Senin, Juli 28, 2008

HSDPA

High-Speed Downlink Packet Access (HSDPA) is a 3G (third generation) mobile telephony communications protocol in the High-Speed Packet Access (HSPA) family, 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 of 1.8, 3.6, 7.2 and 14.4 Mbit/s. Further speed increases are available with HSPA+, which provides speeds of up to 42 Mbit/s downlink.[1]Contents



Technology

The High-Speed Downlink Shared Channel (HS-DSCH) lacks two basic features of other W-CDMA channels — variable spreading factor and fast power control. Instead, it delivers the improved downlink performance using adaptive modulation and coding (AMC), fast packet scheduling at the base station, and fast retransmissions from the base station, known as hybrid automatic repeat-request (HARQ).

Hybrid automatic repeat-request (HARQ)

HARQ uses incremental redundancy, where user data is transmitted multiple times using different codings. When a corrupted packet is received, the user device saves it and later combines it with the retransmissions, to recover the error-free packet as efficiently as possible. Even if the retransmitted packets are corrupted, their combination can yield an error-free packet.

Fast packet scheduling

The HS-DSCH downlink channel is shared between users using channel-dependent scheduling to make the best use of available radio conditions. Each user device periodically transmits an indication of the downlink signal quality, as often as 500 times per second. Using this information from all devices, the base station decides which users will be sent data on the next 2 ms frame and how much data should be sent for each user. More data can be sent to users which report high downlink signal quality.

The amount of the channelisation code tree, and thus network bandwidth, allocated to HSDPA users is determined by the network. The allocation is "semi-static" in that it can be modified while the network is operating, but not on a frame-by-frame basis. This allocation represents a trade-off between bandwidth allocated for HSDPA users, versus that for voice and non-HSDPA data users. The allocation is in units of channelisation codes for Spreading Factor 16, of which 16 exist and up to 15 can be allocated to HSDPA. When the base station decides which users will receive data on the next frame, it also decides which channelisation codes will be used for each user. This information is sent to the user devices over one or more HSDPA "scheduling channels"; these channels are not part of the HSDPA allocation previously mentioned, but are allocated separately. Thus, for a given 2 ms frame, data may be sent to a number of users simultaneously, using different channelisation codes. The maximum number of users to receive data on a given 2 ms frame is determined by the number of allocated channelisation codes. By contrast, in CDMA2000 1xEV-DO, data is sent to only one user at a time.

Adaptive modulation and coding

The modulation scheme and coding is changed on a per-user basis depending on signal quality and cell usage. The initial scheme is Quadrature phase-shift keying (QPSK), but in good radio conditions 16QAM modulation almost doubles data throughput rates. With 5 Code allocation, QPSK typically offers up to 1.8 Mbit/s peak data rates, while 16QAM up to 3.6. Additional codes (e.g. 10, 15) can also be used to improve these data rates or extend the network capacity throughput significantly. Theoretically, HSDPA can give throughput up to 14.4 Mbit/s.

Other improvements

HSDPA is part of the UMTS standards since release 5, which also accompanies an improvement on the uplink providing a new bearer of 384 kbit/s. The previous maximum bearer was 128 kbit/s.

As well as improving data rates, HSDPA also reduces latency and so the round trip time for applications.

Along with the HS-DSCH channel, three new physical channels are also introduced: HS-SCCH, HS-DPCCH and HS-PDSCH. The High Speed-Shared Control Channel (HS-SCCH) informs the user that data will be sent on the HS-DSCH 2 slots ahead. The Uplink High Speed-Dedicated Physical Control Channel (HS-DPCCH) carries acknowledgment information and current channel quality indicator (CQI) of the user. This value is then used by the base station to calculate how much data to send to the user devices on the next transmission. The High Speed-Physical Downlink Shared Channel (HS-PDSCH) is the channel mapped to the above HS-DSCH transport channel that carries actual user data.

HSDPA UE categories

HSDPA comprises various versions with different data speeds.Category Max. number of
HS-DSCH codes Modulation Max. data rate
[Mbit/s]
1 5 QPSK and 16-QAM 1.2
2 5 QPSK and 16-QAM 1.2
3 5 QPSK and 16-QAM 1.8
4 5 QPSK and 16-QAM 1.8
5 5 QPSK and 16-QAM 3.6
6 5 QPSK and 16-QAM 3.6
7 10 QPSK and 16-QAM 7.3
8 10 QPSK and 16-QAM 7.3
9 15 QPSK and 16-QAM 10.2
10 15 QPSK and 16-QAM 14.4
11 5 QPSK only 0.9
12 5 QPSK only 1.8


Roadmap

The first phase of HSDPA has been specified in the 3rd Generation Partnership Project (3GPP) release 5. Phase one introduces new basic functions and is aimed to achieve peak data rates of 14.4 Mbit/s (see above). Newly introduced are the High Speed Downlink Shared Channels (HS-DSCH), the adaptive modulation QPSK and 16QAM and the High Speed Medium Access protocol (MAC-hs) in base station.

