRS. This is because the user of an HSCSDconnection does not have to wait for permission from the network to send

a packet. HSCSD is also an option in enhanced data rates for GSMevolution (EDGE) and universal mobile telephone system (UMTS)

systems where packet data transmission rates are much higher. In the

UMTS system, the advantages of HSCSD over packet data are even lower

since the UMTS radio interface has been specifically designed to supporthigh bandwidth, low latency packet connections. This means that the

primary reason to use HSCSD in this environment would be access to

legacy dial up systems.

GPRS: General packet radio service (GPRS) is a packet oriented mobile

data service available to users of the 2G cellular communication systems

global system for mobile communications (GSM), as well as in the 3Gsystems. In 2G systems, GPRS provides data rates of 56-114 kbit/s. GPRS

data transfer is typically charged per megabyte of traffic transferred, while

data communication via traditional circuit switching is billed per minute ofconnection time, independent of whether the user actually is using the

capacity or is in an idle state. GPRS is a best-effort packet switched

service, as opposed to circuit switching, where a certain quality of service

(QoS) is guaranteed during the connection for non-mobile users.2Gcellular systems combined with GPRS are often described as 2.5G, that is,

a technology between the second (2G) and third (3G) generations of

mobile telephony. It provides moderate speed data transfer, by usingunused time division multiple access (TDMA) channels in, for example,

the GSM system. Originally there was some thought to extend GPRS to

cover other standards, but instead those networks are being converted touse the GSM standard, so that GSM is the only kind of network where

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GPRS is in use. GPRS is integrated into GSM Release 97 and newer

releases. It was originally standardized by European Telecommunications

Standards Institute (ETSI), but now by the 3rd Generation PartnershipProject (3GPP).GPRS was developed as a GSM response to the earlier

CDPD and i-mode packet switched cellular technologies.

EDGE/EGPRS: Enhanced Data rates for GSM Evolution (EDGE) (alsoknown as Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC), or

Enhanced Data rates for Global Evolution) is a backward-compatible

digital mobile phone technology that allows improved data transmissionrates, as an extension on top of standard GSM. EDGE is considered a 3G

radio technology and is part of ITU's 3G definition.[1] EDGE was deployed

on GSM networks beginning in 2003 initially by Cingular (now AT&T)in the United States. EDGE is standardized by 3GPP as part of the GSM

family, and it is an upgrade that provides more than three-fold increase inboth the capacity and performance of GSM/GPRS networks. It does this

by introducing sophisticated methods of coding and transmitting data,delivering higher bit-rates per radio channel. EDGE can be used for any

packet switched application, such as an Internet connection. EDGE-

delivered data services create a broadband internet-like experience for themobile phone user. High bandwidth data applications such as video

services and other multimedia benefit from EGPRS' increased data

capacity. Evolved EDGE continues in Release 7 of the 3GPP standardproviding reduced latency and more than doubled performance e.g. to

complement High-Speed Packet Access (HSPA). Peak bit-rates of up to

1Mbit/s and typical bit-rates of 400kbit/s can be expected. EDGE/EGPRSis implemented as a bolt-on enhancement for 2G and 2.5G GSM andGPRS networks, making it easier for existing GSM carriers to upgrade to

it. EDGE/EGPRS is a superset to GPRS and can function on any network

with GPRS deployed on it, provided the carrier implements the necessaryupgrade. EDGE requires no hardware or software changes to be made in

Global System for Mobile Communications core networks. EDGE

compatible transceiver units must be installed and the base stationsubsystem needs to be upgraded to support EDGE. If the operator already

has this in place, which is often the case today, the network can be

upgraded to EDGE by activating an optional software feature. Today

EDGE is supported by all major chip vendors for both GSM andWCDMA/HSPA.

3GPP2 family

CDMA2000 1xRTT (IS-2000) also known as 1x and 1xRTT, is the coreCDMA2000 wireless air interface standard. The designation "1x",

meaning 1 times Radio Transmission Technology, indicates the same RF

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bandwidth as IS-95: a duplexpair of 1.25 MHz radio channels. 1xRTT

almost doubles the capacity of IS-95 by adding 64 more traffic channels to

the forward link, orthogonal to (in quadrature with) the original set of 64.The 1X standard supports packet data speeds of up to 153 kbps with real

world data transmission averaging 60100 kbps in most commercial

applications. IMT-2000 also made changes to the data link layerfor thegreater use of data services, including medium and link access control

protocols and QoS. The IS-95 data link layer only provided "best effort

delivery" for data and circuit switched channel for voice (i.e., a voiceframe once every 20 ms).