The second phase of HSDPA is specified in the upcoming 3GPP release 7 and has been named HSPA Evolved. It can achieve data rates of up to 42 Mbit/s.[1] It will introduce antenna array technologies such as beamforming and Multiple-input multiple-output communications (MIMO). Beam forming focuses the transmitted power of an antenna in a beam towards the user’s direction. MIMO uses multiple antennas at the sending and receiving side. Deployments are scheduled to begin in the second half of 2008.

After HSDPA the roadmap leads to HSOPA, a technology under development for specification in 3GPP Release 8. This project is called the Long Term Evolution initiative. The first release of LTE offers data rates of over 320 Mbit/s for downlink and over 170 Mbit/s for uplink using OFDMA modulation.

Adoption

As of May 25, 2007, 102 HSDPA networks have commercially launched mobile broadband services in 55 countries. Nearly 40 HSDPA networks support 3.6 Mbit/s peak downlink data throughput. A growing number are delivering 7.2 Mbit/s peak data downlink, leveraging new higher-speed devices coming into the market. One network has been declared as “14.4 Mbit/s (peak) ready” and several others will have this capability by end 2007. The first commercial HSUPA uplink network is launched, with several more set to follow in 2007.

This protocol is a relatively simple upgrade where UMTS is already deployed.[1]

CDMA-EVDO networks had the early lead on performance, and Japanese providers were highly successful benchmarks for it. But lately this seems to be changing in favour of HSDPA as an increasing number of providers worldwide are adopting it. In Australia, Telstra announced that its CDMA-EVDO network would be replaced with a HSDPA network (since named NextG), offering high speed internet, mobile television and traditional telephony and video calling. Rogers Wireless deployed HSDPA system 850/1900 in Canada on April 1, 2007. Singapore is currently the only country boasting nationwide HSDPA.[2]

So far, 171 device models from 47 suppliers have been launched, comprising: 53 handsets, 35 notebooks, 30 datacards, 19 wireless routers, 15 modems, 11 embedded module, 2 wireless modules, 1 wireless residential gateway, 1 media player, 1 camera, 1 GPS handset, 1 convergence platform & 1 baseband processor. [3]

Marketing as mobile broadband

During 2007, an increasing number of telcos worldwide began selling HSDPA USB modems as mobile broadband connections. In addition, the popularity of HSDPA landline replacement boxes grew — providing HSDPA for data via Ethernet and WiFi, and ports for connecting traditional landline telephones. Marketed with connection speeds of "up to 7.2 Mbit/s",[4] which is only attained under ideal conditions. As a result these services can be slower than expected, especially when in fringe coverage indoors. However, signal strength can be greatly improved by using commercial solutions that can attach 3G external antennas.[5]

[+/-] Lanjutkan...

HSDPA

High-Speed Downlink Packet Access (HSDPA) adalah sebuah protokol telepon genggam dan kadangkala disebut sebagai teknologi 3,5G.

HSDPA fase pertama berkapasitas 4,1 Mbps. Kemudian menyusul fase 2 berkapasitas 11 Mbps dan kapsitas maksimal downlink peak data rate hingga mencapai 14 Mbit/s. Teknologi ini dikembangkan dari WCDMA sama seperti EV-DO mengembangkan CDMA2000. HSDPA memberikan jalur evolusi untuk jaringan Universal Mobile Telecommunications System (UMTS) yang memungkinkan untuk penggunaan kapasitas data yang lebih besar (sampai 14,4 Mbit/detik arah turun).



HSDPA merupakan evolusi dari standar W-CDMA dan dirancang untuk meningkatkan kecepatan transfer data 5x lebih tinggi. HSDPA memdefinisikan sebuah saluran W-CDMa yang baru, yaitu high-speed downlink shared channel (HS-DSCH) yang cara operasinya berbeda dengan saluran W-CDMA yang ada sekarang. Hingga kini penggunaan teknologi HSDPA hanya pada komunikasi arah bawah menuju telepon genggam.

Kecepatan unduh data
Di lingkungan perumahan teknologi ini dapat melakukan unduh data hingga berkecepatan 3,7 Mbps.
Dalam keadaan bergerak seseorang yang sedang berkendaraan di jalan tol berkecepatan 100 km/jam dapat mengakses internet berkecepatan 1,2 Mbps.
Di lingkungan perkantoran yang padat pengguna dapat menikmati streaming video dengan perkiraan kecepatan 300 Kbps.

Kelebihan HSDPA

Kelebihan HSDPA adalah mengurangi tertundanya pengunduhan data (delay) dan memberikan umpan balik yang lebih cepat saat pengguna menggunakan aplikasi interaktif seperti mobile office atau akses Internet kecepatan tinggi untuk penggunaan fasilitas permainan atau mengunduh audio dan video. Kelebihan lain HSDPA, meningkatkan kapasitas sistim tanpa memerlukan spektrum frekuensi tambahan. Hal ini menyebabkan berkurangnya biaya layanan mobile data secara signifikan.


[+/-] Lanjutkan...

Trik Rayuan Maut Buat Dapetin Cewek!!!

Cowok : Mbak jangan pegangan sama besi kereta..
Cewek : Emang kenapa..?
Cowok : Kayaknya besinya kotor tuh.. pegangan sama aku aja...

Cowok: Maaf mba, jangan terlalu lama duduk dikursi itu, pindah dideket saya aja
Cewek: Loh?? kenapa??
Cowok: Takut dikerubung semut.. soalnya mba manis..

Cowok : Mbak, orang tuanya pengrajin bantal ya..?
Cewek : Hah..!!!? bukan..Emang kenapa..?
Cowok : kok kalo deket sama mbak rasanya nyaman yach..

Cowok : Mbak jangan ngomong ya..
Cewek : Lho.. emang kenapa..?
Cowok : Karena biasanya aku malemnya enggak bisa tidur.. kalo abis denger suara dari bibir yang indah...

Cowok : Mbak bajunya enggak pernah disetrika ya..?
Cewek : Enak aja... emang kenapa..?
Cowok : biasanya kalo cewek udah cantik enggak perlu lagi nyetrika baju..

Cowok: "kamu itu seperti sendok..."
Cewek: "Kenapa?"
Cowok: "Karena kamu ngaduk-ngaduk perasaan aku..."

Cowok: "Kamu sekali-sekali nyuci piring dooonk"
Cewek: "Hah? emang kenapa ?"
Cowok: "Ini tangan kamu terlalu lembut..."

Cowok: "Kamu pasti enggak pernah maen bola ya.."
Cewek: "Iya laaah.. emang kenapa...?"
Cowok: "Soalnya kaki kamu bagus banget...."

Cowok: "Mbak punya uang koin ? Boleh minta ?"
Cewek: "Buat apa ?"
Cowok: "Aku udah janji sama ibu kalau aku akan menelepon dia bila aku jatuh cinta"





[+/-] Lanjutkan...

Jumat, Juli 18, 2008

What's is 3G??

3G refers to the next generation of wireless communications technology; it is a ‘catch all’ name which encompasses everything from the technology to the branding of mobile communication devices.


The aim of 3G (third generation) is to deliver the capability of much higher data rates to mobile communications devices over a large geographical area. Data rates of up to 2megabits per second will be capable in some areas.


It is also the aim of 3G to unify the wireless devices the world over, so a user from the UK, can travel Europe, and the US, and use the same, highspeed data links, seamlessly as they travel the globe.


3G is a packet switched suite of protocols, a technology which was originally developed for the internet, it also uses techniques such as Code Division Multiple Access (originally developed by the military) to allow efficient, fast, and secure communications over the wireless medium. For a very in-depth technological explanation of 3G, go to the “How Does 3G work?” Section.




To the end user, 3G means fast World Wide Web browsing, file transfers, emailing, even video phoning and video conferencing from their mobile phone, PDA, or laptop. With coverage over all of Europe, the USA, China, Japan, and the rest of the world, with seamless integration between all of these countries and more.


Although 3G is relatively an infant, the technology is growing fast, with more and more wireless technology companies developing devices with 3G capabilities, such as Nokia, Siemens and Sony Ericsson. See the 3G phones section for an overview of the latest 3G handsets on the market.


On the horizon is 4G, a technology which will truly integrate the internet, and mobile telecommunications.




3G History

As you may guess, being called 3G, or third generation, there is, inevitably, a first and second generation.