Other

WiDEN: Wideband Integrated Digital Enhanced Network, or WiDEN, is

a software upgrade developed by Motorola for its iDEN enhanced

specialized mobile radio (or ESMR) wireless telephony protocol. WiDEN

allows compatible subscriber units to communicate across four 25 kHz

channels combined, for up to 100 kbit/s of bandwidth. The protocol isgenerally considered a 2.5G wireless cellular technology

Third Generation (3G) Cellular Network

As the use of 2G phones became more widespread and people began to utilise mobile

phones in their daily lives, it became clear that demand for data services (such as access

to the internet) was growing. Furthermore, if the experience from fixed broadband

services was anything to go by, there would also be a demand for ever greater data

speeds. The 2G technology was nowhere near up to the job, so the industry began to workon the next generation of technology known as 3G. The main technological difference

that distinguishes 3G technology from 2G technology is the use of packet-switchingrather than circuit-switching for data transmission. In addition, the standardization

process focused on requirements more than technology (2 Mbit/s maximum data rate

indoors, 384 kbit/s outdoors, for example).

Inevitably this led to many competing standards with different contenders pushing theirown technologies, and the vision of a single unified worldwide standard looked far from

reality. The standard 2G CDMA networks became 3G compliant with the adoption of

Revision A to EV-DO, which made several additions to the protocol whilst retaining

backwards compatibility:

the introduction of several new forward link data rates that increase the maximum

burst rate from 2.45 Mbit/s to 3.1 Mbit/s.

protocols that would decrease connection establishment time.

the ability for more than one mobile to share the same time slot.

the introduction of QoS flags.

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All these were put in place to allow for low latency, low bit rate communications such as

VoIP. The first pre-commercial trial network with 3G was launched by NTT DoCoMo in

Japan in the Tokyo region in May 2001. NTT DoCoMo launched the first commercial 3Gnetwork on October 1, 2001, using the WCDMA technology. In 2002 the first 3G

networks on the rival CDMA2000 1xEV-DO technology were launched by SK Telecom

and KTF in South Korea, and Monet in the USA. Monet has since gone bankrupt. By theend of 2002, the second WCDMA network was launched in Japan by Vodafone KK (now

Softbank). European launches of 3G were in Italy and the UK by the Three/Hutchison

group, on WCDMA. 2003 saw a further 8 commercial launches of 3G, six more onWCDMA and two more on the EV-DO standard. During the development of 3G systems,

2.5G systems such as CDMA2000 1x and GPRS were developed as extensions to

existing 2G networks. These provide some of the features of 3G without fulfilling the

promised high data rates or full range of multimedia services. CDMA2000-1X deliverstheoretical maximum data speeds of up to 307 kbit/s. Just beyond these is the EDGE

system which in theory covers the requirements for3G system, but is so narrowly above

these that any practical system would be sure to fall short. The high connection speeds of

3G technology enabled a transformation in the industry: for the first time, mediastreaming of radio (and even television) content to 3G handsets became possible , with

companies such as RealNetworks and Disney among the early pioneers in this type ofoffering. In the mid 2000s an evolution of 3G technology begun to be implemented,

namely High-Speed Downlink Packet Access (HSDPA). It is an enhanced 3G (third

generation) mobile telephony communications protocol in the High-Speed Packet Access

(HSPA) family, also coined 3.5G, 3G+ or turbo 3G, which allows networks based onUniversal Mobile Telecommunications System (UMTS) to have higher data transfer

speeds and capacity. Current HSDPA deployments support down-link speeds of 1.8, 3.6,

7.2 and 14.0 Mbit/s. Further speed increases are available with HSPA+, which providesspeeds of up to 42 Mbit/s downlink and 84 Mbit/s with Release 9 of the 3GPP standards.

By the end of 2007 there were 295 Million subscribers on 3G networks worldwide, which

reflected 9% of the total worldwide subscriber base. About two thirds of these were onthe WCDMA standard and one third on the EV-DO standard. The 3G telecoms services

generated over 120 Billion dollars of revenues during 2007 and at many markets the

majority of new phones activated were 3G phones. In Japan and South Korea the marketno longer supplies phones of the second generation. Earlier in the decade there were

doubts about whether 3G might happen, and also whether 3G might become a

commercial success. By the end of 2007 it had become clear that 3G was a reality and

was clearly on the path to become a profitable venture.