1G refers to the original analogue mobile phones, which resembled a brick. They were large, and very heavy, due to the weight of the battery, they were also very expensive. However, they paved the way for something that was soon to become a revolution in the technological world, phones would soon start to be smaller, lighter, cheaper, and better. Operating time increased while battery weight dropped, this was due to advancements in battery technology, as well as circuit design which allowed for much lower power consumption.


2G saw the birth of the digital mobile phone, and a standard which is the greatest success story in the history of the mobile phone to date. The Global System for Mobile Communications (GSM) is a standard that unified Europe’s mobile phone technologies, it allows one phone to be used throughout Western Europe. Using TDMA (Time division multiple access – see the How does 3G work section for more info), the GSM standard allowed millions of users throughout Europe to travel freely and still be able to use there phone. Although Europe enjoyed a unified standard, in America, three standards still exist, from three different companies. Because of this mobile communications haven’t become nearly as popular in the States, as they have done in Europe.


2G worked well for voice communications, it provided data rates of up to 9.6Kbps, good enough for voice, but no where near enough for bandwidth demanding modern day media, such as Video and file transfers. Something which the world was screaming out for, and to provide this, 3G was developed.


Due to the nature of 3G, and its incredible complexity and expensive, the move from 2G to 3G wasn’t going to happen over night, so the 2.5G standard was developed.

The 2.5G standard had a major technically different feature compared to its predecessor, it used Packet Switching technology (see the how does 3G work section for more info) to transmit data. The General Packet Radio Service (GPRS) replaced GSM as the 2.5G standard. GPRS actually overlays a packet switched technology onto the original GSM circuit switched network.


Data rates of 2.5G can reach 50kbps, some may think this is a waste of time, and service provides should have gone straight to the goal and implemented 3G, however, the 2.5G standard is a much needed step, as it gives service providers experience of running packet switched networks, and charging on a data bases, rather than a time basis.

Other than GPRS, another standard called EDGE is another upgrade option from GSM, and is three times faster with a maximum transfer rate of 150Kbps as opposed to GPRS’s 50Kbps. EDGE also can be an upgrade from TDMA networks, so some American operators may go this route – see the How 3G works section for an in depth explanation of this.


Currently there is one 3G enabled network in the UK, known simply as '3'. It is expected that other UK operators will make begin to make the switch in the near future.

How does 3G work?

3G is a packet switched technology, much like the internet. There are some basic principles of Radio Transmission Technologies (RTT’s) you need to understand before you can understand how 3G works, these are:


Simplex and Duplex, TDD and FDD, Symmetric and Asymmetric transmission, and 3G geographical cells.


I will explain each of the following, and then move onto the methods underlying the technology of the 3G network.
Simplex and Duplex

In a simplex transmission, information can only flow one way at one time, this is because there is only one frequency being used to communicate on. The easiest way of explaining this is to use walkie-talkies as an example. With a set of walkie-talkies, only one person can talk to the other at any given time, for the other person to transmit, they must wait until the other person has stopped.


In a duplex transmission, two data transmissions can be sent at any one time, this is how mobile phones work, it allows both people to speak at the same time, without any delay. If more than two data transmissions can happen at any one time, this is called multiplex.


So, you may be wondering how two or more transmissions can happen at the same time, on the same frequency?

TDD and FDD

Up until the recent developments of mobile phones, FDD (frequency division duplex) was used, this is where several frequencies are used, one for the upstream (signals going from the phone to the base station), and one for the downstream (the opposite, from the base station to the phone). A “guard band” is also needed, which sits in between the frequencies to separate them and provide isolation.


Although FDD works, it is very wasteful, as it uses several frequencies in total, and not to there full potential. This is why TDD was developed.


TDD means Time Division Duplex, and as the name suggests, this uses time, rather than frequency to do the duplexing, hence saving valuable frequencies. It works by switching the signals very rapidly. First the upstream transmits, then the downstream transmits and this continues to cycle, this happens so quick, it seems like the upstream and downstream are permanently connected. This gives the same end product as FDD, but uses much less frequencies. As with FDD, this also requires some sort of guard, but as we are duplexing in the time domain, it uses a guard time, rather than a guard frequency.

Symmetric and Asymmetric Transmission

A symmetric transmission is where the upstream, and downstream are the same speed, or data rate. Things such as voice on mobile phones use symmetric transmission, as the data rate needed to transmits your voice is the same as receiving another persons.