3GPP family

UMTS (UTRAN):Universal Mobile Telecommunications System(UMTS)

is one of the third-generation (3G) mobile telecommunications

technologies, which is also being developed into a 4G technology. Thefirst deployment of the UMTS is the release99 (R99) architecture. It is

specified by 3GPP and is part of the global ITU IMT-2000 standard. The

most common form of UMTS usesW-CDMA (IMT Direct Spread) as theunderlying air interface but the system also covers TD-CDMA and TD-

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SCDMA (both IMT CDMA TDD). Being a complete network system,

UMTS also covers the radio access network (UMTS Terrestrial Radio

Access Network, or UTRAN) and the core network (Mobile ApplicationPart, or MAP), as well as authentication of users via USIM cards

(Subscriber Identity Module).Unlike EDGE (IMT Single-Carrier, based on

GSM) and CDMA2000 (IMT Multi-Carrier), UMTS requires new basestations and new frequency allocations. However, it is closely related to

GSM/EDGE as it borrows and builds upon concepts from GSM. Further,

most UMTS handsets also support GSM, allowing seamless dual-modeoperation. Therefore, UMTS is sometimes marketed as 3GSM,

emphasizing the close relationship with GSM and differentiating it from

competing technologies. The name UMTS, introduced by ETSI, is usually

used in Europe. Outside of Europe, the system is also known by othernames such as FOMA or W-CDMA. In marketing, it is often just referred

to as 3G.

UTRAN, short for UMTS Terrestrial Radio Access Network, is acollective term for the Node B's and Radio Network Controllers whichmake up the UMTS radio access network. This communications network,

commonly referred to as 3G (for 3rd Generation Wireless Mobile

Communication Technology), can carry many traffic types from real-timeCircuit Switched to IP based Packet Switched. The UTRAN allows

connectivity between the UE (user equipment) and the core network. The

UTRAN contains the base stations, which are called Node Bs, and RadioNetwork Controllers (RNC). The RNC provides control functionalities for

one or more Node Bs. A Node B and an RNC can be the same device,

although typical implementations have a separate RNC located in a central

office serving multiple Node Bs. Despite the fact that they do not have tobe physically separated, there is a logical interface between them known

as the Iub. The RNC and its corresponding Node Bs are called the Radio

Network Subsystem (RNS). There can be more than one RNS present inan UTRAN. There are four interfaces connecting the UTRAN internally or

externally to other functional entities: Iu, Uu, Iub and Iur. The Iu interface

is an external interface that connects the RNC to the Core Network (CN).The Uu is also external, connecting the Node B with the User Equipment

(UE). The Iub is an internal interface connecting the RNC with the Node

B. And at last there is the Iur interface which is an internal interface mostof the time, but can, exceptionally be an external interface too for some

network architectures. The Iur connects two RNCs with each other.

WCDMA-FDD: Frequency-division duplexing (FDD) means that the

transmitter and receiver operates at different carrier frequencies. The termis frequently used in ham radio operation, where an operator is attempting

to contact a repeater station. The station must be able to send and receive a

transmission at the same time, and does so by slightly altering thefrequency at which it sends and receives. This mode of operation is

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referred to as duplex mode oroffset mode. Uplink and downlink sub-bands

are said to be separated by the frequency offset. Frequency-division

duplexing can be efficient in the case of symmetric traffic. In this casetime-division duplexing tends to waste bandwidth during the switch-over

from transmitting to receiving, has greater inherent latency, and may

require more complex circuitry. Another advantage of frequency-divisionduplexing is that it makes radio planning easier and more efficient, since

base stations do not "hear" each other (as they transmit and receive in

different sub-bands) and therefore will normally not interfere each other.On the converse, with time-division duplexing systems, care must be taken

to keep guard times between neighboring base stations (which decreases

spectral efficiency) or to synchronize base stations, so that they will

transmit and receive at the same time (which increases networkcomplexity and therefore cost, and reduces bandwidth allocation

flexibility as all base stations and sectors will be forced to use the same

uplink/downlink ratio)

WCDMA-TDD: Time-division duplexing (TDD) is the application of

time-division multiplexing to separate outward and return signals. It

emulates full-duplex communication over a half-duplex communicationlink. Time-division duplex has a strong advantage in the case where there

is asymmetry of the uplink and downlink data rates. As the amount of

uplink data increases, more communication capacity can be dynamicallyallocated, and as the traffic load becomes lighter, capacity can be taken

away. The same applies in the downlink direction

UTRA-TDD LCR (TD-SCDMA): Time Division Synchronous CodeDivision Multiple Access (TD-SCDMA) or UTRA/UMTS-TDD 1.28

Mcps Low Chip Rate (LCR), is an air interface found in UMTS mobile

telecommunications networks in China as an alternative to W-CDMA.Together with TD-CDMA, it is also known UMTS-TDD or IMT 2000

Time-Division (IMT-TD). The term "TD-SCDMA" is misleading. While

it suggests covering only a channel access method based on CDMA, it isactually the common name for the whole air interface specification. TD-

SCDMA uses the S-CDMAchannel access method across multiple time

slots. TD-SCDMA is based on spread spectrum technology which makes

it unlikely that it will be able to escape completely the payment of licensefees to western patent holders. The launch of a national TD-SCDMA

network was initially projected by 2005 but has still not been achieved;

the latest stage of "commercial trials" across eight cities was launched onApril 1, 2008 and will eventually include 60,000 users. On January 7,

2009 China granted TD-SCDMA 3G license to China Mobile. On

September 21, 2009 China Mobile officially announced that it had 1.327mTD-SCDMA subscribers as at the end of August, 2009

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3GPP2 family

CDMA2000 1xEV-DO (Evolution-Data Optimized) (IS-856) often

abbreviated as EV-DO or EV, is a telecommunications standard for

the wireless transmission of data through radio signals, typically

for broadband Internet access. It uses multiplexing techniquesincluding code division multiple access (CDMA) as well as time division

multiple access (TDMA) to maximize both individual user's throughput

and the overall system throughput. It is standardized by 3rd GenerationPartnership Project 2 (3GPP2) as part of the CDMA2000 family of

standards and has been adopted by many mobile phone service providers

around the world particularly those previously employing CDMAnetworks. It is also used on the Globalstarsatellite phone network.

Third Generation (3G) transitional (3.5G, 3.9G)

3GPP family

HSDPA:High-Speed Downlink Packet Access (HSDPA) is an enhanced

3G (third generation) mobile telephony communications protocol in theHigh-Speed Packet Access (HSPA) family, also dubbed 3.5G, 3G+ or

turbo 3G, which allows networks based on Universal Mobile

Telecommunications System (UMTS) to have higher data transfer speeds

and capacity. Current HSDPA deployments support down-link speeds of1.8, 3.6, 7.2 and 14.0 Mbit/s. Further speed increases are available with

HSPA+, which provides speeds of up to 42 Mbit/s downlink and 84 Mbit/s

with Release 9 of the 3GPP standards. HSDPA is part of the UMTS

standards since release 5, which also accompanies an improvement on theuplink providing a new bearer of 384 kbit/s. The previous maximum

bearer was 128 kbit/s. As well as improving data rates, HSDPA alsodecreases latency and so the round trip time for applications. In later 3GPP

specification releases HSPA+ increases data rates further by adding

64QAM modulation, MIMO and Dual-Cell HSDPA operation, i.e. two

5 MHz carriers are used simultaneously.

HSUPA: High-Speed Uplink Packet Access (HSUPA) is a 3G mobile

telephony protocol in the HSPA family with up-link speeds up to 5.76Mbit/s. The name HSUPA was created by Nokia. The 3GPP does not

support the name 'HSUPA', but instead uses the name Enhanced Uplink

(EUL).The specifications for HSUPA are included in Universal Mobile

Telecommunications System Release 6 standard published by 3GPP. "The technical purpose of the Enhanced Uplink feature is to improve the

performance of uplink dedicated transport channels, i.e. to increase

capacity and throughput and reduce delay." HSUPA uses an uplink

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enhanced dedicated channel (E-DCH) on which it will employ link

adaptation methods similar to those employed by HSDPA, namely:

o shorter Transmission Time Interval enabling faster link adaptation;

o HARQ (hybrid ARQ) with incremental redundancy making

retransmissions more effective.

Similarly to HSDPA, HSUPA uses a packet scheduler, but it operates on arequest-grant principle where the UEs request a permission to send data

and the scheduler decides when and how many UEs will be allowed to do

so. A request for transmission contains data about the state of thetransmission buffer and the queue at the UE and its available power

margin. However, unlike HSDPA, uplink transmissions are not orthogonal

to each other. In addition to this scheduled mode of transmission thestandards also allows a self-initiated transmission mode from the UEs,

denoted non-scheduled. The non-scheduled mode can, for example, be

used for VoIP services for which even the reduced TTI and the Node B

based scheduler will not be able to provide the very short delay time andconstant bandwidth required. Each MAC-d flow (i.e. QoS flow) is

configured to use either scheduled or non-scheduled modes; the UE

adjusts the data rate for scheduled and non-scheduled flows independently.The maximum data rate of each non-scheduled flow is configured at call

setup, and typically not changed frequently. The power used by the

scheduled flows is controlled dynamically by the Node B through absolutegrant (consisting of an actual value) and relative grant (consisting of a

single up/down bit) messages. At Layer 1, HSUPA introduces new

physical channels E-AGCH (Absolute Grant Channel), E-RGCH (Relative

Grant Channel), F-DPCH (Fractional-DPCH), E-HICH (E-DCH Hybrid

ARQ Indicator Channel), E-DPCCH (E-DCH Dedicated Physical ControlChannel) and E-DPDCH (E-DCH Dedicated Physical Data Channel).E-