For things like video broadcasts, internet surfing etc, a lot more downstream bandwidth is required, as you will mostly be receiving data. Typically the only things being sent upstream in that case is requests (for instance, you clicking on a link in your wap/internet browser), or packet acknowledgments (discussed more later). A typical example of an Asymmetric connection is ADSL broadband, the A, which coincidently enough stands for Asymmetric, usually has 256Kbps of upstream, and 512+kbps on the downstream bandwidth.

3G geographical cells

The 3G network has a hierarchal network of different sized cells. These are:


A Macro cell this is the biggest of the three areas, coverage is normally around the size of a city.


A Micro cell this cell has the coverage, of about the size of city centre.


A Pico cell The smallest coverage, perhaps a office complex, hotel, or airport. A Pico cell is often known as a “hot spot”.


The reason for the above division of regions is simple, shorter range communications are faster, and allow for a higher amount of users. This is why a Pico cell, or hot spot., is located to a small geographical area which is a very busy area, such as an airport.


TDD isn’t good in transmitting long distances, this is because of the delay. If you think, TDD uses time to duplex signals onto the same frequency. The further the mobile phone is away from the base station, the longer it takes a signal to travel, because it takes longer, there is more of a delay, so because of this the switching between time slots cannot happen so quick, so the useable bandwidth decreases.

The Future of 3G

There’s no doubt what is wanted for the future of 3G, and that’s convergence. Leading 3G figureheads around the world want a convergence of the phone networks, to unite the world as a whole with a wireless technology that is compatible across the globe.


There’s a good chance this will happen, as it has already begun to. And it possible won’t be far off that we see perhaps a sub-standard introduced that converges the different 3G standards into one global roaming capable standard.


On the horizon is 4G, which promises to bring true convergence of internet’s IP protocol technology to mobiles. By the time 4G is distributed, IPv6 will be well on its way, and the possibilities will be endless. Ever thought about texting your boiler to tell it to get the heating on just as you leave work?

[+/-] Lanjutkan...

What's is 3G??

3G refers to the third generation of developments in wireless technology, especially mobile communications. The third generation, as its name suggests, follows the first generation (1G) and second generation (2G) in wireless communications.


1G

The 1G period began in the late 1970s and lasted through the 1980s. These systems featured the first true mobile phone systems, known at first as "cellular mobile radio telephone." These networks used analog voice signaling, and were little more sophisticated than the repeater networks used by amateur radio operators.



2G

The 2G phase began in the 1990s and much of this technology is still in use. The 2G cell phone features digital voice encoding. Examples include CDMA and GSM. Since its inception, 2G technology has steadily improved, with increased bandwidth, packet routing, and the introduction of multimedia.


3G includes capabilities and features such as:


Enhanced multimedia (voice, data, video, and remote control).


Usability on all popular modes (cellular telephone, e-mail, paging, fax, videoconferencing, and Web browsing).


Broad bandwidth and high speed (upwards of 2 Mbps).


Roaming capability throughout Europe, Japan, and North America.


While 3G is generally considered applicable mainly to mobile wireless, it is also relevant to fixed wireless and portable wireless. A 3G system should be operational from any location on, or over, the earth's surface, including use in homes, businesses, government offices, medical establishments, the military, personal and commercial land vehicles, private and commercial watercraft and marine craft, private and commercial aircraft (except where passenger use restrictions apply), portable (pedestrians, hikers, cyclists, campers), and space stations and spacecraft.


3G offers the potential to keep people connected at all times and in all places. Researchers, engineers, and marketers are faced with the challenge of accurately predicting how much technology consumers will actually be willing to pay for. Another challenge faced by 3G services is competition from other high-speed wireless technologies, especially mobile WiMAX, and ability to roam between different kinds of wireless networks.


The current status of mobile wireless communications, as of July 2007, is a mix of 2nd and 3rd generation technologies.


3G is the third generation of mobile phone standards and technology, superseding 2G, and preceding 4G. It is based on the International Telecommunication Union (ITU) family of standards under the International Mobile Telecommunications programme, IMT-2000.


3G technologies enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver speeds up to 14.4Mbit/s on the downlink and 5.8Mbit/s on the uplink.