DPDCH is used to carry the E-DCH Transport Channel; and E-DPCCH isused to carry the control information associated with the E-DCH.

HSPA+:HSPA+, also known as Evolved High-Speed Packet Access is a

wireless broadband standard defined in 3GPP release 7.HSPA+ providesHSPA data rates up to 56 Mbit/s on the downlink and 22 Mbit/s on the

uplink with MIMO technologies and higher order modulation (64QAM).

MIMO on CDMA based systems acts like virtual sectors to give extra

capacity closer to the mast. The 56 Mbit/s and 22 Mbit/s represent

theoretical peak sector speeds. The actual speed for a user will be lower.At cell edge and even at half the distance to the cell edge there may only

be slight increase compared with 14.4 Mbit/s HSDPA unless a widerchannel than 5 MHz is used. Future revisions of HSPA+ support up to

168 Mbit/s using multiple carriers. HSPA+ also introduces an optional all-

IP architecture for the network where base stations are directly connectedto IP based backhaul and then to the ISP's edge routers. The technology

also delivers significant battery life improvements and dramatically



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quicker wake-from-idle time - delivering a true always-on connection.

HSPA+ should not be confused with LTE, which uses a new air interface.

As of November 2009, there are 20 HSPA+ networks running in the worldat 21 Mbit/s and two are running at 28 Mbit/s. The first to launch was

Telstra in Australia in late 2008, with Australia-wide access in February

2009 with speeds up to 21 Mbit/sec. An all-IP architecture is an optionwithin HSPA+. Base stations connect to the network via standard gigabit

Ethernet to the ISP's edge routers connected to the internet or other ISP via

peering arrangements. This makes the network faster, cheaper to deployand operate. However the legacy architecture is still possible with the

Evolved HSPA. This 'flat architecture' communicates 'user plane' IP

directly from the base station to the GGSN IP router system, using any

available link technology. It is defined in 3GPP TR25.999. User IP data bypasses the Radio Network Controller (RNC) and the SGSN of the

previous 3GPP UMTS architecture versions. This is a major step towards

the 3GPP Long Term Evolution (LTE) flat architecture as defined in the

3GPP standard Rel-8. In essence the flat architecture turns the cellularbase station into an IP router. It connects to the Internet with cost effective

modern IP link layer technologies like Ethernet, and for user plane data itis not tied to the SONET/SDH infrastructure or T1/E1 lines any more.

LTE (E-UTRA):LTE (Long Term Evolution) is the trademarked project

name of a high performance air interface for cellular mobile telephony. e-UTRAN or eUTRAN is the air interface of 3GPP's Long Term Evolution

(LTE) upgrade path for mobile networks. It is the abbreviation for evolved

UMTS Terrestrial Radio Access Network, also referred to as the 3GPPwork item on the Long Term Evolution (LTE). It is a project of the 3rdGeneration Partnership Project (3GPP), operating under a name

trademarked by one of the associations within the partnership, the

European Telecommunications Standards Institute. LTE is a step towardthe 4th generation (4G) of radio technologies designed to increase the

capacity and speed of mobile telephone networks. Where the current

generation of mobile telecommunication networks are collectively knownas 3G (for "third generation"), LTE is marketed as 4G. Actually LTE is a

3.9G technology since it does not fully comply with the IMT Advanced

4G requirements. Verizon Wireless and AT&T Mobility in the United

States and several worldwide carriers announced plans, beginning in 2009,to convert their networks to LTE. The world's first publicly available

LTE-service was opened by TeliaSonera in the two Scandinavian capitals

Stockholm and Oslo on the 14th of December 2009. LTE is a set ofenhancements to the Universal Mobile Telecommunications System

(UMTS) which was introduced in 3rd Generation Partnership Project

(3GPP) Release 8. Much of 3GPP Release 8 focuses on adopting 4Gmobile communications technology, including an all-IP flat networking



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architecture. On August 18, 2009, the European Commission announced it

will invest a total of 18 million into researching the deployment of LTE

and 4G candidate system LTE Advanced. While it is commonly seen as amobile telephone or common carrier development, LTE is also endorsed

by public safety agencies in the US[ as the preferred technology for the

new 700 MHz public-safety radio band. Agencies in some areas have filedfor waivers hoping to use the 700 MHz spectrum with other technologies

in advance of the adoption of a nationwide standard.