Unlike IEEE 802.11 networks, 3G networks are wide area cellular telephone networks which evolved to incorporate high-speed internet access and video telephony. IEEE 802.11 (common names Wi-Fi or WLAN) networks are short range, high-bandwidth networks primarily developed for data.Contents [hide]

1 Implementation and history

2 Phones and networks

2.1 UMTS terminals

2.2 Speed

2.3 Network standardization

2.3.1 IMT-2000 standards and radio interfaces

2.3.2 Advantages of a layered network architecture

2.4 3G evolution (pre-4G)

3 Evolution from 2G to 3G

3.1 From 2G to 2.5G (GPRS)

3.2 Migrating from GPRS to UMTS

4 Issues

5 References

5.1 Selected significant books on 3G

6 See also

Implementation and history


The first pre-commercial 3G network was launched by NTT DoCoMo in Japan branded FOMA, in May of 2001 on a pre-release of W-CDMA technology. The first commercial launch of 3G was also by NTT DoCoMo in Japan on October 1, 2001. The second network to go commercially live was by SK Telecom in South Korea on the CDMA2000 1xEV-DO technology in January 2002. By May 2002 the second South Korean 3G network was launched by KTF on EV-DO and thus the Koreans were the first to see competition among 3G operators.


The first European pre-commercial network was at the Isle of Man by Manx Telecom, the operator owned by British Telecom, and the first commercial network in Europe was opened for business by Telenor in December 2001 with no commercial handsets and thus no paying customers. These were both on the W-CDMA technology.


The first commercial United States 3G network was by Monet, on CDMA2000 1x EV-DO technology, but this network provider later shut down operations. The second 3G network operator in the USA was Verizon in October 2003 also on CDMA2000 1x EV-DO, and this network has grown strongly since then.


The "first pre-commercial demonstration network" in the southern hemisphere was built in Adelaide, South Australia by m.Net Corporation in February 2002 using UMTS on 2100 MHz. This was a demonstration network for the 2002 IT World Congress. The first "commercial" 3G network was launched by Hutchison Telecommunications branded as Three in April 2003. Australia's largest and fastest 3G UMTS/HSDPA network was launched by Telstra branded as "NextG(tm)" on the 850 MHz band in October 2006, intended as a replacement of their cdmaOne network Australia wide.


In December 2007, 190 3G networks were operating in 40 countries and 154 HSDPA networks were operating in 71 countries, according to the Global mobile Suppliers Association. In Asia, Europe, Canada and the USA, telecommunication companies use W-CDMA technology with the support of around 100 terminal designs to operate 3G mobile networks.


In Europe, mass market commercial 3G services were introduced starting in March 2003 by 3 (Part of Hutchison Whampoa) in the UK and Italy. The European Union Council suggested that the 3G operators should cover 80% of the European national populations by the end of 2005.


Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. (See Telecoms crash.) In many countries, 3G networks do not use the same radio frequencies as 2G, so mobile operators must build entirely new networks and license entirely new frequencies; an exception is the United States where carriers operate 3G service in the same frequencies as other services. The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. Other delays were due to the expenses of upgrading equipment for the new systems.


By June 2007 the 200 millionth 3G subscriber had been connected. Out of 3 billion mobile phone subscriptions worldwide this is only 6.7%. In the countries where 3G was launched first - Japan and South Korea - over half of all subscribers use 3G. In Europe the leading country is Italy with a third of its subscribers migrated to 3G. Other leading countries by 3G migration include UK, Austria, Australia and Singapore at the 20% migration level. A confusing statistic is counting CDMA 2000 1x RTT customers as if they were 3G customers. If using this oft-disputed definition, then the total 3G subscriber base would be 475 million at June 2007 and 15.8% of all subscribers worldwide.


Still several major countries such as Turkey, China etc have not awarded 3G licenses and customers await 3G services. China has been delaying its decisions on 3G for many years, partly hoping to have the Chinese 3G standard, TD-SCDMA, to mature for commercial production.


China announced in May 2008, that the telecoms sector was re-organized and three 3G networks would be allocated so, that the largest mobile operator, China Mobile would retain its GSM customer base and launch 3G onto the Chinese standard, TD-SCDMA. China Unicom would retain its GSM customer base but relinquish its CDMA2000 customer base, and launch 3G on the globally leading WCDMA (UMTS) standard. The CDMA2000 customers of China Unicom would go to China Telecom, which would then launch 3G on the CDMA 1x EV-DO standard. This means that China will have all three main cellular technology 3G standards in commercial use.


The first African use of 3G technology was a 3G videocall made in Johannesburg on the Vodacom network in November 2004. The first commercial launch of 3G in Africa was by EMTEL in Mauritius on the W-CDMA standard. In north African Morocco in late March 2006, a 3G service was provided by the new company Wana.


Rogers Wireless began implementing 3G HSDPA services in eastern Canada early 2007 in the form of Rogers Vision; expansion into western Canada is expected soon.