Much of the standard addresses upgrading 3G UMTS to 4G mobile

communications technology, which is essentially a mobile broadbandsystem with enhanced multimedia services built on top.

The standard includes:

Peak download rates of 326.4 Mbit/s for 4x4 antennas, and

172.8 Mbit/s for 2x2 antennas (utilizing 20 MHz of spectrum). Peak upload rates of 86.4 Mbit/s for every 20 MHz of

spectrum using a single antenna.

Five different terminal classes have been defined from a

voice centric class up to a high end terminal that supports the peakdata rates. All terminals will be able to process 20 MHz

bandwidth.

At least 200 active users in every 5 MHz cell. (Specifically,200 active data clients)

Sub-5 ms latency for small IP packets

Increased spectrum flexibility, with supported spectrum

slices as small as 1.4 MHz and as large as 20 MHz (W-CDMArequires 5 MHz slices, leading to some problems with roll-outs of

the technology in countries where 5 MHz is a commonly allocated

amount of spectrum, and is frequently already in use with legacystandards such as 2G GSM and cdmaOne.) Limiting sizes to

5 MHz also limited the amount of bandwidth per handset

In the 900 MHz frequency band to be used in rural areas,supporting an optimal cell size of 5 km, 30 km sizes with

reasonable performance, and up to 100 km cell sizes supported

with acceptable performance. In city and urban areas, higherfrequency bands (such as 2.6 GHz in EU) are used to support high

speed mobile broadband. In this case, cell sizes may be 1 km or

even less.

Good support for mobility. High performance mobile data

is possible at speeds of up to 350 km/h, or even up to 500 km/h,

depending on the frequency band used.

Co-existence with legacy standards (users can transparentlystart a call or transfer of data in an area using an LTE standard,

and, should coverage be unavailable, continue the operation



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without any action on their part using GSM/GPRS or W-CDMA-

based UMTS or even 3GPP2 networks such as cdmaOne or

CDMA2000)

Support for MBSFN (Multicast Broadcast Single

Frequency Network). This feature can deliver services such as

Mobile TV using the LTE infrastructure, and is a competitor forDVB-H-based TV broadcast.

A large amount of the work is aimed at simplifying the architecture of the

system, as it transits from the existing UMTS circuit + packet switching

combined network, to an all-IP flat architecture system.

3GPP2 family

EV-DO Rev. A: Revision A of EV-DO makes several additions to theprotocol while keeping it completely backwards compatible with Revision

0.These changes included the introduction of several new forward linkdata rates that increase the maximum burst rate from 2.45 Mbit/s to 3.1

Mbit/s. Also included were protocols that would decrease connectionestablishment time (called enhanced access channel MAC), the ability for

more than one mobile to share the same timeslot (multi-user packets) and

the introduction ofQoS flags. All of these were put in place to allow forlow latency, low bit rate communications such as VoIP. In the United

States, Verizon Wireless and Sprint Nextel have migrated 100% of their

EV-DO Rev.0 networks to EV-DO Rev. A. In addition to the changes onthe forward link, the reverse link was enhanced to support higher

complexity modulation (and thus higher bit rates). An optional secondary

pilot was added, which is activated by the mobile when it tries to achieveenhanced data rates. To combat reverse link congestion and noise rise, theprotocol calls for each mobile to be given an interference allowance which

is replenished by the network when the reverse link conditions allow

it. The reverse link has a maximum rate of 1.8 Mbit/s, but under normalconditions users experience a rate of approximately 500-1000kbit/s but

with more latency than cable and dsl.

EV-DO Rev. Bis a multi-carrier evolution of the Rev. A specification. It

maintains the capabilities of EV-DO Rev. A, and provides the following

enhancements:

o Higher rates percarrier(up to 4.9 Mbit/s on the downlink per

carrier). Typical deployments are expected to include 2 or 3

carriers for a peak rate of 14.7 Mbit/s. Higher rates by bundling

multiple channels together enhance the user experience andenables new services such as high definition video streaming.

o Reduced latency by using statistical multiplexing across channels

-enhances the experience for latency sensitive services such as

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gaming, video telephony, remote console sessions and web

browsing.

o Increased talk-time and standby time

o Reduced interference from the adjacent sectors especially to users

at the edge of the cell signal which improves the rates that can be

offered by using Hybrid frequency re-use.o Efficient support for services that have asymmetric download and

upload requirements (i.e. different data rates required in each

direction) such as file transfers, web browsing, and broadband

multimedia content delivery.

Other

Mobile WiMAX (IEEE 802.16e-2005): The Mobile WiMAX (Wired

Interoperability for Microwave Access) (IEEE 802.16e-2005) mobile

wireless broadband access (MWBA) standard is sometimes branded 4G,

and offers peak data rates of 128 Mbit/s downlink and 56 Mbit/s uplinkover 20 MHz wide channels. The IEEE 802.16m evolution of 802.16e is

under development, with the objective to fulfill the IMT-Advanced criteriaof 1 Gbit/s for stationary reception and 100 Mbit/s for mobile reception.

Flash-OFDM: Orthogonal frequency-division multiplexing (OFDM),

essentially identical to coded OFDM (COFDM) and discrete multi-tonemodulation (DMT), is a frequency-division multiplexing (FDM) scheme

utilized as a digital multi-carrier modulation method. A large number of

closely-spaced orthogonal sub-carriers are used to carry data. The data is

divided into several parallel data streams or channels, one for each sub-carrier. Each sub-carrier is modulated with a conventional modulation

scheme (such as quadrature amplitude modulation or phase-shift keying)

at a low symbol rate, maintaining total data rates similar to conventionalsingle-carrier modulation schemes in the same bandwidth. OFDM has

developed into a popular scheme for wideband digital communication,

whether wireless or over copper wires, used in applications such as digitaltelevision and audio broadcasting, wireless networking and broadband

internet access. The primary advantage of OFDM over single-carrier

schemes is its ability to cope with severe channel conditions (for example,

attenuation of high frequencies in a long copper wire, narrowband

interference and frequency-selective fading due to multipath) withoutcomplex equalization filters. Channel equalization is simplified because

OFDM may be viewed as using many slowly-modulated narrowbandsignals rather than one rapidly-modulated wideband signal. The low

symbol rate makes the use of a guard interval between symbols affordable,

making it possible to handle time-spreading and eliminate intersymbolinterference (ISI). This mechanism also facilitates the design of single

frequency networks (SFNs), where several adjacent transmitters send the

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same signal simultaneously at the same frequency, as the signals from

multiple distant transmitters may be combined constructively, rather than

interfering as would typically occur in a traditional single-carrier system.

IEEE 802.20: IEEE 802.20 or Mobile Broadband Wireless Access

(MBWA) is an IEEE Standard to enable worldwide deployment of multi-

vendor interoperable mobile broadband wireless access networks. It ishoped that such an interface will allow the creation of low-cost, always-

on, and truly mobile broadband wirelessnetworks, nicknamed as Mobile-

Fi.IEEE 802.20 will be specified according to a layered architecture,which is consistent with other IEEE 802 specifications. The scope of the

working group consists of the physical (PHY), medium access control

(MAC), and logical link control (LLC) layers. The air interface willoperate in bands below 3.5 GHz and with a peak data rate of over 80

Mbit/s. The goals of 802.20 and 802.16e, the so-called "mobile WiMAX",are similar. A draft 802.20 specification was balloted and approved on

January 18, 2006.The IEEE approved 802.20-2008, Physical and MediaAccess Specification on 12 June 2008. This is now freely available from

the IEEE website. The baseline specifications that have been proposed for

this specification aim considerably higher than those available on ourcurrent mobile architecture.

o The standard's proposed benefits:

IP roaming & handoff (at more than 1 Mbit/s)

New MAC and PHY with IP and adaptive antennas

Optimized for full mobility up to vehicular speeds of

250 km/h Operates in Licensed Bands (below 3.5 GHz)

Utilizes Packet Architecture

Low Latency

o Some technical details

Bandwidths of 5, 10, and 20 MHz.

Peak data rates of 80 Mbit/s.

Spectral efficiency above 1 bit/sec/Hz using MIMO.

Layered frequency hopping allocates OFDM carriers to

near, middle, and far-away handsets, improving SNR

(works best for SISO handsets.) Supports low-bit rates efficiently, carrying up to 100 phone

calls per MHz.

Hybrid ARQ with up to 6 transmissions and several choices

for interleaving.

Basic slot period of 913 microseconds carrying 8 OFDMsymbols.