Phones and networks


3G technologies enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency.


UMTS terminals


The technical complexities of a 3G phone or handset depends on its need to roam onto legacy 2G networks. In the first countries, Japan and South Korea, there was no need to include roaming capabilities to older networks such as GSM, so 3G phones were small and lightweight. In Europe and America, the manufacturers and network operators wanted multi-mode 3G phones which would operate on 3G and 2G networks (e.g., W-CDMA and GSM), which added to the complexity, size, weight, and cost of the handset. As a result, early European W-CDMA phones were significantly larger and heavier than comparable Japanese W-CDMA phones.


Japan's Vodafone KK experienced a great deal of trouble with these differences when its UK-based parent, Vodafone, insisted the Japanese subsidiary use standard Vodafone handsets. Japanese customers who were accustomed to smaller handsets were suddenly required to switch to European handsets that were much bulkier and considered unfashionable by Japanese consumers. During this conversion, Vodafone KK lost 6 customers for every 4 that migrated to 3G. Soon thereafter, Vodafone sold the subsidiary (now known as SoftBank Mobile).


The general trend to smaller and smaller phones seems to have paused, perhaps even turned, with the capability of large-screen phones to provide more video, gaming and internet use on the 3G networks.

Speed


The ITU has not provided a clear definition of the speeds users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the speeds it specifies are not being met. While stating in commentary that "it is expected that IMT-2000 will provide higher transmission rates: a minimum speed of 2Mbit/s for stationary or walking users, and 348 kbit/s in a moving vehicle", [1] the ITU does not actually clearly specify minimum or average speeds or what modes of the interfaces qualify as 3G, so various speeds are sold as 3G intended to meet customers expectations of broadband speed. It is often suggested by industry sources that 3G can be expected to provide 384 kbit/s at or below pedestrian speeds, but only 128 kbit/s in a moving car. While EDGE is part of the 3G standard, some phones report EDGE and 3G network availability as separate things, notably the iPhone.


Network standardization


The International Telecommunication Union (ITU) defined the demands for 3G mobile networks with the IMT-2000 standard. An organization called 3rd Generation Partnership Project (3GPP) has continued that work by defining a mobile system that fulfills the IMT-2000 standard. This system is called Universal Mobile Telecommunications System (UMTS).

IMT-2000 standards and radio interfaces

Main article: IMT-2000


International Telecommunications Union (ITU): IMT-2000 consists of six radio interfaces

W-CDMA also known as UMTS

CDMA2000

TD-CDMA / TD-SCDMA

UWC (often implemented with EDGE)

DECT

Mobile WiMAX[2]

Advantages of a layered network architecture


Unlike GSM, UMTS is based on layered services. At the top is the services layer, which provides fast deployment of services and centralized location. In the middle is the control layer, which helps upgrading procedures and allows the capacity of the network to be dynamically allocated. At the bottom is the connectivity layer where any transmission technology can be used and the voice traffic will transfer over ATM/AAL2 or IP/RTP.

3G evolution (pre-4G)

See also section Pre-4G wireless standards of the 4G article.


The standardization of 3G evolution is working in both 3GPP and 3GPP2. The corresponding specifications of 3GPP and 3GPP2 evolutions are named as LTE and UMB, respectively. 3G evolution uses partly beyond 3G technologies to enhance the performance and to make a smooth migration path.


There are several different paths from 2G to 3G. In Europe the main path starts from GSM when GPRS is added to a system. From this point it is possible to go to the UMTS system. In North America the system evolution will start from Time division multiple access (TDMA), change to Enhanced Data Rates for GSM Evolution (EDGE) and then to UMTS.


In Japan, two 3G standards are used: W-CDMA used by NTT DoCoMo (FOMA, compatible with UMTS) and SoftBank Mobile (UMTS), and CDMA2000, used by KDDI. Transition to 3G was completed in Japan in 2006.

Evolution from 2G to 3G


2G networks were built mainly for voice data and slow transmission. Due to rapid changes in user expectation, they do not meet today's wireless needs.


Cellular mobile telecommunications networks are being upgraded to use 3G technologies from 1999 to 2010. Japan was the first country to introduce 3G nationally, and in Japan the transition to 3G was largely completed in 2006. Korea then adopted 3G Networks soon after and the transition was made as early as 2004.

From 2G to 2.5G (GPRS)


"2.5G" (and even 2.75G) are technologies such as i-mode data services, camera phones, high-speed circuit-switched data (HSCSD) and General packet radio service (GPRS) were created to provide some functionality domains like 3G networks, but without the full transition to 3G network. They were built to introduce the possibilities of wireless application technology to the end consumers, and so increase demand for 3G services.


When converting a GSM network to a UMTS network, the first new technology is General Packet Radio Service (GPRS). It is the trigger to 3G services. The network connection is always on, so the subscriber is online all the time. From the operator's point of view, it is important that GPRS investments are re-used when going to UMTS. Also capitalizing on GPRS business experience is very important.


From GPRS, operators could change the network directly to UMTS, or invest in an EDGE system. One advantage of EDGE over UMTS is that it requires no new licenses. The frequencies are also re-used and no new antennas are needed.

Migrating from GPRS to UMTS


From GPRS network, the following network elements can be reused:

Home location register (HLR)

Visitor location register (VLR)

Equipment identity register (EIR)

Mobile switching centre (MSC) (vendor dependent)

Authentication centre (AUC)

Serving GPRS Support Node (SGSN) (vendor dependent)

Gateway GPRS Support Node (GGSN)


From Global Service for Mobile (GSM) communication radio network, the following elements cannot be reused

Base station controller (BSC)

Base transceiver station (BTS)


They can remain in the network and be used in dual network operation where 2G and 3G networks co-exist while network migration and new 3G terminals become available for use in the network.


The UMTS network introduces new network elements that function as specified by 3GPP:

Node B (base station)

Radio Network Controller (RNC)

Media Gateway (MGW)


The functionality of MSC and SGSN changes when going to UMTS. In a GSM system the MSC handles all the circuit switched operations like connecting A- and B-subscriber through the network. SGSN handles all the packet switched operations and transfers all the data in the network. In UMTS the Media gateway (MGW) take care of all data transfer in both circuit and packet switched networks. MSC and SGSN control MGW operations. The nodes are renamed to MSC-server and GSN-server.

Issues


Although 3G was successfully introduced to users across the world, some issues are debated by 3G providers and users:

Expensive input fees for the 3G service licenses

Numerous differences in the licensing terms

Large amount of debt currently sustained by many telecommunication companies, which makes it a challenge to build the necessary infrastructure for 3G

Lack of member state support for financially troubled operators

Expense of 3G phones

Lack of buy-in by 2G mobile users for the new 3G wireless services

Lack of coverage, because it is still a new service

High prices of 3G mobile services in some countries, including Internet access (see flat rate)

Current lack of user need for 3G voice and data services in a hand-held device

High power usage


What is 3G


What can 3G do for you?


The superior technology and bandwidth of 3G will add an invaluable dimension to modern life. New services will include person to person video, video live streaming and video downloads of entertainment, news, current affairs, and sport content in ways never seen before. In addition, there will be video messaging and global positioning applications. People will be empowered not only talk to each other while on the move, but also see what each other means. After all, a picture is worth a thousand words.


In a digital era characterised by a profusion of information, 3G offers an unprecedented level of personalisation to suit customers' individual interests and needs.


Person to Person Video Calls

People love video and mobile video is at the heart of vision. We can use our 3G devices to make a video call to our family - see them as we talk - and let them see us as well.


Entertainment

With our 3G devices we will soon be able to access video clips of news and sporting events anytime, anywhere. We will be able to exchange "postcards", listen to music, play interactive games or book tickets to see live events. The device could alert us when our favourite sports team or entertainer is performing and it could even tell us where to find the best shopping or restaurants, based on where we are at the time.


News and Information

News, entertainment and a wealth of information tailor-made to meet each individual's specific interests will be available at the touch of a button.


Business

3G mobile linkups will routinely be used in daily business situations. We will hold video conferences with clients, send pictures, documents or data, and be able to receive instant feedback without meeting up or even being in the office. The technology will enhance business logistics and marketing, with applications meeting specific requirements of individual enterprises. Efficiency in time-critical situations, such as medical emergencies, will also improve through the use of 3G technology.


Global Positioning

The "always on" Global Positioning System (GPS) will offer centralised location-based intelligence that will greatly improve deployment of available resources in the field. In turn, operators in the field will enjoy superb navigation assistance, with instant access to street maps, traffic reports and weather information. Furthermore, customers calling via a 3G device could be directly linked to, and located by, service providers. The same application could make all the difference in cases of emergency.


M-commerce

Using our 3G "electronic wallets", we will soon be able to conduct financial transactions while on the move. Simply by keying in our own secure payment pin number, we will be able to place a bet, bid on an on-line auction, trade stocks or simply pay for our groceries or taxi fare.

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