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One of the first standards to support both TDM (FL,RL)

and separate-frequency (FL, RL) deployments

Fourth Generation (4G) Cellular Network

It is a successor to 3G and 2G families of standards. The nomenclature of the generations

generally refers to a change in the fundamental nature of the service, non-backwards

compatible transmission technology and new frequency bands. The first was the movefrom 1981 analogue (1G) to digital (2G) transmission in 1992. This was followed, in

2002, by 3G multi-media support, spread spectrum transmission and at least 200 kbit/s,

soon expected to be followed by 4G, which refers to all-IP packet-switched networks,mobile ultra-broadband (gigabit speed) access and multi-carrier transmission. Pre-4G

technologies such as mobile WiMAX and first-release 3G Long term evolution (LTE) are

available on the market since 2005 and 2009 respectively.

A 4G system is expected to provide a comprehensive and secure all-IP based solutionwhere facilities such as IP telephony, ultra-broadband Internet access, gaming services

and streamed multimedia may be provided to users.

An IMT advanced cellular system must have target peak data rates of up to

approximately 100 Mbit/s for high mobility such as mobile access and up toapproximately 1 Gbit/s for low mobility such as nomadic/local wireless access, according

to the ITU requirements. Scalable bandwidths up to at least 40 MHz should be provided.

In all suggestions for 4G, the CDMA spread spectrum radio technology used in 3G

systems and IS-95 is abandoned and replaced by frequency-domain equalizationschemes, for example multi-carrier transmission such as OFDMA. This is combined with

MIMO (i.e. multiple antennas(Multiple In Multiple Out)), dynamic channel allocation

and channel-dependent scheduling

3GPP family

LTE Advanced: The pre-4G technology 3GPP Long Term Evolution

(LTE) is often branded "4G", but the first LTE release does not fully

comply with the IMT-Advanced requirements. LTE has a theoretical netbit rate capacity of up to 100 Mbit/s in the downlink and 50 Mbit/s in the

uplink if a 20 MHz channel is used - and more if Multiple-input multiple-

output (MIMO), i.e. antenna arrays, are used. Most major mobile carriersin the United States and several worldwide carriers have announced plans

to convert their networks to LTE beginning in 2011. The world's first

publicly available LTE-service was opened in the two Scandinaviancapitals Stockholm andOsloon the 14 December 2009, and branded 4G.

The physical radio interface was at an early stage named High Speed

http://en.wikipedia.org/wiki/Oslohttp://en.wikipedia.org/wiki/Oslohttp://en.wikipedia.org/wiki/Oslohttp://en.wikipedia.org/wiki/Oslo


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OFDM Packet Access (HSOPA), now named Evolved UMTS Terrestrial

Radio Access (E-UTRA).LTE Advanced (Long-term-evolution

Advanced) is a candidate for IMT-Advanced standard, formally submittedby the 3GPP organization to ITU-T in the fall 2009, and expected to be

released in 2012. The target of 3GPP LTE Advanced is to reach and

surpass the ITU requirements. LTE Advanced should be compatible withfirst release LTE equipment, and should share frequency bands with first

release LTE.

WiMAX family

IEEE 802.16m: It is a series of Wireless Broadband standards authored by

the IEEE. The current version is IEEE 802.16-2009 amended by IEEE802.16j-2009.IEEE 802.16 is written by a working group established by

IEEE Standards Board in 1999 to develop standards for the globaldeployment of broadband Wireless Metropolitan Area Networks. The

Workgroup is a unit of the IEEE 802 LAN/MAN Standards Committee.Although the 802.16 family of standards is officially called WirelessMAN

in IEEE, it has been commercialized under the name WiMAX (from

"Worldwide Interoperability for Microwave Access") by the industryalliance called the WiMAX Forum. The mission of the Forum is to

promote and certify compatibility and interoperability of broadband

wireless products based on the IEEE 802.16 standards. The most popularimplementation of the IEEE 802.16 standard is the Mobile WirelessMAN

originally defined by the 802.16e-2005 amendment that is now in process

of being deployed around the world in more than 140 countries by morethan 475 operators.

UMB (Formerly EV-DO Rev. C):UMB (Ultra Mobile Broadband) was the brand namefor a discontinued 4G project within the 3GPP2 standardization group to improve

the CDMA2000 mobile phone standard for next generation applications and

requirements. In November 2008, Qualcomm, UMB's lead sponsor, announced itwas ending development of the technology, favoring LTE instead. The objective

was to achieve data speeds over 275 Mbit/s downstream and over 75 Mbit/s

upstream.

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